diff --git a/schala-lang/language/src/ast/walker.rs b/schala-lang/language/src/ast/walker.rs
index 1125b38..e818565 100644
--- a/schala-lang/language/src/ast/walker.rs
+++ b/schala-lang/language/src/ast/walker.rs
@@ -39,12 +39,12 @@ fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
   use Declaration::*;
   match decl {
     FuncSig(sig) => {
-      v.signature(&sig);
-      signature(v, &sig);
+      v.signature(sig);
+      signature(v, sig);
     },
     FuncDecl(sig, block) => {
-      v.signature(&sig);
-      v.block(&block);
+      v.signature(sig);
+      v.block(block);
       walk_block(v, block);
     },
     TypeDecl { name, body, mutable  } => v.type_declaration(name, body, *mutable),
@@ -52,8 +52,8 @@ fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
     Binding { name, constant, type_anno, expr } => {
       v.binding(name, *constant, type_anno.as_ref(), expr);
       v.type_annotation(type_anno.as_ref());
-      v.expression(&expr);
-      expression(v, &expr);
+      v.expression(expr);
+      expression(v, expr);
     },
     Impl { type_name, interface_name, block } => {
       v.implemention(type_name, interface_name.as_ref(), block);
@@ -172,7 +172,7 @@ fn expression_kind<V: ASTVisitor>(v: &mut V, expression_kind: &ExpressionKind) {
     },
     IfExpression { discriminator, body } => {
       v.if_expression(deref_optional_box(discriminator), body);
-      discriminator.as_ref().map(|d| expression(v, d));
+      if let Some(d) = discriminator.as_ref() { expression(v, d) }
       if_expression_body(v, body);
     },
     WhileExpression { condition, body } => v.while_expression(deref_optional_box(condition), body),
@@ -195,13 +195,13 @@ fn if_expression_body<V: ASTVisitor>(v: &mut V, body: &IfExpressionBody) {
   match body {
     SimpleConditional { then_case, else_case } => {
       walk_block(v, then_case);
-      else_case.as_ref().map(|block| walk_block(v, block));
+      if let Some(block) = else_case.as_ref() { walk_block(v, block) }
     },
     SimplePatternMatch { pattern, then_case, else_case } => {
       v.pattern(pattern);
       walk_pattern(v, pattern);
       walk_block(v, then_case);
-      else_case.as_ref().map(|block| walk_block(v, block));
+      if let Some(block) = else_case.as_ref() { walk_block(v, block) }
     },
     CondList(arms) => {
       for arm in arms {
diff --git a/schala-lang/language/src/eval/test.rs b/schala-lang/language/src/eval/test.rs
index 802bea1..41bfa18 100644
--- a/schala-lang/language/src/eval/test.rs
+++ b/schala-lang/language/src/eval/test.rs
@@ -13,15 +13,15 @@ fn evaluate_all_outputs(input: &str) -> Vec<Result<String, String>> {
   let reduced = reduce(&ast, &symbol_table);
 
   let mut state = State::new();
-  let all_output = state.evaluate(reduced, true);
-  all_output
+  
+  state.evaluate(reduced, true)
 }
 
 macro_rules! test_in_fresh_env {
   ($string:expr, $correct:expr) => {
     {
       let all_output = evaluate_all_outputs($string);
-      let ref output = all_output.last().unwrap();
+      let output = &all_output.last().unwrap();
       assert_eq!(**output, Ok($correct.to_string()));
     }
   }
diff --git a/schala-lang/language/src/typechecking.rs b/schala-lang/language/src/typechecking.rs
index 3f8fa49..d743ded 100644
--- a/schala-lang/language/src/typechecking.rs
+++ b/schala-lang/language/src/typechecking.rs
@@ -83,13 +83,13 @@ impl TypeConst {
   pub fn to_string(&self) -> String {
     use self::TypeConst::*;
     match self {
-      Unit => format!("()"),
-      Nat => format!("Nat"),
-      Int => format!("Int"),
-      Float => format!("Float"),
-      StringT => format!("String"),
-      Bool => format!("Bool"),
-      Ordering => format!("Ordering"),
+      Unit => "()".to_string(),
+      Nat => "Nat".to_string(),
+      Int => "Int".to_string(),
+      Float => "Float".to_string(),
+      StringT => "String".to_string(),
+      Bool => "Bool".to_string(),
+      Ordering => "Ordering".to_string(),
     }
   }
 }
@@ -117,7 +117,7 @@ impl Type {
       Const(c) => c.to_string(),
       Var(v) => format!("t_{}", v.0),
       Arrow { params, box ref ret } => {
-        if params.len() == 0 {
+        if params.is_empty() {
           format!("-> {}", ret.to_string())
         } else {
           let mut buf = String::new();
@@ -128,7 +128,7 @@ impl Type {
           buf
         }
       },
-      Compound { .. } => format!("<some compound type>")
+      Compound { .. } => "<some compound type>".to_string()
     }
   }
 
@@ -256,7 +256,7 @@ impl<'a> TypeContext<'a> {
     use self::TypeIdentifier::*;
     Ok(match name {
       Singleton(TypeSingletonName { name,.. }) =>  {
-        match Type::from_string(&name) {
+        match Type::from_string(name) {
           Some(ty) => ty,
           None => return TypeError::new(format!("Unknown type name: {}", name))
         }
@@ -279,7 +279,7 @@ impl<'a> TypeContext<'a> {
   fn statement(&mut self, statement: &Statement) -> InferResult<Type> {
     match &statement.kind {
       StatementKind::Expression(e) => self.expr(e),
-      StatementKind::Declaration(decl) => self.decl(&decl),
+      StatementKind::Declaration(decl) => self.decl(decl),
       StatementKind::Import(_) => Ok(ty!(Unit)),
       StatementKind::Module(_) => Ok(ty!(Unit)),
     }
@@ -361,7 +361,7 @@ impl<'a> TypeContext<'a> {
     use self::IfExpressionBody::*;
     match (discriminator, body) {
       (Some(expr), SimpleConditional{ then_case, else_case }) => self.handle_simple_if(expr, then_case, else_case),
-      _ => TypeError::new(format!("Complex conditionals not supported"))
+      _ => TypeError::new("Complex conditionals not supported".to_string())
     }
   }
 
@@ -410,7 +410,7 @@ impl<'a> TypeContext<'a> {
         t_ret.clone()
       },
       Type::Arrow { .. } => return TypeError::new("Wrong length"),
-      _ => return TypeError::new(format!("Not a function"))
+      _ => return TypeError::new("Not a function".to_string())
     })
   }
 
@@ -438,26 +438,26 @@ impl<'a> TypeContext<'a> {
       (Const(ref c1), Const(ref c2)) if c1 == c2 => Ok(Const(c1.clone())), //choice of c1 is arbitrary I *think*
       (a @ Var(_), b @ Const(_)) => self.unify(b, a),
       (Const(ref c1), Var(ref v2)) => {
-        self.unification_table.unify_var_value(v2.clone(), Some(c1.clone()))
+        self.unification_table.unify_var_value(*v2, Some(c1.clone()))
           .or_else(|_| TypeError::new(format!("Couldn't unify {:?} and {:?}", Const(c1.clone()), Var(*v2))))?;
         Ok(Const(c1.clone()))
       },
       (Var(v1), Var(v2)) => {
         //TODO add occurs check
-        self.unification_table.unify_var_var(v1.clone(), v2.clone())
+        self.unification_table.unify_var_var(v1, v2)
           .or_else(|e| {
             println!("Unify error: {:?}", e);
             TypeError::new(format!("Two type variables {:?} and {:?} couldn't unify", v1, v2))
           })?;
-        Ok(Var(v1.clone())) //arbitrary decision I think
+        Ok(Var(v1)) //arbitrary decision I think
       },
       (a, b) => TypeError::new(format!("{:?} and {:?} do not unify", a, b)),
     }
   }
 
   fn fresh_type_variable(&mut self) -> TypeVar {
-    let new_type_var = self.unification_table.new_key(None);
-    new_type_var
+    
+    self.unification_table.new_key(None)
   }
 }
 
@@ -468,7 +468,7 @@ mod typechecking_tests {
   macro_rules! assert_type_in_fresh_context {
     ($string:expr, $type:expr) => {
       let mut tc = TypeContext::new();
-      let ref ast = crate::util::quick_ast($string);
+      let ast = &crate::util::quick_ast($string);
       let ty = tc.typecheck(ast).unwrap();
       assert_eq!(ty, $type)
     }
diff --git a/schala-lang/language/src/util.rs b/schala-lang/language/src/util.rs
index 855c87a..0543759 100644
--- a/schala-lang/language/src/util.rs
+++ b/schala-lang/language/src/util.rs
@@ -4,7 +4,7 @@ use std::cmp::Eq;
 use std::ops::Deref;
 
 pub fn deref_optional_box<T>(x: &Option<Box<T>>) -> Option<&T> {
-  x.as_ref().map(|b: &Box<T>| Deref::deref(b))
+  x.as_ref().map(Deref::deref)
 }
 
 #[derive(Default, Debug)]