# 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`)
* Print help message from parameter specification.
* Parse help message to parameter specification.

## Examples

### `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
{}
```

### `ComptimeClap`

The `ComptimeClap` is a wrapper for `StreamingClap`, which parses all the arguments and makes
them available through three functions (`flag`, `option`, `positionals`).

```zig
{}
```

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:

```zig
{}
```

```
zig-clap/src/comptime.zig:109:17: error: --helps is not a parameter.
                @compileError(name ++ " is not a parameter.");
                ^
zig-clap/src/comptime.zig:77:45: note: called from here
            const param = comptime findParam(name);
                                            ^
zig-clap/example/comptime-clap-error.zig:18:18: note: called from here
    _ = args.flag("--helps");
                 ^
```

Ofc, this limits you to 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.

```zig
{}
```

```
	-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.