Minimal CLI command & options parsing

src/cli/help.rs

@@ -0,0 +1,7 @@
+use crate::cli::HELP_TEXT;
+
+
+pub fn help_command(options: &Vec<String>) {
+    println!("{}", HELP_TEXT);
+}
+

src/cli/mod.rs

@@ -0,0 +1,86 @@
+mod help;
+mod types;
+
+use types::{Command, CommandType};
+
+pub const HELP_TEXT: &str = r#"
+Usage: `thp [command] [options]`
+
+Commands
+
+  c _file_	Compiles `file` in-place
+  f _file_	Formats `file`
+  r			Starts the REPL
+
+  init		Initializes a new project in the current directory
+  build		Builds the project
+  fmt		Formats all files in the project
+  watch, w	Starts compilation of the project in watch mode
+
+  help, h	Print this message & exit
+
+General options
+
+    -h, --help	Print command-specific usage
+"#;
+
+fn get_copyright() -> String {
+    let crate_version = env!("CARGO_PKG_VERSION");
+    format!("The THP compiler, linter & formatter, v{}", crate_version)
+}
+
+pub fn run_cli() {
+    let command = match parse_args() {
+        Ok(c) => c,
+        Err(reason) => {
+            println!("{}", HELP_TEXT);
+            println!("Error: {}", reason);
+            return;
+        },
+    };
+
+    command.run();
+}
+
+fn parse_args() -> Result<Command, String> {
+    let mut args = std::env::args().collect::<Vec<String>>();
+    args.remove(0);
+
+    let mut args = args.into_iter();
+
+    let command = match args.next() {
+        Some(command) if !command.starts_with('-') => Some(command),
+        _ => None,
+    };
+
+    let mut options = Vec::new();
+    for arg in args {
+        if arg.starts_with('-') {
+            options.push(arg);
+        } else {
+            return Err(format!(
+                "Unexpected command `{}` after the options",
+                arg
+            ));
+        }
+    }
+
+    let command = match command {
+        Some(command) => match command.as_str() {
+            "c" | "compile" => CommandType::Compile,
+            "f" | "format" => CommandType::Format,
+            "r" | "repl" => CommandType::Repl,
+            "init" => CommandType::Init,
+            "build" => CommandType::Build,
+            "fmt" => CommandType::Fmt,
+            "watch" | "w" => CommandType::Watch,
+            "help" | "h" => CommandType::Help,
+            _ => return Err(format!("Unknown command: {}", command)),
+        },
+        None => CommandType::None,
+    };
+
+    Ok(Command { command, options })
+}
+
+

src/cli/types.rs

@@ -0,0 +1,32 @@
+#[derive(Debug)]
+pub struct Command {
+    pub command: CommandType,
+    pub options: Vec<String>,
+}
+
+#[derive(Debug)]
+pub enum CommandType {
+    Compile,
+    Format,
+    Repl,
+    Init,
+    Build,
+    Fmt,
+    Watch,
+    Help,
+    None,
+}
+
+
+impl Command {
+    pub fn run(&self) {
+        println!("Running command! {:?}", self);
+        self.command.run(&self.options);
+    }
+}
+
+impl CommandType {
+    pub fn run(&self, options: &Vec<String>) {
+        println!("Running command! {:?}", self)
+    }
+}

src/main.rs

@@ -1,3 +1,5 @@
+// Module to handle the CLI
+mod cli;
 
 // Module to handle the repl and its compilation
 mod repl;
@@ -13,12 +15,6 @@ mod utils;
 
 mod error_handling;
 
-fn get_copyright() -> String {
-    let crate_version = env!("CARGO_PKG_VERSION");
-    format!("The THP compiler, linter & formatter, v{}", crate_version,)
-}
-
 fn main() {
-    println!("{}", get_copyright());
-    println!("Rewriting CLI...");
+    cli::run_cli();
 }