diff --git a/schala-repl/src/language.rs b/schala-repl/src/language.rs
index 1d532ce..fe5b1b5 100644
--- a/schala-repl/src/language.rs
+++ b/schala-repl/src/language.rs
@@ -12,6 +12,7 @@ pub enum ExecutionMethod {
   Compile,
   Interpret,
 }
+
 impl Default for ExecutionMethod {
   fn default() -> ExecutionMethod {
     ExecutionMethod::Interpret
diff --git a/schala-repl/src/repl/command_tree.rs b/schala-repl/src/repl/command_tree.rs
index dcf19ac..f4508b6 100644
--- a/schala-repl/src/repl/command_tree.rs
+++ b/schala-repl/src/repl/command_tree.rs
@@ -1,6 +1,6 @@
 use super::Repl;
 
-type BoxedCommandFunction = Box<(fn(&mut Repl, Vec<String>) -> Option<String>)>;
+pub type BoxedCommandFunction = Box<(fn(&mut Repl, Vec<&str>) -> Option<String>)>;
 
 #[derive(Clone)]
 pub enum CommandTree {
diff --git a/schala-repl/src/repl/mod.rs b/schala-repl/src/repl/mod.rs
index 8bd0e28..a478fdc 100644
--- a/schala-repl/src/repl/mod.rs
+++ b/schala-repl/src/repl/mod.rs
@@ -7,7 +7,7 @@ use colored::*;
 use itertools::Itertools;
 use crate::language::{ProgrammingLanguageInterface, EvalOptions, ComputationRequest, ComputationResponse};
 mod command_tree;
-use self::command_tree::CommandTree;
+use self::command_tree::{CommandTree, BoxedCommandFunction};
 
 const HISTORY_SAVE_FILE: &'static str = ".schala_history";
 const OPTIONS_SAVE_FILE: &'static str = ".schala_repl";
@@ -92,6 +92,32 @@ impl Repl {
     */
   }
 
+  fn get_function_from_directives<'a>(directives: &'a CommandTree, commands: &Vec<&str>) -> Result<&'a BoxedCommandFunction, String> {
+    let mut dir_pointer: &CommandTree = &directives;
+    let mut idx = 0;
+
+    loop {
+      match dir_pointer {
+        CommandTree::Top(subcommands) | CommandTree::NonTerminal { children: subcommands, .. } => {
+          let next_command = match commands.get(idx) {
+            Some(cmd) => cmd,
+            None => break Err(format!("Command requires arguments"))
+          };
+          idx += 1;
+          match subcommands.iter().find(|sc| sc.get_cmd() == *next_command) {
+            Some(command_tree) => {
+              dir_pointer = command_tree;
+            },
+            None => break Err(format!("Command {} not found", next_command))
+          };
+        },
+        CommandTree::Terminal { name, function, .. } => {
+          break function.as_ref().ok_or(format!("No action specified for: {:?}", commands));
+        }
+      }
+    }
+  }
+
   fn handle_interpreter_directive(&mut self, input: &str) -> Option<String> {
     let mut iter = input.chars();
     iter.next();
@@ -105,21 +131,11 @@ impl Repl {
     }
 
     let directives = self.get_directives();
-
-    let mut dir_pointer: &CommandTree = &directives;
-    for command in commands.iter() {
-      match dir_pointer {
-        CommandTree::Top(subcommands) | CommandTree::NonTerminal { children: subcommands, .. } => {
-          let q = subcommands;
-
-
-        },
-        CommandTree::Terminal { name, .. } => {
-
-        }
-      }
+    let result: Result<&BoxedCommandFunction, String> = Repl::get_function_from_directives(&directives, &commands);
+    match result {
+      Ok(f) => f(self, commands),
+      Err(err) => Some(err.red().to_string())
     }
-    Some(format!("you typed {:?}", commands))
   }
 
   fn get_cur_language_state(&mut self) -> &mut Box<ProgrammingLanguageInterface> {
@@ -167,11 +183,11 @@ impl Repl {
       */
 
     CommandTree::Top(vec![
-      CommandTree::term_with_function("exit", Some("exit the REPL"), Box::new(|repl: &mut Repl, cmds: Vec<String>| {
+      CommandTree::term_with_function("exit", Some("exit the REPL"), Box::new(|repl: &mut Repl, _cmds: Vec<&str>| {
         repl.save_before_exit();
         ::std::process::exit(0)
       })),
-      CommandTree::term_with_function("quit", Some("exit the REPL"), Box::new(|repl: &mut Repl, cmds: Vec<String>| {
+      CommandTree::term_with_function("quit", Some("exit the REPL"), Box::new(|repl: &mut Repl, _cmds: Vec<&str>| {
         repl.save_before_exit();
         ::std::process::exit(0)
       })),