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use std::collections::BTreeMap;
use std::ffi::OsString;
use std::process;
use crate::name::Name;
use crate::registry::Flag;
use crate::token::{Token, Tokenizer};
/// Initialize the value of all flags based on arguments from the command line
/// at runtime.
///
/// This function must be called before accessing the values of any flags. After
/// this function has been called, the values of flags are available in the
/// `.FLAG` field of each flag.
///
/// The return vector contains everything on the command line which is not a
/// flag. These are sometimes called positional arguments.
///
/// # Examples
///
/// If we execute the following program with command line `./my_program a b c`
/// then nothing is printed because `--print-args` is not set. If we execute it
/// with `./my_program --print-args a b c` then the positional arguments `a` `b`
/// `c` are printed.
///
/// ```
/// gflags::define! {
/// --print-args = false
/// }
///
/// fn main() {
/// let args = gflags::parse();
///
/// if print_args.FLAG {
/// println!("args = {:?}", args);
/// }
/// }
/// ```
pub fn parse() -> Vec<OsString> {
let mut shorts = BTreeMap::new();
let mut longs = BTreeMap::new();
for flag in inventory::iter::<Flag> {
if let Some(short) = flag.short {
shorts.insert(short, flag);
}
longs.insert(flag.name, flag);
}
let mut args = Vec::new();
let mut tokens = Tokenizer::new();
while let Some(token) = tokens.next() {
match token {
Token::Short(ch) => match shorts.get(&ch) {
Some(flag) => {
let name = Name::short(ch);
flag.parser.parse(name, &mut tokens);
}
None => {
eprintln!("Unrecognized flag: -{}", ch);
process::exit(1);
}
},
Token::Long(name) => match longs.get(name.as_str()) {
Some(flag) => {
let name = Name::long(flag.name);
flag.parser.parse(name, &mut tokens);
}
None => {
if name.starts_with("no") {
if let Some(flag) = longs.get(&name[2..]) {
if flag.parser.is_bool() {
flag.parser.unset_bool();
continue;
}
}
}
eprintln!("Unrecognized flag: --{}", name);
process::exit(1);
}
},
Token::Arg(arg) => args.push(arg),
}
}
args
}