Provides a very light weight command line tokeniser and a BYO (Bring Your Own) argument parser.
The name is a play on CLAP, the Command Line Argument Parser. This library is an attempt at a polar opposite, a minimally featured library to parse command lines.
This library provides a very simple command line tokenizer and a state enum indicating the current parser state. With these you can easily create your own argument parser:
Try this example out: cargo run --example readme.
extern crate clop;
fn main() {
// Holds the current parser state
let mut state = clop::State::Command;
// When parsing options with values as a separate argument,
// the value needs to know what option it is associated with.
let mut opt_name = String::new();
for token in std::env::args() {
// Expecting to start with the command
if let clop::State::Command = state {
// After the command we're expecting a number of options
state = clop::State::Options;
continue;
}
else if let clop::State::Options = state {
if token == "-o" {
println!("Got the -o option");
continue;
}
else if token == "--long-arg" {
opt_name = token;
state = clop::State::Value;
continue;
}
else if token == "--" {
println!("No more options");
state = clop::State::Fixed(0);
continue;
}
else if token.starts_with("-") {
println!("Unknown option: {}", token);
continue;
}
// Next expecting a fixed argument, target
state = clop::State::Fixed(0);
// Fallthrough is on purpose!
// The current iteration `token` holds the fixed argument
}
else if let clop::State::Value = state {
if opt_name == "--long-arg" {
println!("Got value for {}: {}", opt_name, token);
state = clop::State::Options;
continue;
}
else {
unreachable!()
}
}
if let clop::State::Fixed(_) = state {
println!("Got the fixed argument target: {}", token);
state = clop::State::Args;
continue;
}
if let clop::State::Args = state {
println!("Got a variable argument: {}", token);
continue;
}
}
}Licensed under MIT License, see license.txt.
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