diff --git a/schala-lang/language/src/lib.rs b/schala-lang/language/src/lib.rs
index 5e4de2c..c7425fc 100644
--- a/schala-lang/language/src/lib.rs
+++ b/schala-lang/language/src/lib.rs
@@ -262,40 +262,40 @@ impl ProgrammingLanguageInterface for Schala {
   fn get_source_file_suffix(&self) -> String { format!("schala") }
 
   fn run_computation(&mut self, request: ComputationRequest) -> ComputationResponse {
-    let ComputationRequest { source, debug_requests } = request;
-    self.source_reference.load_new_source(source);
+    struct PassToken<'a> {
+      schala: &'a mut Schala,
+      stage_durations: &'a mut Vec<(String, Duration)>,
+      sw: &'a Stopwatch,
+      debug_requests: &'a HashSet<DebugAsk>
+    }
 
-    fn output_wrapper<Input, Output, F>(
-      n: usize,
-      func: F,
-      input: Input,
-      schala: &mut Schala,
-      stage_durations: &mut Vec<(String, Duration)>,
-      sw: &Stopwatch,
-      debug_requests: &HashSet<DebugAsk>) -> Result<Output, String>
-      where F: Fn(Input, &mut Schala, Option<&mut PassDebugArtifact>) -> Result<Output, String>,
+    fn output_wrapper<Input, Output, F>(n: usize, func: F, input: Input, tok: &mut PassToken) -> Result<Output, String>
+      where F: Fn(Input, &mut Schala, Option<&mut PassDebugArtifact>) -> Result<Output, String>
     {
       let stage_names = stage_names();
-      let mut debug_artifact = if debug_requests.contains(&DebugAsk::ByStage { stage_name: stage_names[n].to_string() }) {
+      let mut debug_artifact = if tok.debug_requests.contains(&DebugAsk::ByStage { stage_name: stage_names[n].to_string() }) {
         Some(PassDebugArtifact::default())
       } else {
         None
       };
-      let output = func(input, schala, debug_artifact.as_mut());
-      stage_durations.push((stage_names[n].to_string(), sw.elapsed()));
+      let output = func(input, tok.schala, debug_artifact.as_mut());
+      tok.stage_durations.push((stage_names[n].to_string(), tok.sw.elapsed()));
       output
     }
 
+    let ComputationRequest { source, debug_requests } = request;
+    self.source_reference.load_new_source(source);
     let sw = Stopwatch::start_new();
     let mut stage_durations = Vec::new();
+    let mut tok = PassToken { schala: self, stage_durations: &mut stage_durations, sw: &sw, debug_requests: &debug_requests };
 
     let main_output: Result<String, String> = Ok(source)
-      .and_then(|source| output_wrapper(0, tokenizing, source, self, &mut stage_durations, &sw, &debug_requests))
-      .and_then(|tokens| output_wrapper(1, parsing, tokens, self, &mut stage_durations, &sw, &debug_requests))
-      .and_then(|ast| output_wrapper(2, symbol_table, ast, self, &mut stage_durations, &sw, &debug_requests))
-      .and_then(|ast| output_wrapper(3, typechecking, ast, self, &mut stage_durations, &sw, &debug_requests))
-      .and_then(|ast| output_wrapper(4, ast_reducing, ast, self, &mut stage_durations, &sw, &debug_requests))
-      .and_then(|reduced_ast| output_wrapper(5, eval, reduced_ast, self, &mut stage_durations, &sw, &debug_requests));
+      .and_then(|source| output_wrapper(0, tokenizing, source, &mut tok))
+      .and_then(|tokens| output_wrapper(1, parsing, tokens, &mut tok))
+      .and_then(|ast| output_wrapper(2, symbol_table, ast, &mut tok))
+      .and_then(|ast| output_wrapper(3, typechecking, ast, &mut tok))
+      .and_then(|ast| output_wrapper(4, ast_reducing, ast, &mut tok))
+      .and_then(|reduced_ast| output_wrapper(5, eval, reduced_ast, &mut tok));
 
     let total_duration = sw.elapsed();
     let global_output_stats = GlobalOutputStats {