Initial commit (v. 0.1.0)v0.1.0

1 files changed, 82 insertions, 0 deletions

diff --git a/src/argparse.rs b/src/argparse.rs
new file mode 100644
index 0000000..8fd6ae5
--- /dev/null
+++ b/src/argparse.rs
@@ -0,0 +1,82 @@
+use std::collections::{HashMap, HashSet};
+use std::fmt::Debug;
+use std::hash::Hash;
+
+#[derive(Debug)]
+pub struct Args<Flag, Param> {
+	flags: HashSet<Flag>,
+	params: HashMap<Param, String>,
+	lone_args: Vec<String>,
+}
+
+impl<Flag: Hash + Eq, Param: Hash + Eq> Args<Flag, Param> {
+	pub fn is_set(&self, flag: Flag) -> bool {
+		self.flags.contains(&flag)
+	}
+	pub fn get(&self, param: Param) -> Option<&str> {
+		Some(self.params.get(&param)?.as_ref())
+	}
+	pub fn lone_args(&self) -> impl '_ + Iterator<Item = &str> {
+		self.lone_args.iter().map(|x| x.as_ref())
+	}
+	pub fn lone_args_count(&self) -> usize {
+		self.lone_args.len()
+	}
+}
+
+pub fn parse_args<Flag: Copy + Hash + Eq + Debug, Param: Copy + Hash + Eq + Debug>(
+	flag_names: &HashMap<&str, Flag>,
+	param_names: &HashMap<&str, Param>,
+) -> Result<Args<Flag, Param>, String> {
+	let mut arg_iter = std::env::args_os();
+	arg_iter.next(); // program name
+	let mut args = Args {
+		flags: HashSet::new(),
+		params: HashMap::new(),
+		lone_args: vec![],
+	};
+	let mut double_dash = false;
+	let mut param: Option<(String, Param)> = None;
+	assert!(flag_names.keys().all(|x| x.starts_with('-')));
+	assert!(param_names.keys().all(|x| x.starts_with('-')));
+	for arg in arg_iter {
+		let arg = arg
+			.into_string()
+			.map_err(|arg| format!("Argument includes bad UTF-8: {arg:?}"))?;
+		if let Some((_name, p)) = param.as_ref() {
+			args.params.insert(*p, arg);
+			param = None;
+			continue;
+		}
+		if double_dash {
+			args.lone_args.push(arg);
+			continue;
+		}
+		if arg == "--" {
+			double_dash = true;
+			continue;
+		}
+		if let Some(flag) = flag_names.get(arg.as_str()) {
+			args.flags.insert(*flag);
+			continue;
+		}
+		if let Some(p) = param_names.get(arg.as_str()) {
+			param = Some((arg, *p));
+			continue;
+		}
+		if let Some((p, value)) = arg.split_once('=')
+			&& let Some(p) = param_names.get(p)
+		{
+			args.params.insert(*p, value.into());
+			continue;
+		}
+		if arg.starts_with('-') {
+			return Err(format!("Unrecognized option: {arg}"));
+		}
+		args.lone_args.push(arg);
+	}
+	if let Some((name, _p)) = param {
+		return Err(format!("No argument provided to {name}"));
+	}
+	Ok(args)
+}