diff --git a/schala-lang/language/src/ast/visitor.rs b/schala-lang/language/src/ast/visitor.rs
index 628832a..c1dc9f2 100644
--- a/schala-lang/language/src/ast/visitor.rs
+++ b/schala-lang/language/src/ast/visitor.rs
@@ -8,93 +8,36 @@ use crate::ast::walker;
 
 //TODO default implmentations should call walk methods - then I can test printing
 pub trait ASTVisitor: Sized {
-  fn ast(&mut self, ast: &AST) {
-  }
-
+  fn ast(&mut self, ast: &AST) {}
   fn block(&mut self, statements: &Vec<Statement>) {}
-
   fn statement(&mut self, statement: &Statement) {}
-
-  fn declaration(&mut self, declaration: &Declaration) {
-  }
-
-  fn signature(&mut self, signature: &Signature) {
-  }
-
-  fn type_declaration(&mut self, name: &TypeSingletonName, body: &TypeBody, mutable: bool) {
-  }
-
-  fn type_alias(&mut self, old_name: &Rc<String>, new_name: &Rc<String>) {
-  }
-
-  fn binding(&mut self, name: &Rc<String>, constant: bool, type_anno: Option<&TypeIdentifier>, expr: &Expression) {
-  }
-
-  fn implemention(&mut self, type_name: &TypeIdentifier, interface_name: Option<&TypeSingletonName>, block: &Vec<Declaration>) {
-  }
-
-  fn interface(&mut self, name: &Rc<String>, signatures: &Vec<Signature>) {
-  }
-
-  fn expression(&mut self, expression: &Expression) {
-  }
-
-  fn expression_kind(&mut self, kind: &ExpressionKind) {
-    walker::expression_kind(self, kind);
-  }
-
-  fn maybe_type_identifier(&mut self, type_anno: Option<&TypeIdentifier>) {
-    walker::maybe_type_identifier(self, type_anno);
-  }
-
-  fn named_struct(&mut self, name: &QualifiedName, fields: &Vec<(Rc<String>, Expression)>) {
-    walker::named_struct(self, name, fields);
-  }
-
-  fn call(&mut self, f: &Expression, arguments: &Vec<InvocationArgument>) {
-    walker::call(self, f, arguments);
-  }
-
-  fn index(&mut self, indexee: &Expression, indexers: &Vec<Expression>) {
-    walker::index(self, indexee, indexers);
-  }
-
-  fn if_expression(&mut self, discrim: &Discriminator, body: &IfExpressionBody) {
-  }
-
-  fn while_expression(&mut self, condition: Option<&Expression>, body: &Block) {
-
-  }
-  fn for_expression(&mut self, enumerators: &Vec<Enumerator>, body: &ForBody) {
-
-  }
-
-  fn lambda(&mut self, params: &Vec<FormalParam>, type_anno: Option<&TypeIdentifier>, body: &Block) {
-    walker::lambda(self, params, type_anno, body);
-  }
-
-  fn invocation_argument(&mut self, arg: &InvocationArgument) {
-  }
-
-  fn formal_param(&mut self, param: &FormalParam) {
-    walker::formal_param(self, param);
-  }
-
-  fn type_anno(&mut self, anno: &TypeIdentifier) { }
+  fn declaration(&mut self, declaration: &Declaration) {}
+  fn signature(&mut self, signature: &Signature) {}
+  fn type_declaration(&mut self, name: &TypeSingletonName, body: &TypeBody, mutable: bool) {}
+  fn type_alias(&mut self, old_name: &Rc<String>, new_name: &Rc<String>) {}
+  fn binding(&mut self, name: &Rc<String>, constant: bool, type_anno: Option<&TypeIdentifier>, expr: &Expression) {}
+  fn implemention(&mut self, type_name: &TypeIdentifier, interface_name: Option<&TypeSingletonName>, block: &Vec<Declaration>) {}
+  fn interface(&mut self, name: &Rc<String>, signatures: &Vec<Signature>) {}
+  fn expression(&mut self, expression: &Expression) {}
+  fn expression_kind(&mut self, kind: &ExpressionKind) {}
+  fn type_annotation(&mut self, type_anno: Option<&TypeIdentifier>) {}
+  fn named_struct(&mut self, name: &QualifiedName, fields: &Vec<(Rc<String>, Expression)>) {}
+  fn call(&mut self, f: &Expression, arguments: &Vec<InvocationArgument>) {}
+  fn index(&mut self, indexee: &Expression, indexers: &Vec<Expression>) {}
+  fn if_expression(&mut self, discrim: &Discriminator, body: &IfExpressionBody) {}
+  fn while_expression(&mut self, condition: Option<&Expression>, body: &Block) {}
+  fn for_expression(&mut self, enumerators: &Vec<Enumerator>, body: &ForBody) {}
+  fn lambda(&mut self, params: &Vec<FormalParam>, type_anno: Option<&TypeIdentifier>, body: &Block) {}
+  fn invocation_argument(&mut self, arg: &InvocationArgument) {}
+  fn formal_param(&mut self, param: &FormalParam) {}
   fn import(&mut self, import: &ImportSpecifier) {}
   fn qualified_name(&mut self, name: &QualifiedName) {}
   fn nat_literal(&mut self, n: u64) {}
   fn float_literal(&mut self, f: f64) {}
   fn string_literal(&mut self, s: &Rc<String>) {}
   fn bool_literal(&mut self, b: bool) {}
-  fn binexp(&mut self, op: &BinOp, lhs: &Expression, rhs: &Expression) {
-    walker::expression(self, lhs);
-    walker::expression(self, rhs);
-  }
-
-  fn prefix_exp(&mut self, op: &PrefixOp, arg: &Expression) {
-    walker::expression(self, arg);
-  }
+  fn binexp(&mut self, op: &BinOp, lhs: &Expression, rhs: &Expression) {}
+  fn prefix_exp(&mut self, op: &PrefixOp, arg: &Expression) {}
 }
 
 
diff --git a/schala-lang/language/src/ast/walker.rs b/schala-lang/language/src/ast/walker.rs
index 527736c..7aef9f3 100644
--- a/schala-lang/language/src/ast/walker.rs
+++ b/schala-lang/language/src/ast/walker.rs
@@ -15,7 +15,7 @@ pub fn walk_block<V: ASTVisitor>(v: &mut V, block: &Vec<Statement>) {
   }
 }
 
-pub fn statement<V: ASTVisitor>(v: &mut V, statement: &Statement) {
+fn statement<V: ASTVisitor>(v: &mut V, statement: &Statement) {
   use StatementKind::*;
   match statement.kind {
     Expression(ref expr) => {
@@ -30,7 +30,7 @@ pub fn statement<V: ASTVisitor>(v: &mut V, statement: &Statement) {
   }
 }
 
-pub fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
+fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
   use Declaration::*;
   match decl {
     FuncSig(sig) => {
@@ -46,7 +46,7 @@ pub fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
     TypeAlias(n, a) => v.type_alias(n, a), 
     Binding { name, constant, type_anno, expr } => {
       v.binding(name, *constant, type_anno.as_ref(), expr);
-      maybe_type_identifier(v, type_anno.as_ref());
+      v.type_annotation(type_anno.as_ref());
       expression(v, &expr);
     },
     Impl { type_name, interface_name, block } => {
@@ -56,78 +56,99 @@ pub fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
   }
 }
 
-pub fn signature<V: ASTVisitor>(v: &mut V, signature: &Signature) {
+fn signature<V: ASTVisitor>(v: &mut V, signature: &Signature) {
   for p in signature.params.iter() {
     v.formal_param(p);
   }
-  v.maybe_type_identifier(signature.type_anno.as_ref());
+  v.type_annotation(signature.type_anno.as_ref());
+  for p in signature.params.iter() {
+    formal_param(v, p);
+  }
 }
 
-pub fn expression<V: ASTVisitor>(v: &mut V, expression: &Expression) {
+fn expression<V: ASTVisitor>(v: &mut V, expression: &Expression) {
   v.expression_kind(&expression.kind);
-  v.maybe_type_identifier(expression.type_anno.as_ref());
+  v.type_annotation(expression.type_anno.as_ref());
+  expression_kind(v, &expression.kind);
 }
 
-pub fn maybe_type_identifier<V: ASTVisitor>(v: &mut V, maybe_ty_identifier: Option<&TypeIdentifier>) {
 
-}
-
-pub fn call<V: ASTVisitor>(v: &mut V, f: &Expression, args: &Vec<InvocationArgument>) {
+fn call<V: ASTVisitor>(v: &mut V, f: &Expression, args: &Vec<InvocationArgument>) {
   v.expression(f);
   for arg in args.iter() {
     v.invocation_argument(arg);
   }
 }
 
-pub fn index<V: ASTVisitor>(v: &mut V, indexee: &Expression, indexers: &Vec<Expression>) {
+fn index<V: ASTVisitor>(v: &mut V, indexee: &Expression, indexers: &Vec<Expression>) {
   v.expression(indexee);
   for i in indexers.iter() {
     v.expression(i);
   }
 }
 
-pub fn named_struct<V: ASTVisitor>(v: &mut V, n: &QualifiedName, fields: &Vec<(Rc<String>, Expression)>) {
+fn named_struct<V: ASTVisitor>(v: &mut V, n: &QualifiedName, fields: &Vec<(Rc<String>, Expression)>) {
   v.qualified_name(n);
   for (_, expr) in fields.iter() {
     v.expression(expr);
   }
 }
 
-pub fn lambda<V: ASTVisitor>(v: &mut V, params: &Vec<FormalParam>, type_anno: Option<&TypeIdentifier>, body: &Block) {
+fn lambda<V: ASTVisitor>(v: &mut V, params: &Vec<FormalParam>, type_anno: Option<&TypeIdentifier>, body: &Block) {
   for param in params {
     v.formal_param(param);
   }
-  type_anno.map(|anno| v.type_anno(anno));
+  v.type_annotation(type_anno);
   v.block(body);
+  walk_block(v, body);
 }
 
-pub fn formal_param<V: ASTVisitor>(v: &mut V, param: &FormalParam) {
+fn formal_param<V: ASTVisitor>(v: &mut V, param: &FormalParam) {
   param.default.as_ref().map(|p| v.expression(p));
-  param.anno.as_ref().map(|a| v.type_anno(a));
+  v.type_annotation(param.anno.as_ref());
 }
 
-pub fn expression_kind<V: ASTVisitor>(v: &mut V, expression_kind: &ExpressionKind) {
+fn expression_kind<V: ASTVisitor>(v: &mut V, expression_kind: &ExpressionKind) {
   use ExpressionKind::*;
   match expression_kind {
     NatLiteral(n) => v.nat_literal(*n),
     FloatLiteral(f) => v.float_literal(*f),
     StringLiteral(s) => v.string_literal(s),
     BoolLiteral(b) => v.bool_literal(*b),
-    BinExp(op, lhs, rhs) => v.binexp(op, lhs, rhs),
-    PrefixExp(op, arg) => v.prefix_exp(op, arg),
+    BinExp(op, lhs, rhs) => {
+      v.binexp(op, lhs, rhs);
+      expression(v, lhs);
+      expression(v, rhs);
+    },
+    PrefixExp(op, arg) => {
+      v.prefix_exp(op, arg);
+      expression(v, arg);
+    }
     TupleLiteral(exprs) => {
       for expr in exprs {
         v.expression(expr);
       }
     },
     Value(name) => v.qualified_name(name),
-    NamedStruct { name, fields } => v.named_struct(name, fields),
-    Call { f, arguments } => v.call(f, arguments),
-    Index { indexee, indexers } => v.index(indexee, indexers),
+    NamedStruct { name, fields } => {
+      v.named_struct(name, fields);
+      named_struct(v, name, fields);
+    }
+    Call { f, arguments } => {
+      v.call(f, arguments);
+      call(v, f, arguments);
+    },
+    Index { indexee, indexers } => {
+      v.index(indexee, indexers);
+      index(v, indexee, indexers);
+    },
     IfExpression { discriminator, body } => v.if_expression(discriminator, body),
     WhileExpression { condition, body } => v.while_expression(condition.as_ref().map(|b: &Box<Expression>| Deref::deref(b)), body),
     ForExpression { enumerators, body } => v.for_expression(enumerators, body),
-    Lambda { params , type_anno, body } => v.lambda(params, type_anno.as_ref(), body),
+    Lambda { params , type_anno, body } => {
+      v.lambda(params, type_anno.as_ref(), body);
+      lambda(v, params, type_anno.as_ref(), body);
+    },
     ListLiteral(exprs) => {
       for expr in exprs {
         v.expression(expr);