standalone: Implement command-line parser using clap

In preparation for adding more command-line options.

Cargo.lock

@@ -34,6 +34,54 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "anstream"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1f58811cfac344940f1a400b6e6231ce35171f614f26439e80f8c1465c5cc0c"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b84bf0a05bbb2a83e5eb6fa36bb6e87baa08193c35ff52bbf6b38d8af2890e46"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "938874ff5980b03a87c5524b3ae5b59cf99b1d6bc836848df7bc5ada9643c333"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ca11d4be1bab0c8bc8734a9aa7bf4ee8316d462a08c6ac5052f888fef5b494b"
+dependencies = [
+ "windows-sys 0.48.0",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58f54d10c6dfa51283a066ceab3ec1ab78d13fae00aa49243a45e4571fb79dfd"
+dependencies = [
+ "anstyle",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "ascii-canvas"
 version = "3.0.0"
@@ -94,6 +142,52 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "clap"
+version = "4.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a13b88d2c62ff462f88e4a121f17a82c1af05693a2f192b5c38d14de73c19f6"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2bb9faaa7c2ef94b2743a21f5a29e6f0010dff4caa69ac8e9d6cf8b6fa74da08"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0862016ff20d69b84ef8247369fabf5c008a7417002411897d40ee1f4532b873"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.29",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd7cc57abe963c6d3b9d8be5b06ba7c8957a930305ca90304f24ef040aa6f961"
+
+[[package]]
+name = "colorchoice"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
+
 [[package]]
 name = "console"
 version = "0.15.7"
@@ -313,6 +407,12 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
 
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
 [[package]]
 name = "hermit-abi"
 version = "0.3.2"
@@ -618,6 +718,7 @@ dependencies = [
 name = "nac3standalone"
 version = "0.1.0"
 dependencies = [
+ "clap",
  "inkwell",
  "nac3core",
  "nac3parser",
@@ -1079,6 +1180,12 @@ dependencies = [
  "precomputed-hash",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
 [[package]]
 name = "syn"
 version = "1.0.109"
@@ -1288,6 +1395,12 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e1766d682d402817b5ac4490b3c3002d91dfa0d22812f341609f97b08757359c"
 
+[[package]]
+name = "utf8parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
+
 [[package]]
 name = "version_check"
 version = "0.9.4"

nac3standalone/Cargo.toml

@@ -9,6 +9,10 @@ parking_lot = "0.12"
 nac3parser = { path = "../nac3parser" }
 nac3core = { path = "../nac3core" }
 
+[dependencies.clap]
+version = "4.4"
+features = ["derive"]
+
 [dependencies.inkwell]
 version = "0.2"
 default-features = false

nac3standalone/src/main.rs

@@ -1,3 +1,4 @@
+use clap::Parser;
 use inkwell::{
     memory_buffer::MemoryBuffer,
     passes::{PassManager, PassManagerBuilder},
@@ -5,7 +6,7 @@ use inkwell::{
     OptimizationLevel,
 };
 use parking_lot::{Mutex, RwLock};
-use std::{borrow::Borrow, collections::HashMap, env, fs, path::Path, sync::Arc};
+use std::{borrow::Borrow, collections::HashMap, fs, path::Path, sync::Arc};
 
 use nac3core::{
     codegen::{
@@ -30,6 +31,18 @@ use nac3parser::{
 mod basic_symbol_resolver;
 use basic_symbol_resolver::*;
 
+/// Command-line argument parser definition.
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+struct CommandLineArgs {
+    /// The name of the input file.
+    file_name: String,
+
+    /// The number of threads allocated to processing the source file.
+    #[arg(default_value_t = 1)]
+    threads: u32,
+}
+
 fn handle_typevar_definition(
     var: &Expr,
     resolver: &(dyn SymbolResolver + Send + Sync),
@@ -155,8 +168,8 @@ fn handle_assignment_pattern(
 }
 
 fn main() {
-    let file_name = env::args().nth(1).unwrap();
-    let threads: u32 = env::args().nth(2).map(|s| str::parse(&s).unwrap()).unwrap_or(1);
+    let cli = CommandLineArgs::parse();
+    let CommandLineArgs { file_name, threads } = cli;
 
     Target::initialize_all(&InitializationConfig::default());