diff --git a/schala-lang/language/src/lib.rs b/schala-lang/language/src/lib.rs
index c5675d7..d024369 100644
--- a/schala-lang/language/src/lib.rs
+++ b/schala-lang/language/src/lib.rs
@@ -31,4 +31,4 @@ mod identifier;
 
 mod schala;
 
-pub use schala::Schala;
+pub use schala::{Schala, SchalaConfig};
diff --git a/schala-lang/language/src/schala.rs b/schala-lang/language/src/schala.rs
index 5751137..90e350f 100644
--- a/schala-lang/language/src/schala.rs
+++ b/schala-lang/language/src/schala.rs
@@ -57,7 +57,7 @@ impl<'a> Schala<'a> {
         let prelude = include_str!("../source-files/prelude.schala");
         let mut env = Schala::new_blank_env();
 
-        let response = env.run_pipeline(prelude);
+        let response = env.run_pipeline(prelude, SchalaConfig::default());
         if let Err(err) = response {
             panic!("Error in prelude, panicking: {}", err.display());
         }
@@ -67,7 +67,7 @@ impl<'a> Schala<'a> {
     /// This is where the actual action of interpreting/compilation happens.
     /// Note: this should eventually use a query-based system for parallelization, cf.
     /// https://rustc-dev-guide.rust-lang.org/overview.html
-    fn run_pipeline(&mut self, source: &str) -> Result<String, SchalaError> {
+    fn run_pipeline(&mut self, source: &str, config: SchalaConfig) -> Result<String, SchalaError> {
         // 1st stage - tokenization
         // TODO tokenize should return its own error type
         let tokens = tokenizing::tokenize(source);
@@ -93,7 +93,7 @@ impl<'a> Schala<'a> {
 
         let reduced_ir = reduced_ir::reduce(&ast, &self.symbol_table, &self.type_context);
 
-        let evaluation_outputs = self.eval_state.evaluate(reduced_ir, &self.type_context, true);
+        let evaluation_outputs = self.eval_state.evaluate(reduced_ir, &self.type_context, config.repl);
         let text_output: Result<Vec<String>, String> = evaluation_outputs.into_iter().collect();
 
         let text_output: Result<Vec<String>, SchalaError> =
@@ -145,9 +145,14 @@ fn stage_names() -> Vec<&'static str> {
     vec!["tokenizing", "parsing", "symbol-table", "typechecking", "ast-reduction", "ast-walking-evaluation"]
 }
 
+#[derive(Default, Clone)]
+pub struct SchalaConfig {
+    pub repl: bool,
+}
+
 impl<'a> ProgrammingLanguageInterface for Schala<'a> {
     //TODO flesh out Config
-    type Config = ();
+    type Config = SchalaConfig;
     fn language_name() -> String {
         "Schala".to_owned()
     }
@@ -161,7 +166,8 @@ impl<'a> ProgrammingLanguageInterface for Schala<'a> {
         self.source_reference.load_new_source(source);
         let sw = Stopwatch::start_new();
 
-        let main_output = self.run_pipeline(source).map_err(|schala_err| schala_err.display());
+        let main_output =
+            self.run_pipeline(source, request.config).map_err(|schala_err| schala_err.display());
 
         let global_output_stats = GlobalOutputStats { total_duration: sw.elapsed(), stage_durations: vec![] };
 
diff --git a/schala-lang/language/src/tree_walk_eval/evaluator.rs b/schala-lang/language/src/tree_walk_eval/evaluator.rs
index 8760f79..734a79f 100644
--- a/schala-lang/language/src/tree_walk_eval/evaluator.rs
+++ b/schala-lang/language/src/tree_walk_eval/evaluator.rs
@@ -50,7 +50,6 @@ impl<'a, 'b> Evaluator<'a, 'b> {
     fn statement(&mut self, stmt: Statement) -> EvalResult<Option<MemoryValue>> {
         match stmt {
             Statement::Binding { ref id, expr, constant: _ } => {
-                println!("eval() binding id: {}", id);
                 let evaluated = self.expression(expr)?;
                 self.state.environments.insert(id.into(), evaluated.into());
                 Ok(None)
diff --git a/schala-repl/src/language.rs b/schala-repl/src/language.rs
index d205446..eb11629 100644
--- a/schala-repl/src/language.rs
+++ b/schala-repl/src/language.rs
@@ -2,7 +2,7 @@ use std::collections::HashSet;
 use std::time;
 
 pub trait ProgrammingLanguageInterface {
-    type Config: Default;
+    type Config: Default + Clone;
     fn language_name() -> String;
     fn source_file_suffix() -> String;
 
diff --git a/schala-repl/src/lib.rs b/schala-repl/src/lib.rs
index fc75deb..72cddb0 100644
--- a/schala-repl/src/lib.rs
+++ b/schala-repl/src/lib.rs
@@ -66,14 +66,14 @@ impl<L: ProgrammingLanguageInterface> Repl<L> {
         }
     }
 
-    pub fn run_repl(&mut self) {
+    pub fn run_repl(&mut self, config: L::Config) {
         println!("Schala meta-interpeter version {}", VERSION_STRING);
         println!(
             "Type {} for help with the REPL",
             format!("{}help", self.sigil).bright_green().bold()
         );
         self.load_options();
-        self.handle_repl_loop();
+        self.handle_repl_loop(config);
         self.save_before_exit();
         println!("Exiting...");
     }
@@ -90,7 +90,7 @@ impl<L: ProgrammingLanguageInterface> Repl<L> {
         }
     }
 
-    fn handle_repl_loop(&mut self) {
+    fn handle_repl_loop(&mut self, config: L::Config) {
         use linefeed::ReadResult::*;
 
         'main: loop {
@@ -128,7 +128,7 @@ impl<L: ProgrammingLanguageInterface> Repl<L> {
                                 buf.push('\n');
                             }
                         }
-                        self.handle_input(&buf)
+                        self.handle_input(&buf, &config)
                     } else {
                         if let Some(output) =  self.handle_interpreter_directive(input.get(1..).unwrap()) {
                           println!("{}", output);
@@ -136,7 +136,7 @@ impl<L: ProgrammingLanguageInterface> Repl<L> {
                         continue;
                     }
                 }
-                _ => self.handle_input(input),
+                _ => self.handle_input(input, &config),
             };
 
             for repl_response in repl_responses.iter() {
@@ -179,7 +179,7 @@ impl<L: ProgrammingLanguageInterface> Repl<L> {
         directives.perform(self, &arguments)
     }
 
-    fn handle_input(&mut self, input: &str) -> Vec<ReplResponse> {
+    fn handle_input(&mut self, input: &str, config: &L::Config) -> Vec<ReplResponse> {
         let mut debug_requests = HashSet::new();
         for ask in self.options.debug_asks.iter() {
             debug_requests.insert(ask.clone());
@@ -187,7 +187,7 @@ impl<L: ProgrammingLanguageInterface> Repl<L> {
 
         let request = ComputationRequest {
             source: input,
-            config: Default::default(),
+            config: config.clone(),
             debug_requests,
         };
         let response = self.language_state.run_computation(request);
diff --git a/src/main.rs b/src/main.rs
index af17153..6caa217 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,7 @@
 use schala_repl::{Repl, ProgrammingLanguageInterface, ComputationRequest};
 
 use std::{fs::File, io::Read, path::PathBuf, process::exit, collections::HashSet};
-use schala_lang::Schala;
+use schala_lang::{Schala, SchalaConfig};
 
 //TODO specify multiple langs, and have a way to switch between them
 fn main() {
@@ -21,7 +21,8 @@ fn main() {
     if matches.free.is_empty() {
         let state = Schala::new();
         let mut repl = Repl::new(state);
-        repl.run_repl();
+        let config = SchalaConfig { repl: true };
+        repl.run_repl(config);
     } else {
         let paths: Vec<PathBuf> = matches.free.iter().map(PathBuf::from).collect();
         //TODO handle more than one file
@@ -34,7 +35,11 @@ fn main() {
 
         //TODO this proably should be a macro for every supported language
         if extension == Schala::source_file_suffix() {
-          run_noninteractive(paths, Schala::new());
+            let config = SchalaConfig {
+                repl: false,
+            };
+
+          run_noninteractive(paths, Schala::new(), config);
         } else {
           eprintln!("Extension .{} not recognized", extension);
           exit(1);
@@ -42,7 +47,7 @@ fn main() {
     }
 }
 
-pub fn run_noninteractive<L: ProgrammingLanguageInterface>(filenames: Vec<PathBuf>, mut language: L) {
+pub fn run_noninteractive<L: ProgrammingLanguageInterface>(filenames: Vec<PathBuf>, mut language: L, config: L::Config) {
     // for now, ony do something with the first filename
 
     let filename = &filenames[0];
@@ -52,7 +57,7 @@ pub fn run_noninteractive<L: ProgrammingLanguageInterface>(filenames: Vec<PathBu
 
     let request = ComputationRequest {
         source: &buffer,
-        config: Default::default(),
+        config,
         debug_requests: HashSet::new(),
     };