Move base BTreeMap API to alloc-only

jaarg/Cargo.toml

@@ -9,4 +9,5 @@ authors.workspace = true
 
 [features]
 default = ["std"]
-std = []
+alloc = []
+std = ["alloc"]

jaarg/examples/btreemap.rs

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: MIT
  */
 
-use jaarg::{std::ParseMapResult, Opt, Opts};
+use jaarg::{alloc::ParseMapResult, Opt, Opts};
 use std::process::ExitCode;
 
 fn main() -> ExitCode {
@@ -16,7 +16,8 @@ fn main() -> ExitCode {
 
   let map = match OPTIONS.parse_map_easy() {
     ParseMapResult::Map(map) => map,
-    ParseMapResult::Exit(code) => { return code; }
+    ParseMapResult::ExitSuccess => { return ExitCode::SUCCESS; }
+    ParseMapResult::ExitFailure => { return ExitCode::FAILURE; }
   };
 
   println!("{:?}", map);

jaarg/src/alloc.rs

@@ -0,0 +1,40 @@
+/* jaarg - Argument parser
+ * SPDX-FileCopyrightText: (C) 2025 Gay Pizza Specifications
+ * SPDX-License-Identifier: MIT
+ */
+
+extern crate alloc;
+
+use alloc::collections::BTreeMap;
+use alloc::string::String;
+use crate::{Opts, ParseControl, ParseError, ParseResult};
+
+impl Opts<&'static str> {
+  /// Parse an iterator of strings as arguments and return the results in a [`BTreeMap`].
+  ///
+  /// Requires `features = ["alloc"]`.
+  pub fn parse_map<'a, S: AsRef<str> + 'a, I: Iterator<Item = S>>(&self, program_name: &str, args: I,
+    help: impl Fn(&str), error: impl FnOnce(&str, ParseError)
+  ) -> ParseMapResult {
+    let mut out: BTreeMap<&'static str, String> = BTreeMap::new();
+    match self.parse(&program_name, args, |_program_name, id, opt, _name, arg| {
+      if opt.is_help() {
+        help(program_name);
+        Ok(ParseControl::Quit)
+      } else {
+        out.insert(id, arg.into());
+        Ok(ParseControl::Continue)
+      }
+    }, error) {
+      ParseResult::ContinueSuccess => ParseMapResult::Map(out),
+      ParseResult::ExitSuccess => ParseMapResult::ExitSuccess,
+      ParseResult::ExitError => ParseMapResult::ExitFailure,
+    }
+  }
+}
+
+/// The result of parsing commands with [Opts::parse_map].
+pub enum ParseMapResult {
+  Map(BTreeMap<&'static str, String>),
+  ExitSuccess, ExitFailure
+}

jaarg/src/lib.rs

@@ -13,5 +13,7 @@ include!("options.rs");
 include!("argparse.rs");
 include!("help.rs");
 
+#[cfg(feature = "alloc")]
+pub mod alloc;
 #[cfg(feature = "std")]
 pub mod std;

jaarg/src/std.rs

@@ -5,18 +5,17 @@
 
 extern crate std;
 
+use crate::alloc::ParseMapResult;
 use crate::{HandlerResult, HelpWriter, HelpWriterContext, Opt, Opts, ParseControl, ParseError, ParseResult, StandardFullHelpWriter, StandardShortUsageWriter};
-use std::collections::BTreeMap;
 use std::path::Path;
 use std::rc::Rc;
-use std::string::String;
 use std::{env, eprintln, println};
 
 impl<ID: 'static> Opts<ID> {
   /// Wrapper around [Opts::parse] that gathers arguments from the command line and prints errors to stderr.
   /// The errors are formatted in a standard user-friendly format.
   ///
-  /// Requires `features = [std]`.
+  /// Requires `features = ["std"]`.
   pub fn parse_easy<'a>(&self, handler: impl FnMut(&str, &ID, &Opt<ID>, &str, &str) -> HandlerResult<'a, ParseControl>
   ) -> ParseResult {
     let (program_name, argv) = Self::easy_args();
@@ -25,14 +24,14 @@ impl<ID: 'static> Opts<ID> {
 
   /// Prints full help text for the options using the standard full.
   ///
-  /// Requires `features = [std]`.
+  /// Requires `features = ["std"]`.
   pub fn print_full_help(&self, program_name: &str) {
     self.print_help::<StandardFullHelpWriter<'_, ID>>(program_name);
   }
 
   /// Print help text to stdout using the provided help writer.
   ///
-  /// Requires `features = [std]`.
+  /// Requires `features = ["std"]`.
   pub fn print_help<'a, W: HelpWriter<'a, ID>>(&'a self, program_name: &'a str) {
     let ctx = HelpWriterContext { options: self, program_name };
     println!("{}", W::new(ctx));
@@ -40,7 +39,7 @@ impl<ID: 'static> Opts<ID> {
 
   /// Print help text to stderr using the provided help writer.
   ///
-  /// Requires `features = [std]`.
+  /// Requires `features = ["std"]`.
   pub fn eprint_help<'a, W: HelpWriter<'a, ID>>(&'a self, program_name: &'a str) {
     let ctx = HelpWriterContext { options: self, program_name };
     eprintln!("{}", W::new(ctx));
@@ -63,39 +62,11 @@ impl<ID: 'static> Opts<ID> {
   }
 }
 
-/// The result of parsing commands with [Opts::parse_map].
-pub enum ParseMapResult {
-  Map(BTreeMap<&'static str, String>),
-  Exit(std::process::ExitCode),
-}
-
 impl Opts<&'static str> {
-  /// Parse an iterator of strings as arguments and return the results in a [BTreeMap].
+  /// Parse arguments from the command line and return the results in a [`alloc::collections::BTreeMap`].
-  ///
-  /// Requires `features = [std]`.
-  pub fn parse_map<'a, S: AsRef<str> + 'a, I: Iterator<Item = S>>(&self, program_name: &str, args: I,
-    help: impl Fn(&str), error: impl FnOnce(&str, ParseError)
-  ) -> ParseMapResult {
-    let mut out: BTreeMap<&'static str, String> = BTreeMap::new();
-    match self.parse(&program_name, args, |_program_name, id, opt, _name, arg| {
-      if opt.is_help() {
-        help(program_name);
-        Ok(ParseControl::Quit)
-      } else {
-        out.insert(id, arg.into());
-        Ok(ParseControl::Continue)
-      }
-    }, error) {
-      ParseResult::ContinueSuccess => ParseMapResult::Map(out),
-      ParseResult::ExitSuccess => ParseMapResult::Exit(std::process::ExitCode::SUCCESS),
-      ParseResult::ExitError => ParseMapResult::Exit(std::process::ExitCode::FAILURE),
-    }
-  }
-
-  /// Parse arguments from the command line and return the results in a [BTreeMap].
   /// Help and errors are formatted in a standard user-friendly format.
   ///
-  /// Requires `features = [std]`.
+  /// Requires `features = ["std"]`.
   pub fn parse_map_easy(&self) -> ParseMapResult {
     let (program_name, argv) = Self::easy_args();
     self.parse_map(&program_name, argv,