# zig-clap
A simple and easy to use command line argument parser library for Zig.
## Features
* Short arguments `-a`
* Chaining `-abc` where `a` and `b` does not take values.
* 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`)
* Supports options that can be specified multiple times (`-e 1 -e 2 -e 3`)
* Print help message from parameter specification.
* Parse help message to parameter specification.
## Examples
### `clap.parse`
The simplest way to use this library is to just call the `clap.parse` function.
```zig
{s}
```
The data structure returned has lookup speed on par with array access (`arr[i]`) and validates
that the strings you pass to `option`, `options` and `flag` are actually parameters that the
program can take:
```zig
{s}
```
```
zig-clap/clap/comptime.zig:109:17: error: --helps is not a parameter.
@compileError(name ++ " is not a parameter.");
^
zig-clap/clap/comptime.zig:77:45: note: called from here
const param = comptime findParam(name);
^
zig-clap/clap.zig:238:31: note: called from here
return a.clap.flag(name);
^
zig-clap/example/simple-error.zig:16:18: note: called from here
_ = args.flag("--helps");
```
There is also a `parseEx` variant that takes an argument iterator.
### `StreamingClap`
The `StreamingClap` is the base of all the other parsers. It's a streaming parser that uses an
`args.Iterator` to provide it with arguments lazily.
```zig
{s}
```
Currently, this parse is the only parser that allow an array of `Param` tha
is generated at runtime.
### `help`
The `help`, `helpEx` and `helpFull` are functions for printing a simple list of all parameters the
program can take.
```zig
{s}
```
```
$ zig-out/bin/help --help
-h, --help Display this help and exit.
-v, --version Output version information and exit.
```
The `help` functions are the simplest to call. It only takes an `OutStream` and a slice of
`Param(Help)`.
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.
### `usage`
The `usage`, `usageEx` and `usageFull` are functions for printing a small abbreviated version
of the help message.
```zig
{s}
```
```
$ zig-out/bin/usage --help
[-hv] [--value <N>]
```
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