Improve CLI and remove rere.py

Makefile

@@ -4,12 +4,6 @@ build:
 release:
 	cargo build --release --bin chs
 
-test: build
-	./rere.py replay test.list
-
-record: build
-	./rere.py record test.list
-
 chsc: release
 
 help:

chs/src/cli.rs

@@ -0,0 +1,64 @@
+use std::{env::Args, process::ExitCode};
+
+pub const COMMANDS: &[Command] = &[
+    Command {
+        name: "help",
+        descripition: "Print this message",
+        run: |program, _| {
+            usage(program);
+            ExitCode::SUCCESS
+        },
+    },
+    Command {
+        name: "compile",
+        descripition: "Compile a program: chs compile <file.chs>",
+        run: |program, args| {
+            if let Some(file_path) = args.next() {
+                ExitCode::SUCCESS
+            } else {
+                eprintln!("Expect file path.");
+                ExitCode::FAILURE
+            }
+        },
+    },
+    Command {
+        name: "parse",
+        descripition: "Parse a program and it's AST: chs parse <file.chs>",
+        run: |program, args| {
+            if let Some(file_path) = args.next() {
+                match chs_ast::parse_file(file_path) {
+                    Ok(ast) => {
+                        println!("{ast}");
+                        ExitCode::SUCCESS
+                    }
+                    Err(err) => {
+                        eprintln!("{err}");
+                        ExitCode::FAILURE
+                    }
+                }
+            } else {
+                eprintln!("Expect file path.");
+                ExitCode::FAILURE
+            }
+        },
+    },
+];
+
+pub struct Command {
+    pub name: &'static str,
+    pub descripition: &'static str,
+    pub run: fn(&str, &mut Args) -> ExitCode,
+}
+
+pub fn usage(program: &str) {
+    println!("USAGE: {program} <COMMAND> [OPTIONS]");
+    println!("COMMANDS:");
+
+    for ele in COMMANDS.iter() {
+        println!(
+            "      {name}      {descripition}",
+            name = ele.name,
+            descripition = ele.descripition,
+        );
+    }
+}

chs/src/main.rs

@@ -1,38 +1,24 @@
 #![allow(unused)]
 
-use std::{env, process::exit};
+use std::{env, process::{exit, ExitCode}};
 
-fn main() {
-    let mut argv = env::args();
-    let program = argv.next().expect("Program always provided.");
-    let cmd = argv.next().unwrap_or_else(|| usage_err(&program, "Expect Command"));
-    match cmd.as_str() {
-        "help" => usage(&program),
-        "com"|"compile" => {}
-        "parse" => {
-            let file_path = argv.next().unwrap_or_else(|| msg_err("ERROR: File not provided."));
-            let ast = chs_ast::parse_file(file_path).unwrap_or_else(|err| msg_err(err));
-            println!("{ast}");
+use cli::{usage, COMMANDS};
+mod cli;
+
+fn main() -> ExitCode {
+    let mut args = env::args();
+    let program = args.next().expect("Program always provided.");
+    if let Some(cmd) = args.next() {
+        if let Some(cmd) = COMMANDS.iter().find(|c| c.name == cmd) {
+           (cmd.run)(&program, &mut args)
+        } else {
+            println!("Invalid command.");
+            usage(&program);
+            ExitCode::FAILURE
         }
-        c => usage_err(&program, format!("Invalid Command \"{c}\""))
+    } else {
+        println!("Expect command.");
+        usage(&program);
+        ExitCode::FAILURE
     }
 }
-
-fn usage(program: &str) {
-    println!("USAGE: {program} <COMMAND> [OPTIONS]");
-    println!("COMMANDS:");
-    println!("    help - Show this message.");
-    println!("    com|compile - Compile a program: chs com <file.chs>");
-    println!("    parse - Parse a program and print its AST: chs parse <file.chs>");
-}
-
-fn usage_err(program: &str, err: impl ToString) -> ! {
-    eprintln!("ERROR: {}", err.to_string());
-    usage(&program);
-    exit(1);
-}
-
-fn msg_err(err: impl ToString) -> ! {
-    eprintln!("{}", err.to_string());
-    exit(1);
-}