Run clj file as script & evaluate expression

Hardcoding based on arguments.len() == 3 for now

Examples:
--init/-i for script or --eval/-e for evaluate expression
cargo run -- --init examples/hello_world.clj
cargo run -- --eval "(println \"eh\")"
cargo run -- --eval "(+ 1 2)"

Author: zackteo

examples/hello_world.clj

@@ -0,0 +1,4 @@
+(defn hello-world[]
+  (println "Hello, world"))
+
+(hello-world)

src/main.rs

@@ -23,11 +23,26 @@ mod symbol;
 mod type_tag;
 mod util;
 mod value;
+mod user_action;
 
 fn main() {
-    //
-    // Start repl
-    //
+    let cli_args: user_action::Action = user_action::parse_args();
+
+    // instantiate the core environment
     let repl = repl::Repl::default();
-    repl.run();
+    
+    match cli_args {
+	// eval the file/script
+	user_action::Action::RunScript(script) => {
+	    println!("{:?}", repl::Repl::try_eval_file(&repl, script.as_str()));
+	},
+
+	// eval the expression
+	user_action::Action::Evaluate(expression) => {
+	    println!("{:?}", repl::Repl::eval(&repl, &repl::Repl::read_string(&expression)));
+	}, 
+
+	// Start repl
+	user_action::Action::Nothing => { repl.run(); }
+    }
 }

src/user_action.rs

@@ -0,0 +1,34 @@
+use std::env;
+use std::fmt;
+
+pub enum Action{
+    RunScript(String),
+    Evaluate(String),
+    Nothing,	
+}
+
+impl fmt::Display for Action {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+       match &*self {
+	   Action::RunScript(filepath) => write!(f, "RunScript"),
+	   Action::Evaluate(expression) => write!(f, "Evaluate"),
+	   Action::Nothing => write!(f, "Nothing"),
+       }
+    }
+}
+
+pub fn parse_args() -> Action{
+    
+    let arguments: Vec<String> = env::args().collect();
+
+    if arguments.len() == 3 {
+	if arguments[1] == "-i" || arguments[1] == "--init" {
+	    return Action::RunScript(arguments[2].clone());
+	}else if arguments[1] == "-e" || arguments[1] == "--eval" {
+	    return Action::Evaluate(arguments[2].clone());
+	}else { return Action::Nothing; }
+    }else {
+	return Action::Nothing;
+    }	    
+}
+