diff --git a/dust-lang/src/abstract_tree/as.rs b/dust-lang/src/abstract_tree/as.rs
index 99c47b4..8742acd 100644
--- a/dust-lang/src/abstract_tree/as.rs
+++ b/dust-lang/src/abstract_tree/as.rs
@@ -30,12 +30,13 @@ impl As {
 }
 
 impl AbstractNode for As {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
-        self.expression.define_types(_context)
-    }
-
-    fn validate(&self, _context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
-        self.expression.validate(_context, _manage_memory)?;
+    fn define_and_validate(
+        &self,
+        _context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
+        self.expression
+            .define_and_validate(_context, _manage_memory)?;
 
         match self.constructor {
             TypeConstructor::Raw(_) => {}
diff --git a/dust-lang/src/abstract_tree/assignment.rs b/dust-lang/src/abstract_tree/assignment.rs
index f4199a1..e20452f 100644
--- a/dust-lang/src/abstract_tree/assignment.rs
+++ b/dust-lang/src/abstract_tree/assignment.rs
@@ -43,9 +43,11 @@ impl Assignment {
 }
 
 impl AbstractNode for Assignment {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
-        self.statement.define_types(context)?;
-
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         if let Some(constructor) = &self.constructor {
             let r#type = constructor.construct(&context)?;
 
@@ -58,11 +60,7 @@ impl AbstractNode for Assignment {
             ));
         };
 
-        Ok(())
-    }
-
-    fn validate(&self, context: &Context, manage_memory: bool) -> Result<(), ValidationError> {
-        self.statement.validate(context, manage_memory)?;
+        self.statement.define_and_validate(context, manage_memory)?;
 
         let statement_type = self.statement.expected_type(context)?;
 
diff --git a/dust-lang/src/abstract_tree/async_block.rs b/dust-lang/src/abstract_tree/async_block.rs
index 9d219cb..4851820 100644
--- a/dust-lang/src/abstract_tree/async_block.rs
+++ b/dust-lang/src/abstract_tree/async_block.rs
@@ -25,17 +25,13 @@ impl AsyncBlock {
 }
 
 impl AbstractNode for AsyncBlock {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        _context: &Context,
+        manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         for statement in &self.statements {
-            statement.define_types(_context)?;
-        }
-
-        Ok(())
-    }
-
-    fn validate(&self, _context: &Context, manage_memory: bool) -> Result<(), ValidationError> {
-        for statement in &self.statements {
-            statement.validate(_context, manage_memory)?;
+            statement.define_and_validate(_context, manage_memory)?;
         }
 
         Ok(())
diff --git a/dust-lang/src/abstract_tree/block.rs b/dust-lang/src/abstract_tree/block.rs
index 2ca57a3..7ae11f3 100644
--- a/dust-lang/src/abstract_tree/block.rs
+++ b/dust-lang/src/abstract_tree/block.rs
@@ -29,17 +29,13 @@ impl Block {
 }
 
 impl AbstractNode for Block {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        _context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         for statement in &self.statements {
-            statement.define_types(_context)?;
-        }
-
-        Ok(())
-    }
-
-    fn validate(&self, _context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
-        for statement in &self.statements {
-            statement.validate(_context, _manage_memory)?;
+            statement.define_and_validate(_context, _manage_memory)?;
         }
 
         Ok(())
diff --git a/dust-lang/src/abstract_tree/enum_declaration.rs b/dust-lang/src/abstract_tree/enum_declaration.rs
index 460f8ae..1c367bf 100644
--- a/dust-lang/src/abstract_tree/enum_declaration.rs
+++ b/dust-lang/src/abstract_tree/enum_declaration.rs
@@ -32,7 +32,7 @@ impl EnumDeclaration {
 }
 
 impl AbstractNode for EnumDeclaration {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(&self, context: &Context, _: bool) -> Result<(), ValidationError> {
         let EnumDeclaration {
             name,
             type_parameters,
@@ -79,10 +79,6 @@ impl AbstractNode for EnumDeclaration {
         Ok(())
     }
 
-    fn validate(&self, _: &Context, _: bool) -> Result<(), ValidationError> {
-        Ok(())
-    }
-
     fn evaluate(self, _: &Context, _: bool) -> Result<Option<Evaluation>, RuntimeError> {
         Ok(None)
     }
diff --git a/dust-lang/src/abstract_tree/expression.rs b/dust-lang/src/abstract_tree/expression.rs
index d0ea068..b1d8c55 100644
--- a/dust-lang/src/abstract_tree/expression.rs
+++ b/dust-lang/src/abstract_tree/expression.rs
@@ -41,25 +41,16 @@ impl Expression {
 }
 
 impl AbstractNode for Expression {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         match self {
-            Expression::As(inner) => inner.node.define_types(_context),
-            Expression::FunctionCall(inner) => inner.node.define_types(_context),
-            Expression::Identifier(_) => Ok(()),
-            Expression::MapIndex(inner) => inner.node.define_types(_context),
-            Expression::ListIndex(inner) => inner.node.define_types(_context),
-            Expression::Logic(inner) => inner.node.define_types(_context),
-            Expression::Math(inner) => inner.node.define_types(_context),
-            Expression::Value(inner) => inner.node.define_types(_context),
-        }
-    }
-
-    fn validate(&self, context: &Context, manage_memory: bool) -> Result<(), ValidationError> {
-        match self {
-            Expression::As(r#as) => r#as.node.validate(context, manage_memory),
-            Expression::FunctionCall(function_call) => {
-                function_call.node.validate(context, manage_memory)
-            }
+            Expression::As(r#as) => r#as.node.define_and_validate(context, manage_memory),
+            Expression::FunctionCall(function_call) => function_call
+                .node
+                .define_and_validate(context, manage_memory),
             Expression::Identifier(identifier) => {
                 let found = context.add_expected_use(&identifier.node)?;
 
@@ -72,11 +63,17 @@ impl AbstractNode for Expression {
                     })
                 }
             }
-            Expression::MapIndex(map_index) => map_index.node.validate(context, manage_memory),
-            Expression::ListIndex(list_index) => list_index.node.validate(context, manage_memory),
-            Expression::Logic(logic) => logic.node.validate(context, manage_memory),
-            Expression::Math(math) => math.node.validate(context, manage_memory),
-            Expression::Value(value_node) => value_node.node.validate(context, manage_memory),
+            Expression::MapIndex(map_index) => {
+                map_index.node.define_and_validate(context, manage_memory)
+            }
+            Expression::ListIndex(list_index) => {
+                list_index.node.define_and_validate(context, manage_memory)
+            }
+            Expression::Logic(logic) => logic.node.define_and_validate(context, manage_memory),
+            Expression::Math(math) => math.node.define_and_validate(context, manage_memory),
+            Expression::Value(value_node) => {
+                value_node.node.define_and_validate(context, manage_memory)
+            }
         }
     }
 
diff --git a/dust-lang/src/abstract_tree/function_call.rs b/dust-lang/src/abstract_tree/function_call.rs
index 999c9bd..7da0b10 100644
--- a/dust-lang/src/abstract_tree/function_call.rs
+++ b/dust-lang/src/abstract_tree/function_call.rs
@@ -39,31 +39,18 @@ impl FunctionCall {
 }
 
 impl AbstractNode for FunctionCall {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
-        self.function_expression.define_types(context)?;
-
-        if let Some(expressions) = &self.value_arguments {
-            for expression in expressions {
-                expression.define_types(context)?;
-            }
-        }
-
-        self.context.set_parent(context.clone())?;
-
-        Ok(())
-    }
-
-    fn validate(
+    fn define_and_validate(
         &self,
         outer_context: &Context,
         manage_memory: bool,
     ) -> Result<(), ValidationError> {
+        self.context.set_parent(outer_context.clone())?;
         self.function_expression
-            .validate(outer_context, manage_memory)?;
+            .define_and_validate(outer_context, manage_memory)?;
 
         if let Some(value_arguments) = &self.value_arguments {
             for expression in value_arguments {
-                expression.validate(outer_context, manage_memory)?;
+                expression.define_and_validate(outer_context, manage_memory)?;
             }
         }
 
diff --git a/dust-lang/src/abstract_tree/if_else.rs b/dust-lang/src/abstract_tree/if_else.rs
index a75cad8..4886b5d 100644
--- a/dust-lang/src/abstract_tree/if_else.rs
+++ b/dust-lang/src/abstract_tree/if_else.rs
@@ -35,27 +35,16 @@ impl IfElse {
 }
 
 impl AbstractNode for IfElse {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
-        self.if_expression.define_types(_context)?;
-        self.if_block.node.define_types(_context)?;
-
-        if let Some(else_ifs) = &self.else_ifs {
-            for (expression, block) in else_ifs {
-                expression.define_types(_context)?;
-                block.node.define_types(_context)?;
-            }
-        }
-
-        if let Some(else_block) = &self.else_block {
-            else_block.node.define_types(_context)?;
-        }
-
-        Ok(())
-    }
-
-    fn validate(&self, context: &Context, manage_memory: bool) -> Result<(), ValidationError> {
-        self.if_expression.validate(context, manage_memory)?;
-        self.if_block.node.validate(context, manage_memory)?;
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        manage_memory: bool,
+    ) -> Result<(), ValidationError> {
+        self.if_expression
+            .define_and_validate(context, manage_memory)?;
+        self.if_block
+            .node
+            .define_and_validate(context, manage_memory)?;
 
         let if_expression_type = if let Some(r#type) = self.if_expression.expected_type(context)? {
             r#type
@@ -71,7 +60,7 @@ impl AbstractNode for IfElse {
                 let expression_type = expression.expected_type(context)?;
 
                 if let Some(Type::Boolean) = expression_type {
-                    block.node.validate(context, manage_memory)?;
+                    block.node.define_and_validate(context, manage_memory)?;
 
                     let else_if_block_type = block.node.expected_type(context)?;
 
@@ -94,7 +83,7 @@ impl AbstractNode for IfElse {
         }
 
         if let Some(block) = &self.else_block {
-            block.node.validate(context, manage_memory)?;
+            block.node.define_and_validate(context, manage_memory)?;
 
             let else_if_block_type = block.node.expected_type(context)?;
 
diff --git a/dust-lang/src/abstract_tree/list_index.rs b/dust-lang/src/abstract_tree/list_index.rs
index 92e463a..03fb612 100644
--- a/dust-lang/src/abstract_tree/list_index.rs
+++ b/dust-lang/src/abstract_tree/list_index.rs
@@ -25,14 +25,14 @@ impl ListIndex {
 }
 
 impl AbstractNode for ListIndex {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
-        self.collection.define_types(context)?;
-        self.index.define_types(context)
-    }
-
-    fn validate(&self, context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
-        self.collection.validate(context, _manage_memory)?;
-        self.index.validate(context, _manage_memory)?;
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
+        self.collection
+            .define_and_validate(context, _manage_memory)?;
+        self.index.define_and_validate(context, _manage_memory)?;
 
         let collection_type = if let Some(r#type) = self.collection.expected_type(context)? {
             r#type
diff --git a/dust-lang/src/abstract_tree/logic.rs b/dust-lang/src/abstract_tree/logic.rs
index 0935748..a589b1f 100644
--- a/dust-lang/src/abstract_tree/logic.rs
+++ b/dust-lang/src/abstract_tree/logic.rs
@@ -25,45 +25,11 @@ pub enum Logic {
 }
 
 impl AbstractNode for Logic {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
-        match self {
-            Logic::Equal(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::NotEqual(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::Greater(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::Less(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::GreaterOrEqual(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::LessOrEqual(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::And(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::Or(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Logic::Not(expression) => expression.define_types(_context),
-        }
-    }
-
-    fn validate(&self, context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         match self {
             Logic::Equal(left, right)
             | Logic::NotEqual(left, right)
@@ -71,8 +37,8 @@ impl AbstractNode for Logic {
             | Logic::Less(left, right)
             | Logic::GreaterOrEqual(left, right)
             | Logic::LessOrEqual(left, right) => {
-                left.validate(context, _manage_memory)?;
-                right.validate(context, _manage_memory)?;
+                left.define_and_validate(context, _manage_memory)?;
+                right.define_and_validate(context, _manage_memory)?;
 
                 let left_type = if let Some(r#type) = left.expected_type(context)? {
                     r#type
@@ -96,8 +62,8 @@ impl AbstractNode for Logic {
                 Ok(())
             }
             Logic::And(left, right) | Logic::Or(left, right) => {
-                left.validate(context, _manage_memory)?;
-                right.validate(context, _manage_memory)?;
+                left.define_and_validate(context, _manage_memory)?;
+                right.define_and_validate(context, _manage_memory)?;
 
                 let left_type = if let Some(r#type) = left.expected_type(context)? {
                     r#type
@@ -129,7 +95,7 @@ impl AbstractNode for Logic {
                 Ok(())
             }
             Logic::Not(expression) => {
-                expression.validate(context, _manage_memory)?;
+                expression.define_and_validate(context, _manage_memory)?;
 
                 let expression_type = if let Some(r#type) = expression.expected_type(context)? {
                     r#type
diff --git a/dust-lang/src/abstract_tree/loop.rs b/dust-lang/src/abstract_tree/loop.rs
index e05b3ea..8091b95 100644
--- a/dust-lang/src/abstract_tree/loop.rs
+++ b/dust-lang/src/abstract_tree/loop.rs
@@ -25,17 +25,13 @@ impl Loop {
 }
 
 impl AbstractNode for Loop {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        _context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         for statement in &self.statements {
-            statement.define_types(_context)?;
-        }
-
-        Ok(())
-    }
-
-    fn validate(&self, _context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
-        for statement in &self.statements {
-            statement.validate(_context, false)?;
+            statement.define_and_validate(_context, false)?;
         }
 
         Ok(())
diff --git a/dust-lang/src/abstract_tree/map_index.rs b/dust-lang/src/abstract_tree/map_index.rs
index a91645b..8546f1c 100644
--- a/dust-lang/src/abstract_tree/map_index.rs
+++ b/dust-lang/src/abstract_tree/map_index.rs
@@ -26,13 +26,13 @@ impl MapIndex {
 }
 
 impl AbstractNode for MapIndex {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
-        self.collection.define_types(_context)?;
-        self.index.define_types(_context)
-    }
-
-    fn validate(&self, context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
-        self.collection.validate(context, _manage_memory)?;
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
+        self.collection
+            .define_and_validate(context, _manage_memory)?;
 
         let collection_type = if let Some(r#type) = self.collection.expected_type(context)? {
             r#type
@@ -56,7 +56,7 @@ impl AbstractNode for MapIndex {
         if let Expression::Identifier(_) = &self.index {
             Ok(())
         } else {
-            self.index.validate(context, _manage_memory)
+            self.index.define_and_validate(context, _manage_memory)
         }
     }
 
diff --git a/dust-lang/src/abstract_tree/math.rs b/dust-lang/src/abstract_tree/math.rs
index ca24503..df43a17 100644
--- a/dust-lang/src/abstract_tree/math.rs
+++ b/dust-lang/src/abstract_tree/math.rs
@@ -21,32 +21,11 @@ pub enum Math {
 }
 
 impl AbstractNode for Math {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
-        match self {
-            Math::Add(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Math::Subtract(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Math::Multiply(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Math::Divide(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-            Math::Modulo(left, right) => {
-                left.define_types(_context)?;
-                right.define_types(_context)
-            }
-        }
-    }
-
-    fn validate(&self, context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         match self {
             Math::Add(left, right) => {
                 let left_type = if let Some(r#type) = left.expected_type(context)? {
diff --git a/dust-lang/src/abstract_tree/mod.rs b/dust-lang/src/abstract_tree/mod.rs
index a424dfa..a90460c 100644
--- a/dust-lang/src/abstract_tree/mod.rs
+++ b/dust-lang/src/abstract_tree/mod.rs
@@ -58,6 +58,7 @@ pub use self::{
 use crate::{
     context::Context,
     error::{DustError, RuntimeError, ValidationError},
+    identifier::Identifier,
     Value,
 };
 
@@ -128,18 +129,7 @@ impl AbstractTree {
         let mut errors = Vec::new();
 
         for statement in &self.0 {
-            let define_result = statement.define_types(context);
-
-            if let Err(error) = define_result {
-                errors.push(DustError::Validation {
-                    error,
-                    position: statement.position(),
-                });
-
-                continue;
-            }
-
-            let validation_result = statement.validate(context, manage_memory);
+            let validation_result = statement.define_and_validate(context, manage_memory);
 
             if let Err(error) = validation_result {
                 errors.push(DustError::Validation {
@@ -187,17 +177,13 @@ impl Index<usize> for AbstractTree {
 }
 
 impl AbstractNode for AbstractTree {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         for statement in &self.0 {
-            statement.define_types(context)?;
-        }
-
-        Ok(())
-    }
-
-    fn validate(&self, context: &Context, manage_memory: bool) -> Result<(), ValidationError> {
-        for statement in &self.0 {
-            statement.validate(context, manage_memory)?;
+            statement.define_and_validate(context, manage_memory)?;
         }
 
         Ok(())
@@ -223,9 +209,11 @@ impl AbstractNode for AbstractTree {
 }
 
 pub trait AbstractNode {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError>;
-
-    fn validate(&self, context: &Context, manage_memory: bool) -> Result<(), ValidationError>;
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        manage_memory: bool,
+    ) -> Result<(), ValidationError>;
 
     fn evaluate(
         self,
diff --git a/dust-lang/src/abstract_tree/statement.rs b/dust-lang/src/abstract_tree/statement.rs
index 08278ec..f55ae43 100644
--- a/dust-lang/src/abstract_tree/statement.rs
+++ b/dust-lang/src/abstract_tree/statement.rs
@@ -58,44 +58,40 @@ impl Statement {
 }
 
 impl AbstractNode for Statement {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
-        log::trace!("Defining types for statement at {}", self.position());
-
-        match self {
-            Statement::Expression(expression) => expression.define_types(_context),
-            Statement::IfElse(if_else) => if_else.node.define_types(_context),
-            Statement::Block(block) => block.node.define_types(_context),
-            Statement::AsyncBlock(async_block) => async_block.node.define_types(_context),
-            Statement::Assignment(assignment) => assignment.node.define_types(_context),
-            Statement::Loop(r#loop) => r#loop.node.define_types(_context),
-            Statement::StructureDefinition(struct_definition) => {
-                struct_definition.node.define_types(_context)
-            }
-            Statement::TypeAlias(type_alias) => type_alias.node.define_types(_context),
-            Statement::EnumDeclaration(enum_declaration) => {
-                enum_declaration.node.define_types(_context)
-            }
-            Statement::While(r#while) => r#while.node.define_types(_context),
-            Statement::Use(r#use) => r#use.node.define_types(_context),
-            Statement::Break(_) | Statement::Null(_) => Ok(()),
-        }
-    }
-
-    fn validate(&self, _context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        _context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         log::trace!("Validating statement at {}", self.position());
 
         match self {
-            Statement::Assignment(assignment) => assignment.node.validate(_context, _manage_memory),
-            Statement::AsyncBlock(async_block) => {
-                async_block.node.validate(_context, _manage_memory)
+            Statement::Assignment(assignment) => assignment
+                .node
+                .define_and_validate(_context, _manage_memory),
+            Statement::AsyncBlock(async_block) => async_block
+                .node
+                .define_and_validate(_context, _manage_memory),
+            Statement::Block(block) => block.node.define_and_validate(_context, _manage_memory),
+            Statement::EnumDeclaration(enum_declaration) => enum_declaration
+                .node
+                .define_and_validate(_context, _manage_memory),
+            Statement::Expression(expression) => {
+                expression.define_and_validate(_context, _manage_memory)
             }
-            Statement::Block(block) => block.node.validate(_context, _manage_memory),
-            Statement::Expression(expression) => expression.validate(_context, _manage_memory),
-            Statement::IfElse(if_else) => if_else.node.validate(_context, _manage_memory),
-            Statement::Loop(r#loop) => r#loop.node.validate(_context, _manage_memory),
-            Statement::While(r#while) => r#while.node.validate(_context, _manage_memory),
-            Statement::Use(r#use) => r#use.node.validate(_context, _manage_memory),
-            _ => Ok(()),
+            Statement::IfElse(if_else) => {
+                if_else.node.define_and_validate(_context, _manage_memory)
+            }
+            Statement::Loop(r#loop) => r#loop.node.define_and_validate(_context, _manage_memory),
+            Statement::StructureDefinition(struct_definition) => struct_definition
+                .node
+                .define_and_validate(_context, _manage_memory),
+            Statement::TypeAlias(type_alias) => type_alias
+                .node
+                .define_and_validate(_context, _manage_memory),
+            Statement::While(r#while) => r#while.node.define_and_validate(_context, _manage_memory),
+            Statement::Use(r#use) => r#use.node.define_and_validate(_context, _manage_memory),
+            Statement::Break(_) | Statement::Null(_) => Ok(()),
         }
     }
 
diff --git a/dust-lang/src/abstract_tree/structure_definition.rs b/dust-lang/src/abstract_tree/structure_definition.rs
index 0b04f87..4040c6a 100644
--- a/dust-lang/src/abstract_tree/structure_definition.rs
+++ b/dust-lang/src/abstract_tree/structure_definition.rs
@@ -23,7 +23,7 @@ impl StructureDefinition {
 }
 
 impl AbstractNode for StructureDefinition {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(&self, context: &Context, _: bool) -> Result<(), ValidationError> {
         let mut fields = Vec::with_capacity(self.fields.len());
 
         for (identifier, constructor) in &self.fields {
@@ -42,10 +42,6 @@ impl AbstractNode for StructureDefinition {
         Ok(())
     }
 
-    fn validate(&self, _: &Context, _: bool) -> Result<(), ValidationError> {
-        Ok(())
-    }
-
     fn evaluate(
         self,
         context: &Context,
diff --git a/dust-lang/src/abstract_tree/type_alias.rs b/dust-lang/src/abstract_tree/type_alias.rs
index 73555d1..dd183eb 100644
--- a/dust-lang/src/abstract_tree/type_alias.rs
+++ b/dust-lang/src/abstract_tree/type_alias.rs
@@ -26,7 +26,7 @@ impl TypeAlias {
 }
 
 impl AbstractNode for TypeAlias {
-    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(&self, context: &Context, _: bool) -> Result<(), ValidationError> {
         let r#type = self.constructor.construct(&context)?;
 
         context.set_type(self.identifier.node.clone(), r#type)?;
@@ -34,10 +34,6 @@ impl AbstractNode for TypeAlias {
         Ok(())
     }
 
-    fn validate(&self, _: &Context, _: bool) -> Result<(), ValidationError> {
-        Ok(())
-    }
-
     fn evaluate(self, _: &Context, _: bool) -> Result<Option<Evaluation>, RuntimeError> {
         Ok(None)
     }
diff --git a/dust-lang/src/abstract_tree/use.rs b/dust-lang/src/abstract_tree/use.rs
index ffba015..6a536e1 100644
--- a/dust-lang/src/abstract_tree/use.rs
+++ b/dust-lang/src/abstract_tree/use.rs
@@ -37,7 +37,11 @@ impl Use {
 }
 
 impl AbstractNode for Use {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         let abstract_tree = match self.path.as_str() {
             "std.fs" => std_fs_compiled().clone(),
             "std.json" => std_json_compiled().clone(),
@@ -52,16 +56,10 @@ impl AbstractNode for Use {
             }
         };
 
-        abstract_tree.define_types(_context)?;
-
         *self.abstract_tree.write()? = Some(abstract_tree);
 
-        Ok(())
-    }
-
-    fn validate(&self, context: &Context, manage_memory: bool) -> Result<(), ValidationError> {
         if let Some(abstract_tree) = self.abstract_tree.read()?.as_ref() {
-            abstract_tree.validate(context, manage_memory)
+            abstract_tree.define_and_validate(context, manage_memory)
         } else {
             Err(ValidationError::Uninitialized)
         }
diff --git a/dust-lang/src/abstract_tree/value_node.rs b/dust-lang/src/abstract_tree/value_node.rs
index 94f8034..b4f8f0f 100644
--- a/dust-lang/src/abstract_tree/value_node.rs
+++ b/dust-lang/src/abstract_tree/value_node.rs
@@ -59,68 +59,11 @@ impl ValueNode {
 }
 
 impl AbstractNode for ValueNode {
-    fn define_types(&self, outer_context: &Context) -> Result<(), ValidationError> {
-        match self {
-            ValueNode::EnumInstance { content, .. } => {
-                if let Some(expressions) = content {
-                    for expression in expressions {
-                        expression.define_types(outer_context)?;
-                    }
-                }
-            }
-            ValueNode::List(expressions) => {
-                for expression in expressions {
-                    expression.define_types(outer_context)?;
-                }
-            }
-            ValueNode::Map(fields) => {
-                for (_, _, expression) in fields {
-                    expression.define_types(outer_context)?;
-                }
-            }
-            ValueNode::Structure { fields, .. } => {
-                for (_, expression) in fields {
-                    expression.define_types(outer_context)?;
-                }
-            }
-            ValueNode::Function(FunctionNode {
-                body,
-                type_parameters,
-                value_parameters,
-                validation_context,
-                ..
-            }) => {
-                validation_context.set_parent(outer_context.clone())?;
-
-                if let Some(type_parameters) = type_parameters {
-                    for identifier in type_parameters {
-                        validation_context.set_type(
-                            identifier.clone(),
-                            Type::Generic {
-                                identifier: identifier.clone(),
-                                concrete_type: None,
-                            },
-                        )?;
-                    }
-                }
-
-                if let Some(value_parameters) = value_parameters {
-                    for (identifier, type_constructor) in value_parameters {
-                        let r#type = type_constructor.clone().construct(outer_context)?;
-
-                        validation_context.set_type(identifier.clone(), r#type)?;
-                    }
-                }
-
-                body.node.define_types(validation_context)?;
-            }
-            _ => {}
-        }
-
-        Ok(())
-    }
-
-    fn validate(&self, context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
+    fn define_and_validate(
+        &self,
+        context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
         if let ValueNode::List(list) = self {
             let mut items = list.into_iter();
             let first_item = items.next().unwrap();
@@ -133,6 +76,8 @@ impl AbstractNode for ValueNode {
             };
 
             for item in items {
+                item.define_and_validate(context, _manage_memory)?;
+
                 let item_type = if let Some(r#type) = item.expected_type(context)? {
                     r#type
                 } else {
@@ -150,9 +95,17 @@ impl AbstractNode for ValueNode {
         }
 
         if let ValueNode::EnumInstance {
-            type_name, variant, ..
+            type_name,
+            variant,
+            content,
         } = self
         {
+            if let Some(expressions) = content {
+                for expression in expressions {
+                    expression.define_and_validate(context, _manage_memory)?;
+                }
+            }
+
             if let Some(Type::Enum { variants, .. }) = context.get_type(&type_name.node)? {
                 if variants
                     .iter()
@@ -174,7 +127,7 @@ impl AbstractNode for ValueNode {
 
         if let ValueNode::Map(map_assignments) = self {
             for (_identifier, constructor_option, expression) in map_assignments {
-                expression.validate(context, _manage_memory)?;
+                expression.define_and_validate(context, _manage_memory)?;
 
                 if let Some(constructor) = constructor_option {
                     let actual_type = if let Some(r#type) = expression.expected_type(context)? {
@@ -203,10 +156,36 @@ impl AbstractNode for ValueNode {
             return_type,
             body,
             validation_context,
-            ..
+            type_parameters,
+            value_parameters,
         }) = self
         {
-            body.node.validate(&validation_context, _manage_memory)?;
+            let outer_context = context;
+
+            validation_context.set_parent(outer_context.clone())?;
+
+            if let Some(type_parameters) = type_parameters {
+                for identifier in type_parameters {
+                    validation_context.set_type(
+                        identifier.clone(),
+                        Type::Generic {
+                            identifier: identifier.clone(),
+                            concrete_type: None,
+                        },
+                    )?;
+                }
+            }
+
+            if let Some(value_parameters) = value_parameters {
+                for (identifier, type_constructor) in value_parameters {
+                    let r#type = type_constructor.clone().construct(outer_context)?;
+
+                    validation_context.set_type(identifier.clone(), r#type)?;
+                }
+            }
+
+            body.node
+                .define_and_validate(&validation_context, _manage_memory)?;
 
             let ((expected_return, expected_position), actual_return) =
                 match (return_type, body.node.expected_type(&validation_context)?) {
@@ -259,6 +238,8 @@ impl AbstractNode for ValueNode {
             }) = context.get_type(&name.node)?
             {
                 for ((_, expression), (_, expected_type)) in expressions.iter().zip(types.iter()) {
+                    expression.define_and_validate(context, _manage_memory)?;
+
                     let actual_type = if let Some(r#type) = expression.expected_type(context)? {
                         r#type
                     } else {
diff --git a/dust-lang/src/abstract_tree/while.rs b/dust-lang/src/abstract_tree/while.rs
index d4d1cf3..8186445 100644
--- a/dust-lang/src/abstract_tree/while.rs
+++ b/dust-lang/src/abstract_tree/while.rs
@@ -27,21 +27,15 @@ impl While {
 }
 
 impl AbstractNode for While {
-    fn define_types(&self, _context: &Context) -> Result<(), ValidationError> {
-        self.expression.define_types(_context)?;
+    fn define_and_validate(
+        &self,
+        _context: &Context,
+        _manage_memory: bool,
+    ) -> Result<(), ValidationError> {
+        self.expression.define_and_validate(_context, false)?;
 
         for statement in &self.statements {
-            statement.define_types(_context)?;
-        }
-
-        Ok(())
-    }
-
-    fn validate(&self, _context: &Context, _manage_memory: bool) -> Result<(), ValidationError> {
-        self.expression.validate(_context, false)?;
-
-        for statement in &self.statements {
-            statement.validate(_context, false)?;
+            statement.define_and_validate(_context, false)?;
         }
 
         Ok(())
diff --git a/dust-lang/src/standard_library.rs b/dust-lang/src/standard_library.rs
index 495cd8d..f3cd903 100644
--- a/dust-lang/src/standard_library.rs
+++ b/dust-lang/src/standard_library.rs
@@ -32,10 +32,7 @@ pub fn core_context<'a>() -> &'a Context {
         let std_core = std_core_compiled().clone();
 
         std_core
-            .define_types(&context)
-            .expect("Failed to define types for std.core");
-        std_core
-            .validate(&context, true)
+            .define_and_validate(&context, true)
             .expect("Failed to validate std.core");
         std_core
             .evaluate(&context, true)