diff --git a/src/bytecode_compiler.rs b/src/bytecode_compiler.rs
index 88a82e0..2618b52 100644
--- a/src/bytecode_compiler.rs
+++ b/src/bytecode_compiler.rs
@@ -85,9 +85,10 @@ impl Compiler {
             }
             Statement::FunctionStmt { function } => {
                 let function_name = function.name.lexeme.clone();
-                let compiled_function = compile_function(function)?;
-                let name_index = self.chunk.add_function(compiled_function);
+                let name_index = self.chunk.add_constant(Value::String(function_name.clone()));
                 self.functions.insert(function_name, name_index);
+                let compiled_function = compile_function(function)?;
+                self.chunk.add_function(compiled_function);
             }
         }
         Ok(())
@@ -99,11 +100,11 @@ impl Compiler {
                 name, arguments, ..
             } => {
                 println!("call {}",name);
-                let function_index = *self.functions.get(name).unwrap();
+                let name_index = *self.functions.get(name).unwrap();
                 for argument in arguments {
                     self.compile_expression(argument)?;
                 }
-                self.emit_bytes(OP_CALL, function_index as u16);
+                self.emit_bytes(OP_CALL, name_index as u16);
                 self.emit_byte(arguments.len() as u16);
             }
             Expression::Variable { name, .. } => {
diff --git a/src/chunk.rs b/src/chunk.rs
index 27528fe..87d9fc4 100644
--- a/src/chunk.rs
+++ b/src/chunk.rs
@@ -14,7 +14,7 @@ pub struct Chunk {
     pub constants: Vec<Value>,
     lines: Vec<usize>,
     pub functions: HashMap<String, Chunk>,
-    pub(crate) functions_by_index: Vec<Chunk>,
+    // pub(crate) functions_by_index: Vec<Chunk>,
 }
 
 impl Chunk {
@@ -25,7 +25,7 @@ impl Chunk {
             constants: vec![],
             lines: vec![],
             functions: HashMap::new(),
-            functions_by_index: Vec::new(),
+            // functions_by_index: Vec::new(),
         }
     }
 
@@ -39,10 +39,9 @@ impl Chunk {
         self.constants.len() - 1
     }
 
-    pub fn add_function(&mut self, function: Chunk) -> usize {
-        self.functions_by_index.push(function.clone());
+    pub fn add_function(&mut self, function: Chunk) {
+        // self.functions_by_index.push(function.clone());
         self.functions.insert(function.name.to_string(), function);
-        self.functions.len() - 1
     }
 
     pub fn disassemble(&self) {
@@ -103,29 +102,29 @@ impl Chunk {
         }
     }
 
-    fn simple_inst(&self, name: &str, offset: usize) -> usize {
-        println!("{}", name);
+    fn simple_inst(&self, op: &str, offset: usize) -> usize {
+        println!("{}", op);
         offset + 1
     }
 
-    fn call_inst(&self, name: &str, offset: usize) -> usize {
+    fn call_inst(&self, op: &str, offset: usize) -> usize {
         let constant = self.code[offset + 1];
         let num_args = self.code[offset + 2];
-        println!("{} {}({}):", name, constant, num_args);
+        println!("{} {}:{}({}):", op, constant, &self.constants[constant as usize], num_args);
         offset + 3
     }
 
-    fn new_inst(&self, name: &str, offset: usize) -> usize {
+    fn new_inst(&self, op: &str, offset: usize) -> usize {
         let constant = self.code[offset + 1];
         let len = self.code[offset + 2];
-        print!("{} len: {}:", name, len);
+        print!("{} len: {}:", op, len);
         self.print_value(&self.constants[constant as usize]);
         offset + 3
     }
 
-    fn constant_inst(&self, name: &str, offset: usize) -> usize {
+    fn constant_inst(&self, op: &str, offset: usize) -> usize {
         let constant = self.code[offset + 1];
-        print!("{} {}:", name, constant);
+        print!("{} {}:", op, constant);
         self.print_value(&self.constants[constant as usize]);
         offset + 2
     }
diff --git a/src/main.rs b/src/main.rs
index 6673dca..e85e54b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -64,16 +64,32 @@ async fn handle_get(State(state): State<Arc<AppState>>) -> Result<Json<String>,
     Ok(Json(interpret(&state.code).await.unwrap().to_string()))
 }
 
-// let tokens = scan("");
 //
-// match ast_compiler::compile(tokens) {
-//     Ok(statements) => {
-//         println!("{:?}", statements);
-//         let chunk = compile(&statements)?;
-//         chunk.disassemble();
-//         println!("{}",interpret(&chunk)?);
-//     }
-//     Err(e) => {
-//         println!("{}", e)
-//     }
-// }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn test_compile() -> anyhow::Result<()> {
+        let tokens = scan(
+            r#"
+fn hello(name: string) -> string:
+    "Hello "+name
+hello("sander")"#,
+        );
+
+        match ast_compiler::compile(tokens) {
+            Ok(statements) => {
+                println!("{:?}", statements);
+                let chunk = compile(&statements)?;
+                chunk.disassemble();
+                println!("{}", interpret(&chunk).await?);
+            }
+            Err(e) => {
+                println!("{}", e)
+            }
+        }
+        Ok(())
+    }
+}
diff --git a/src/vm.rs b/src/vm.rs
index 82bfbab..a721010 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -144,8 +144,9 @@ impl Vm {
                     debug!("after get {:?}", self.stack);
                 }
                 OP_CALL => {
-                    let function_index = self.read(chunk);
-                    let function = chunk.functions_by_index.get(function_index).unwrap();
+                    let function_name_index = self.read(chunk);
+                    let function_name = chunk.constants[function_name_index].to_string();
+                    let function = chunk.functions.get(&function_name).unwrap();
                     let mut args = vec![];
                     let num_args = self.read(chunk);
                     for _ in 0..num_args {