argwerk

Define a simple command-line parser through a declarative macro.

This is not intended to be a complete command-line parser library. Instead this can be used as an alternative quick-and-dirty approach that can be cheaply incorporated into a tool.

For a more complete command-line parsing library, use clap.

We provide:

• A dependency-free command-line parsing framework using declarative macros.
• A flexible mechanism for parsing.
• Formatting of decent looking help messages.

We do not provide:

• As-close-to correct line wrapping with wide unicode characters as possible (see textwrap).
• Complex command structures like subcommands.
• Parsing into OsStrings. The default parser will panic in case not valid unicode is passed into it in accordance with [std::env::args].

For how to use, see the documentation of argwerk::define and argwerk::parse.

Examples

This is available as a runnable example:

cargo run --example tour

let args = argwerk::parse! {
    /// A command touring the capabilities of argwerk.
    "tour [-h]" {
        help: bool,
        #[required = "--file must be specified"]
        file: String,
        input: Option<String>,
        limit: usize = 10,
        positional: Option<(String, Option<String>)>,
        rest: Vec<String>,
    }
    /// Prints the help.
    ///
    /// This includes:
    ///    * All the available switches.
    ///    * All the available positional arguments.
    ///    * Whatever else the developer decided to put in here! We even support wrapping comments which are overly //!long.
    ["-h" | "--help"] => {
        println!("{}", HELP);
        help = true;
    }
    /// Limit the number of things by <n> (default: 10).
    ["--limit" | "-l", n] => {
        limit = str::parse(&n)?;
    }
    /// Write to the file specified by <path>.
    ["--file", path] if !file.is_some() => {
        file = Some(path);
    }
    /// Read from the specified input.
    ["--input", #[option] path] => {
        input = path;
    }
    /// Takes argument at <foo> and <bar>.
    ///
    ///    * This is an indented message. The first alphanumeric character determines the indentation to use.
    [foo, #[option] bar, #[rest] args] if positional.is_none() => {
        positional = Some((foo, bar));
        rest = args;
    }
}?;

dbg!(args);

License: MIT/Apache-2.0