diff --git a/rustfmt.toml b/rustfmt.toml
new file mode 100644
index 0000000..36327c7
--- /dev/null
+++ b/rustfmt.toml
@@ -0,0 +1,7 @@
+
+max_width = 110
+use_small_heuristics = "max"
+imports_indent = "block"
+imports_granularity = "crate"
+group_imports = "stdexternalcrate"
+
diff --git a/schala-lang/language/src/tree_walk_eval/mod.rs b/schala-lang/language/src/tree_walk_eval/mod.rs
index 42cdebe..5923c54 100644
--- a/schala-lang/language/src/tree_walk_eval/mod.rs
+++ b/schala-lang/language/src/tree_walk_eval/mod.rs
@@ -1,12 +1,14 @@
-use crate::reduced_ir::{ReducedIR, Expression, Lookup, Callable, FunctionDefinition, Statement, Literal, Alternative, Pattern};
-use crate::symbol_table::{DefId};
-use crate::util::ScopeStack;
-use crate::builtin::Builtin;
-use crate::typechecking::TypeId;
+use std::{convert::From, fmt::Write, rc::Rc};
 
-use std::fmt::Write;
-use std::rc::Rc;
-use std::convert::From;
+use crate::{
+    builtin::Builtin,
+    reduced_ir::{
+        Alternative, Callable, Expression, FunctionDefinition, Literal, Lookup, Pattern, ReducedIR, Statement,
+    },
+    symbol_table::DefId,
+    typechecking::TypeId,
+    util::ScopeStack,
+};
 
 mod test;
 
@@ -14,14 +16,14 @@ type EvalResult<T> = Result<T, RuntimeError>;
 
 #[derive(Debug)]
 pub struct State<'a> {
-  environments: ScopeStack<'a, Memory, MemoryValue>,
+    environments: ScopeStack<'a, Memory, MemoryValue>,
 }
 
 //TODO - eh, I dunno, maybe it doesn't matter exactly how memory works in the tree-walking
 //evaluator
 #[derive(Debug, PartialEq, Eq, Hash, Clone)]
 enum Memory {
-    Index(u32)
+    Index(u32),
 }
 
 // This is for function param lookups, and is a hack
@@ -39,22 +41,18 @@ impl From<&DefId> for Memory {
 
 #[derive(Debug)]
 struct RuntimeError {
-    msg: String
+    msg: String,
 }
 
 impl From<String> for RuntimeError {
     fn from(msg: String) -> Self {
-        Self {
-            msg
-        }
+        Self { msg }
     }
 }
 
 impl From<&str> for RuntimeError {
     fn from(msg: &str) -> Self {
-        Self {
-            msg: msg.to_string(),
-        }
+        Self { msg: msg.to_string() }
     }
 }
 
@@ -65,17 +63,17 @@ impl RuntimeError {
     }
 }
 
-fn paren_wrapped(terms: impl Iterator<Item=String>) -> String {
-  let mut buf = String::new();
-  write!(buf, "(").unwrap();
-  for term in terms.map(Some).intersperse(None) {
-    match term {
-      Some(e) => write!(buf, "{}", e).unwrap(),
-      None => write!(buf, ", ").unwrap(),
-    };
-  }
-  write!(buf, ")").unwrap();
-  buf
+fn paren_wrapped(terms: impl Iterator<Item = String>) -> String {
+    let mut buf = String::new();
+    write!(buf, "(").unwrap();
+    for term in terms.map(Some).intersperse(None) {
+        match term {
+            Some(e) => write!(buf, "{}", e).unwrap(),
+            None => write!(buf, ", ").unwrap(),
+        };
+    }
+    write!(buf, ")").unwrap();
+    buf
 }
 
 /// Anything that can be stored in memory; that is, a function definition, or a fully-evaluated
@@ -92,7 +90,6 @@ impl From<Primitive> for MemoryValue {
     }
 }
 
-
 impl MemoryValue {
     fn to_repl(&self) -> String {
         match self {
@@ -126,26 +123,23 @@ enum Primitive {
     Tuple(Vec<Primitive>),
     Literal(Literal),
     Callable(Callable),
-    Object {
-        type_id: TypeId,
-        tag: u32,
-        items: Vec<Primitive>
-    },
+    Object { type_id: TypeId, tag: u32, items: Vec<Primitive> },
 }
 
 impl Primitive {
     fn to_repl(&self) -> String {
         match self {
             Primitive::Object { type_id, items, .. } if items.is_empty() => type_id.local_name().to_string(),
-            Primitive::Object { type_id, items, .. } =>
-                format!("{}{}", type_id.local_name(), paren_wrapped(items.iter().map(|item| item.to_repl()))),
+            Primitive::Object { type_id, items, .. } => {
+                format!("{}{}", type_id.local_name(), paren_wrapped(items.iter().map(|item| item.to_repl())))
+            }
             Primitive::Literal(lit) => match lit {
                 Literal::Nat(n) => format!("{}", n),
                 Literal::Int(i) => format!("{}", i),
                 Literal::Float(f) => format!("{}", f),
                 Literal::Bool(b) => format!("{}", b),
                 Literal::StringLit(s) => format!("\"{}\"", s),
-            }
+            },
             Primitive::Tuple(terms) => paren_wrapped(terms.iter().map(|x| x.to_repl())),
             Primitive::Callable(..) => "<some-callable>".to_string(),
         }
@@ -164,9 +158,7 @@ impl From<Literal> for Primitive {
 
 impl<'a> State<'a> {
     pub fn new() -> Self {
-        Self {
-            environments: ScopeStack::new(Some("global".to_string()))
-        }
+        Self { environments: ScopeStack::new(Some("global".to_string())) }
     }
 
     pub fn evaluate(&mut self, reduced: ReducedIR, repl: bool) -> Vec<Result<String, String>> {
@@ -179,9 +171,7 @@ impl<'a> State<'a> {
 
         for statement in reduced.entrypoint.into_iter() {
             match self.statement(statement) {
-                Ok(Some(output)) if repl => {
-                    acc.push(Ok(output.to_repl()))
-                },
+                Ok(Some(output)) if repl => acc.push(Ok(output.to_repl())),
                 Ok(_) => (),
                 Err(error) => {
                     acc.push(Err(error.msg));
@@ -200,11 +190,7 @@ impl<'a> State<'a> {
                 ret = Some(prim);
             }
         }
-        Ok(if let Some(ret) = ret {
-            ret
-        } else {
-            self.expression(Expression::unit())?
-        })
+        Ok(if let Some(ret) = ret { ret } else { self.expression(Expression::unit())? })
     }
 
     fn statement(&mut self, stmt: Statement) -> EvalResult<Option<MemoryValue>> {
@@ -214,7 +200,7 @@ impl<'a> State<'a> {
                 let evaluated = self.expression(expr)?;
                 self.environments.insert(id.into(), evaluated.into());
                 Ok(None)
-            },
+            }
             Statement::Expression(expr) => {
                 let evaluated = self.expression(expr)?;
                 Ok(Some(evaluated.into()))
@@ -222,252 +208,286 @@ impl<'a> State<'a> {
         }
     }
 
-  fn expression(&mut self, expression: Expression) -> EvalResult<Primitive> {
-      Ok(match expression {
-          Expression::Literal(lit) => Primitive::Literal(lit),
-          Expression::Tuple(items) => Primitive::Tuple(items.into_iter().map(|expr| self.expression(expr)).collect::<EvalResult<Vec<Primitive>>>()?),
-          Expression::Lookup(kind) => match kind {
-              Lookup::Function(ref id) => {
-                  let mem = id.into();
-                  match self.environments.lookup(&mem) {
-                      // This just checks that the function exists in "memory" by ID, we don't
-                      // actually retrieve it until `apply_function()`
-                      Some(MemoryValue::Function(_)) => Primitive::Callable(Callable::UserDefined(id.clone())),
-                      x => return Err(format!("Function not found for id: {} : {:?}", id, x).into()),
-                  }
-              },
-              Lookup::Param(n) => {
-                  let mem = n.into();
-                  match self.environments.lookup(&mem) {
-                      Some(MemoryValue::Primitive(prim)) => prim.clone(),
-                      e => return Err(format!("Param lookup error, got {:?}", e).into()),
-                  }
-              },
-              Lookup::LocalVar(ref id) | Lookup::GlobalVar(ref id) => {
-                  let mem = id.into();
-                  match self.environments.lookup(&mem) {
-                      Some(MemoryValue::Primitive(expr)) => expr.clone(),
-                      _ => return Err(format!("Nothing found for local/gloval variable lookup {}", id).into()),
-                  }
-              },
-          },
-          Expression::Assign { ref lval, box rval } => {
-              let mem = lval.into();
-              let evaluated = self.expression(rval)?;
-              self.environments.insert(mem, MemoryValue::Primitive(evaluated));
-              Primitive::unit()
-          },
-          Expression::Call { box f, args } => self.call_expression(f, args)?,
-          Expression::Callable(Callable::DataConstructor { type_id, arity, tag }) if arity == 0 => Primitive::Object {
-              type_id, tag, items: vec![]
-          },
-          Expression::Callable(func) => Primitive::Callable(func),
-          Expression::Conditional { box cond, then_clause, else_clause } => {
-              let cond = self.expression(cond)?;
-              match cond {
-                  Primitive::Literal(Literal::Bool(true)) => self.block(then_clause)?,
-                  Primitive::Literal(Literal::Bool(false)) => self.block(else_clause)?,
-                  v => return Err(format!("Non-boolean value {:?} in if-statement", v).into())
-              }
-          },
-          Expression::CaseMatch { box cond, alternatives } => self.case_match_expression(cond, alternatives)?,
-          Expression::ReductionError(e) => return Err(e.into()),
-      })
-  }
+    fn expression(&mut self, expression: Expression) -> EvalResult<Primitive> {
+        Ok(match expression {
+            Expression::Literal(lit) => Primitive::Literal(lit),
+            Expression::Tuple(items) => Primitive::Tuple(
+                items
+                    .into_iter()
+                    .map(|expr| self.expression(expr))
+                    .collect::<EvalResult<Vec<Primitive>>>()?,
+            ),
+            Expression::Lookup(kind) => match kind {
+                Lookup::Function(ref id) => {
+                    let mem = id.into();
+                    match self.environments.lookup(&mem) {
+                        // This just checks that the function exists in "memory" by ID, we don't
+                        // actually retrieve it until `apply_function()`
+                        Some(MemoryValue::Function(_)) => {
+                            Primitive::Callable(Callable::UserDefined(id.clone()))
+                        }
+                        x => return Err(format!("Function not found for id: {} : {:?}", id, x).into()),
+                    }
+                }
+                Lookup::Param(n) => {
+                    let mem = n.into();
+                    match self.environments.lookup(&mem) {
+                        Some(MemoryValue::Primitive(prim)) => prim.clone(),
+                        e => return Err(format!("Param lookup error, got {:?}", e).into()),
+                    }
+                }
+                Lookup::LocalVar(ref id) | Lookup::GlobalVar(ref id) => {
+                    let mem = id.into();
+                    match self.environments.lookup(&mem) {
+                        Some(MemoryValue::Primitive(expr)) => expr.clone(),
+                        _ => {
+                            return Err(
+                                format!("Nothing found for local/gloval variable lookup {}", id).into()
+                            )
+                        }
+                    }
+                }
+            },
+            Expression::Assign { ref lval, box rval } => {
+                let mem = lval.into();
+                let evaluated = self.expression(rval)?;
+                self.environments.insert(mem, MemoryValue::Primitive(evaluated));
+                Primitive::unit()
+            }
+            Expression::Call { box f, args } => self.call_expression(f, args)?,
+            Expression::Callable(Callable::DataConstructor { type_id, arity, tag }) if arity == 0 => {
+                Primitive::Object { type_id, tag, items: vec![] }
+            }
+            Expression::Callable(func) => Primitive::Callable(func),
+            Expression::Conditional { box cond, then_clause, else_clause } => {
+                let cond = self.expression(cond)?;
+                match cond {
+                    Primitive::Literal(Literal::Bool(true)) => self.block(then_clause)?,
+                    Primitive::Literal(Literal::Bool(false)) => self.block(else_clause)?,
+                    v => return Err(format!("Non-boolean value {:?} in if-statement", v).into()),
+                }
+            }
+            Expression::CaseMatch { box cond, alternatives } => {
+                self.case_match_expression(cond, alternatives)?
+            }
+            Expression::ReductionError(e) => return Err(e.into()),
+        })
+    }
 
-  fn case_match_expression(&mut self, cond: Expression, alternatives: Vec<Alternative>) -> EvalResult<Primitive> {
-      fn matches(scrut: &Primitive, pat: &Pattern, scope: &mut ScopeStack<Memory, MemoryValue>) -> bool {
-          match pat {
-              Pattern::Ignored => true,
-              Pattern::Binding(ref def_id) => {
-                  let mem = def_id.into();
-                  scope.insert(mem, MemoryValue::Primitive(scrut.clone())); //TODO make sure this doesn't cause problems with nesting
-                  true
-              },
-              Pattern::Literal(pat_literal) => if let Primitive::Literal(scrut_literal) = scrut {
-                  pat_literal == scrut_literal
-              } else {
-                  false
-              },
-              Pattern::Tuple { subpatterns, tag } =>  match tag {
-                  None => match scrut {
-                      Primitive::Tuple(items) if items.len() == subpatterns.len() =>
-                          items.iter().zip(subpatterns.iter()).all(|(item, subpat)| matches(item, subpat, scope)),
-                      _ => false //TODO should be a type error
-                  },
-                  Some(pattern_tag) => match scrut {
-                      //TODO should test type_ids for runtime type checking, once those work
-                      Primitive::Object { tag, items, .. } if tag == pattern_tag && items.len() == subpatterns.len() => {
-                          items.iter().zip(subpatterns.iter()).all(|(item, subpat)| matches(item, subpat, scope))
-                      }
-                      _ => false
-                  }
-              }
-          }
-      }
-      let cond = self.expression(cond)?;
+    fn case_match_expression(
+        &mut self,
+        cond: Expression,
+        alternatives: Vec<Alternative>,
+    ) -> EvalResult<Primitive> {
+        fn matches(scrut: &Primitive, pat: &Pattern, scope: &mut ScopeStack<Memory, MemoryValue>) -> bool {
+            match pat {
+                Pattern::Ignored => true,
+                Pattern::Binding(ref def_id) => {
+                    let mem = def_id.into();
+                    scope.insert(mem, MemoryValue::Primitive(scrut.clone())); //TODO make sure this doesn't cause problems with nesting
+                    true
+                }
+                Pattern::Literal(pat_literal) => {
+                    if let Primitive::Literal(scrut_literal) = scrut {
+                        pat_literal == scrut_literal
+                    } else {
+                        false
+                    }
+                }
+                Pattern::Tuple { subpatterns, tag } => match tag {
+                    None => match scrut {
+                        Primitive::Tuple(items) if items.len() == subpatterns.len() => items
+                            .iter()
+                            .zip(subpatterns.iter())
+                            .all(|(item, subpat)| matches(item, subpat, scope)),
+                        _ => false, //TODO should be a type error
+                    },
+                    Some(pattern_tag) => match scrut {
+                        //TODO should test type_ids for runtime type checking, once those work
+                        Primitive::Object { tag, items, .. }
+                            if tag == pattern_tag && items.len() == subpatterns.len() =>
+                        {
+                            items
+                                .iter()
+                                .zip(subpatterns.iter())
+                                .all(|(item, subpat)| matches(item, subpat, scope))
+                        }
+                        _ => false,
+                    },
+                },
+            }
+        }
+        let cond = self.expression(cond)?;
 
-      for alt in alternatives.into_iter() {
-          let mut new_scope = self.environments.new_scope(None);
-          if matches(&cond, &alt.pattern, &mut new_scope) {
-              let mut new_state = State {
-                  environments: new_scope
-              };
+        for alt in alternatives.into_iter() {
+            let mut new_scope = self.environments.new_scope(None);
+            if matches(&cond, &alt.pattern, &mut new_scope) {
+                let mut new_state = State { environments: new_scope };
 
-              return new_state.block(alt.item)
-          }
-      }
-      Err("No valid match in match expression".into())
-  }
+                return new_state.block(alt.item);
+            }
+        }
+        Err("No valid match in match expression".into())
+    }
 
-  fn call_expression(&mut self, f: Expression, args: Vec<Expression>) -> EvalResult<Primitive> {
-      let func = match self.expression(f)? {
-          Primitive::Callable(func) => func,
-          other => return Err(format!("Trying to call non-function value: {:?}", other).into()),
-      };
-      match func {
-          Callable::Builtin(builtin) => self.apply_builtin(builtin, args),
-          Callable::UserDefined(def_id) => {
-              let mem = (&def_id).into();
-              match self.environments.lookup(&mem) {
-                  Some(MemoryValue::Function(FunctionDefinition { body })) => {
-                      let body = body.clone(); //TODO ideally this clone would not happen
-                      self.apply_function(body, args)
-                  },
-                  e => Err(format!("Error looking up function with id {}: {:?}", def_id, e).into())
-              }
-          },
-          Callable::Lambda { arity, body } => {
-              if arity as usize != args.len() {
-                  return Err(format!("Lambda expression requries {} arguments, only {} provided", arity, args.len()).into());
-              }
-              self.apply_function(body, args)
-          }
-          Callable::DataConstructor { type_id, arity, tag } => {
-              if arity as usize != args.len() {
-                  return Err(format!("Constructor expression requries {} arguments, only {} provided", arity, args.len()).into());
-              }
+    fn call_expression(&mut self, f: Expression, args: Vec<Expression>) -> EvalResult<Primitive> {
+        let func = match self.expression(f)? {
+            Primitive::Callable(func) => func,
+            other => return Err(format!("Trying to call non-function value: {:?}", other).into()),
+        };
+        match func {
+            Callable::Builtin(builtin) => self.apply_builtin(builtin, args),
+            Callable::UserDefined(def_id) => {
+                let mem = (&def_id).into();
+                match self.environments.lookup(&mem) {
+                    Some(MemoryValue::Function(FunctionDefinition { body })) => {
+                        let body = body.clone(); //TODO ideally this clone would not happen
+                        self.apply_function(body, args)
+                    }
+                    e => Err(format!("Error looking up function with id {}: {:?}", def_id, e).into()),
+                }
+            }
+            Callable::Lambda { arity, body } => {
+                if arity as usize != args.len() {
+                    return Err(format!(
+                        "Lambda expression requries {} arguments, only {} provided",
+                        arity,
+                        args.len()
+                    )
+                    .into());
+                }
+                self.apply_function(body, args)
+            }
+            Callable::DataConstructor { type_id, arity, tag } => {
+                if arity as usize != args.len() {
+                    return Err(format!(
+                        "Constructor expression requries {} arguments, only {} provided",
+                        arity,
+                        args.len()
+                    )
+                    .into());
+                }
 
-              let mut evaluated_args: Vec<Primitive> = vec![];
-              for arg in args.into_iter() {
-                  evaluated_args.push(self.expression(arg)?);
-              }
-              Ok(Primitive::Object {
-                  type_id,
-                  tag,
-                  items: evaluated_args
-              })
-          }
-          Callable::RecordConstructor { type_id: _, tag: _ } => {
-              unimplemented!()
-          }
-      }
-  }
+                let mut evaluated_args: Vec<Primitive> = vec![];
+                for arg in args.into_iter() {
+                    evaluated_args.push(self.expression(arg)?);
+                }
+                Ok(Primitive::Object { type_id, tag, items: evaluated_args })
+            }
+            Callable::RecordConstructor { type_id: _, tag: _ } => {
+                unimplemented!()
+            }
+        }
+    }
 
-  fn apply_builtin(&mut self, builtin: Builtin, args: Vec<Expression>) -> EvalResult<Primitive> {
-      use Builtin::*;
-      use Literal::*;
-      use Primitive::Literal as Lit;
+    fn apply_builtin(&mut self, builtin: Builtin, args: Vec<Expression>) -> EvalResult<Primitive> {
+        use Builtin::*;
+        use Literal::*;
+        use Primitive::Literal as Lit;
 
-      let evaled_args: EvalResult<Vec<Primitive>> =
-          args.into_iter().map(|arg| self.expression(arg)).collect();
-      let evaled_args = evaled_args?;
+        let evaled_args: EvalResult<Vec<Primitive>> =
+            args.into_iter().map(|arg| self.expression(arg)).collect();
+        let evaled_args = evaled_args?;
 
-      Ok(match (builtin, evaled_args.as_slice()) {
-          (FieldAccess, /*&[Node::PrimObject { .. }]*/ _) => {
-              return Err("Field access unimplemented".into());
-          }
-          /* builtin functions */
-          (IOPrint, &[ref anything]) => {
-              print!("{}", anything.to_repl());
-              Primitive::Tuple(vec![])
-          },
-          (IOPrintLn, &[ref anything]) => {
-              print!("{}", anything.to_repl());
-              Primitive::Tuple(vec![])
-          },
-          (IOGetLine, &[]) => {
-              let mut buf = String::new();
-              std::io::stdin().read_line(&mut buf).expect("Error readling line in 'getline'");
-              StringLit(Rc::new(buf.trim().to_string())).into()
-          },
-          /* Binops */
-          (binop, &[ref lhs, ref rhs]) => match (binop, lhs, rhs) {
-              // TODO need a better way of handling these literals
-              (Add, Lit(Nat(l)), Lit(Nat(r))) => Nat(l + r).into(),
-              (Add, Lit(Int(l)), Lit(Int(r))) => Int(l + r).into(),
-              (Add, Lit(Nat(l)), Lit(Int(r))) => Int((*l as i64) + (*r as i64)).into(),
-              (Add, Lit(Int(l)), Lit(Nat(r))) => Int((*l as i64) + (*r as i64)).into(),
-              (Concatenate, Lit(StringLit(ref s1)), Lit(StringLit(ref s2))) => StringLit(Rc::new(format!("{}{}", s1, s2))).into(),
-              (Subtract, Lit(Nat(l)), Lit(Nat(r))) => Nat(l - r).into(),
-              (Multiply, Lit(Nat(l)), Lit(Nat(r))) => Nat(l * r).into(),
-              (Divide, Lit(Nat(l)), Lit(Nat(r))) => Float((*l as f64)/ (*r as f64)).into(),
-              (Quotient, Lit(Nat(l)), Lit(Nat(r))) => if *r == 0 {
-                  return Err("Divide-by-zero error".into());
-              } else {
-                  Nat(l / r).into()
-              },
-              (Modulo, Lit(Nat(l)), Lit(Nat(r))) => Nat(l % r).into(),
-              (Exponentiation, Lit(Nat(l)), Lit(Nat(r))) => Nat(l ^ r).into(),
-              (BitwiseAnd, Lit(Nat(l)), Lit(Nat(r))) => Nat(l & r).into(),
-              (BitwiseOr, Lit(Nat(l)), Lit(Nat(r))) => Nat(l | r).into(),
+        Ok(match (builtin, evaled_args.as_slice()) {
+            (FieldAccess, /*&[Node::PrimObject { .. }]*/ _) => {
+                return Err("Field access unimplemented".into());
+            }
+            /* builtin functions */
+            (IOPrint, &[ref anything]) => {
+                print!("{}", anything.to_repl());
+                Primitive::Tuple(vec![])
+            }
+            (IOPrintLn, &[ref anything]) => {
+                print!("{}", anything.to_repl());
+                Primitive::Tuple(vec![])
+            }
+            (IOGetLine, &[]) => {
+                let mut buf = String::new();
+                std::io::stdin().read_line(&mut buf).expect("Error readling line in 'getline'");
+                StringLit(Rc::new(buf.trim().to_string())).into()
+            }
+            /* Binops */
+            (binop, &[ref lhs, ref rhs]) => match (binop, lhs, rhs) {
+                // TODO need a better way of handling these literals
+                (Add, Lit(Nat(l)), Lit(Nat(r))) => Nat(l + r).into(),
+                (Add, Lit(Int(l)), Lit(Int(r))) => Int(l + r).into(),
+                (Add, Lit(Nat(l)), Lit(Int(r))) => Int((*l as i64) + (*r as i64)).into(),
+                (Add, Lit(Int(l)), Lit(Nat(r))) => Int((*l as i64) + (*r as i64)).into(),
+                (Concatenate, Lit(StringLit(ref s1)), Lit(StringLit(ref s2))) => {
+                    StringLit(Rc::new(format!("{}{}", s1, s2))).into()
+                }
+                (Subtract, Lit(Nat(l)), Lit(Nat(r))) => Nat(l - r).into(),
+                (Multiply, Lit(Nat(l)), Lit(Nat(r))) => Nat(l * r).into(),
+                (Divide, Lit(Nat(l)), Lit(Nat(r))) => Float((*l as f64) / (*r as f64)).into(),
+                (Quotient, Lit(Nat(l)), Lit(Nat(r))) => {
+                    if *r == 0 {
+                        return Err("Divide-by-zero error".into());
+                    } else {
+                        Nat(l / r).into()
+                    }
+                }
+                (Modulo, Lit(Nat(l)), Lit(Nat(r))) => Nat(l % r).into(),
+                (Exponentiation, Lit(Nat(l)), Lit(Nat(r))) => Nat(l ^ r).into(),
+                (BitwiseAnd, Lit(Nat(l)), Lit(Nat(r))) => Nat(l & r).into(),
+                (BitwiseOr, Lit(Nat(l)), Lit(Nat(r))) => Nat(l | r).into(),
 
-              /* comparisons */
-              (Equality, Lit(Nat(l)), Lit(Nat(r))) => Bool(l == r).into(),
-              (Equality, Lit(Int(l)), Lit(Int(r))) => Bool(l == r).into(),
-              (Equality, Lit(Float(l)), Lit(Float(r))) => Bool(l == r).into(),
-              (Equality, Lit(Bool(l)), Lit(Bool(r))) => Bool(l == r).into(),
-              (Equality, Lit(StringLit(ref l)), Lit(StringLit(ref r))) => Bool(l == r).into(),
+                /* comparisons */
+                (Equality, Lit(Nat(l)), Lit(Nat(r))) => Bool(l == r).into(),
+                (Equality, Lit(Int(l)), Lit(Int(r))) => Bool(l == r).into(),
+                (Equality, Lit(Float(l)), Lit(Float(r))) => Bool(l == r).into(),
+                (Equality, Lit(Bool(l)), Lit(Bool(r))) => Bool(l == r).into(),
+                (Equality, Lit(StringLit(ref l)), Lit(StringLit(ref r))) => Bool(l == r).into(),
 
-              (LessThan, Lit(Nat(l)), Lit(Nat(r))) => Bool(l < r).into(),
-              (LessThan, Lit(Int(l)), Lit(Int(r))) => Bool(l < r).into(),
-              (LessThan, Lit(Float(l)), Lit(Float(r))) => Bool(l < r).into(),
+                (LessThan, Lit(Nat(l)), Lit(Nat(r))) => Bool(l < r).into(),
+                (LessThan, Lit(Int(l)), Lit(Int(r))) => Bool(l < r).into(),
+                (LessThan, Lit(Float(l)), Lit(Float(r))) => Bool(l < r).into(),
 
-              (LessThanOrEqual, Lit(Nat(l)), Lit(Nat(r))) => Bool(l <= r).into(),
-              (LessThanOrEqual, Lit(Int(l)), Lit(Int(r))) => Bool(l <= r).into(),
-              (LessThanOrEqual, Lit(Float(l)), Lit(Float(r))) => Bool(l <= r).into(),
+                (LessThanOrEqual, Lit(Nat(l)), Lit(Nat(r))) => Bool(l <= r).into(),
+                (LessThanOrEqual, Lit(Int(l)), Lit(Int(r))) => Bool(l <= r).into(),
+                (LessThanOrEqual, Lit(Float(l)), Lit(Float(r))) => Bool(l <= r).into(),
 
-              (GreaterThan, Lit(Nat(l)), Lit(Nat(r))) => Bool(l > r).into(),
-              (GreaterThan, Lit(Int(l)), Lit(Int(r))) => Bool(l > r).into(),
-              (GreaterThan, Lit(Float(l)), Lit(Float(r))) => Bool(l > r).into(),
+                (GreaterThan, Lit(Nat(l)), Lit(Nat(r))) => Bool(l > r).into(),
+                (GreaterThan, Lit(Int(l)), Lit(Int(r))) => Bool(l > r).into(),
+                (GreaterThan, Lit(Float(l)), Lit(Float(r))) => Bool(l > r).into(),
 
-              (GreaterThanOrEqual, Lit(Nat(l)), Lit(Nat(r))) => Bool(l >= r).into(),
-              (GreaterThanOrEqual, Lit(Int(l)), Lit(Int(r))) => Bool(l >= r).into(),
-              (GreaterThanOrEqual, Lit(Float(l)), Lit(Float(r))) => Bool(l >= r).into(),
+                (GreaterThanOrEqual, Lit(Nat(l)), Lit(Nat(r))) => Bool(l >= r).into(),
+                (GreaterThanOrEqual, Lit(Int(l)), Lit(Int(r))) => Bool(l >= r).into(),
+                (GreaterThanOrEqual, Lit(Float(l)), Lit(Float(r))) => Bool(l >= r).into(),
 
-              (binop, lhs, rhs) => return Err(format!("Invalid binop expression {:?} {:?} {:?}", lhs, binop, rhs).into()),
-          },
-          (prefix, &[ref arg]) => match (prefix, arg) {
-              (BooleanNot, Lit(Bool(true))) => Bool(false),
-              (BooleanNot, Lit(Bool(false))) => Bool(true),
-              (Negate, Lit(Nat(n))) => Int(-(*n as i64)),
-              (Negate, Lit(Int(n))) => Int(-(*n as i64)),
-              (Negate, Lit(Float(f))) => Float(-(*f as f64)),
-              (Increment, Lit(Int(n))) => Int(*n),
-              (Increment, Lit(Nat(n))) => Nat(*n),
-              _ => return Err("No valid prefix op".into())
-          }.into(),
-          (x, args) => return Err(format!("bad or unimplemented builtin {:?} | {:?}", x, args).into()),
-      })
-  }
+                (binop, lhs, rhs) => {
+                    return Err(format!("Invalid binop expression {:?} {:?} {:?}", lhs, binop, rhs).into())
+                }
+            },
+            (prefix, &[ref arg]) => match (prefix, arg) {
+                (BooleanNot, Lit(Bool(true))) => Bool(false),
+                (BooleanNot, Lit(Bool(false))) => Bool(true),
+                (Negate, Lit(Nat(n))) => Int(-(*n as i64)),
+                (Negate, Lit(Int(n))) => Int(-(*n as i64)),
+                (Negate, Lit(Float(f))) => Float(-(*f as f64)),
+                (Increment, Lit(Int(n))) => Int(*n),
+                (Increment, Lit(Nat(n))) => Nat(*n),
+                _ => return Err("No valid prefix op".into()),
+            }
+            .into(),
+            (x, args) => return Err(format!("bad or unimplemented builtin {:?} | {:?}", x, args).into()),
+        })
+    }
 
-  fn apply_function(&mut self, body: Vec<Statement>, args: Vec<Expression>) -> EvalResult<Primitive> {
-      let mut evaluated_args: Vec<Primitive> = vec![];
-      for arg in args.into_iter() {
-          evaluated_args.push(self.expression(arg)?);
-      }
+    fn apply_function(&mut self, body: Vec<Statement>, args: Vec<Expression>) -> EvalResult<Primitive> {
+        let mut evaluated_args: Vec<Primitive> = vec![];
+        for arg in args.into_iter() {
+            evaluated_args.push(self.expression(arg)?);
+        }
 
-      let mut frame_state = State {
-          environments: self.environments.new_scope(None)
-      };
+        let mut frame_state = State { environments: self.environments.new_scope(None) };
 
-      for (n, evaled) in evaluated_args.into_iter().enumerate() {
-          let n = n as u8;
-          let mem = n.into();
-          frame_state.environments.insert(mem, MemoryValue::Primitive(evaled));
-      }
+        for (n, evaled) in evaluated_args.into_iter().enumerate() {
+            let n = n as u8;
+            let mem = n.into();
+            frame_state.environments.insert(mem, MemoryValue::Primitive(evaled));
+        }
 
-      frame_state.block(body)
-  }
+        frame_state.block(body)
+    }
 }
-
diff --git a/schala-lang/language/src/tree_walk_eval/test.rs b/schala-lang/language/src/tree_walk_eval/test.rs
index 3a434b6..2fe2912 100644
--- a/schala-lang/language/src/tree_walk_eval/test.rs
+++ b/schala-lang/language/src/tree_walk_eval/test.rs
@@ -1,20 +1,19 @@
 #![cfg(test)]
 use test_case::test_case;
 
-use crate::symbol_table::SymbolTable;
-use crate::tree_walk_eval::State;
+use crate::{symbol_table::SymbolTable, tree_walk_eval::State};
 
 fn evaluate_input(input: &str) -> Result<String, String> {
-  let ast = crate::util::quick_ast(input);
-  let mut symbol_table = SymbolTable::new();
-  symbol_table.process_ast(&ast).unwrap();
-  let reduced_ir = crate::reduced_ir::reduce(&ast, &symbol_table);
-  reduced_ir.debug(&symbol_table);
-  println!("========");
-  symbol_table.debug();
-  let mut state = State::new();
-  let mut outputs = state.evaluate(reduced_ir, true);
-  outputs.pop().unwrap()
+    let ast = crate::util::quick_ast(input);
+    let mut symbol_table = SymbolTable::new();
+    symbol_table.process_ast(&ast).unwrap();
+    let reduced_ir = crate::reduced_ir::reduce(&ast, &symbol_table);
+    reduced_ir.debug(&symbol_table);
+    println!("========");
+    symbol_table.debug();
+    let mut state = State::new();
+    let mut outputs = state.evaluate(reduced_ir, true);
+    outputs.pop().unwrap()
 }
 
 fn eval_assert(input: &str, expected: &str) {
@@ -23,26 +22,26 @@ fn eval_assert(input: &str, expected: &str) {
 
 #[test]
 fn test_basic_eval() {
-  eval_assert("1 + 2", "3");
-  eval_assert("let mut a = 1; a = 2", "()");
-  eval_assert("let mut a = 1; a = a + 2; a", "3");
+    eval_assert("1 + 2", "3");
+    eval_assert("let mut a = 1; a = 2", "()");
+    eval_assert("let mut a = 1; a = a + 2; a", "3");
 }
 
 #[test]
 fn op_eval() {
-  eval_assert("- 13", "-13");
-  eval_assert("10 - 2", "8");
+    eval_assert("- 13", "-13");
+    eval_assert("10 - 2", "8");
 }
 
 #[test]
 fn function_eval() {
-  eval_assert("fn oi(x) { x + 1 }; oi(4)", "5");
-  eval_assert("fn oi(x) { x + 1 }; oi(1+2)", "4");
+    eval_assert("fn oi(x) { x + 1 }; oi(4)", "5");
+    eval_assert("fn oi(x) { x + 1 }; oi(1+2)", "4");
 }
 
 #[test]
 fn scopes() {
-  let scope_ok = r#"
+    let scope_ok = r#"
     let a = 20
     fn haha() {
       let something = 38
@@ -79,7 +78,7 @@ let b = Option::Some(10)
 
 #[test]
 fn basic_if_statement() {
-  let source = r#"
+    let source = r#"
     let a = 10
     let b = 10
     if a == b then { 69 } else { 420 }
@@ -89,7 +88,7 @@ fn basic_if_statement() {
 
 #[test]
 fn basic_patterns_1() {
-    let source =r#"
+    let source = r#"
 let x = 10
 let a = if x is 10 then { 255 } else { 256 }
 let b = if 23 is 99 then { 255 } else { 256 }
@@ -106,14 +105,16 @@ let d = if "xxx" is "yyy" then { 20 } else { 30 }
 #[test_case("cyrus", "4")]
 fn basic_patterns_2(input: &str, expected: &str) {
     let mut source = format!(r#"let x = "{}""#, input);
-    source.push_str(r#"
+    source.push_str(
+        r#"
 if x {
     is "sanchez" then 1
     is "mouri" then 2
     is "hella" then 3
     is _ then 4
 }
-"#);
+"#,
+    );
     eval_assert(&source, expected);
 }
 
@@ -121,31 +122,33 @@ if x {
 #[test_case(r#"(99, "panda", false, -2.45)"#, r#""maybe""#)]
 fn tuple_patterns(input: &str, expected: &str) {
     let mut source = format!("let x = {}", input);
-    source.push_str(r#"
+    source.push_str(
+        r#"
 if x {
     is (45, "pablo", _, 28.4) then "no"
     is (_, "panda", _, 2.2) then "yes"
     is _ then "maybe"
-}"#);
+}"#,
+    );
 
     eval_assert(&source, expected);
 }
 
 #[test]
 fn if_is_patterns() {
-  let source = r#"
+    let source = r#"
 type Option<T> = Some(T) | None
 let q = "a string"
 let x = Option::Some(9); if x is Option::Some(q) then { q } else { 0 }"#;
 
-  eval_assert(source, "9");
+    eval_assert(source, "9");
 
-  let source = r#"
+    let source = r#"
 type Option<T> = Some(T) | None
 let q = "a string"
 let outer = 2
 let x = Option::None; if x is Option::Some(q) then { q } else { -2 + outer }"#;
-  eval_assert(source, "0");
+    eval_assert(source, "0");
 }
 
 #[test]
@@ -189,7 +192,7 @@ if a { is "foo" then "x", is _ then "y" }
 
 #[test]
 fn boolean_pattern() {
-  let source = r#"
+    let source = r#"
 let a = true
 if a {
   is true then "x",
@@ -201,7 +204,7 @@ if a {
 
 #[test]
 fn boolean_pattern_2() {
-  let source = r#"
+    let source = r#"
 let a = false
 if a { is true then "x", is false then "y" }
 "#;
@@ -210,7 +213,7 @@ if a { is true then "x", is false then "y" }
 
 #[test]
 fn ignore_pattern() {
-  let source = r#"
+    let source = r#"
 type Option<T> = Some(T) | None
 if Option::Some(10) {
   is _ then "hella"
@@ -221,7 +224,7 @@ if Option::Some(10) {
 
 #[test]
 fn tuple_pattern() {
-  let source = r#"
+    let source = r#"
 if (1, 2) {
   is (1, x) then x,
   is _ then 99
@@ -230,10 +233,9 @@ if (1, 2) {
     eval_assert(source, "2");
 }
 
-
 #[test]
 fn tuple_pattern_2() {
-  let source = r#"
+    let source = r#"
 if (1, 2) {
   is (10, x) then x,
   is (y, x) then x + y
@@ -244,7 +246,7 @@ if (1, 2) {
 
 #[test]
 fn tuple_pattern_3() {
-  let source = r#"
+    let source = r#"
 if (1, 5) {
   is (10, x) then x,
   is (1, x) then x
@@ -255,7 +257,7 @@ if (1, 5) {
 
 #[test]
 fn tuple_pattern_4() {
-  let source = r#"
+    let source = r#"
 if (1, 5) {
   is (10, x) then x,
   is (1, x) then x,
@@ -264,10 +266,9 @@ if (1, 5) {
     eval_assert(source, "5");
 }
 
-
 #[test]
-fn  prim_obj_pattern() {
-  let source = r#"
+fn prim_obj_pattern() {
+    let source = r#"
 type Stuff = Mulch(Nat) | Jugs(Nat, String) | Mardok
 let a = Stuff::Mulch(20)
 let b = Stuff::Jugs(1, "haha")
@@ -305,26 +306,26 @@ let y = \(m, n, o) { m + n + o }(1,2,3)
 (x, y)
 "#;
 
-eval_assert(source, r"(10, 6)");
+    eval_assert(source, r"(10, 6)");
 }
 
 #[test]
 fn basic_lambda_evaluation_2() {
-  let source = r#"
+    let source = r#"
 fn milta() {
   \(x) { x + 33 }
 }
 milta()(10)
   "#;
 
-  eval_assert(source, "43");
-  }
+    eval_assert(source, "43");
+}
 
 #[test]
 fn import_all() {
-  let source = r#"
+    let source = r#"
 type Option<T> = Some(T) | None
 import Option::*
 let x = Some(9); if x is Some(q) then { q } else { 0 }"#;
-  eval_assert(source, "9");
+    eval_assert(source, "9");
 }