3405 lines
119 KiB
Zig
3405 lines
119 KiB
Zig
const std = @import("std.zig");
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const builtin = @import("builtin");
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const debug = std.debug;
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const assert = debug.assert;
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const math = std.math;
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const mem = @This();
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const meta = std.meta;
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const trait = meta.trait;
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const testing = std.testing;
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const Endian = std.builtin.Endian;
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const native_endian = builtin.cpu.arch.endian();
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/// Compile time known minimum page size.
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/// https://github.com/ziglang/zig/issues/4082
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pub const page_size = switch (builtin.cpu.arch) {
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.wasm32, .wasm64 => 64 * 1024,
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.aarch64 => switch (builtin.os.tag) {
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.macos, .ios, .watchos, .tvos => 16 * 1024,
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else => 4 * 1024,
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},
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.sparc64 => 8 * 1024,
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else => 4 * 1024,
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};
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/// The standard library currently thoroughly depends on byte size
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/// being 8 bits. (see the use of u8 throughout allocation code as
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/// the "byte" type.) Code which depends on this can reference this
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/// declaration. If we ever try to port the standard library to a
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/// non-8-bit-byte platform, this will allow us to search for things
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/// which need to be updated.
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pub const byte_size_in_bits = 8;
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pub const Allocator = @import("mem/Allocator.zig");
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/// Detects and asserts if the std.mem.Allocator interface is violated by the caller
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/// or the allocator.
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pub fn ValidationAllocator(comptime T: type) type {
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return struct {
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const Self = @This();
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underlying_allocator: T,
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pub fn init(underlying_allocator: T) @This() {
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return .{
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.underlying_allocator = underlying_allocator,
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};
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}
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pub fn allocator(self: *Self) Allocator {
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return Allocator.init(self, alloc, resize, free);
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}
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fn getUnderlyingAllocatorPtr(self: *Self) Allocator {
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if (T == Allocator) return self.underlying_allocator;
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return self.underlying_allocator.allocator();
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}
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pub fn alloc(
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self: *Self,
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n: usize,
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ptr_align: u29,
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len_align: u29,
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ret_addr: usize,
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) Allocator.Error![]u8 {
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assert(n > 0);
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assert(mem.isValidAlign(ptr_align));
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if (len_align != 0) {
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assert(mem.isAlignedAnyAlign(n, len_align));
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assert(n >= len_align);
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}
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const underlying = self.getUnderlyingAllocatorPtr();
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const result = try underlying.rawAlloc(n, ptr_align, len_align, ret_addr);
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assert(mem.isAligned(@ptrToInt(result.ptr), ptr_align));
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if (len_align == 0) {
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assert(result.len == n);
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} else {
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assert(result.len >= n);
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assert(mem.isAlignedAnyAlign(result.len, len_align));
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}
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return result;
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}
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pub fn resize(
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self: *Self,
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buf: []u8,
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buf_align: u29,
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new_len: usize,
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len_align: u29,
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ret_addr: usize,
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) ?usize {
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assert(buf.len > 0);
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if (len_align != 0) {
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assert(mem.isAlignedAnyAlign(new_len, len_align));
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assert(new_len >= len_align);
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}
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const underlying = self.getUnderlyingAllocatorPtr();
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const result = underlying.rawResize(buf, buf_align, new_len, len_align, ret_addr) orelse return null;
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if (len_align == 0) {
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assert(result == new_len);
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} else {
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assert(result >= new_len);
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assert(mem.isAlignedAnyAlign(result, len_align));
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}
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return result;
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}
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pub fn free(
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self: *Self,
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buf: []u8,
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buf_align: u29,
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ret_addr: usize,
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) void {
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_ = self;
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_ = buf_align;
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_ = ret_addr;
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assert(buf.len > 0);
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}
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pub usingnamespace if (T == Allocator or !@hasDecl(T, "reset")) struct {} else struct {
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pub fn reset(self: *Self) void {
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self.underlying_allocator.reset();
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}
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};
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};
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}
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pub fn validationWrap(allocator: anytype) ValidationAllocator(@TypeOf(allocator)) {
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return ValidationAllocator(@TypeOf(allocator)).init(allocator);
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}
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/// An allocator helper function. Adjusts an allocation length satisfy `len_align`.
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/// `full_len` should be the full capacity of the allocation which may be greater
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/// than the `len` that was requsted. This function should only be used by allocators
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/// that are unaffected by `len_align`.
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pub fn alignAllocLen(full_len: usize, alloc_len: usize, len_align: u29) usize {
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assert(alloc_len > 0);
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assert(alloc_len >= len_align);
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assert(full_len >= alloc_len);
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if (len_align == 0)
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return alloc_len;
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const adjusted = alignBackwardAnyAlign(full_len, len_align);
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assert(adjusted >= alloc_len);
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return adjusted;
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}
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const fail_allocator = Allocator{
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.ptr = undefined,
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.vtable = &failAllocator_vtable,
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};
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const failAllocator_vtable = Allocator.VTable{
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.alloc = failAllocatorAlloc,
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.resize = Allocator.NoResize(anyopaque).noResize,
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.free = Allocator.NoOpFree(anyopaque).noOpFree,
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};
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fn failAllocatorAlloc(_: *anyopaque, n: usize, alignment: u29, len_align: u29, ra: usize) Allocator.Error![]u8 {
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_ = n;
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_ = alignment;
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_ = len_align;
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_ = ra;
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return error.OutOfMemory;
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}
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test "Allocator basics" {
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try testing.expectError(error.OutOfMemory, fail_allocator.alloc(u8, 1));
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try testing.expectError(error.OutOfMemory, fail_allocator.allocSentinel(u8, 1, 0));
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}
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test "Allocator.resize" {
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const primitiveIntTypes = .{
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i8,
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u8,
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i16,
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u16,
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i32,
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u32,
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i64,
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u64,
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i128,
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u128,
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isize,
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usize,
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};
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inline for (primitiveIntTypes) |T| {
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var values = try testing.allocator.alloc(T, 100);
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defer testing.allocator.free(values);
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for (values) |*v, i| v.* = @intCast(T, i);
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values = testing.allocator.resize(values, values.len + 10) orelse return error.OutOfMemory;
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try testing.expect(values.len == 110);
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}
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const primitiveFloatTypes = .{
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f16,
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f32,
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f64,
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f128,
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};
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inline for (primitiveFloatTypes) |T| {
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var values = try testing.allocator.alloc(T, 100);
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defer testing.allocator.free(values);
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for (values) |*v, i| v.* = @intToFloat(T, i);
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values = testing.allocator.resize(values, values.len + 10) orelse return error.OutOfMemory;
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try testing.expect(values.len == 110);
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}
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}
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/// Copy all of source into dest at position 0.
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/// dest.len must be >= source.len.
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/// If the slices overlap, dest.ptr must be <= src.ptr.
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pub fn copy(comptime T: type, dest: []T, source: []const T) void {
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// TODO instead of manually doing this check for the whole array
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// and turning off runtime safety, the compiler should detect loops like
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// this and automatically omit safety checks for loops
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@setRuntimeSafety(false);
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assert(dest.len >= source.len);
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for (source) |s, i|
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dest[i] = s;
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}
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/// Copy all of source into dest at position 0.
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/// dest.len must be >= source.len.
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/// If the slices overlap, dest.ptr must be >= src.ptr.
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pub fn copyBackwards(comptime T: type, dest: []T, source: []const T) void {
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// TODO instead of manually doing this check for the whole array
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// and turning off runtime safety, the compiler should detect loops like
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// this and automatically omit safety checks for loops
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@setRuntimeSafety(false);
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assert(dest.len >= source.len);
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var i = source.len;
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while (i > 0) {
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i -= 1;
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dest[i] = source[i];
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}
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}
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/// Sets all elements of `dest` to `value`.
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pub fn set(comptime T: type, dest: []T, value: T) void {
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for (dest) |*d|
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d.* = value;
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}
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/// Generally, Zig users are encouraged to explicitly initialize all fields of a struct explicitly rather than using this function.
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/// However, it is recognized that there are sometimes use cases for initializing all fields to a "zero" value. For example, when
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/// interfacing with a C API where this practice is more common and relied upon. If you are performing code review and see this
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/// function used, examine closely - it may be a code smell.
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/// Zero initializes the type.
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/// This can be used to zero initialize a any type for which it makes sense. Structs will be initialized recursively.
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pub fn zeroes(comptime T: type) T {
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switch (@typeInfo(T)) {
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.ComptimeInt, .Int, .ComptimeFloat, .Float => {
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return @as(T, 0);
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},
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.Enum, .EnumLiteral => {
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return @intToEnum(T, 0);
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},
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.Void => {
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return {};
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},
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.Bool => {
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return false;
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},
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.Optional, .Null => {
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return null;
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},
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.Struct => |struct_info| {
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if (@sizeOf(T) == 0) return undefined;
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if (struct_info.layout == .Extern) {
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var item: T = undefined;
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set(u8, asBytes(&item), 0);
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return item;
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} else {
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var structure: T = undefined;
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inline for (struct_info.fields) |field| {
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if (!field.is_comptime) {
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@field(structure, field.name) = zeroes(@TypeOf(@field(structure, field.name)));
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}
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}
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return structure;
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}
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},
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.Pointer => |ptr_info| {
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switch (ptr_info.size) {
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.Slice => {
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return &[_]ptr_info.child{};
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},
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.C => {
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return null;
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},
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.One, .Many => {
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@compileError("Can't set a non nullable pointer to zero.");
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},
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}
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},
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.Array => |info| {
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if (info.sentinel) |sentinel_ptr| {
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const sentinel = @ptrCast(*const info.child, sentinel_ptr).*;
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return [_:sentinel]info.child{zeroes(info.child)} ** info.len;
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}
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return [_]info.child{zeroes(info.child)} ** info.len;
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},
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.Vector => |info| {
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return @splat(info.len, zeroes(info.child));
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},
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.Union => |info| {
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if (comptime meta.containerLayout(T) == .Extern) {
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// The C language specification states that (global) unions
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// should be zero initialized to the first named member.
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return @unionInit(T, info.fields[0].name, zeroes(info.fields[0].field_type));
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}
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@compileError("Can't set a " ++ @typeName(T) ++ " to zero.");
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},
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.ErrorUnion,
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.ErrorSet,
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.Fn,
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.BoundFn,
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.Type,
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.NoReturn,
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.Undefined,
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.Opaque,
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.Frame,
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.AnyFrame,
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=> {
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@compileError("Can't set a " ++ @typeName(T) ++ " to zero.");
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},
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}
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}
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test "zeroes" {
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if (builtin.zig_backend == .stage1 or builtin.zig_backend == .stage2_llvm) {
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// Regressed in LLVM 14:
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// https://github.com/llvm/llvm-project/issues/55522
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return error.SkipZigTest;
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}
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const C_struct = extern struct {
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x: u32,
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y: u32,
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};
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var a = zeroes(C_struct);
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a.y += 10;
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try testing.expect(a.x == 0);
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try testing.expect(a.y == 10);
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const ZigStruct = struct {
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comptime comptime_field: u8 = 5,
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integral_types: struct {
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integer_0: i0,
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integer_8: i8,
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integer_16: i16,
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integer_32: i32,
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integer_64: i64,
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integer_128: i128,
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unsigned_0: u0,
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unsigned_8: u8,
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unsigned_16: u16,
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unsigned_32: u32,
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unsigned_64: u64,
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unsigned_128: u128,
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float_32: f32,
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float_64: f64,
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},
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pointers: struct {
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optional: ?*u8,
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c_pointer: [*c]u8,
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slice: []u8,
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},
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array: [2]u32,
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vector_u32: @Vector(2, u32),
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vector_f32: @Vector(2, f32),
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vector_bool: @Vector(2, bool),
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optional_int: ?u8,
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empty: void,
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sentinel: [3:0]u8,
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};
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const b = zeroes(ZigStruct);
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try testing.expectEqual(@as(u8, 5), b.comptime_field);
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try testing.expectEqual(@as(i8, 0), b.integral_types.integer_0);
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try testing.expectEqual(@as(i8, 0), b.integral_types.integer_8);
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try testing.expectEqual(@as(i16, 0), b.integral_types.integer_16);
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try testing.expectEqual(@as(i32, 0), b.integral_types.integer_32);
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try testing.expectEqual(@as(i64, 0), b.integral_types.integer_64);
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try testing.expectEqual(@as(i128, 0), b.integral_types.integer_128);
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try testing.expectEqual(@as(u8, 0), b.integral_types.unsigned_0);
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try testing.expectEqual(@as(u8, 0), b.integral_types.unsigned_8);
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try testing.expectEqual(@as(u16, 0), b.integral_types.unsigned_16);
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try testing.expectEqual(@as(u32, 0), b.integral_types.unsigned_32);
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try testing.expectEqual(@as(u64, 0), b.integral_types.unsigned_64);
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try testing.expectEqual(@as(u128, 0), b.integral_types.unsigned_128);
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try testing.expectEqual(@as(f32, 0), b.integral_types.float_32);
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try testing.expectEqual(@as(f64, 0), b.integral_types.float_64);
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try testing.expectEqual(@as(?*u8, null), b.pointers.optional);
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try testing.expectEqual(@as([*c]u8, null), b.pointers.c_pointer);
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try testing.expectEqual(@as([]u8, &[_]u8{}), b.pointers.slice);
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for (b.array) |e| {
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try testing.expectEqual(@as(u32, 0), e);
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}
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try testing.expectEqual(@splat(2, @as(u32, 0)), b.vector_u32);
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try testing.expectEqual(@splat(2, @as(f32, 0.0)), b.vector_f32);
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try testing.expectEqual(@splat(2, @as(bool, false)), b.vector_bool);
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try testing.expectEqual(@as(?u8, null), b.optional_int);
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for (b.sentinel) |e| {
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try testing.expectEqual(@as(u8, 0), e);
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}
|
|
|
|
const C_union = extern union {
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a: u8,
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b: u32,
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};
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|
|
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var c = zeroes(C_union);
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try testing.expectEqual(@as(u8, 0), c.a);
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|
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comptime var comptime_union = zeroes(C_union);
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try testing.expectEqual(@as(u8, 0), comptime_union.a);
|
|
|
|
// Ensure zero sized struct with fields is initialized correctly.
|
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_ = zeroes(struct { handle: void });
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}
|
|
|
|
/// Initializes all fields of the struct with their default value, or zero values if no default value is present.
|
|
/// If the field is present in the provided initial values, it will have that value instead.
|
|
/// Structs are initialized recursively.
|
|
pub fn zeroInit(comptime T: type, init: anytype) T {
|
|
const Init = @TypeOf(init);
|
|
|
|
switch (@typeInfo(T)) {
|
|
.Struct => |struct_info| {
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|
switch (@typeInfo(Init)) {
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|
.Struct => |init_info| {
|
|
var value = std.mem.zeroes(T);
|
|
|
|
inline for (struct_info.fields) |field| {
|
|
if (field.default_value) |default_value_ptr| {
|
|
const default_value = @ptrCast(*const field.field_type, default_value_ptr).*;
|
|
@field(value, field.name) = default_value;
|
|
}
|
|
}
|
|
|
|
if (init_info.is_tuple) {
|
|
inline for (init_info.fields) |field, i| {
|
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@field(value, struct_info.fields[i].name) = @field(init, field.name);
|
|
}
|
|
return value;
|
|
}
|
|
|
|
inline for (init_info.fields) |field| {
|
|
if (!@hasField(T, field.name)) {
|
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@compileError("Encountered an initializer for `" ++ field.name ++ "`, but it is not a field of " ++ @typeName(T));
|
|
}
|
|
|
|
switch (@typeInfo(field.field_type)) {
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|
.Struct => {
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|
@field(value, field.name) = zeroInit(field.field_type, @field(init, field.name));
|
|
},
|
|
else => {
|
|
@field(value, field.name) = @field(init, field.name);
|
|
},
|
|
}
|
|
}
|
|
|
|
return value;
|
|
},
|
|
else => {
|
|
@compileError("The initializer must be a struct");
|
|
},
|
|
}
|
|
},
|
|
else => {
|
|
@compileError("Can't default init a " ++ @typeName(T));
|
|
},
|
|
}
|
|
}
|
|
|
|
test "zeroInit" {
|
|
const I = struct {
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|
d: f64,
|
|
};
|
|
|
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const S = struct {
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a: u32,
|
|
b: ?bool,
|
|
c: I,
|
|
e: [3]u8,
|
|
f: i64 = -1,
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|
};
|
|
|
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const s = zeroInit(S, .{
|
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.a = 42,
|
|
});
|
|
|
|
try testing.expectEqual(S{
|
|
.a = 42,
|
|
.b = null,
|
|
.c = .{
|
|
.d = 0,
|
|
},
|
|
.e = [3]u8{ 0, 0, 0 },
|
|
.f = -1,
|
|
}, s);
|
|
|
|
const Color = struct {
|
|
r: u8,
|
|
g: u8,
|
|
b: u8,
|
|
a: u8,
|
|
};
|
|
|
|
const c = zeroInit(Color, .{ 255, 255 });
|
|
try testing.expectEqual(Color{
|
|
.r = 255,
|
|
.g = 255,
|
|
.b = 0,
|
|
.a = 0,
|
|
}, c);
|
|
|
|
const Foo = struct {
|
|
foo: u8 = 69,
|
|
bar: u8,
|
|
};
|
|
|
|
const f = zeroInit(Foo, .{});
|
|
try testing.expectEqual(Foo{
|
|
.foo = 69,
|
|
.bar = 0,
|
|
}, f);
|
|
|
|
const Bar = struct {
|
|
foo: u32 = 666,
|
|
bar: u32 = 420,
|
|
};
|
|
|
|
const b = zeroInit(Bar, .{69});
|
|
try testing.expectEqual(Bar{
|
|
.foo = 69,
|
|
.bar = 420,
|
|
}, b);
|
|
}
|
|
|
|
/// Compares two slices of numbers lexicographically. O(n).
|
|
pub fn order(comptime T: type, lhs: []const T, rhs: []const T) math.Order {
|
|
const n = math.min(lhs.len, rhs.len);
|
|
var i: usize = 0;
|
|
while (i < n) : (i += 1) {
|
|
switch (math.order(lhs[i], rhs[i])) {
|
|
.eq => continue,
|
|
.lt => return .lt,
|
|
.gt => return .gt,
|
|
}
|
|
}
|
|
return math.order(lhs.len, rhs.len);
|
|
}
|
|
|
|
test "order" {
|
|
try testing.expect(order(u8, "abcd", "bee") == .lt);
|
|
try testing.expect(order(u8, "abc", "abc") == .eq);
|
|
try testing.expect(order(u8, "abc", "abc0") == .lt);
|
|
try testing.expect(order(u8, "", "") == .eq);
|
|
try testing.expect(order(u8, "", "a") == .lt);
|
|
}
|
|
|
|
/// Returns true if lhs < rhs, false otherwise
|
|
pub fn lessThan(comptime T: type, lhs: []const T, rhs: []const T) bool {
|
|
return order(T, lhs, rhs) == .lt;
|
|
}
|
|
|
|
test "lessThan" {
|
|
try testing.expect(lessThan(u8, "abcd", "bee"));
|
|
try testing.expect(!lessThan(u8, "abc", "abc"));
|
|
try testing.expect(lessThan(u8, "abc", "abc0"));
|
|
try testing.expect(!lessThan(u8, "", ""));
|
|
try testing.expect(lessThan(u8, "", "a"));
|
|
}
|
|
|
|
/// Compares two slices and returns whether they are equal.
|
|
pub fn eql(comptime T: type, a: []const T, b: []const T) bool {
|
|
if (a.len != b.len) return false;
|
|
if (a.ptr == b.ptr) return true;
|
|
for (a) |item, index| {
|
|
if (b[index] != item) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// Compares two slices and returns the index of the first inequality.
|
|
/// Returns null if the slices are equal.
|
|
pub fn indexOfDiff(comptime T: type, a: []const T, b: []const T) ?usize {
|
|
const shortest = math.min(a.len, b.len);
|
|
if (a.ptr == b.ptr)
|
|
return if (a.len == b.len) null else shortest;
|
|
var index: usize = 0;
|
|
while (index < shortest) : (index += 1) if (a[index] != b[index]) return index;
|
|
return if (a.len == b.len) null else shortest;
|
|
}
|
|
|
|
test "indexOfDiff" {
|
|
try testing.expectEqual(indexOfDiff(u8, "one", "one"), null);
|
|
try testing.expectEqual(indexOfDiff(u8, "one two", "one"), 3);
|
|
try testing.expectEqual(indexOfDiff(u8, "one", "one two"), 3);
|
|
try testing.expectEqual(indexOfDiff(u8, "one twx", "one two"), 6);
|
|
try testing.expectEqual(indexOfDiff(u8, "xne", "one"), 0);
|
|
}
|
|
|
|
/// Takes a pointer to an array, a sentinel-terminated pointer, or a slice, and
|
|
/// returns a slice. If there is a sentinel on the input type, there will be a
|
|
/// sentinel on the output type. The constness of the output type matches
|
|
/// the constness of the input type. `[*c]` pointers are assumed to be 0-terminated,
|
|
/// and assumed to not allow null.
|
|
pub fn Span(comptime T: type) type {
|
|
switch (@typeInfo(T)) {
|
|
.Optional => |optional_info| {
|
|
return ?Span(optional_info.child);
|
|
},
|
|
.Pointer => |ptr_info| {
|
|
var new_ptr_info = ptr_info;
|
|
switch (ptr_info.size) {
|
|
.One => switch (@typeInfo(ptr_info.child)) {
|
|
.Array => |info| {
|
|
new_ptr_info.child = info.child;
|
|
new_ptr_info.sentinel = info.sentinel;
|
|
},
|
|
else => @compileError("invalid type given to std.mem.Span"),
|
|
},
|
|
.C => {
|
|
new_ptr_info.sentinel = &@as(ptr_info.child, 0);
|
|
new_ptr_info.is_allowzero = false;
|
|
},
|
|
.Many, .Slice => {},
|
|
}
|
|
new_ptr_info.size = .Slice;
|
|
return @Type(.{ .Pointer = new_ptr_info });
|
|
},
|
|
else => @compileError("invalid type given to std.mem.Span"),
|
|
}
|
|
}
|
|
|
|
test "Span" {
|
|
try testing.expect(Span(*[5]u16) == []u16);
|
|
try testing.expect(Span(?*[5]u16) == ?[]u16);
|
|
try testing.expect(Span(*const [5]u16) == []const u16);
|
|
try testing.expect(Span(?*const [5]u16) == ?[]const u16);
|
|
try testing.expect(Span([]u16) == []u16);
|
|
try testing.expect(Span(?[]u16) == ?[]u16);
|
|
try testing.expect(Span([]const u8) == []const u8);
|
|
try testing.expect(Span(?[]const u8) == ?[]const u8);
|
|
try testing.expect(Span([:1]u16) == [:1]u16);
|
|
try testing.expect(Span(?[:1]u16) == ?[:1]u16);
|
|
try testing.expect(Span([:1]const u8) == [:1]const u8);
|
|
try testing.expect(Span(?[:1]const u8) == ?[:1]const u8);
|
|
try testing.expect(Span([*:1]u16) == [:1]u16);
|
|
try testing.expect(Span(?[*:1]u16) == ?[:1]u16);
|
|
try testing.expect(Span([*:1]const u8) == [:1]const u8);
|
|
try testing.expect(Span(?[*:1]const u8) == ?[:1]const u8);
|
|
try testing.expect(Span([*c]u16) == [:0]u16);
|
|
try testing.expect(Span(?[*c]u16) == ?[:0]u16);
|
|
try testing.expect(Span([*c]const u8) == [:0]const u8);
|
|
try testing.expect(Span(?[*c]const u8) == ?[:0]const u8);
|
|
}
|
|
|
|
/// Takes a pointer to an array, a sentinel-terminated pointer, or a slice, and
|
|
/// returns a slice. If there is a sentinel on the input type, there will be a
|
|
/// sentinel on the output type. The constness of the output type matches
|
|
/// the constness of the input type.
|
|
///
|
|
/// When there is both a sentinel and an array length or slice length, the
|
|
/// length value is used instead of the sentinel.
|
|
pub fn span(ptr: anytype) Span(@TypeOf(ptr)) {
|
|
if (@typeInfo(@TypeOf(ptr)) == .Optional) {
|
|
if (ptr) |non_null| {
|
|
return span(non_null);
|
|
} else {
|
|
return null;
|
|
}
|
|
}
|
|
const Result = Span(@TypeOf(ptr));
|
|
const l = len(ptr);
|
|
const ptr_info = @typeInfo(Result).Pointer;
|
|
if (ptr_info.sentinel) |s_ptr| {
|
|
const s = @ptrCast(*const ptr_info.child, s_ptr).*;
|
|
return ptr[0..l :s];
|
|
} else {
|
|
return ptr[0..l];
|
|
}
|
|
}
|
|
|
|
test "span" {
|
|
var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
|
|
const ptr = @as([*:3]u16, array[0..2 :3]);
|
|
try testing.expect(eql(u16, span(ptr), &[_]u16{ 1, 2 }));
|
|
try testing.expect(eql(u16, span(&array), &[_]u16{ 1, 2, 3, 4, 5 }));
|
|
try testing.expectEqual(@as(?[:0]u16, null), span(@as(?[*:0]u16, null)));
|
|
}
|
|
|
|
pub const spanZ = @compileError("deprecated; use use std.mem.span() or std.mem.sliceTo()");
|
|
|
|
/// Helper for the return type of sliceTo()
|
|
fn SliceTo(comptime T: type, comptime end: meta.Elem(T)) type {
|
|
switch (@typeInfo(T)) {
|
|
.Optional => |optional_info| {
|
|
return ?SliceTo(optional_info.child, end);
|
|
},
|
|
.Pointer => |ptr_info| {
|
|
var new_ptr_info = ptr_info;
|
|
new_ptr_info.size = .Slice;
|
|
switch (ptr_info.size) {
|
|
.One => switch (@typeInfo(ptr_info.child)) {
|
|
.Array => |array_info| {
|
|
new_ptr_info.child = array_info.child;
|
|
// The return type must only be sentinel terminated if we are guaranteed
|
|
// to find the value searched for, which is only the case if it matches
|
|
// the sentinel of the type passed.
|
|
if (array_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @ptrCast(*const array_info.child, sentinel_ptr).*;
|
|
if (end == sentinel) {
|
|
new_ptr_info.sentinel = &end;
|
|
} else {
|
|
new_ptr_info.sentinel = null;
|
|
}
|
|
}
|
|
},
|
|
else => {},
|
|
},
|
|
.Many, .Slice => {
|
|
// The return type must only be sentinel terminated if we are guaranteed
|
|
// to find the value searched for, which is only the case if it matches
|
|
// the sentinel of the type passed.
|
|
if (ptr_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @ptrCast(*const ptr_info.child, sentinel_ptr).*;
|
|
if (end == sentinel) {
|
|
new_ptr_info.sentinel = &end;
|
|
} else {
|
|
new_ptr_info.sentinel = null;
|
|
}
|
|
}
|
|
},
|
|
.C => {
|
|
new_ptr_info.sentinel = &end;
|
|
// C pointers are always allowzero, but we don't want the return type to be.
|
|
assert(new_ptr_info.is_allowzero);
|
|
new_ptr_info.is_allowzero = false;
|
|
},
|
|
}
|
|
return @Type(.{ .Pointer = new_ptr_info });
|
|
},
|
|
else => {},
|
|
}
|
|
@compileError("invalid type given to std.mem.sliceTo: " ++ @typeName(T));
|
|
}
|
|
|
|
/// Takes an array, a pointer to an array, a sentinel-terminated pointer, or a slice and
|
|
/// iterates searching for the first occurrence of `end`, returning the scanned slice.
|
|
/// If `end` is not found, the full length of the array/slice/sentinel terminated pointer is returned.
|
|
/// If the pointer type is sentinel terminated and `end` matches that terminator, the
|
|
/// resulting slice is also sentinel terminated.
|
|
/// Pointer properties such as mutability and alignment are preserved.
|
|
/// C pointers are assumed to be non-null.
|
|
pub fn sliceTo(ptr: anytype, comptime end: meta.Elem(@TypeOf(ptr))) SliceTo(@TypeOf(ptr), end) {
|
|
if (@typeInfo(@TypeOf(ptr)) == .Optional) {
|
|
const non_null = ptr orelse return null;
|
|
return sliceTo(non_null, end);
|
|
}
|
|
const Result = SliceTo(@TypeOf(ptr), end);
|
|
const length = lenSliceTo(ptr, end);
|
|
const ptr_info = @typeInfo(Result).Pointer;
|
|
if (ptr_info.sentinel) |s_ptr| {
|
|
const s = @ptrCast(*const ptr_info.child, s_ptr).*;
|
|
return ptr[0..length :s];
|
|
} else {
|
|
return ptr[0..length];
|
|
}
|
|
}
|
|
|
|
test "sliceTo" {
|
|
try testing.expectEqualSlices(u8, "aoeu", sliceTo("aoeu", 0));
|
|
|
|
{
|
|
var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqualSlices(u16, &array, sliceTo(&array, 0));
|
|
try testing.expectEqualSlices(u16, array[0..3], sliceTo(array[0..3], 0));
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(&array, 3));
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(array[0..3], 3));
|
|
|
|
const sentinel_ptr = @ptrCast([*:5]u16, &array);
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(sentinel_ptr, 3));
|
|
try testing.expectEqualSlices(u16, array[0..4], sliceTo(sentinel_ptr, 99));
|
|
|
|
const optional_sentinel_ptr = @ptrCast(?[*:5]u16, &array);
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(optional_sentinel_ptr, 3).?);
|
|
try testing.expectEqualSlices(u16, array[0..4], sliceTo(optional_sentinel_ptr, 99).?);
|
|
|
|
const c_ptr = @as([*c]u16, &array);
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(c_ptr, 3));
|
|
|
|
const slice: []u16 = &array;
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(slice, 3));
|
|
try testing.expectEqualSlices(u16, &array, sliceTo(slice, 99));
|
|
|
|
const sentinel_slice: [:5]u16 = array[0..4 :5];
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(sentinel_slice, 3));
|
|
try testing.expectEqualSlices(u16, array[0..4], sliceTo(sentinel_slice, 99));
|
|
}
|
|
{
|
|
var sentinel_array: [5:0]u16 = [_:0]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqualSlices(u16, sentinel_array[0..2], sliceTo(&sentinel_array, 3));
|
|
try testing.expectEqualSlices(u16, &sentinel_array, sliceTo(&sentinel_array, 0));
|
|
try testing.expectEqualSlices(u16, &sentinel_array, sliceTo(&sentinel_array, 99));
|
|
}
|
|
|
|
try testing.expectEqual(@as(?[]u8, null), sliceTo(@as(?[]u8, null), 0));
|
|
}
|
|
|
|
/// Private helper for sliceTo(). If you want the length, use sliceTo(foo, x).len
|
|
fn lenSliceTo(ptr: anytype, comptime end: meta.Elem(@TypeOf(ptr))) usize {
|
|
switch (@typeInfo(@TypeOf(ptr))) {
|
|
.Pointer => |ptr_info| switch (ptr_info.size) {
|
|
.One => switch (@typeInfo(ptr_info.child)) {
|
|
.Array => |array_info| {
|
|
if (array_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @ptrCast(*const array_info.child, sentinel_ptr).*;
|
|
if (sentinel == end) {
|
|
return indexOfSentinel(array_info.child, end, ptr);
|
|
}
|
|
}
|
|
return indexOfScalar(array_info.child, ptr, end) orelse array_info.len;
|
|
},
|
|
else => {},
|
|
},
|
|
.Many => if (ptr_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @ptrCast(*const ptr_info.child, sentinel_ptr).*;
|
|
// We may be looking for something other than the sentinel,
|
|
// but iterating past the sentinel would be a bug so we need
|
|
// to check for both.
|
|
var i: usize = 0;
|
|
while (ptr[i] != end and ptr[i] != sentinel) i += 1;
|
|
return i;
|
|
},
|
|
.C => {
|
|
assert(ptr != null);
|
|
return indexOfSentinel(ptr_info.child, end, ptr);
|
|
},
|
|
.Slice => {
|
|
if (ptr_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @ptrCast(*const ptr_info.child, sentinel_ptr).*;
|
|
if (sentinel == end) {
|
|
return indexOfSentinel(ptr_info.child, sentinel, ptr);
|
|
}
|
|
}
|
|
return indexOfScalar(ptr_info.child, ptr, end) orelse ptr.len;
|
|
},
|
|
},
|
|
else => {},
|
|
}
|
|
@compileError("invalid type given to std.mem.sliceTo: " ++ @typeName(@TypeOf(ptr)));
|
|
}
|
|
|
|
test "lenSliceTo" {
|
|
try testing.expect(lenSliceTo("aoeu", 0) == 4);
|
|
|
|
{
|
|
var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(&array, 0));
|
|
try testing.expectEqual(@as(usize, 3), lenSliceTo(array[0..3], 0));
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(&array, 3));
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(array[0..3], 3));
|
|
|
|
const sentinel_ptr = @ptrCast([*:5]u16, &array);
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(sentinel_ptr, 3));
|
|
try testing.expectEqual(@as(usize, 4), lenSliceTo(sentinel_ptr, 99));
|
|
|
|
const c_ptr = @as([*c]u16, &array);
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(c_ptr, 3));
|
|
|
|
const slice: []u16 = &array;
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(slice, 3));
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(slice, 99));
|
|
|
|
const sentinel_slice: [:5]u16 = array[0..4 :5];
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(sentinel_slice, 3));
|
|
try testing.expectEqual(@as(usize, 4), lenSliceTo(sentinel_slice, 99));
|
|
}
|
|
{
|
|
var sentinel_array: [5:0]u16 = [_:0]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(&sentinel_array, 3));
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(&sentinel_array, 0));
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(&sentinel_array, 99));
|
|
}
|
|
}
|
|
|
|
/// Takes a pointer to an array, an array, a vector, a sentinel-terminated pointer,
|
|
/// a slice or a tuple, and returns the length.
|
|
/// In the case of a sentinel-terminated array, it uses the array length.
|
|
/// For C pointers it assumes it is a pointer-to-many with a 0 sentinel.
|
|
pub fn len(value: anytype) usize {
|
|
return switch (@typeInfo(@TypeOf(value))) {
|
|
.Array => |info| info.len,
|
|
.Vector => |info| info.len,
|
|
.Pointer => |info| switch (info.size) {
|
|
.One => switch (@typeInfo(info.child)) {
|
|
.Array => value.len,
|
|
else => @compileError("invalid type given to std.mem.len"),
|
|
},
|
|
.Many => {
|
|
const sentinel_ptr = info.sentinel orelse
|
|
@compileError("length of pointer with no sentinel");
|
|
const sentinel = @ptrCast(*const info.child, sentinel_ptr).*;
|
|
return indexOfSentinel(info.child, sentinel, value);
|
|
},
|
|
.C => {
|
|
assert(value != null);
|
|
return indexOfSentinel(info.child, 0, value);
|
|
},
|
|
.Slice => value.len,
|
|
},
|
|
.Struct => |info| if (info.is_tuple) {
|
|
return info.fields.len;
|
|
} else @compileError("invalid type given to std.mem.len"),
|
|
else => @compileError("invalid type given to std.mem.len"),
|
|
};
|
|
}
|
|
|
|
test "len" {
|
|
try testing.expect(len("aoeu") == 4);
|
|
|
|
{
|
|
var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expect(len(&array) == 5);
|
|
try testing.expect(len(array[0..3]) == 3);
|
|
array[2] = 0;
|
|
const ptr = @as([*:0]u16, array[0..2 :0]);
|
|
try testing.expect(len(ptr) == 2);
|
|
}
|
|
{
|
|
var array: [5:0]u16 = [_:0]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expect(len(&array) == 5);
|
|
array[2] = 0;
|
|
try testing.expect(len(&array) == 5);
|
|
}
|
|
{
|
|
const vector: meta.Vector(2, u32) = [2]u32{ 1, 2 };
|
|
try testing.expect(len(vector) == 2);
|
|
}
|
|
{
|
|
const tuple = .{ 1, 2 };
|
|
try testing.expect(len(tuple) == 2);
|
|
try testing.expect(tuple[0] == 1);
|
|
}
|
|
}
|
|
|
|
pub const lenZ = @compileError("deprecated; use std.mem.len() or std.mem.sliceTo().len");
|
|
|
|
pub fn indexOfSentinel(comptime Elem: type, comptime sentinel: Elem, ptr: [*:sentinel]const Elem) usize {
|
|
var i: usize = 0;
|
|
while (ptr[i] != sentinel) {
|
|
i += 1;
|
|
}
|
|
return i;
|
|
}
|
|
|
|
/// Returns true if all elements in a slice are equal to the scalar value provided
|
|
pub fn allEqual(comptime T: type, slice: []const T, scalar: T) bool {
|
|
for (slice) |item| {
|
|
if (item != scalar) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
pub const dupe = @compileError("deprecated; use `Allocator.dupe`");
|
|
pub const dupeZ = @compileError("deprecated; use `Allocator.dupeZ`");
|
|
|
|
/// Remove values from the beginning of a slice.
|
|
pub fn trimLeft(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
|
|
var begin: usize = 0;
|
|
while (begin < slice.len and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
|
|
return slice[begin..];
|
|
}
|
|
|
|
/// Remove values from the end of a slice.
|
|
pub fn trimRight(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
|
|
var end: usize = slice.len;
|
|
while (end > 0 and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
|
|
return slice[0..end];
|
|
}
|
|
|
|
/// Remove values from the beginning and end of a slice.
|
|
pub fn trim(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
|
|
var begin: usize = 0;
|
|
var end: usize = slice.len;
|
|
while (begin < end and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
|
|
while (end > begin and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
|
|
return slice[begin..end];
|
|
}
|
|
|
|
test "trim" {
|
|
try testing.expectEqualSlices(u8, "foo\n ", trimLeft(u8, " foo\n ", " \n"));
|
|
try testing.expectEqualSlices(u8, " foo", trimRight(u8, " foo\n ", " \n"));
|
|
try testing.expectEqualSlices(u8, "foo", trim(u8, " foo\n ", " \n"));
|
|
try testing.expectEqualSlices(u8, "foo", trim(u8, "foo", " \n"));
|
|
}
|
|
|
|
/// Linear search for the index of a scalar value inside a slice.
|
|
pub fn indexOfScalar(comptime T: type, slice: []const T, value: T) ?usize {
|
|
return indexOfScalarPos(T, slice, 0, value);
|
|
}
|
|
|
|
/// Linear search for the last index of a scalar value inside a slice.
|
|
pub fn lastIndexOfScalar(comptime T: type, slice: []const T, value: T) ?usize {
|
|
var i: usize = slice.len;
|
|
while (i != 0) {
|
|
i -= 1;
|
|
if (slice[i] == value) return i;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
pub fn indexOfScalarPos(comptime T: type, slice: []const T, start_index: usize, value: T) ?usize {
|
|
var i: usize = start_index;
|
|
while (i < slice.len) : (i += 1) {
|
|
if (slice[i] == value) return i;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
pub fn indexOfAny(comptime T: type, slice: []const T, values: []const T) ?usize {
|
|
return indexOfAnyPos(T, slice, 0, values);
|
|
}
|
|
|
|
pub fn lastIndexOfAny(comptime T: type, slice: []const T, values: []const T) ?usize {
|
|
var i: usize = slice.len;
|
|
while (i != 0) {
|
|
i -= 1;
|
|
for (values) |value| {
|
|
if (slice[i] == value) return i;
|
|
}
|
|
}
|
|
return null;
|
|
}
|
|
|
|
pub fn indexOfAnyPos(comptime T: type, slice: []const T, start_index: usize, values: []const T) ?usize {
|
|
var i: usize = start_index;
|
|
while (i < slice.len) : (i += 1) {
|
|
for (values) |value| {
|
|
if (slice[i] == value) return i;
|
|
}
|
|
}
|
|
return null;
|
|
}
|
|
|
|
pub fn indexOf(comptime T: type, haystack: []const T, needle: []const T) ?usize {
|
|
return indexOfPos(T, haystack, 0, needle);
|
|
}
|
|
|
|
/// Find the index in a slice of a sub-slice, searching from the end backwards.
|
|
/// To start looking at a different index, slice the haystack first.
|
|
/// Consider using `lastIndexOf` instead of this, which will automatically use a
|
|
/// more sophisticated algorithm on larger inputs.
|
|
pub fn lastIndexOfLinear(comptime T: type, haystack: []const T, needle: []const T) ?usize {
|
|
var i: usize = haystack.len - needle.len;
|
|
while (true) : (i -= 1) {
|
|
if (mem.eql(T, haystack[i .. i + needle.len], needle)) return i;
|
|
if (i == 0) return null;
|
|
}
|
|
}
|
|
|
|
/// Consider using `indexOfPos` instead of this, which will automatically use a
|
|
/// more sophisticated algorithm on larger inputs.
|
|
pub fn indexOfPosLinear(comptime T: type, haystack: []const T, start_index: usize, needle: []const T) ?usize {
|
|
var i: usize = start_index;
|
|
const end = haystack.len - needle.len;
|
|
while (i <= end) : (i += 1) {
|
|
if (eql(T, haystack[i .. i + needle.len], needle)) return i;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
fn boyerMooreHorspoolPreprocessReverse(pattern: []const u8, table: *[256]usize) void {
|
|
for (table) |*c| {
|
|
c.* = pattern.len;
|
|
}
|
|
|
|
var i: usize = pattern.len - 1;
|
|
// The first item is intentionally ignored and the skip size will be pattern.len.
|
|
// This is the standard way boyer-moore-horspool is implemented.
|
|
while (i > 0) : (i -= 1) {
|
|
table[pattern[i]] = i;
|
|
}
|
|
}
|
|
|
|
fn boyerMooreHorspoolPreprocess(pattern: []const u8, table: *[256]usize) void {
|
|
for (table) |*c| {
|
|
c.* = pattern.len;
|
|
}
|
|
|
|
var i: usize = 0;
|
|
// The last item is intentionally ignored and the skip size will be pattern.len.
|
|
// This is the standard way boyer-moore-horspool is implemented.
|
|
while (i < pattern.len - 1) : (i += 1) {
|
|
table[pattern[i]] = pattern.len - 1 - i;
|
|
}
|
|
}
|
|
/// Find the index in a slice of a sub-slice, searching from the end backwards.
|
|
/// To start looking at a different index, slice the haystack first.
|
|
/// Uses the Reverse boyer-moore-horspool algorithm on large inputs;
|
|
/// `lastIndexOfLinear` on small inputs.
|
|
pub fn lastIndexOf(comptime T: type, haystack: []const T, needle: []const T) ?usize {
|
|
if (needle.len > haystack.len) return null;
|
|
if (needle.len == 0) return haystack.len;
|
|
|
|
if (!meta.trait.hasUniqueRepresentation(T) or haystack.len < 52 or needle.len <= 4)
|
|
return lastIndexOfLinear(T, haystack, needle);
|
|
|
|
const haystack_bytes = sliceAsBytes(haystack);
|
|
const needle_bytes = sliceAsBytes(needle);
|
|
|
|
var skip_table: [256]usize = undefined;
|
|
boyerMooreHorspoolPreprocessReverse(needle_bytes, skip_table[0..]);
|
|
|
|
var i: usize = haystack_bytes.len - needle_bytes.len;
|
|
while (true) {
|
|
if (i % @sizeOf(T) == 0 and mem.eql(u8, haystack_bytes[i .. i + needle_bytes.len], needle_bytes)) {
|
|
return @divExact(i, @sizeOf(T));
|
|
}
|
|
const skip = skip_table[haystack_bytes[i]];
|
|
if (skip > i) break;
|
|
i -= skip;
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
/// Uses Boyer-moore-horspool algorithm on large inputs; `indexOfPosLinear` on small inputs.
|
|
pub fn indexOfPos(comptime T: type, haystack: []const T, start_index: usize, needle: []const T) ?usize {
|
|
if (needle.len > haystack.len) return null;
|
|
if (needle.len == 0) return start_index;
|
|
|
|
if (!meta.trait.hasUniqueRepresentation(T) or haystack.len < 52 or needle.len <= 4)
|
|
return indexOfPosLinear(T, haystack, start_index, needle);
|
|
|
|
const haystack_bytes = sliceAsBytes(haystack);
|
|
const needle_bytes = sliceAsBytes(needle);
|
|
|
|
var skip_table: [256]usize = undefined;
|
|
boyerMooreHorspoolPreprocess(needle_bytes, skip_table[0..]);
|
|
|
|
var i: usize = start_index * @sizeOf(T);
|
|
while (i <= haystack_bytes.len - needle_bytes.len) {
|
|
if (i % @sizeOf(T) == 0 and mem.eql(u8, haystack_bytes[i .. i + needle_bytes.len], needle_bytes)) {
|
|
return @divExact(i, @sizeOf(T));
|
|
}
|
|
i += skip_table[haystack_bytes[i + needle_bytes.len - 1]];
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
test "indexOf" {
|
|
try testing.expect(indexOf(u8, "one two three four five six seven eight nine ten eleven", "three four").? == 8);
|
|
try testing.expect(lastIndexOf(u8, "one two three four five six seven eight nine ten eleven", "three four").? == 8);
|
|
try testing.expect(indexOf(u8, "one two three four five six seven eight nine ten eleven", "two two") == null);
|
|
try testing.expect(lastIndexOf(u8, "one two three four five six seven eight nine ten eleven", "two two") == null);
|
|
|
|
try testing.expect(indexOf(u8, "one two three four five six seven eight nine ten", "").? == 0);
|
|
try testing.expect(lastIndexOf(u8, "one two three four five six seven eight nine ten", "").? == 48);
|
|
|
|
try testing.expect(indexOf(u8, "one two three four", "four").? == 14);
|
|
try testing.expect(lastIndexOf(u8, "one two three two four", "two").? == 14);
|
|
try testing.expect(indexOf(u8, "one two three four", "gour") == null);
|
|
try testing.expect(lastIndexOf(u8, "one two three four", "gour") == null);
|
|
try testing.expect(indexOf(u8, "foo", "foo").? == 0);
|
|
try testing.expect(lastIndexOf(u8, "foo", "foo").? == 0);
|
|
try testing.expect(indexOf(u8, "foo", "fool") == null);
|
|
try testing.expect(lastIndexOf(u8, "foo", "lfoo") == null);
|
|
try testing.expect(lastIndexOf(u8, "foo", "fool") == null);
|
|
|
|
try testing.expect(indexOf(u8, "foo foo", "foo").? == 0);
|
|
try testing.expect(lastIndexOf(u8, "foo foo", "foo").? == 4);
|
|
try testing.expect(lastIndexOfAny(u8, "boo, cat", "abo").? == 6);
|
|
try testing.expect(lastIndexOfScalar(u8, "boo", 'o').? == 2);
|
|
}
|
|
|
|
test "indexOf multibyte" {
|
|
{
|
|
// make haystack and needle long enough to trigger boyer-moore-horspool algorithm
|
|
const haystack = [1]u16{0} ** 100 ++ [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee, 0x00ff };
|
|
const needle = [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee };
|
|
try testing.expectEqual(indexOfPos(u16, &haystack, 0, &needle), 100);
|
|
|
|
// check for misaligned false positives (little and big endian)
|
|
const needleLE = [_]u16{ 0xbbbb, 0xcccc, 0xdddd, 0xeeee, 0xffff };
|
|
try testing.expectEqual(indexOfPos(u16, &haystack, 0, &needleLE), null);
|
|
const needleBE = [_]u16{ 0xaacc, 0xbbdd, 0xccee, 0xddff, 0xee00 };
|
|
try testing.expectEqual(indexOfPos(u16, &haystack, 0, &needleBE), null);
|
|
}
|
|
|
|
{
|
|
// make haystack and needle long enough to trigger boyer-moore-horspool algorithm
|
|
const haystack = [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee, 0x00ff } ++ [1]u16{0} ** 100;
|
|
const needle = [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee };
|
|
try testing.expectEqual(lastIndexOf(u16, &haystack, &needle), 0);
|
|
|
|
// check for misaligned false positives (little and big endian)
|
|
const needleLE = [_]u16{ 0xbbbb, 0xcccc, 0xdddd, 0xeeee, 0xffff };
|
|
try testing.expectEqual(lastIndexOf(u16, &haystack, &needleLE), null);
|
|
const needleBE = [_]u16{ 0xaacc, 0xbbdd, 0xccee, 0xddff, 0xee00 };
|
|
try testing.expectEqual(lastIndexOf(u16, &haystack, &needleBE), null);
|
|
}
|
|
}
|
|
|
|
test "indexOfPos empty needle" {
|
|
try testing.expectEqual(indexOfPos(u8, "abracadabra", 5, ""), 5);
|
|
}
|
|
|
|
/// Returns the number of needles inside the haystack
|
|
/// needle.len must be > 0
|
|
/// does not count overlapping needles
|
|
pub fn count(comptime T: type, haystack: []const T, needle: []const T) usize {
|
|
assert(needle.len > 0);
|
|
var i: usize = 0;
|
|
var found: usize = 0;
|
|
|
|
while (indexOfPos(T, haystack, i, needle)) |idx| {
|
|
i = idx + needle.len;
|
|
found += 1;
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
test "count" {
|
|
try testing.expect(count(u8, "", "h") == 0);
|
|
try testing.expect(count(u8, "h", "h") == 1);
|
|
try testing.expect(count(u8, "hh", "h") == 2);
|
|
try testing.expect(count(u8, "world!", "hello") == 0);
|
|
try testing.expect(count(u8, "hello world!", "hello") == 1);
|
|
try testing.expect(count(u8, " abcabc abc", "abc") == 3);
|
|
try testing.expect(count(u8, "udexdcbvbruhasdrw", "bruh") == 1);
|
|
try testing.expect(count(u8, "foo bar", "o bar") == 1);
|
|
try testing.expect(count(u8, "foofoofoo", "foo") == 3);
|
|
try testing.expect(count(u8, "fffffff", "ff") == 3);
|
|
try testing.expect(count(u8, "owowowu", "owowu") == 1);
|
|
}
|
|
|
|
/// Returns true if the haystack contains expected_count or more needles
|
|
/// needle.len must be > 0
|
|
/// does not count overlapping needles
|
|
pub fn containsAtLeast(comptime T: type, haystack: []const T, expected_count: usize, needle: []const T) bool {
|
|
assert(needle.len > 0);
|
|
if (expected_count == 0) return true;
|
|
|
|
var i: usize = 0;
|
|
var found: usize = 0;
|
|
|
|
while (indexOfPos(T, haystack, i, needle)) |idx| {
|
|
i = idx + needle.len;
|
|
found += 1;
|
|
if (found == expected_count) return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
test "containsAtLeast" {
|
|
try testing.expect(containsAtLeast(u8, "aa", 0, "a"));
|
|
try testing.expect(containsAtLeast(u8, "aa", 1, "a"));
|
|
try testing.expect(containsAtLeast(u8, "aa", 2, "a"));
|
|
try testing.expect(!containsAtLeast(u8, "aa", 3, "a"));
|
|
|
|
try testing.expect(containsAtLeast(u8, "radaradar", 1, "radar"));
|
|
try testing.expect(!containsAtLeast(u8, "radaradar", 2, "radar"));
|
|
|
|
try testing.expect(containsAtLeast(u8, "radarradaradarradar", 3, "radar"));
|
|
try testing.expect(!containsAtLeast(u8, "radarradaradarradar", 4, "radar"));
|
|
|
|
try testing.expect(containsAtLeast(u8, " radar radar ", 2, "radar"));
|
|
try testing.expect(!containsAtLeast(u8, " radar radar ", 3, "radar"));
|
|
}
|
|
|
|
/// Reads an integer from memory with size equal to bytes.len.
|
|
/// T specifies the return type, which must be large enough to store
|
|
/// the result.
|
|
pub fn readVarInt(comptime ReturnType: type, bytes: []const u8, endian: Endian) ReturnType {
|
|
var result: ReturnType = 0;
|
|
switch (endian) {
|
|
.Big => {
|
|
for (bytes) |b| {
|
|
result = (result << 8) | b;
|
|
}
|
|
},
|
|
.Little => {
|
|
const ShiftType = math.Log2Int(ReturnType);
|
|
for (bytes) |b, index| {
|
|
result = result | (@as(ReturnType, b) << @intCast(ShiftType, index * 8));
|
|
}
|
|
},
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// Reads an integer from memory with bit count specified by T.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
/// This function cannot fail and cannot cause undefined behavior.
|
|
/// Assumes the endianness of memory is native. This means the function can
|
|
/// simply pointer cast memory.
|
|
pub fn readIntNative(comptime T: type, bytes: *const [@divExact(@typeInfo(T).Int.bits, 8)]u8) T {
|
|
return @ptrCast(*align(1) const T, bytes).*;
|
|
}
|
|
|
|
/// Reads an integer from memory with bit count specified by T.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
/// This function cannot fail and cannot cause undefined behavior.
|
|
/// Assumes the endianness of memory is foreign, so it must byte-swap.
|
|
pub fn readIntForeign(comptime T: type, bytes: *const [@divExact(@typeInfo(T).Int.bits, 8)]u8) T {
|
|
return @byteSwap(readIntNative(T, bytes));
|
|
}
|
|
|
|
pub const readIntLittle = switch (native_endian) {
|
|
.Little => readIntNative,
|
|
.Big => readIntForeign,
|
|
};
|
|
|
|
pub const readIntBig = switch (native_endian) {
|
|
.Little => readIntForeign,
|
|
.Big => readIntNative,
|
|
};
|
|
|
|
/// Asserts that bytes.len >= @typeInfo(T).Int.bits / 8. Reads the integer starting from index 0
|
|
/// and ignores extra bytes.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
/// Assumes the endianness of memory is native. This means the function can
|
|
/// simply pointer cast memory.
|
|
pub fn readIntSliceNative(comptime T: type, bytes: []const u8) T {
|
|
const n = @divExact(@typeInfo(T).Int.bits, 8);
|
|
assert(bytes.len >= n);
|
|
return readIntNative(T, bytes[0..n]);
|
|
}
|
|
|
|
/// Asserts that bytes.len >= @typeInfo(T).Int.bits / 8. Reads the integer starting from index 0
|
|
/// and ignores extra bytes.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
/// Assumes the endianness of memory is foreign, so it must byte-swap.
|
|
pub fn readIntSliceForeign(comptime T: type, bytes: []const u8) T {
|
|
return @byteSwap(readIntSliceNative(T, bytes));
|
|
}
|
|
|
|
pub const readIntSliceLittle = switch (native_endian) {
|
|
.Little => readIntSliceNative,
|
|
.Big => readIntSliceForeign,
|
|
};
|
|
|
|
pub const readIntSliceBig = switch (native_endian) {
|
|
.Little => readIntSliceForeign,
|
|
.Big => readIntSliceNative,
|
|
};
|
|
|
|
/// Reads an integer from memory with bit count specified by T.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
/// This function cannot fail and cannot cause undefined behavior.
|
|
pub fn readInt(comptime T: type, bytes: *const [@divExact(@typeInfo(T).Int.bits, 8)]u8, endian: Endian) T {
|
|
if (endian == native_endian) {
|
|
return readIntNative(T, bytes);
|
|
} else {
|
|
return readIntForeign(T, bytes);
|
|
}
|
|
}
|
|
|
|
/// Asserts that bytes.len >= @typeInfo(T).Int.bits / 8. Reads the integer starting from index 0
|
|
/// and ignores extra bytes.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
pub fn readIntSlice(comptime T: type, bytes: []const u8, endian: Endian) T {
|
|
const n = @divExact(@typeInfo(T).Int.bits, 8);
|
|
assert(bytes.len >= n);
|
|
return readInt(T, bytes[0..n], endian);
|
|
}
|
|
|
|
test "comptime read/write int" {
|
|
comptime {
|
|
var bytes: [2]u8 = undefined;
|
|
writeIntLittle(u16, &bytes, 0x1234);
|
|
const result = readIntBig(u16, &bytes);
|
|
try testing.expect(result == 0x3412);
|
|
}
|
|
comptime {
|
|
var bytes: [2]u8 = undefined;
|
|
writeIntBig(u16, &bytes, 0x1234);
|
|
const result = readIntLittle(u16, &bytes);
|
|
try testing.expect(result == 0x3412);
|
|
}
|
|
}
|
|
|
|
test "readIntBig and readIntLittle" {
|
|
try testing.expect(readIntSliceBig(u0, &[_]u8{}) == 0x0);
|
|
try testing.expect(readIntSliceLittle(u0, &[_]u8{}) == 0x0);
|
|
|
|
try testing.expect(readIntSliceBig(u8, &[_]u8{0x32}) == 0x32);
|
|
try testing.expect(readIntSliceLittle(u8, &[_]u8{0x12}) == 0x12);
|
|
|
|
try testing.expect(readIntSliceBig(u16, &[_]u8{ 0x12, 0x34 }) == 0x1234);
|
|
try testing.expect(readIntSliceLittle(u16, &[_]u8{ 0x12, 0x34 }) == 0x3412);
|
|
|
|
try testing.expect(readIntSliceBig(u72, &[_]u8{ 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x24 }) == 0x123456789abcdef024);
|
|
try testing.expect(readIntSliceLittle(u72, &[_]u8{ 0xec, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }) == 0xfedcba9876543210ec);
|
|
|
|
try testing.expect(readIntSliceBig(i8, &[_]u8{0xff}) == -1);
|
|
try testing.expect(readIntSliceLittle(i8, &[_]u8{0xfe}) == -2);
|
|
|
|
try testing.expect(readIntSliceBig(i16, &[_]u8{ 0xff, 0xfd }) == -3);
|
|
try testing.expect(readIntSliceLittle(i16, &[_]u8{ 0xfc, 0xff }) == -4);
|
|
}
|
|
|
|
/// Writes an integer to memory, storing it in twos-complement.
|
|
/// This function always succeeds, has defined behavior for all inputs, and
|
|
/// accepts any integer bit width.
|
|
/// This function stores in native endian, which means it is implemented as a simple
|
|
/// memory store.
|
|
pub fn writeIntNative(comptime T: type, buf: *[(@typeInfo(T).Int.bits + 7) / 8]u8, value: T) void {
|
|
@ptrCast(*align(1) T, buf).* = value;
|
|
}
|
|
|
|
/// Writes an integer to memory, storing it in twos-complement.
|
|
/// This function always succeeds, has defined behavior for all inputs, but
|
|
/// the integer bit width must be divisible by 8.
|
|
/// This function stores in foreign endian, which means it does a @byteSwap first.
|
|
pub fn writeIntForeign(comptime T: type, buf: *[@divExact(@typeInfo(T).Int.bits, 8)]u8, value: T) void {
|
|
writeIntNative(T, buf, @byteSwap(value));
|
|
}
|
|
|
|
pub const writeIntLittle = switch (native_endian) {
|
|
.Little => writeIntNative,
|
|
.Big => writeIntForeign,
|
|
};
|
|
|
|
pub const writeIntBig = switch (native_endian) {
|
|
.Little => writeIntForeign,
|
|
.Big => writeIntNative,
|
|
};
|
|
|
|
/// Writes an integer to memory, storing it in twos-complement.
|
|
/// This function always succeeds, has defined behavior for all inputs, but
|
|
/// the integer bit width must be divisible by 8.
|
|
pub fn writeInt(comptime T: type, buffer: *[@divExact(@typeInfo(T).Int.bits, 8)]u8, value: T, endian: Endian) void {
|
|
if (endian == native_endian) {
|
|
return writeIntNative(T, buffer, value);
|
|
} else {
|
|
return writeIntForeign(T, buffer, value);
|
|
}
|
|
}
|
|
|
|
/// Writes a twos-complement little-endian integer to memory.
|
|
/// Asserts that buf.len >= @typeInfo(T).Int.bits / 8.
|
|
/// The bit count of T must be divisible by 8.
|
|
/// Any extra bytes in buffer after writing the integer are set to zero. To
|
|
/// avoid the branch to check for extra buffer bytes, use writeIntLittle
|
|
/// instead.
|
|
pub fn writeIntSliceLittle(comptime T: type, buffer: []u8, value: T) void {
|
|
assert(buffer.len >= @divExact(@typeInfo(T).Int.bits, 8));
|
|
|
|
if (@typeInfo(T).Int.bits == 0) {
|
|
return set(u8, buffer, 0);
|
|
} else if (@typeInfo(T).Int.bits == 8) {
|
|
set(u8, buffer, 0);
|
|
buffer[0] = @bitCast(u8, value);
|
|
return;
|
|
}
|
|
// TODO I want to call writeIntLittle here but comptime eval facilities aren't good enough
|
|
const uint = std.meta.Int(.unsigned, @typeInfo(T).Int.bits);
|
|
var bits = @bitCast(uint, value);
|
|
for (buffer) |*b| {
|
|
b.* = @truncate(u8, bits);
|
|
bits >>= 8;
|
|
}
|
|
}
|
|
|
|
/// Writes a twos-complement big-endian integer to memory.
|
|
/// Asserts that buffer.len >= @typeInfo(T).Int.bits / 8.
|
|
/// The bit count of T must be divisible by 8.
|
|
/// Any extra bytes in buffer before writing the integer are set to zero. To
|
|
/// avoid the branch to check for extra buffer bytes, use writeIntBig instead.
|
|
pub fn writeIntSliceBig(comptime T: type, buffer: []u8, value: T) void {
|
|
assert(buffer.len >= @divExact(@typeInfo(T).Int.bits, 8));
|
|
|
|
if (@typeInfo(T).Int.bits == 0) {
|
|
return set(u8, buffer, 0);
|
|
} else if (@typeInfo(T).Int.bits == 8) {
|
|
set(u8, buffer, 0);
|
|
buffer[buffer.len - 1] = @bitCast(u8, value);
|
|
return;
|
|
}
|
|
|
|
// TODO I want to call writeIntBig here but comptime eval facilities aren't good enough
|
|
const uint = std.meta.Int(.unsigned, @typeInfo(T).Int.bits);
|
|
var bits = @bitCast(uint, value);
|
|
var index: usize = buffer.len;
|
|
while (index != 0) {
|
|
index -= 1;
|
|
buffer[index] = @truncate(u8, bits);
|
|
bits >>= 8;
|
|
}
|
|
}
|
|
|
|
pub const writeIntSliceNative = switch (native_endian) {
|
|
.Little => writeIntSliceLittle,
|
|
.Big => writeIntSliceBig,
|
|
};
|
|
|
|
pub const writeIntSliceForeign = switch (native_endian) {
|
|
.Little => writeIntSliceBig,
|
|
.Big => writeIntSliceLittle,
|
|
};
|
|
|
|
/// Writes a twos-complement integer to memory, with the specified endianness.
|
|
/// Asserts that buf.len >= @typeInfo(T).Int.bits / 8.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
/// Any extra bytes in buffer not part of the integer are set to zero, with
|
|
/// respect to endianness. To avoid the branch to check for extra buffer bytes,
|
|
/// use writeInt instead.
|
|
pub fn writeIntSlice(comptime T: type, buffer: []u8, value: T, endian: Endian) void {
|
|
comptime assert(@typeInfo(T).Int.bits % 8 == 0);
|
|
return switch (endian) {
|
|
.Little => writeIntSliceLittle(T, buffer, value),
|
|
.Big => writeIntSliceBig(T, buffer, value),
|
|
};
|
|
}
|
|
|
|
test "writeIntBig and writeIntLittle" {
|
|
var buf0: [0]u8 = undefined;
|
|
var buf1: [1]u8 = undefined;
|
|
var buf2: [2]u8 = undefined;
|
|
var buf9: [9]u8 = undefined;
|
|
|
|
writeIntBig(u0, &buf0, 0x0);
|
|
try testing.expect(eql(u8, buf0[0..], &[_]u8{}));
|
|
writeIntLittle(u0, &buf0, 0x0);
|
|
try testing.expect(eql(u8, buf0[0..], &[_]u8{}));
|
|
|
|
writeIntBig(u8, &buf1, 0x12);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0x12}));
|
|
writeIntLittle(u8, &buf1, 0x34);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0x34}));
|
|
|
|
writeIntBig(u16, &buf2, 0x1234);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0x12, 0x34 }));
|
|
writeIntLittle(u16, &buf2, 0x5678);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0x78, 0x56 }));
|
|
|
|
writeIntBig(u72, &buf9, 0x123456789abcdef024);
|
|
try testing.expect(eql(u8, buf9[0..], &[_]u8{ 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x24 }));
|
|
writeIntLittle(u72, &buf9, 0xfedcba9876543210ec);
|
|
try testing.expect(eql(u8, buf9[0..], &[_]u8{ 0xec, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }));
|
|
|
|
writeIntBig(i8, &buf1, -1);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0xff}));
|
|
writeIntLittle(i8, &buf1, -2);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0xfe}));
|
|
|
|
writeIntBig(i16, &buf2, -3);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0xff, 0xfd }));
|
|
writeIntLittle(i16, &buf2, -4);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0xfc, 0xff }));
|
|
}
|
|
|
|
/// TODO delete this deprecated declaration after 0.10.0 is released
|
|
pub const bswapAllFields = @compileError("bswapAllFields has been renamed to byteSwapAllFields");
|
|
|
|
/// Swap the byte order of all the members of the fields of a struct
|
|
/// (Changing their endianess)
|
|
pub fn byteSwapAllFields(comptime S: type, ptr: *S) void {
|
|
if (@typeInfo(S) != .Struct) @compileError("byteSwapAllFields expects a struct as the first argument");
|
|
inline for (std.meta.fields(S)) |f| {
|
|
@field(ptr, f.name) = @byteSwap(@field(ptr, f.name));
|
|
}
|
|
}
|
|
|
|
test "byteSwapAllFields" {
|
|
const T = extern struct {
|
|
f0: u8,
|
|
f1: u16,
|
|
f2: u32,
|
|
};
|
|
var s = T{
|
|
.f0 = 0x12,
|
|
.f1 = 0x1234,
|
|
.f2 = 0x12345678,
|
|
};
|
|
byteSwapAllFields(T, &s);
|
|
try std.testing.expectEqual(T{
|
|
.f0 = 0x12,
|
|
.f1 = 0x3412,
|
|
.f2 = 0x78563412,
|
|
}, s);
|
|
}
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that are not
|
|
/// any of the bytes in `delimiter_bytes`.
|
|
///
|
|
/// `tokenize(u8, " abc def ghi ", " ")` will return slices
|
|
/// for "abc", "def", "ghi", null, in that order.
|
|
///
|
|
/// If `buffer` is empty, the iterator will return null.
|
|
/// If `delimiter_bytes` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
///
|
|
/// See also: `split` and `splitBackwards`.
|
|
pub fn tokenize(comptime T: type, buffer: []const T, delimiter_bytes: []const T) TokenIterator(T) {
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter_bytes = delimiter_bytes,
|
|
};
|
|
}
|
|
|
|
test "tokenize" {
|
|
var it = tokenize(u8, " abc def ghi ", " ");
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.peek().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = tokenize(u8, "..\\bob", "\\");
|
|
try testing.expect(eql(u8, it.next().?, ".."));
|
|
try testing.expect(eql(u8, "..", "..\\bob"[0..it.index]));
|
|
try testing.expect(eql(u8, it.next().?, "bob"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = tokenize(u8, "//a/b", "/");
|
|
try testing.expect(eql(u8, it.next().?, "a"));
|
|
try testing.expect(eql(u8, it.next().?, "b"));
|
|
try testing.expect(eql(u8, "//a/b", "//a/b"[0..it.index]));
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = tokenize(u8, "|", "|");
|
|
try testing.expect(it.next() == null);
|
|
try testing.expect(it.peek() == null);
|
|
|
|
it = tokenize(u8, "", "|");
|
|
try testing.expect(it.next() == null);
|
|
try testing.expect(it.peek() == null);
|
|
|
|
it = tokenize(u8, "hello", "");
|
|
try testing.expect(eql(u8, it.next().?, "hello"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = tokenize(u8, "hello", " ");
|
|
try testing.expect(eql(u8, it.next().?, "hello"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = tokenize(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("hello"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(" "),
|
|
);
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("hello")));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "tokenize (multibyte)" {
|
|
var it = tokenize(u8, "a|b,c/d e", " /,|");
|
|
try testing.expect(eql(u8, it.next().?, "a"));
|
|
try testing.expect(eql(u8, it.peek().?, "b"));
|
|
try testing.expect(eql(u8, it.next().?, "b"));
|
|
try testing.expect(eql(u8, it.next().?, "c"));
|
|
try testing.expect(eql(u8, it.next().?, "d"));
|
|
try testing.expect(eql(u8, it.next().?, "e"));
|
|
try testing.expect(it.next() == null);
|
|
try testing.expect(it.peek() == null);
|
|
|
|
var it16 = tokenize(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a|b,c/d e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(" /,|"),
|
|
);
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e")));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "tokenize (reset)" {
|
|
var it = tokenize(u8, " abc def ghi ", " ");
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that
|
|
/// are separated by bytes in `delimiter`.
|
|
///
|
|
/// `split(u8, "abc|def||ghi", "|")` will return slices
|
|
/// for "abc", "def", "", "ghi", null, in that order.
|
|
///
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
/// The delimiter length must not be zero.
|
|
///
|
|
/// See also: `tokenize` and `splitBackwards`.
|
|
pub fn split(comptime T: type, buffer: []const T, delimiter: []const T) SplitIterator(T) {
|
|
assert(delimiter.len != 0);
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
test "split" {
|
|
var it = split(u8, "abc|def||ghi", "|");
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def||ghi");
|
|
try testing.expectEqualSlices(u8, it.first(), "abc");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "def||ghi");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "|ghi");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "ghi");
|
|
try testing.expectEqualSlices(u8, it.next().?, "ghi");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = split(u8, "", "|");
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = split(u8, "|", "|");
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = split(u8, "hello", " ");
|
|
try testing.expectEqualSlices(u8, it.first(), "hello");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = split(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("hello"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(" "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("hello"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "split (multibyte)" {
|
|
var it = split(u8, "a, b ,, c, d, e", ", ");
|
|
try testing.expectEqualSlices(u8, it.first(), "a");
|
|
try testing.expectEqualSlices(u8, it.rest(), "b ,, c, d, e");
|
|
try testing.expectEqualSlices(u8, it.next().?, "b ,");
|
|
try testing.expectEqualSlices(u8, it.next().?, "c");
|
|
try testing.expectEqualSlices(u8, it.next().?, "d");
|
|
try testing.expectEqualSlices(u8, it.next().?, "e");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = split(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a, b ,, c, d, e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(", "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("a"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b ,"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "split (reset)" {
|
|
var it = split(u8, "abc def ghi", " ");
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
|
|
/// Returns an iterator that iterates backwards over the slices of `buffer`
|
|
/// that are separated by bytes in `delimiter`.
|
|
///
|
|
/// `splitBackwards(u8, "abc|def||ghi", "|")` will return slices
|
|
/// for "ghi", "", "def", "abc", null, in that order.
|
|
///
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
/// The delimiter length must not be zero.
|
|
///
|
|
/// See also: `tokenize` and `split`.
|
|
pub fn splitBackwards(comptime T: type, buffer: []const T, delimiter: []const T) SplitBackwardsIterator(T) {
|
|
assert(delimiter.len != 0);
|
|
return SplitBackwardsIterator(T){
|
|
.index = buffer.len,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
test "splitBackwards" {
|
|
var it = splitBackwards(u8, "abc|def||ghi", "|");
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def||ghi");
|
|
try testing.expectEqualSlices(u8, it.first(), "ghi");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def|");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc");
|
|
try testing.expectEqualSlices(u8, it.next().?, "abc");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitBackwards(u8, "", "|");
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitBackwards(u8, "|", "|");
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitBackwards(u8, "hello", " ");
|
|
try testing.expectEqualSlices(u8, it.first(), "hello");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitBackwards(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("hello"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(" "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("hello"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "splitBackwards (multibyte)" {
|
|
var it = splitBackwards(u8, "a, b ,, c, d, e", ", ");
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c, d, e");
|
|
try testing.expectEqualSlices(u8, it.first(), "e");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c, d");
|
|
try testing.expectEqualSlices(u8, it.next().?, "d");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c");
|
|
try testing.expectEqualSlices(u8, it.next().?, "c");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,");
|
|
try testing.expectEqualSlices(u8, it.next().?, "b ,");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a");
|
|
try testing.expectEqualSlices(u8, it.next().?, "a");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitBackwards(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a, b ,, c, d, e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(", "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("e"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b ,"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "splitBackwards (reset)" {
|
|
var it = splitBackwards(u8, "abc def ghi", " ");
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
|
|
pub fn startsWith(comptime T: type, haystack: []const T, needle: []const T) bool {
|
|
return if (needle.len > haystack.len) false else eql(T, haystack[0..needle.len], needle);
|
|
}
|
|
|
|
test "startsWith" {
|
|
try testing.expect(startsWith(u8, "Bob", "Bo"));
|
|
try testing.expect(!startsWith(u8, "Needle in haystack", "haystack"));
|
|
}
|
|
|
|
pub fn endsWith(comptime T: type, haystack: []const T, needle: []const T) bool {
|
|
return if (needle.len > haystack.len) false else eql(T, haystack[haystack.len - needle.len ..], needle);
|
|
}
|
|
|
|
test "endsWith" {
|
|
try testing.expect(endsWith(u8, "Needle in haystack", "haystack"));
|
|
try testing.expect(!endsWith(u8, "Bob", "Bo"));
|
|
}
|
|
|
|
pub fn TokenIterator(comptime T: type) type {
|
|
return struct {
|
|
buffer: []const T,
|
|
delimiter_bytes: []const T,
|
|
index: usize,
|
|
|
|
const Self = @This();
|
|
|
|
/// Returns a slice of the current token, or null if tokenization is
|
|
/// complete, and advances to the next token.
|
|
pub fn next(self: *Self) ?[]const T {
|
|
const result = self.peek() orelse return null;
|
|
self.index += result.len;
|
|
return result;
|
|
}
|
|
|
|
/// Returns a slice of the current token, or null if tokenization is
|
|
/// complete. Does not advance to the next token.
|
|
pub fn peek(self: *Self) ?[]const T {
|
|
// move to beginning of token
|
|
while (self.index < self.buffer.len and self.isSplitByte(self.buffer[self.index])) : (self.index += 1) {}
|
|
const start = self.index;
|
|
if (start == self.buffer.len) {
|
|
return null;
|
|
}
|
|
|
|
// move to end of token
|
|
var end = start;
|
|
while (end < self.buffer.len and !self.isSplitByte(self.buffer[end])) : (end += 1) {}
|
|
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Returns a slice of the remaining bytes. Does not affect iterator state.
|
|
pub fn rest(self: Self) []const T {
|
|
// move to beginning of token
|
|
var index: usize = self.index;
|
|
while (index < self.buffer.len and self.isSplitByte(self.buffer[index])) : (index += 1) {}
|
|
return self.buffer[index..];
|
|
}
|
|
|
|
/// Resets the iterator to the initial token.
|
|
pub fn reset(self: *Self) void {
|
|
self.index = 0;
|
|
}
|
|
|
|
fn isSplitByte(self: Self, byte: T) bool {
|
|
for (self.delimiter_bytes) |delimiter_byte| {
|
|
if (byte == delimiter_byte) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
};
|
|
}
|
|
|
|
pub fn SplitIterator(comptime T: type) type {
|
|
return struct {
|
|
buffer: []const T,
|
|
index: ?usize,
|
|
delimiter: []const T,
|
|
|
|
const Self = @This();
|
|
|
|
/// Returns a slice of the first field. This never fails.
|
|
/// Call this only to get the first field and then use `next` to get all subsequent fields.
|
|
pub fn first(self: *Self) []const T {
|
|
assert(self.index.? == 0);
|
|
return self.next().?;
|
|
}
|
|
|
|
/// Returns a slice of the next field, or null if splitting is complete.
|
|
pub fn next(self: *Self) ?[]const T {
|
|
const start = self.index orelse return null;
|
|
const end = if (indexOfPos(T, self.buffer, start, self.delimiter)) |delim_start| blk: {
|
|
self.index = delim_start + self.delimiter.len;
|
|
break :blk delim_start;
|
|
} else blk: {
|
|
self.index = null;
|
|
break :blk self.buffer.len;
|
|
};
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Returns a slice of the remaining bytes. Does not affect iterator state.
|
|
pub fn rest(self: Self) []const T {
|
|
const end = self.buffer.len;
|
|
const start = self.index orelse end;
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Resets the iterator to the initial slice.
|
|
pub fn reset(self: *Self) void {
|
|
self.index = 0;
|
|
}
|
|
};
|
|
}
|
|
|
|
pub fn SplitBackwardsIterator(comptime T: type) type {
|
|
return struct {
|
|
buffer: []const T,
|
|
index: ?usize,
|
|
delimiter: []const T,
|
|
|
|
const Self = @This();
|
|
|
|
/// Returns a slice of the first field. This never fails.
|
|
/// Call this only to get the first field and then use `next` to get all subsequent fields.
|
|
pub fn first(self: *Self) []const T {
|
|
assert(self.index.? == self.buffer.len);
|
|
return self.next().?;
|
|
}
|
|
|
|
/// Returns a slice of the next field, or null if splitting is complete.
|
|
pub fn next(self: *Self) ?[]const T {
|
|
const end = self.index orelse return null;
|
|
const start = if (lastIndexOf(T, self.buffer[0..end], self.delimiter)) |delim_start| blk: {
|
|
self.index = delim_start;
|
|
break :blk delim_start + self.delimiter.len;
|
|
} else blk: {
|
|
self.index = null;
|
|
break :blk 0;
|
|
};
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Returns a slice of the remaining bytes. Does not affect iterator state.
|
|
pub fn rest(self: Self) []const T {
|
|
const end = self.index orelse 0;
|
|
return self.buffer[0..end];
|
|
}
|
|
|
|
/// Resets the iterator to the initial slice.
|
|
pub fn reset(self: *Self) void {
|
|
self.index = self.buffer.len;
|
|
}
|
|
};
|
|
}
|
|
|
|
/// Naively combines a series of slices with a separator.
|
|
/// Allocates memory for the result, which must be freed by the caller.
|
|
pub fn join(allocator: Allocator, separator: []const u8, slices: []const []const u8) ![]u8 {
|
|
return joinMaybeZ(allocator, separator, slices, false);
|
|
}
|
|
|
|
/// Naively combines a series of slices with a separator and null terminator.
|
|
/// Allocates memory for the result, which must be freed by the caller.
|
|
pub fn joinZ(allocator: Allocator, separator: []const u8, slices: []const []const u8) ![:0]u8 {
|
|
const out = try joinMaybeZ(allocator, separator, slices, true);
|
|
return out[0 .. out.len - 1 :0];
|
|
}
|
|
|
|
fn joinMaybeZ(allocator: Allocator, separator: []const u8, slices: []const []const u8, zero: bool) ![]u8 {
|
|
if (slices.len == 0) return if (zero) try allocator.dupe(u8, &[1]u8{0}) else &[0]u8{};
|
|
|
|
const total_len = blk: {
|
|
var sum: usize = separator.len * (slices.len - 1);
|
|
for (slices) |slice| sum += slice.len;
|
|
if (zero) sum += 1;
|
|
break :blk sum;
|
|
};
|
|
|
|
const buf = try allocator.alloc(u8, total_len);
|
|
errdefer allocator.free(buf);
|
|
|
|
copy(u8, buf, slices[0]);
|
|
var buf_index: usize = slices[0].len;
|
|
for (slices[1..]) |slice| {
|
|
copy(u8, buf[buf_index..], separator);
|
|
buf_index += separator.len;
|
|
copy(u8, buf[buf_index..], slice);
|
|
buf_index += slice.len;
|
|
}
|
|
|
|
if (zero) buf[buf.len - 1] = 0;
|
|
|
|
// No need for shrink since buf is exactly the correct size.
|
|
return buf;
|
|
}
|
|
|
|
test "join" {
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, ""));
|
|
}
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{ "a", "b", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,b,c"));
|
|
}
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{"a"});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a"));
|
|
}
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{ "a", "", "b", "", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,,b,,c"));
|
|
}
|
|
}
|
|
|
|
test "joinZ" {
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, ""));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{ "a", "b", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,b,c"));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{"a"});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a"));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{ "a", "", "b", "", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,,b,,c"));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
}
|
|
|
|
/// Copies each T from slices into a new slice that exactly holds all the elements.
|
|
pub fn concat(allocator: Allocator, comptime T: type, slices: []const []const T) ![]T {
|
|
return concatMaybeSentinel(allocator, T, slices, null);
|
|
}
|
|
|
|
/// Copies each T from slices into a new slice that exactly holds all the elements.
|
|
pub fn concatWithSentinel(allocator: Allocator, comptime T: type, slices: []const []const T, comptime s: T) ![:s]T {
|
|
const ret = try concatMaybeSentinel(allocator, T, slices, s);
|
|
return ret[0 .. ret.len - 1 :s];
|
|
}
|
|
|
|
/// Copies each T from slices into a new slice that exactly holds all the elements as well as the sentinel.
|
|
pub fn concatMaybeSentinel(allocator: Allocator, comptime T: type, slices: []const []const T, comptime s: ?T) ![]T {
|
|
if (slices.len == 0) return if (s) |sentinel| try allocator.dupe(T, &[1]T{sentinel}) else &[0]T{};
|
|
|
|
const total_len = blk: {
|
|
var sum: usize = 0;
|
|
for (slices) |slice| {
|
|
sum += slice.len;
|
|
}
|
|
|
|
if (s) |_| {
|
|
sum += 1;
|
|
}
|
|
|
|
break :blk sum;
|
|
};
|
|
|
|
const buf = try allocator.alloc(T, total_len);
|
|
errdefer allocator.free(buf);
|
|
|
|
var buf_index: usize = 0;
|
|
for (slices) |slice| {
|
|
copy(T, buf[buf_index..], slice);
|
|
buf_index += slice.len;
|
|
}
|
|
|
|
if (s) |sentinel| {
|
|
buf[buf.len - 1] = sentinel;
|
|
}
|
|
|
|
// No need for shrink since buf is exactly the correct size.
|
|
return buf;
|
|
}
|
|
|
|
test "concat" {
|
|
{
|
|
const str = try concat(testing.allocator, u8, &[_][]const u8{ "abc", "def", "ghi" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "abcdefghi"));
|
|
}
|
|
{
|
|
const str = try concat(testing.allocator, u32, &[_][]const u32{
|
|
&[_]u32{ 0, 1 },
|
|
&[_]u32{ 2, 3, 4 },
|
|
&[_]u32{},
|
|
&[_]u32{5},
|
|
});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u32, str, &[_]u32{ 0, 1, 2, 3, 4, 5 }));
|
|
}
|
|
{
|
|
const str = try concatWithSentinel(testing.allocator, u8, &[_][]const u8{ "abc", "def", "ghi" }, 0);
|
|
defer testing.allocator.free(str);
|
|
try testing.expectEqualSentinel(u8, 0, str, "abcdefghi");
|
|
}
|
|
{
|
|
const slice = try concatWithSentinel(testing.allocator, u8, &[_][]const u8{}, 0);
|
|
defer testing.allocator.free(slice);
|
|
try testing.expectEqualSentinel(u8, 0, slice, &[_:0]u8{});
|
|
}
|
|
{
|
|
const slice = try concatWithSentinel(testing.allocator, u32, &[_][]const u32{
|
|
&[_]u32{ 0, 1 },
|
|
&[_]u32{ 2, 3, 4 },
|
|
&[_]u32{},
|
|
&[_]u32{5},
|
|
}, 2);
|
|
defer testing.allocator.free(slice);
|
|
try testing.expectEqualSentinel(u32, 2, slice, &[_:2]u32{ 0, 1, 2, 3, 4, 5 });
|
|
}
|
|
}
|
|
|
|
test "testStringEquality" {
|
|
try testing.expect(eql(u8, "abcd", "abcd"));
|
|
try testing.expect(!eql(u8, "abcdef", "abZdef"));
|
|
try testing.expect(!eql(u8, "abcdefg", "abcdef"));
|
|
}
|
|
|
|
test "testReadInt" {
|
|
try testReadIntImpl();
|
|
comptime try testReadIntImpl();
|
|
}
|
|
fn testReadIntImpl() !void {
|
|
{
|
|
const bytes = [_]u8{
|
|
0x12,
|
|
0x34,
|
|
0x56,
|
|
0x78,
|
|
};
|
|
try testing.expect(readInt(u32, &bytes, Endian.Big) == 0x12345678);
|
|
try testing.expect(readIntBig(u32, &bytes) == 0x12345678);
|
|
try testing.expect(readIntBig(i32, &bytes) == 0x12345678);
|
|
try testing.expect(readInt(u32, &bytes, Endian.Little) == 0x78563412);
|
|
try testing.expect(readIntLittle(u32, &bytes) == 0x78563412);
|
|
try testing.expect(readIntLittle(i32, &bytes) == 0x78563412);
|
|
}
|
|
{
|
|
const buf = [_]u8{
|
|
0x00,
|
|
0x00,
|
|
0x12,
|
|
0x34,
|
|
};
|
|
const answer = readInt(u32, &buf, Endian.Big);
|
|
try testing.expect(answer == 0x00001234);
|
|
}
|
|
{
|
|
const buf = [_]u8{
|
|
0x12,
|
|
0x34,
|
|
0x00,
|
|
0x00,
|
|
};
|
|
const answer = readInt(u32, &buf, Endian.Little);
|
|
try testing.expect(answer == 0x00003412);
|
|
}
|
|
{
|
|
const bytes = [_]u8{
|
|
0xff,
|
|
0xfe,
|
|
};
|
|
try testing.expect(readIntBig(u16, &bytes) == 0xfffe);
|
|
try testing.expect(readIntBig(i16, &bytes) == -0x0002);
|
|
try testing.expect(readIntLittle(u16, &bytes) == 0xfeff);
|
|
try testing.expect(readIntLittle(i16, &bytes) == -0x0101);
|
|
}
|
|
}
|
|
|
|
test "writeIntSlice" {
|
|
try testWriteIntImpl();
|
|
comptime try testWriteIntImpl();
|
|
}
|
|
fn testWriteIntImpl() !void {
|
|
var bytes: [8]u8 = undefined;
|
|
|
|
writeIntSlice(u0, bytes[0..], 0, Endian.Big);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00,
|
|
}));
|
|
|
|
writeIntSlice(u0, bytes[0..], 0, Endian.Little);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00,
|
|
}));
|
|
|
|
writeIntSlice(u64, bytes[0..], 0x12345678CAFEBABE, Endian.Big);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x12,
|
|
0x34,
|
|
0x56,
|
|
0x78,
|
|
0xCA,
|
|
0xFE,
|
|
0xBA,
|
|
0xBE,
|
|
}));
|
|
|
|
writeIntSlice(u64, bytes[0..], 0xBEBAFECA78563412, Endian.Little);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x12,
|
|
0x34,
|
|
0x56,
|
|
0x78,
|
|
0xCA,
|
|
0xFE,
|
|
0xBA,
|
|
0xBE,
|
|
}));
|
|
|
|
writeIntSlice(u32, bytes[0..], 0x12345678, Endian.Big);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x12,
|
|
0x34,
|
|
0x56,
|
|
0x78,
|
|
}));
|
|
|
|
writeIntSlice(u32, bytes[0..], 0x78563412, Endian.Little);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x12,
|
|
0x34,
|
|
0x56,
|
|
0x78,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
}));
|
|
|
|
writeIntSlice(u16, bytes[0..], 0x1234, Endian.Big);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x12,
|
|
0x34,
|
|
}));
|
|
|
|
writeIntSlice(u16, bytes[0..], 0x1234, Endian.Little);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x34,
|
|
0x12,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
}));
|
|
|
|
writeIntSlice(i16, bytes[0..], @as(i16, -21555), Endian.Little);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0xCD,
|
|
0xAB,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
}));
|
|
|
|
writeIntSlice(i16, bytes[0..], @as(i16, -21555), Endian.Big);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0x00,
|
|
0xAB,
|
|
0xCD,
|
|
}));
|
|
|
|
writeIntSlice(u8, bytes[0..], 0x12, Endian.Big);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x12,
|
|
}));
|
|
|
|
writeIntSlice(u8, bytes[0..], 0x12, Endian.Little);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x12, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00,
|
|
}));
|
|
|
|
writeIntSlice(i8, bytes[0..], -1, Endian.Big);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0xff,
|
|
}));
|
|
|
|
writeIntSlice(i8, bytes[0..], -1, Endian.Little);
|
|
try testing.expect(eql(u8, &bytes, &[_]u8{
|
|
0xff, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00,
|
|
}));
|
|
}
|
|
|
|
/// Returns the smallest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn min(comptime T: type, slice: []const T) T {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
for (slice[1..]) |item| {
|
|
best = math.min(best, item);
|
|
}
|
|
return best;
|
|
}
|
|
|
|
test "min" {
|
|
try testing.expectEqual(min(u8, "abcdefg"), 'a');
|
|
try testing.expectEqual(min(u8, "bcdefga"), 'a');
|
|
try testing.expectEqual(min(u8, "a"), 'a');
|
|
}
|
|
|
|
/// Returns the largest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn max(comptime T: type, slice: []const T) T {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
for (slice[1..]) |item| {
|
|
best = math.max(best, item);
|
|
}
|
|
return best;
|
|
}
|
|
|
|
test "max" {
|
|
try testing.expectEqual(max(u8, "abcdefg"), 'g');
|
|
try testing.expectEqual(max(u8, "gabcdef"), 'g');
|
|
try testing.expectEqual(max(u8, "g"), 'g');
|
|
}
|
|
|
|
/// Finds the smallest and largest number in a slice. O(n).
|
|
/// Returns an anonymous struct with the fields `min` and `max`.
|
|
/// `slice` must not be empty.
|
|
pub fn minMax(comptime T: type, slice: []const T) struct { min: T, max: T } {
|
|
assert(slice.len > 0);
|
|
var minVal = slice[0];
|
|
var maxVal = slice[0];
|
|
for (slice[1..]) |item| {
|
|
minVal = math.min(minVal, item);
|
|
maxVal = math.max(maxVal, item);
|
|
}
|
|
return .{ .min = minVal, .max = maxVal };
|
|
}
|
|
|
|
test "minMax" {
|
|
try testing.expectEqual(minMax(u8, "abcdefg"), .{ .min = 'a', .max = 'g' });
|
|
try testing.expectEqual(minMax(u8, "bcdefga"), .{ .min = 'a', .max = 'g' });
|
|
try testing.expectEqual(minMax(u8, "a"), .{ .min = 'a', .max = 'a' });
|
|
}
|
|
|
|
/// Returns the index of the smallest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn indexOfMin(comptime T: type, slice: []const T) usize {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
var index: usize = 0;
|
|
for (slice[1..]) |item, i| {
|
|
if (item < best) {
|
|
best = item;
|
|
index = i + 1;
|
|
}
|
|
}
|
|
return index;
|
|
}
|
|
|
|
test "indexOfMin" {
|
|
try testing.expectEqual(indexOfMin(u8, "abcdefg"), 0);
|
|
try testing.expectEqual(indexOfMin(u8, "bcdefga"), 6);
|
|
try testing.expectEqual(indexOfMin(u8, "a"), 0);
|
|
}
|
|
|
|
/// Returns the index of the largest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn indexOfMax(comptime T: type, slice: []const T) usize {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
var index: usize = 0;
|
|
for (slice[1..]) |item, i| {
|
|
if (item > best) {
|
|
best = item;
|
|
index = i + 1;
|
|
}
|
|
}
|
|
return index;
|
|
}
|
|
|
|
test "indexOfMax" {
|
|
try testing.expectEqual(indexOfMax(u8, "abcdefg"), 6);
|
|
try testing.expectEqual(indexOfMax(u8, "gabcdef"), 0);
|
|
try testing.expectEqual(indexOfMax(u8, "a"), 0);
|
|
}
|
|
|
|
/// Finds the indices of the smallest and largest number in a slice. O(n).
|
|
/// Returns an anonymous struct with the fields `index_min` and `index_max`.
|
|
/// `slice` must not be empty.
|
|
pub fn indexOfMinMax(comptime T: type, slice: []const T) struct { index_min: usize, index_max: usize } {
|
|
assert(slice.len > 0);
|
|
var minVal = slice[0];
|
|
var maxVal = slice[0];
|
|
var minIdx: usize = 0;
|
|
var maxIdx: usize = 0;
|
|
for (slice[1..]) |item, i| {
|
|
if (item < minVal) {
|
|
minVal = item;
|
|
minIdx = i + 1;
|
|
}
|
|
if (item > maxVal) {
|
|
maxVal = item;
|
|
maxIdx = i + 1;
|
|
}
|
|
}
|
|
return .{ .index_min = minIdx, .index_max = maxIdx };
|
|
}
|
|
|
|
test "indexOfMinMax" {
|
|
try testing.expectEqual(indexOfMinMax(u8, "abcdefg"), .{ .index_min = 0, .index_max = 6 });
|
|
try testing.expectEqual(indexOfMinMax(u8, "gabcdef"), .{ .index_min = 1, .index_max = 0 });
|
|
try testing.expectEqual(indexOfMinMax(u8, "a"), .{ .index_min = 0, .index_max = 0 });
|
|
}
|
|
|
|
pub fn swap(comptime T: type, a: *T, b: *T) void {
|
|
const tmp = a.*;
|
|
a.* = b.*;
|
|
b.* = tmp;
|
|
}
|
|
|
|
/// In-place order reversal of a slice
|
|
pub fn reverse(comptime T: type, items: []T) void {
|
|
var i: usize = 0;
|
|
const end = items.len / 2;
|
|
while (i < end) : (i += 1) {
|
|
swap(T, &items[i], &items[items.len - i - 1]);
|
|
}
|
|
}
|
|
|
|
test "reverse" {
|
|
var arr = [_]i32{ 5, 3, 1, 2, 4 };
|
|
reverse(i32, arr[0..]);
|
|
|
|
try testing.expect(eql(i32, &arr, &[_]i32{ 4, 2, 1, 3, 5 }));
|
|
}
|
|
|
|
/// In-place rotation of the values in an array ([0 1 2 3] becomes [1 2 3 0] if we rotate by 1)
|
|
/// Assumes 0 <= amount <= items.len
|
|
pub fn rotate(comptime T: type, items: []T, amount: usize) void {
|
|
reverse(T, items[0..amount]);
|
|
reverse(T, items[amount..]);
|
|
reverse(T, items);
|
|
}
|
|
|
|
test "rotate" {
|
|
var arr = [_]i32{ 5, 3, 1, 2, 4 };
|
|
rotate(i32, arr[0..], 2);
|
|
|
|
try testing.expect(eql(i32, &arr, &[_]i32{ 1, 2, 4, 5, 3 }));
|
|
}
|
|
|
|
/// Replace needle with replacement as many times as possible, writing to an output buffer which is assumed to be of
|
|
/// appropriate size. Use replacementSize to calculate an appropriate buffer size.
|
|
/// The needle must not be empty.
|
|
pub fn replace(comptime T: type, input: []const T, needle: []const T, replacement: []const T, output: []T) usize {
|
|
// Empty needle will loop until output buffer overflows.
|
|
assert(needle.len > 0);
|
|
|
|
var i: usize = 0;
|
|
var slide: usize = 0;
|
|
var replacements: usize = 0;
|
|
while (slide < input.len) {
|
|
if (mem.startsWith(T, input[slide..], needle)) {
|
|
mem.copy(T, output[i .. i + replacement.len], replacement);
|
|
i += replacement.len;
|
|
slide += needle.len;
|
|
replacements += 1;
|
|
} else {
|
|
output[i] = input[slide];
|
|
i += 1;
|
|
slide += 1;
|
|
}
|
|
}
|
|
|
|
return replacements;
|
|
}
|
|
|
|
test "replace" {
|
|
var output: [29]u8 = undefined;
|
|
var replacements = replace(u8, "All your base are belong to us", "base", "Zig", output[0..]);
|
|
var expected: []const u8 = "All your Zig are belong to us";
|
|
try testing.expect(replacements == 1);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
replacements = replace(u8, "Favor reading code over writing code.", "code", "", output[0..]);
|
|
expected = "Favor reading over writing .";
|
|
try testing.expect(replacements == 2);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
// Empty needle is not allowed but input may be empty.
|
|
replacements = replace(u8, "", "x", "y", output[0..0]);
|
|
expected = "";
|
|
try testing.expect(replacements == 0);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
// Adjacent replacements.
|
|
|
|
replacements = replace(u8, "\\n\\n", "\\n", "\n", output[0..]);
|
|
expected = "\n\n";
|
|
try testing.expect(replacements == 2);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
replacements = replace(u8, "abbba", "b", "cd", output[0..]);
|
|
expected = "acdcdcda";
|
|
try testing.expect(replacements == 3);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
}
|
|
|
|
/// Replace all occurences of `needle` with `replacement`.
|
|
pub fn replaceScalar(comptime T: type, slice: []T, needle: T, replacement: T) void {
|
|
for (slice) |e, i| {
|
|
if (e == needle) {
|
|
slice[i] = replacement;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Collapse consecutive duplicate elements into one entry.
|
|
pub fn collapseRepeatsLen(comptime T: type, slice: []T, elem: T) usize {
|
|
if (slice.len == 0) return 0;
|
|
var write_idx: usize = 1;
|
|
var read_idx: usize = 1;
|
|
while (read_idx < slice.len) : (read_idx += 1) {
|
|
if (slice[read_idx - 1] != elem or slice[read_idx] != elem) {
|
|
slice[write_idx] = slice[read_idx];
|
|
write_idx += 1;
|
|
}
|
|
}
|
|
return write_idx;
|
|
}
|
|
|
|
/// Collapse consecutive duplicate elements into one entry.
|
|
pub fn collapseRepeats(comptime T: type, slice: []T, elem: T) []T {
|
|
return slice[0..collapseRepeatsLen(T, slice, elem)];
|
|
}
|
|
|
|
fn testCollapseRepeats(str: []const u8, elem: u8, expected: []const u8) !void {
|
|
const mutable = try std.testing.allocator.dupe(u8, str);
|
|
defer std.testing.allocator.free(mutable);
|
|
try testing.expect(std.mem.eql(u8, collapseRepeats(u8, mutable, elem), expected));
|
|
}
|
|
test "collapseRepeats" {
|
|
try testCollapseRepeats("", '/', "");
|
|
try testCollapseRepeats("a", '/', "a");
|
|
try testCollapseRepeats("/", '/', "/");
|
|
try testCollapseRepeats("//", '/', "/");
|
|
try testCollapseRepeats("/a", '/', "/a");
|
|
try testCollapseRepeats("//a", '/', "/a");
|
|
try testCollapseRepeats("a/", '/', "a/");
|
|
try testCollapseRepeats("a//", '/', "a/");
|
|
try testCollapseRepeats("a/a", '/', "a/a");
|
|
try testCollapseRepeats("a//a", '/', "a/a");
|
|
try testCollapseRepeats("//a///a////", '/', "/a/a/");
|
|
}
|
|
|
|
/// Calculate the size needed in an output buffer to perform a replacement.
|
|
/// The needle must not be empty.
|
|
pub fn replacementSize(comptime T: type, input: []const T, needle: []const T, replacement: []const T) usize {
|
|
// Empty needle will loop forever.
|
|
assert(needle.len > 0);
|
|
|
|
var i: usize = 0;
|
|
var size: usize = input.len;
|
|
while (i < input.len) {
|
|
if (mem.startsWith(T, input[i..], needle)) {
|
|
size = size - needle.len + replacement.len;
|
|
i += needle.len;
|
|
} else {
|
|
i += 1;
|
|
}
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
test "replacementSize" {
|
|
try testing.expect(replacementSize(u8, "All your base are belong to us", "base", "Zig") == 29);
|
|
try testing.expect(replacementSize(u8, "Favor reading code over writing code.", "code", "") == 29);
|
|
try testing.expect(replacementSize(u8, "Only one obvious way to do things.", "things.", "things in Zig.") == 41);
|
|
|
|
// Empty needle is not allowed but input may be empty.
|
|
try testing.expect(replacementSize(u8, "", "x", "y") == 0);
|
|
|
|
// Adjacent replacements.
|
|
try testing.expect(replacementSize(u8, "\\n\\n", "\\n", "\n") == 2);
|
|
try testing.expect(replacementSize(u8, "abbba", "b", "cd") == 8);
|
|
}
|
|
|
|
/// Perform a replacement on an allocated buffer of pre-determined size. Caller must free returned memory.
|
|
pub fn replaceOwned(comptime T: type, allocator: Allocator, input: []const T, needle: []const T, replacement: []const T) Allocator.Error![]T {
|
|
var output = try allocator.alloc(T, replacementSize(T, input, needle, replacement));
|
|
_ = replace(T, input, needle, replacement, output);
|
|
return output;
|
|
}
|
|
|
|
test "replaceOwned" {
|
|
const gpa = std.testing.allocator;
|
|
|
|
const base_replace = replaceOwned(u8, gpa, "All your base are belong to us", "base", "Zig") catch @panic("out of memory");
|
|
defer gpa.free(base_replace);
|
|
try testing.expect(eql(u8, base_replace, "All your Zig are belong to us"));
|
|
|
|
const zen_replace = replaceOwned(u8, gpa, "Favor reading code over writing code.", " code", "") catch @panic("out of memory");
|
|
defer gpa.free(zen_replace);
|
|
try testing.expect(eql(u8, zen_replace, "Favor reading over writing."));
|
|
}
|
|
|
|
/// Converts a little-endian integer to host endianness.
|
|
pub fn littleToNative(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.Little => x,
|
|
.Big => @byteSwap(x),
|
|
};
|
|
}
|
|
|
|
/// Converts a big-endian integer to host endianness.
|
|
pub fn bigToNative(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.Little => @byteSwap(x),
|
|
.Big => x,
|
|
};
|
|
}
|
|
|
|
/// Converts an integer from specified endianness to host endianness.
|
|
pub fn toNative(comptime T: type, x: T, endianness_of_x: Endian) T {
|
|
return switch (endianness_of_x) {
|
|
.Little => littleToNative(T, x),
|
|
.Big => bigToNative(T, x),
|
|
};
|
|
}
|
|
|
|
/// Converts an integer which has host endianness to the desired endianness.
|
|
pub fn nativeTo(comptime T: type, x: T, desired_endianness: Endian) T {
|
|
return switch (desired_endianness) {
|
|
.Little => nativeToLittle(T, x),
|
|
.Big => nativeToBig(T, x),
|
|
};
|
|
}
|
|
|
|
/// Converts an integer which has host endianness to little endian.
|
|
pub fn nativeToLittle(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.Little => x,
|
|
.Big => @byteSwap(x),
|
|
};
|
|
}
|
|
|
|
/// Converts an integer which has host endianness to big endian.
|
|
pub fn nativeToBig(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.Little => @byteSwap(x),
|
|
.Big => x,
|
|
};
|
|
}
|
|
|
|
/// Returns the number of elements that, if added to the given pointer, align it
|
|
/// to a multiple of the given quantity, or `null` if one of the following
|
|
/// conditions is met:
|
|
/// - The aligned pointer would not fit the address space,
|
|
/// - The delta required to align the pointer is not a multiple of the pointee's
|
|
/// type.
|
|
pub fn alignPointerOffset(ptr: anytype, align_to: u29) ?usize {
|
|
assert(align_to != 0 and @popCount(align_to) == 1);
|
|
|
|
const T = @TypeOf(ptr);
|
|
const info = @typeInfo(T);
|
|
if (info != .Pointer or info.Pointer.size != .Many)
|
|
@compileError("expected many item pointer, got " ++ @typeName(T));
|
|
|
|
// Do nothing if the pointer is already well-aligned.
|
|
if (align_to <= info.Pointer.alignment)
|
|
return 0;
|
|
|
|
// Calculate the aligned base address with an eye out for overflow.
|
|
const addr = @ptrToInt(ptr);
|
|
var new_addr: usize = undefined;
|
|
if (@addWithOverflow(usize, addr, align_to - 1, &new_addr)) return null;
|
|
new_addr &= ~@as(usize, align_to - 1);
|
|
|
|
// The delta is expressed in terms of bytes, turn it into a number of child
|
|
// type elements.
|
|
const delta = new_addr - addr;
|
|
const pointee_size = @sizeOf(info.Pointer.child);
|
|
if (delta % pointee_size != 0) return null;
|
|
return delta / pointee_size;
|
|
}
|
|
|
|
/// Aligns a given pointer value to a specified alignment factor.
|
|
/// Returns an aligned pointer or null if one of the following conditions is
|
|
/// met:
|
|
/// - The aligned pointer would not fit the address space,
|
|
/// - The delta required to align the pointer is not a multiple of the pointee's
|
|
/// type.
|
|
pub fn alignPointer(ptr: anytype, align_to: u29) ?@TypeOf(ptr) {
|
|
const adjust_off = alignPointerOffset(ptr, align_to) orelse return null;
|
|
const T = @TypeOf(ptr);
|
|
// Avoid the use of intToPtr to avoid losing the pointer provenance info.
|
|
return @alignCast(@typeInfo(T).Pointer.alignment, ptr + adjust_off);
|
|
}
|
|
|
|
test "alignPointer" {
|
|
const S = struct {
|
|
fn checkAlign(comptime T: type, base: usize, align_to: u29, expected: usize) !void {
|
|
var ptr = @intToPtr(T, base);
|
|
var aligned = alignPointer(ptr, align_to);
|
|
try testing.expectEqual(expected, @ptrToInt(aligned));
|
|
}
|
|
};
|
|
|
|
try S.checkAlign([*]u8, 0x123, 0x200, 0x200);
|
|
try S.checkAlign([*]align(4) u8, 0x10, 2, 0x10);
|
|
try S.checkAlign([*]u32, 0x10, 2, 0x10);
|
|
try S.checkAlign([*]u32, 0x4, 16, 0x10);
|
|
// Misaligned.
|
|
try S.checkAlign([*]align(1) u32, 0x3, 2, 0);
|
|
// Overflow.
|
|
try S.checkAlign([*]u32, math.maxInt(usize) - 3, 8, 0);
|
|
}
|
|
|
|
fn CopyPtrAttrs(
|
|
comptime source: type,
|
|
comptime size: std.builtin.Type.Pointer.Size,
|
|
comptime child: type,
|
|
) type {
|
|
const info = @typeInfo(source).Pointer;
|
|
return @Type(.{
|
|
.Pointer = .{
|
|
.size = size,
|
|
.is_const = info.is_const,
|
|
.is_volatile = info.is_volatile,
|
|
.is_allowzero = info.is_allowzero,
|
|
.alignment = info.alignment,
|
|
.address_space = info.address_space,
|
|
.child = child,
|
|
.sentinel = null,
|
|
},
|
|
});
|
|
}
|
|
|
|
fn AsBytesReturnType(comptime P: type) type {
|
|
if (!trait.isSingleItemPtr(P))
|
|
@compileError("expected single item pointer, passed " ++ @typeName(P));
|
|
|
|
const size = @sizeOf(meta.Child(P));
|
|
|
|
return CopyPtrAttrs(P, .One, [size]u8);
|
|
}
|
|
|
|
/// Given a pointer to a single item, returns a slice of the underlying bytes, preserving pointer attributes.
|
|
pub fn asBytes(ptr: anytype) AsBytesReturnType(@TypeOf(ptr)) {
|
|
const P = @TypeOf(ptr);
|
|
return @ptrCast(AsBytesReturnType(P), ptr);
|
|
}
|
|
|
|
test "asBytes" {
|
|
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
|
|
|
|
const deadbeef = @as(u32, 0xDEADBEEF);
|
|
const deadbeef_bytes = switch (native_endian) {
|
|
.Big => "\xDE\xAD\xBE\xEF",
|
|
.Little => "\xEF\xBE\xAD\xDE",
|
|
};
|
|
|
|
try testing.expect(eql(u8, asBytes(&deadbeef), deadbeef_bytes));
|
|
|
|
var codeface = @as(u32, 0xC0DEFACE);
|
|
for (asBytes(&codeface).*) |*b|
|
|
b.* = 0;
|
|
try testing.expect(codeface == 0);
|
|
|
|
const S = packed struct {
|
|
a: u8,
|
|
b: u8,
|
|
c: u8,
|
|
d: u8,
|
|
};
|
|
|
|
const inst = S{
|
|
.a = 0xBE,
|
|
.b = 0xEF,
|
|
.c = 0xDE,
|
|
.d = 0xA1,
|
|
};
|
|
switch (native_endian) {
|
|
.Little => {
|
|
try testing.expect(eql(u8, asBytes(&inst), "\xBE\xEF\xDE\xA1"));
|
|
},
|
|
.Big => {
|
|
try testing.expect(eql(u8, asBytes(&inst), "\xA1\xDE\xEF\xBE"));
|
|
},
|
|
}
|
|
|
|
const ZST = struct {};
|
|
const zero = ZST{};
|
|
try testing.expect(eql(u8, asBytes(&zero), ""));
|
|
}
|
|
|
|
test "asBytes preserves pointer attributes" {
|
|
const inArr: u32 align(16) = 0xDEADBEEF;
|
|
const inPtr = @ptrCast(*align(16) const volatile u32, &inArr);
|
|
const outSlice = asBytes(inPtr);
|
|
|
|
const in = @typeInfo(@TypeOf(inPtr)).Pointer;
|
|
const out = @typeInfo(@TypeOf(outSlice)).Pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
/// Given any value, returns a copy of its bytes in an array.
|
|
pub fn toBytes(value: anytype) [@sizeOf(@TypeOf(value))]u8 {
|
|
return asBytes(&value).*;
|
|
}
|
|
|
|
test "toBytes" {
|
|
var my_bytes = toBytes(@as(u32, 0x12345678));
|
|
switch (native_endian) {
|
|
.Big => try testing.expect(eql(u8, &my_bytes, "\x12\x34\x56\x78")),
|
|
.Little => try testing.expect(eql(u8, &my_bytes, "\x78\x56\x34\x12")),
|
|
}
|
|
|
|
my_bytes[0] = '\x99';
|
|
switch (native_endian) {
|
|
.Big => try testing.expect(eql(u8, &my_bytes, "\x99\x34\x56\x78")),
|
|
.Little => try testing.expect(eql(u8, &my_bytes, "\x99\x56\x34\x12")),
|
|
}
|
|
}
|
|
|
|
fn BytesAsValueReturnType(comptime T: type, comptime B: type) type {
|
|
const size = @as(usize, @sizeOf(T));
|
|
|
|
if (comptime !trait.is(.Pointer)(B) or
|
|
(meta.Child(B) != [size]u8 and meta.Child(B) != [size:0]u8))
|
|
{
|
|
comptime var buf: [100]u8 = undefined;
|
|
@compileError(std.fmt.bufPrint(&buf, "expected *[{}]u8, passed " ++ @typeName(B), .{size}) catch unreachable);
|
|
}
|
|
|
|
return CopyPtrAttrs(B, .One, T);
|
|
}
|
|
|
|
/// Given a pointer to an array of bytes, returns a pointer to a value of the specified type
|
|
/// backed by those bytes, preserving pointer attributes.
|
|
pub fn bytesAsValue(comptime T: type, bytes: anytype) BytesAsValueReturnType(T, @TypeOf(bytes)) {
|
|
return @ptrCast(BytesAsValueReturnType(T, @TypeOf(bytes)), bytes);
|
|
}
|
|
|
|
test "bytesAsValue" {
|
|
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
|
|
|
|
const deadbeef = @as(u32, 0xDEADBEEF);
|
|
const deadbeef_bytes = switch (native_endian) {
|
|
.Big => "\xDE\xAD\xBE\xEF",
|
|
.Little => "\xEF\xBE\xAD\xDE",
|
|
};
|
|
|
|
try testing.expect(deadbeef == bytesAsValue(u32, deadbeef_bytes).*);
|
|
|
|
var codeface_bytes: [4]u8 = switch (native_endian) {
|
|
.Big => "\xC0\xDE\xFA\xCE",
|
|
.Little => "\xCE\xFA\xDE\xC0",
|
|
}.*;
|
|
var codeface = bytesAsValue(u32, &codeface_bytes);
|
|
try testing.expect(codeface.* == 0xC0DEFACE);
|
|
codeface.* = 0;
|
|
for (codeface_bytes) |b|
|
|
try testing.expect(b == 0);
|
|
|
|
const S = packed struct {
|
|
a: u8,
|
|
b: u8,
|
|
c: u8,
|
|
d: u8,
|
|
};
|
|
|
|
const inst = S{
|
|
.a = 0xBE,
|
|
.b = 0xEF,
|
|
.c = 0xDE,
|
|
.d = 0xA1,
|
|
};
|
|
const inst_bytes = switch (native_endian) {
|
|
.Little => "\xBE\xEF\xDE\xA1",
|
|
.Big => "\xA1\xDE\xEF\xBE",
|
|
};
|
|
const inst2 = bytesAsValue(S, inst_bytes);
|
|
try testing.expect(meta.eql(inst, inst2.*));
|
|
}
|
|
|
|
test "bytesAsValue preserves pointer attributes" {
|
|
const inArr align(16) = [4]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
const inSlice = @ptrCast(*align(16) const volatile [4]u8, &inArr)[0..];
|
|
const outPtr = bytesAsValue(u32, inSlice);
|
|
|
|
const in = @typeInfo(@TypeOf(inSlice)).Pointer;
|
|
const out = @typeInfo(@TypeOf(outPtr)).Pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
/// Given a pointer to an array of bytes, returns a value of the specified type backed by a
|
|
/// copy of those bytes.
|
|
pub fn bytesToValue(comptime T: type, bytes: anytype) T {
|
|
return bytesAsValue(T, bytes).*;
|
|
}
|
|
test "bytesToValue" {
|
|
const deadbeef_bytes = switch (native_endian) {
|
|
.Big => "\xDE\xAD\xBE\xEF",
|
|
.Little => "\xEF\xBE\xAD\xDE",
|
|
};
|
|
|
|
const deadbeef = bytesToValue(u32, deadbeef_bytes);
|
|
try testing.expect(deadbeef == @as(u32, 0xDEADBEEF));
|
|
}
|
|
|
|
fn BytesAsSliceReturnType(comptime T: type, comptime bytesType: type) type {
|
|
if (!(trait.isSlice(bytesType) or trait.isPtrTo(.Array)(bytesType)) or meta.Elem(bytesType) != u8) {
|
|
@compileError("expected []u8 or *[_]u8, passed " ++ @typeName(bytesType));
|
|
}
|
|
|
|
if (trait.isPtrTo(.Array)(bytesType) and @typeInfo(meta.Child(bytesType)).Array.len % @sizeOf(T) != 0) {
|
|
@compileError("number of bytes in " ++ @typeName(bytesType) ++ " is not divisible by size of " ++ @typeName(T));
|
|
}
|
|
|
|
return CopyPtrAttrs(bytesType, .Slice, T);
|
|
}
|
|
|
|
/// Given a slice of bytes, returns a slice of the specified type
|
|
/// backed by those bytes, preserving pointer attributes.
|
|
pub fn bytesAsSlice(comptime T: type, bytes: anytype) BytesAsSliceReturnType(T, @TypeOf(bytes)) {
|
|
// let's not give an undefined pointer to @ptrCast
|
|
// it may be equal to zero and fail a null check
|
|
if (bytes.len == 0) {
|
|
return &[0]T{};
|
|
}
|
|
|
|
const cast_target = CopyPtrAttrs(@TypeOf(bytes), .Many, T);
|
|
|
|
return @ptrCast(cast_target, bytes)[0..@divExact(bytes.len, @sizeOf(T))];
|
|
}
|
|
|
|
test "bytesAsSlice" {
|
|
{
|
|
const bytes = [_]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
const slice = bytesAsSlice(u16, bytes[0..]);
|
|
try testing.expect(slice.len == 2);
|
|
try testing.expect(bigToNative(u16, slice[0]) == 0xDEAD);
|
|
try testing.expect(bigToNative(u16, slice[1]) == 0xBEEF);
|
|
}
|
|
{
|
|
const bytes = [_]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
var runtime_zero: usize = 0;
|
|
const slice = bytesAsSlice(u16, bytes[runtime_zero..]);
|
|
try testing.expect(slice.len == 2);
|
|
try testing.expect(bigToNative(u16, slice[0]) == 0xDEAD);
|
|
try testing.expect(bigToNative(u16, slice[1]) == 0xBEEF);
|
|
}
|
|
}
|
|
|
|
test "bytesAsSlice keeps pointer alignment" {
|
|
{
|
|
var bytes = [_]u8{ 0x01, 0x02, 0x03, 0x04 };
|
|
const numbers = bytesAsSlice(u32, bytes[0..]);
|
|
comptime try testing.expect(@TypeOf(numbers) == []align(@alignOf(@TypeOf(bytes))) u32);
|
|
}
|
|
{
|
|
var bytes = [_]u8{ 0x01, 0x02, 0x03, 0x04 };
|
|
var runtime_zero: usize = 0;
|
|
const numbers = bytesAsSlice(u32, bytes[runtime_zero..]);
|
|
comptime try testing.expect(@TypeOf(numbers) == []align(@alignOf(@TypeOf(bytes))) u32);
|
|
}
|
|
}
|
|
|
|
test "bytesAsSlice on a packed struct" {
|
|
const F = packed struct {
|
|
a: u8,
|
|
};
|
|
|
|
var b = [1]u8{9};
|
|
var f = bytesAsSlice(F, &b);
|
|
try testing.expect(f[0].a == 9);
|
|
}
|
|
|
|
test "bytesAsSlice with specified alignment" {
|
|
var bytes align(4) = [_]u8{
|
|
0x33,
|
|
0x33,
|
|
0x33,
|
|
0x33,
|
|
};
|
|
const slice: []u32 = std.mem.bytesAsSlice(u32, bytes[0..]);
|
|
try testing.expect(slice[0] == 0x33333333);
|
|
}
|
|
|
|
test "bytesAsSlice preserves pointer attributes" {
|
|
const inArr align(16) = [4]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
const inSlice = @ptrCast(*align(16) const volatile [4]u8, &inArr)[0..];
|
|
const outSlice = bytesAsSlice(u16, inSlice);
|
|
|
|
const in = @typeInfo(@TypeOf(inSlice)).Pointer;
|
|
const out = @typeInfo(@TypeOf(outSlice)).Pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
fn SliceAsBytesReturnType(comptime sliceType: type) type {
|
|
if (!trait.isSlice(sliceType) and !trait.isPtrTo(.Array)(sliceType)) {
|
|
@compileError("expected []T or *[_]T, passed " ++ @typeName(sliceType));
|
|
}
|
|
|
|
return CopyPtrAttrs(sliceType, .Slice, u8);
|
|
}
|
|
|
|
/// Given a slice, returns a slice of the underlying bytes, preserving pointer attributes.
|
|
pub fn sliceAsBytes(slice: anytype) SliceAsBytesReturnType(@TypeOf(slice)) {
|
|
const Slice = @TypeOf(slice);
|
|
|
|
// let's not give an undefined pointer to @ptrCast
|
|
// it may be equal to zero and fail a null check
|
|
if (slice.len == 0 and comptime meta.sentinel(Slice) == null) {
|
|
return &[0]u8{};
|
|
}
|
|
|
|
const cast_target = CopyPtrAttrs(Slice, .Many, u8);
|
|
|
|
return @ptrCast(cast_target, slice)[0 .. slice.len * @sizeOf(meta.Elem(Slice))];
|
|
}
|
|
|
|
test "sliceAsBytes" {
|
|
const bytes = [_]u16{ 0xDEAD, 0xBEEF };
|
|
const slice = sliceAsBytes(bytes[0..]);
|
|
try testing.expect(slice.len == 4);
|
|
try testing.expect(eql(u8, slice, switch (native_endian) {
|
|
.Big => "\xDE\xAD\xBE\xEF",
|
|
.Little => "\xAD\xDE\xEF\xBE",
|
|
}));
|
|
}
|
|
|
|
test "sliceAsBytes with sentinel slice" {
|
|
const empty_string: [:0]const u8 = "";
|
|
const bytes = sliceAsBytes(empty_string);
|
|
try testing.expect(bytes.len == 0);
|
|
}
|
|
|
|
test "sliceAsBytes packed struct at runtime and comptime" {
|
|
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
|
|
|
|
const Foo = packed struct {
|
|
a: u4,
|
|
b: u4,
|
|
};
|
|
const S = struct {
|
|
fn doTheTest() !void {
|
|
var foo: Foo = undefined;
|
|
var slice = sliceAsBytes(@as(*[1]Foo, &foo)[0..1]);
|
|
slice[0] = 0x13;
|
|
try testing.expect(foo.a == 0x3);
|
|
try testing.expect(foo.b == 0x1);
|
|
}
|
|
};
|
|
try S.doTheTest();
|
|
comptime try S.doTheTest();
|
|
}
|
|
|
|
test "sliceAsBytes and bytesAsSlice back" {
|
|
try testing.expect(@sizeOf(i32) == 4);
|
|
|
|
var big_thing_array = [_]i32{ 1, 2, 3, 4 };
|
|
const big_thing_slice: []i32 = big_thing_array[0..];
|
|
|
|
const bytes = sliceAsBytes(big_thing_slice);
|
|
try testing.expect(bytes.len == 4 * 4);
|
|
|
|
bytes[4] = 0;
|
|
bytes[5] = 0;
|
|
bytes[6] = 0;
|
|
bytes[7] = 0;
|
|
try testing.expect(big_thing_slice[1] == 0);
|
|
|
|
const big_thing_again = bytesAsSlice(i32, bytes);
|
|
try testing.expect(big_thing_again[2] == 3);
|
|
|
|
big_thing_again[2] = -1;
|
|
try testing.expect(bytes[8] == math.maxInt(u8));
|
|
try testing.expect(bytes[9] == math.maxInt(u8));
|
|
try testing.expect(bytes[10] == math.maxInt(u8));
|
|
try testing.expect(bytes[11] == math.maxInt(u8));
|
|
}
|
|
|
|
test "sliceAsBytes preserves pointer attributes" {
|
|
const inArr align(16) = [2]u16{ 0xDEAD, 0xBEEF };
|
|
const inSlice = @ptrCast(*align(16) const volatile [2]u16, &inArr)[0..];
|
|
const outSlice = sliceAsBytes(inSlice);
|
|
|
|
const in = @typeInfo(@TypeOf(inSlice)).Pointer;
|
|
const out = @typeInfo(@TypeOf(outSlice)).Pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
/// Round an address up to the next (or current) aligned address.
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
pub fn alignForward(addr: usize, alignment: usize) usize {
|
|
return alignForwardGeneric(usize, addr, alignment);
|
|
}
|
|
|
|
/// Round an address up to the next (or current) aligned address.
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
pub fn alignForwardGeneric(comptime T: type, addr: T, alignment: T) T {
|
|
return alignBackwardGeneric(T, addr + (alignment - 1), alignment);
|
|
}
|
|
|
|
/// Force an evaluation of the expression; this tries to prevent
|
|
/// the compiler from optimizing the computation away even if the
|
|
/// result eventually gets discarded.
|
|
pub fn doNotOptimizeAway(val: anytype) void {
|
|
asm volatile (""
|
|
:
|
|
: [val] "rm" (val),
|
|
: "memory"
|
|
);
|
|
}
|
|
|
|
test "alignForward" {
|
|
try testing.expect(alignForward(1, 1) == 1);
|
|
try testing.expect(alignForward(2, 1) == 2);
|
|
try testing.expect(alignForward(1, 2) == 2);
|
|
try testing.expect(alignForward(2, 2) == 2);
|
|
try testing.expect(alignForward(3, 2) == 4);
|
|
try testing.expect(alignForward(4, 2) == 4);
|
|
try testing.expect(alignForward(7, 8) == 8);
|
|
try testing.expect(alignForward(8, 8) == 8);
|
|
try testing.expect(alignForward(9, 8) == 16);
|
|
try testing.expect(alignForward(15, 8) == 16);
|
|
try testing.expect(alignForward(16, 8) == 16);
|
|
try testing.expect(alignForward(17, 8) == 24);
|
|
}
|
|
|
|
/// Round an address down to the previous (or current) aligned address.
|
|
/// Unlike `alignBackward`, `alignment` can be any positive number, not just a power of 2.
|
|
pub fn alignBackwardAnyAlign(i: usize, alignment: usize) usize {
|
|
if (@popCount(alignment) == 1)
|
|
return alignBackward(i, alignment);
|
|
assert(alignment != 0);
|
|
return i - @mod(i, alignment);
|
|
}
|
|
|
|
/// Round an address down to the previous (or current) aligned address.
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
pub fn alignBackward(addr: usize, alignment: usize) usize {
|
|
return alignBackwardGeneric(usize, addr, alignment);
|
|
}
|
|
|
|
/// Round an address down to the previous (or current) aligned address.
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
pub fn alignBackwardGeneric(comptime T: type, addr: T, alignment: T) T {
|
|
assert(@popCount(alignment) == 1);
|
|
// 000010000 // example alignment
|
|
// 000001111 // subtract 1
|
|
// 111110000 // binary not
|
|
return addr & ~(alignment - 1);
|
|
}
|
|
|
|
/// Returns whether `alignment` is a valid alignment, meaning it is
|
|
/// a positive power of 2.
|
|
pub fn isValidAlign(alignment: u29) bool {
|
|
return @popCount(alignment) == 1;
|
|
}
|
|
|
|
pub fn isAlignedAnyAlign(i: usize, alignment: usize) bool {
|
|
if (@popCount(alignment) == 1)
|
|
return isAligned(i, alignment);
|
|
assert(alignment != 0);
|
|
return 0 == @mod(i, alignment);
|
|
}
|
|
|
|
/// Given an address and an alignment, return true if the address is a multiple of the alignment
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
pub fn isAligned(addr: usize, alignment: usize) bool {
|
|
return isAlignedGeneric(u64, addr, alignment);
|
|
}
|
|
|
|
pub fn isAlignedGeneric(comptime T: type, addr: T, alignment: T) bool {
|
|
return alignBackwardGeneric(T, addr, alignment) == addr;
|
|
}
|
|
|
|
test "isAligned" {
|
|
try testing.expect(isAligned(0, 4));
|
|
try testing.expect(isAligned(1, 1));
|
|
try testing.expect(isAligned(2, 1));
|
|
try testing.expect(isAligned(2, 2));
|
|
try testing.expect(!isAligned(2, 4));
|
|
try testing.expect(isAligned(3, 1));
|
|
try testing.expect(!isAligned(3, 2));
|
|
try testing.expect(!isAligned(3, 4));
|
|
try testing.expect(isAligned(4, 4));
|
|
try testing.expect(isAligned(4, 2));
|
|
try testing.expect(isAligned(4, 1));
|
|
try testing.expect(!isAligned(4, 8));
|
|
try testing.expect(!isAligned(4, 16));
|
|
}
|
|
|
|
test "freeing empty string with null-terminated sentinel" {
|
|
const empty_string = try testing.allocator.dupeZ(u8, "");
|
|
testing.allocator.free(empty_string);
|
|
}
|
|
|
|
/// Returns a slice with the given new alignment,
|
|
/// all other pointer attributes copied from `AttributeSource`.
|
|
fn AlignedSlice(comptime AttributeSource: type, comptime new_alignment: u29) type {
|
|
const info = @typeInfo(AttributeSource).Pointer;
|
|
return @Type(.{
|
|
.Pointer = .{
|
|
.size = .Slice,
|
|
.is_const = info.is_const,
|
|
.is_volatile = info.is_volatile,
|
|
.is_allowzero = info.is_allowzero,
|
|
.alignment = new_alignment,
|
|
.address_space = info.address_space,
|
|
.child = info.child,
|
|
.sentinel = null,
|
|
},
|
|
});
|
|
}
|
|
|
|
/// Returns the largest slice in the given bytes that conforms to the new alignment,
|
|
/// or `null` if the given bytes contain no conforming address.
|
|
pub fn alignInBytes(bytes: []u8, comptime new_alignment: usize) ?[]align(new_alignment) u8 {
|
|
const begin_address = @ptrToInt(bytes.ptr);
|
|
const end_address = begin_address + bytes.len;
|
|
|
|
const begin_address_aligned = mem.alignForward(begin_address, new_alignment);
|
|
const new_length = std.math.sub(usize, end_address, begin_address_aligned) catch |e| switch (e) {
|
|
error.Overflow => return null,
|
|
};
|
|
const alignment_offset = begin_address_aligned - begin_address;
|
|
return @alignCast(new_alignment, bytes[alignment_offset .. alignment_offset + new_length]);
|
|
}
|
|
|
|
/// Returns the largest sub-slice within the given slice that conforms to the new alignment,
|
|
/// or `null` if the given slice contains no conforming address.
|
|
pub fn alignInSlice(slice: anytype, comptime new_alignment: usize) ?AlignedSlice(@TypeOf(slice), new_alignment) {
|
|
const bytes = sliceAsBytes(slice);
|
|
const aligned_bytes = alignInBytes(bytes, new_alignment) orelse return null;
|
|
|
|
const Element = @TypeOf(slice[0]);
|
|
const slice_length_bytes = aligned_bytes.len - (aligned_bytes.len % @sizeOf(Element));
|
|
const aligned_slice = bytesAsSlice(Element, aligned_bytes[0..slice_length_bytes]);
|
|
return @alignCast(new_alignment, aligned_slice);
|
|
}
|