938b3ff778
* This makes arg iterators easier to understand and implement * It should also be faster than using the fieldToParent builtin |
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example | ||
src | ||
.gitattributes | ||
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build.zig | ||
LICENSE | ||
README.md |
zig-clap
A simple and easy to use command line argument parser library for Zig.
Features
- Short arguments
-a
- Chaining
-abc
wherea
andb
does not take values.
- Chaining
- Long arguments
--long
- Supports both passing values using spacing and
=
(-a 100
,-a=100
)- Short args also support passing values with no spacing or
=
(-a100
) - This all works with chaining (
-ba 100
,-ba=100
,-ba100
)
- Short args also support passing values with no spacing or
Examples
StreamingClap
The StreamingClap
is base of all the other parsers. It's a streaming parser that uses an
args.Iterator
to provide it with arguments lazily.
const params = []clap.Param(u8){
clap.Param(void).flag('h', false, clap.Names.prefix("help")),
clap.Param(void).option('n', true, clap.Names.prefix("number")),
clap.Param(void).positional('f'),
};
var os_iter = clap.args.OsIterator.init(allocator);
const iter = &os_iter.iter;
defer os_iter.deinit();
const exe = try iter.next();
var parser = clap.StreamingClap(u8, clap.args.OsIterator.Error).init(params, iter);
while (try parser.next()) |arg| {
switch (arg.param.id) {
'h' => debug.warn("Help!\n"),
'n' => debug.warn("--number = {}\n", arg.value.?),
'f' => debug.warn("{}\n", arg.value.?),
else => unreachable,
}
}
ComptimeClap
The ComptimeClap
is a wrapper for StreamingClap
, which parses all the arguments and makes
them available through three functions (flag
, option
, positionals
).
const params = comptime []clap.Param(void){
clap.Param(void).flag({}, false, clap.Names.prefix("help")),
clap.Param(void).option({}, true, clap.Names.prefix("number")),
clap.Param(void).positional({}),
};
var os_iter = clap.args.OsIterator.init(allocator);
const iter = &os_iter.iter;
defer os_iter.deinit();
const exe = try iter.next();
var args = try clap.ComptimeClap(void, params).parse(allocator, clap.args.OsIterator.Error, iter);
defer args.deinit();
if (args.flag("--help"))
debug.warn("Help!\n");
if (args.option("--number")) |n|
debug.warn("--number = {}\n", n);
for (args.positionals()) |pos|
debug.warn("{}\n", pos);
The data structure returned from this parser has lookup speed on par with array access (arr[i]
)
and validates that the strings you pass to option
and flag
are actually parameters that the
program can take:
const params = comptime []clap.Param(void){
clap.Param(void).init({}, false, clap.Names.prefix("help")),
};
var os_iter = clap.args.OsIterator.init(allocator);
const iter = &os_iter.iter;
defer os_iter.deinit();
const exe = try iter.next();
var args = try clap.ComptimeClap(params).parse(allocator, clap.args.OsIterator.Error, iter);
defer args.deinit();
if (args.flag("--helps"))
debug.warn("Help!\n");
zig-clap/src/comptime.zig:103:17: error: --helps is not a parameter.
@compileError(name ++ " is not a parameter.");
^
zig-clap/src/comptime.zig:71:45: note: called from here
const param = comptime findParam(name);
^
zig-clap/example/comptime-clap.zig:41:18: note: called from here
if (args.flag("--helps"))
^
Ofc, this limits you to use only parameters that are comptime known.
help
The help
, helpEx
and helpFull
are functions for printing a simple list of all parameters the
program can take.
const stderr_file = try std.io.getStdErr();
var stderr_out_stream = stderr_file.outStream();
const stderr = &stderr_out_stream.stream;
try clap.help(
stderr,
[]clap.Param([]const u8){
clap.Param([]const u8).flag(
"Display this help and exit.",
clap.Names.prefix("help"),
),
clap.Param([]const u8).flag(
"Output version information and exit.",
clap.Names.prefix("version"),
),
},
);
-h, --help Display this help and exit.
-v, --version Output version information and exit.
The help
function is the simplest to call. It only takes an OutStream
and a slice of
Param([]const u8)
. This function assumes that the id of each parameter is the help message.
The helpEx
is the generic version of help
. It can print a help message for any
Param
give that the caller provides functions for getting the help and value strings.
The helpFull
is even more generic, allowing the functions that get the help and value strings
to return errors and take a context as a parameter.