Added (load-file ..), a relatively useful primitive

Author: Tko1

src/environment.rs

@@ -78,6 +78,7 @@ impl Environment {
         let print_string_fn = rust_core::PrintStringFn {};
         let assoc_fn = rust_core::AssocFn {};
 	let get_fn = rust_core::GetFn {};
+	
         // Hardcoded fns
         let lexical_eval_fn = Value::LexicalEvalFn {};
         // Hardcoded macros
@@ -88,7 +89,8 @@ impl Environment {
         let defmacro_macro = Value::DefmacroMacro {};
 	let if_macro = Value::IfMacro {};
         let environment = Rc::new(Environment::new_main_environment());
-
+	
+	let load_file_fn = rust_core::LoadFileFn::new(Rc::clone(&environment));
         let eval_fn = rust_core::EvalFn::new(Rc::clone(&environment));
 
         environment.insert(Symbol::intern("+"), add_fn.to_rc_value());
@@ -115,6 +117,7 @@ impl Environment {
             Symbol::intern("lexical-eval"),
             lexical_eval_fn.to_rc_value(),
         );
+	environment.insert(Symbol::intern("load-file"), load_file_fn.to_rc_value());
         environment.insert(Symbol::intern("nth"), nth_fn.to_rc_value());
 	environment.insert(Symbol::intern("assoc"), assoc_fn.to_rc_value());
 	environment.insert(Symbol::intern("get"), get_fn.to_rc_value());

src/rust_core.rs

@@ -317,3 +317,41 @@ impl IFn for GetFn {
         Value::Nil
     }
 }
+
+#[derive(Debug, Clone)]
+pub struct LoadFileFn {
+    enclosing_environment: Rc<Environment>,
+}
+impl LoadFileFn {
+    pub fn new(enclosing_environment: Rc<Environment>) -> LoadFileFn {
+        LoadFileFn {
+            enclosing_environment,
+        }
+    }
+}
+impl ToValue for LoadFileFn {
+    fn to_value(&self) -> Value {
+        Value::IFn(Rc::new(self.clone()))
+    }
+}
+impl IFn for LoadFileFn {
+    fn invoke(&self, args: Vec<Rc<Value>>) -> Value {
+        if args.len() != 1 {
+            Value::Condition(format!(
+                "Wrong number of arguments given to function (Given: {}, Expected: 1)",
+                args.len()
+            ))
+        } else if let Value::String(file) = &**args.get(0).unwrap() {
+            // @TODO clean this
+            Repl::new(Rc::clone(&self.enclosing_environment)).try_eval_file(file);
+            //@TODO remove this placeholder value, return last value evaluated in try_eval_file
+            Value::Nil
+        } else {
+            Value::Condition(format!(
+                "Type mismatch; Expected instance of {}, Recieved type {}",
+                TypeTag::String,
+                args.len()
+            ))
+        }
+    }
+}