Initial parser implementation and bin2h example program

src/std.rs

@@ -0,0 +1,21 @@
+/* jaarg - Argument parser
+ * SPDX-FileCopyrightText: (C) 2025 Gay Pizza Specifications
+ * SPDX-License-Identifier: MIT
+ */
+
+extern crate std;
+
+use crate::{HandlerResult, Opt, Opts, ParseControl, ParseResult};
+
+impl<ID: 'static> Opts<ID> {
+  /// Wrapper around `parse` that gathers arguments from the command line and prints errors to stderr.
+  ///
+  /// Requires std
+  pub fn parse_env<'a>(&self, handler: impl FnMut(&ID, &Opt<ID>, &str, &str) -> HandlerResult<'a, ParseControl>
+  ) -> ParseResult {
+    let mut argv = std::env::args();
+    let argv0 = argv.next().unwrap();
+    let program_name = std::path::Path::new(&argv0).file_name().unwrap().to_string_lossy();
+    self.parse(&program_name, argv, handler, |e| { std::eprintln!("error: {e}") })
+  }
+}