diff --git a/src/abstract_tree/assignment.rs b/src/abstract_tree/assignment.rs
index d32e879..4dddfa1 100644
--- a/src/abstract_tree/assignment.rs
+++ b/src/abstract_tree/assignment.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, AssignmentOperator, Error, Format, Identifier, Map, SourcePosition, Statement,
+    AbstractTree, AssignmentOperator, Format, Identifier, Map, SourcePosition, Statement,
     SyntaxNode, Type, TypeSpecification, Value,
 };
 
@@ -23,7 +23,7 @@ impl AbstractTree for Assignment {
         source: &str,
         context: &Map,
     ) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "assignment", syntax_node)?;
+        SyntaxError::expect_syntax_node(source, "assignment", syntax_node)?;
 
         let child_count = syntax_node.child_count();
 
diff --git a/src/abstract_tree/assignment_operator.rs b/src/abstract_tree/assignment_operator.rs
index 0fa4e30..8b996d0 100644
--- a/src/abstract_tree/assignment_operator.rs
+++ b/src/abstract_tree/assignment_operator.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, Map, SyntaxNode, Type, Value,
+    AbstractTree, Format, Map, SyntaxNode, Type, Value,
 };
 
 /// Operators that be used in an assignment statement.
@@ -19,7 +19,7 @@ impl AbstractTree for AssignmentOperator {
         source: &str,
         _context: &crate::Map,
     ) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "assignment_operator", node)?;
+        SyntaxError::expect_syntax_node(source, "assignment_operator", node)?;
 
         let operator_node = node.child(0).unwrap();
         let operator = match operator_node.kind() {
diff --git a/src/abstract_tree/block.rs b/src/abstract_tree/block.rs
index 1d19cc9..25c9ff5 100644
--- a/src/abstract_tree/block.rs
+++ b/src/abstract_tree/block.rs
@@ -5,7 +5,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{rw_lock_error::RwLockError, RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, Map, Statement, SyntaxNode, Type, Value,
+    AbstractTree, Format, Map, Statement, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of a block.
@@ -24,7 +24,7 @@ pub struct Block {
 
 impl AbstractTree for Block {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "block", node)?;
+        SyntaxError::expect_syntax_node(source, "block", node)?;
 
         let first_child = node.child(0).unwrap();
         let is_async = first_child.kind() == "async";
diff --git a/src/abstract_tree/command.rs b/src/abstract_tree/command.rs
index b172bb3..2adfd99 100644
--- a/src/abstract_tree/command.rs
+++ b/src/abstract_tree/command.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, Map, Type, Value,
+    AbstractTree, Format, Map, Type, Value,
 };
 
 /// An external program invokation.
@@ -20,7 +20,7 @@ impl AbstractTree for Command {
         source: &str,
         _context: &crate::Map,
     ) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "command", node)?;
+        SyntaxError::expect_syntax_node(source, "command", node)?;
 
         let command_text_node = node.child(1).unwrap();
         let command_text = source[command_text_node.byte_range()].to_string();
diff --git a/src/abstract_tree/expression.rs b/src/abstract_tree/expression.rs
index 3571986..aaf43b5 100644
--- a/src/abstract_tree/expression.rs
+++ b/src/abstract_tree/expression.rs
@@ -3,7 +3,7 @@ use serde::{Deserialize, Serialize};
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
     value_node::ValueNode,
-    AbstractTree, Command, Error, Format, FunctionCall, Identifier, Index, Logic, Map, Math, New,
+    AbstractTree, Command, Format, FunctionCall, Identifier, Index, Logic, Map, Math, New,
     SyntaxNode, Type, Value, Yield,
 };
 
@@ -27,7 +27,7 @@ pub enum Expression {
 
 impl AbstractTree for Expression {
     fn from_syntax(node: SyntaxNode, source: &str, _context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "expression", node)?;
+        SyntaxError::expect_syntax_node(source, "expression", node)?;
 
         let child = if node.child(0).unwrap().is_named() {
             node.child(0).unwrap()
diff --git a/src/abstract_tree/for.rs b/src/abstract_tree/for.rs
index daad3d3..22c250d 100644
--- a/src/abstract_tree/for.rs
+++ b/src/abstract_tree/for.rs
@@ -3,7 +3,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Block, Error, Expression, Format, Identifier, Map, SyntaxNode, Type, Value,
+    AbstractTree, Block, Expression, Format, Identifier, Map, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of a for loop statement.
@@ -17,7 +17,7 @@ pub struct For {
 
 impl AbstractTree for For {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "for", node)?;
+        SyntaxError::expect_syntax_node(source, "for", node)?;
 
         let for_node = node.child(0).unwrap();
         let is_async = match for_node.kind() {
diff --git a/src/abstract_tree/function_call.rs b/src/abstract_tree/function_call.rs
index eb72510..5c5d9c4 100644
--- a/src/abstract_tree/function_call.rs
+++ b/src/abstract_tree/function_call.rs
@@ -2,8 +2,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Expression, Format, FunctionExpression, Map, SourcePosition, SyntaxNode,
-    Type, Value,
+    AbstractTree, Expression, Format, FunctionExpression, Map, SourcePosition, SyntaxNode, Type,
+    Value,
 };
 
 /// A function being invoked and the arguments it is being passed.
@@ -31,7 +31,7 @@ impl FunctionCall {
 
 impl AbstractTree for FunctionCall {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "function_call", node)?;
+        SyntaxError::expect_syntax_node(source, "function_call", node)?;
 
         let function_node = node.child(0).unwrap();
         let function_expression = FunctionExpression::from_syntax(function_node, source, context)?;
diff --git a/src/abstract_tree/function_expression.rs b/src/abstract_tree/function_expression.rs
index c957751..65a3e79 100644
--- a/src/abstract_tree/function_expression.rs
+++ b/src/abstract_tree/function_expression.rs
@@ -2,8 +2,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, FunctionCall, Identifier, Index, Map, SyntaxNode, Type, Value,
-    ValueNode, Yield,
+    AbstractTree, Format, FunctionCall, Identifier, Index, Map, SyntaxNode, Type, Value, ValueNode,
+    Yield,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
@@ -17,7 +17,7 @@ pub enum FunctionExpression {
 
 impl AbstractTree for FunctionExpression {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "function_expression", node)?;
+        SyntaxError::expect_syntax_node(source, "function_expression", node)?;
 
         let first_child = node.child(0).unwrap();
         let child = if first_child.is_named() {
diff --git a/src/abstract_tree/function_node.rs b/src/abstract_tree/function_node.rs
index 66d8d92..a69a1ff 100644
--- a/src/abstract_tree/function_node.rs
+++ b/src/abstract_tree/function_node.rs
@@ -4,8 +4,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Block, Error, Format, Function, Identifier, Map, SourcePosition, SyntaxNode,
-    Type, TypeSpecification, Value,
+    AbstractTree, Block, Format, Function, Identifier, Map, SourcePosition, SyntaxNode, Type,
+    TypeSpecification, Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
@@ -90,7 +90,7 @@ impl AbstractTree for FunctionNode {
         source: &str,
         outer_context: &Map,
     ) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "function", node)?;
+        SyntaxError::expect_syntax_node(source, "function", node)?;
 
         let child_count = node.child_count();
         let mut parameters = Vec::new();
diff --git a/src/abstract_tree/identifier.rs b/src/abstract_tree/identifier.rs
index 229606e..9c1eb35 100644
--- a/src/abstract_tree/identifier.rs
+++ b/src/abstract_tree/identifier.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, Map, SyntaxNode, Type, Value,
+    AbstractTree, Format, Map, SyntaxNode, Type, Value,
 };
 
 /// A string by which a variable is known to a context.
@@ -30,7 +30,7 @@ impl Identifier {
 
 impl AbstractTree for Identifier {
     fn from_syntax(node: SyntaxNode, source: &str, _context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "identifier", node)?;
+        SyntaxError::expect_syntax_node(source, "identifier", node)?;
 
         let text = &source[node.byte_range()];
 
diff --git a/src/abstract_tree/index.rs b/src/abstract_tree/index.rs
index cab03d2..8872338 100644
--- a/src/abstract_tree/index.rs
+++ b/src/abstract_tree/index.rs
@@ -2,8 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, IndexExpression, List, Map, SourcePosition, SyntaxNode, Type,
-    Value,
+    AbstractTree, Format, IndexExpression, List, Map, SourcePosition, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of an index expression.
@@ -19,7 +18,7 @@ pub struct Index {
 
 impl AbstractTree for Index {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "index", node)?;
+        SyntaxError::expect_syntax_node(source, "index", node)?;
 
         let collection_node = node.child(0).unwrap();
         let collection = IndexExpression::from_syntax(collection_node, source, context)?;
diff --git a/src/abstract_tree/index_assignment.rs b/src/abstract_tree/index_assignment.rs
index b538806..022d96b 100644
--- a/src/abstract_tree/index_assignment.rs
+++ b/src/abstract_tree/index_assignment.rs
@@ -2,8 +2,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, AssignmentOperator, Error, Format, Index, IndexExpression, Map, Statement,
-    SyntaxNode, Type, Value,
+    AbstractTree, AssignmentOperator, Format, Index, IndexExpression, Map, Statement, SyntaxNode,
+    Type, Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
@@ -15,7 +15,7 @@ pub struct IndexAssignment {
 
 impl AbstractTree for IndexAssignment {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "index_assignment", node)?;
+        SyntaxError::expect_syntax_node(source, "index_assignment", node)?;
 
         let index_node = node.child(0).unwrap();
         let index = Index::from_syntax(index_node, source, context)?;
diff --git a/src/abstract_tree/index_expression.rs b/src/abstract_tree/index_expression.rs
index 11630e0..8a9b775 100644
--- a/src/abstract_tree/index_expression.rs
+++ b/src/abstract_tree/index_expression.rs
@@ -3,7 +3,7 @@ use serde::{Deserialize, Serialize};
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
     value_node::ValueNode,
-    AbstractTree, Error, Format, FunctionCall, Identifier, Index, Map, SyntaxNode, Type, Value,
+    AbstractTree, Format, FunctionCall, Identifier, Index, Map, SyntaxNode, Type, Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
@@ -16,7 +16,7 @@ pub enum IndexExpression {
 
 impl AbstractTree for IndexExpression {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "index_expression", node)?;
+        SyntaxError::expect_syntax_node(source, "index_expression", node)?;
 
         let first_child = node.child(0).unwrap();
         let child = if first_child.is_named() {
diff --git a/src/abstract_tree/logic.rs b/src/abstract_tree/logic.rs
index e7bcbca..8ea9db5 100644
--- a/src/abstract_tree/logic.rs
+++ b/src/abstract_tree/logic.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Expression, Format, LogicOperator, Map, SyntaxNode, Type, Value,
+    AbstractTree, Expression, Format, LogicOperator, Map, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of a logic expression.
@@ -15,7 +15,7 @@ pub struct Logic {
 
 impl AbstractTree for Logic {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "logic", node)?;
+        SyntaxError::expect_syntax_node(source, "logic", node)?;
 
         let first_node = node.child(0).unwrap();
         let (left_node, operator_node, right_node) = {
diff --git a/src/abstract_tree/logic_operator.rs b/src/abstract_tree/logic_operator.rs
index 58971e3..21c671e 100644
--- a/src/abstract_tree/logic_operator.rs
+++ b/src/abstract_tree/logic_operator.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, Map, SyntaxNode, Type, Value,
+    AbstractTree, Format, Map, SyntaxNode, Type, Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
@@ -19,7 +19,7 @@ pub enum LogicOperator {
 
 impl AbstractTree for LogicOperator {
     fn from_syntax(node: SyntaxNode, source: &str, _context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "logic_operator", node)?;
+        SyntaxError::expect_syntax_node(source, "logic_operator", node)?;
 
         let operator_node = node.child(0).unwrap();
         let operator = match operator_node.kind() {
diff --git a/src/abstract_tree/match.rs b/src/abstract_tree/match.rs
index 8c1d3e4..c6490dc 100644
--- a/src/abstract_tree/match.rs
+++ b/src/abstract_tree/match.rs
@@ -6,7 +6,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Expression, Format, Map, Statement, SyntaxNode, Type, Value,
+    AbstractTree, Expression, Format, Map, Statement, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of a match statement.
@@ -19,7 +19,7 @@ pub struct Match {
 
 impl AbstractTree for Match {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "match", node)?;
+        SyntaxError::expect_syntax_node(source, "match", node)?;
 
         let matcher_node = node.child(1).unwrap();
         let matcher = Expression::from_syntax(matcher_node, source, context)?;
diff --git a/src/abstract_tree/math.rs b/src/abstract_tree/math.rs
index c7a80aa..3dc477e 100644
--- a/src/abstract_tree/math.rs
+++ b/src/abstract_tree/math.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Expression, Format, Map, MathOperator, SyntaxNode, Type, Value,
+    AbstractTree, Expression, Format, Map, MathOperator, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of a math operation.
@@ -18,7 +18,7 @@ pub struct Math {
 
 impl AbstractTree for Math {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "math", node)?;
+        SyntaxError::expect_syntax_node(source, "math", node)?;
 
         let left_node = node.child(0).unwrap();
         let left = Expression::from_syntax(left_node, source, context)?;
diff --git a/src/abstract_tree/mod.rs b/src/abstract_tree/mod.rs
index 42cef9d..c53e314 100644
--- a/src/abstract_tree/mod.rs
+++ b/src/abstract_tree/mod.rs
@@ -46,7 +46,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    Error, Map, SyntaxNode, Value,
+    Map, SyntaxNode, Value,
 };
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
@@ -82,7 +82,7 @@ pub struct Root {
 // top-level statements in the tree.
 impl AbstractTree for Root {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "root", node)?;
+        SyntaxError::expect_syntax_node(source, "root", node)?;
 
         let statement_count = node.child_count();
         let mut statements = Vec::with_capacity(statement_count);
diff --git a/src/abstract_tree/statement.rs b/src/abstract_tree/statement.rs
index 8c326f9..b0612f9 100644
--- a/src/abstract_tree/statement.rs
+++ b/src/abstract_tree/statement.rs
@@ -2,8 +2,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Assignment, Block, Error, Expression, For, Format, IfElse, IndexAssignment, Map,
-    Match, SyntaxNode, Type, Value, While,
+    AbstractTree, Assignment, Block, Expression, For, Format, IfElse, IndexAssignment, Map, Match,
+    SyntaxNode, Type, Value, While,
 };
 
 /// Abstract representation of a statement.
@@ -22,7 +22,7 @@ pub enum Statement {
 
 impl AbstractTree for Statement {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "statement", node)?;
+        SyntaxError::expect_syntax_node(source, "statement", node)?;
 
         let child = node.child(0).unwrap();
 
diff --git a/src/abstract_tree/type.rs b/src/abstract_tree/type.rs
index 3e5ca93..13b01e6 100644
--- a/src/abstract_tree/type.rs
+++ b/src/abstract_tree/type.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, Identifier, Map, Structure, SyntaxNode, Value,
+    AbstractTree, Format, Identifier, Map, Structure, SyntaxNode, Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
@@ -127,7 +127,7 @@ impl Type {
 
 impl AbstractTree for Type {
     fn from_syntax(node: SyntaxNode, _source: &str, _context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(_source, "type", node)?;
+        SyntaxError::expect_syntax_node(_source, "type", node)?;
 
         let type_node = node.child(0).unwrap();
 
diff --git a/src/abstract_tree/type_specification.rs b/src/abstract_tree/type_specification.rs
index f5aa116..a158b84 100644
--- a/src/abstract_tree/type_specification.rs
+++ b/src/abstract_tree/type_specification.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Error, Format, Map, SyntaxNode, Type, Value,
+    AbstractTree, Format, Map, SyntaxNode, Type, Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
@@ -26,7 +26,7 @@ impl TypeSpecification {
 
 impl AbstractTree for TypeSpecification {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "type_specification", node)?;
+        SyntaxError::expect_syntax_node(source, "type_specification", node)?;
 
         let type_node = node.child(1).unwrap();
         let r#type = Type::from_syntax(type_node, source, context)?;
diff --git a/src/abstract_tree/value_node.rs b/src/abstract_tree/value_node.rs
index e2fe159..0ed962f 100644
--- a/src/abstract_tree/value_node.rs
+++ b/src/abstract_tree/value_node.rs
@@ -4,8 +4,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, BuiltInValue, Error, Expression, Format, Function, FunctionNode, Identifier,
-    List, Map, Statement, Structure, SyntaxNode, Type, TypeSpecification, Value,
+    AbstractTree, BuiltInValue, Expression, Format, Function, FunctionNode, Identifier, List, Map,
+    Statement, Structure, SyntaxNode, Type, TypeSpecification, Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
@@ -25,7 +25,7 @@ pub enum ValueNode {
 
 impl AbstractTree for ValueNode {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "value", node)?;
+        SyntaxError::expect_syntax_node(source, "value", node)?;
 
         let child = node.child(0).unwrap();
         let value_node = match child.kind() {
diff --git a/src/abstract_tree/while.rs b/src/abstract_tree/while.rs
index 22243f1..f373573 100644
--- a/src/abstract_tree/while.rs
+++ b/src/abstract_tree/while.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Block, Error, Expression, Format, Map, SyntaxNode, Type, Value,
+    AbstractTree, Block, Expression, Format, Map, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of a while loop.
@@ -16,7 +16,7 @@ pub struct While {
 
 impl AbstractTree for While {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "while", node)?;
+        SyntaxError::expect_syntax_node(source, "while", node)?;
 
         let expression_node = node.child(1).unwrap();
         let expression = Expression::from_syntax(expression_node, source, context)?;
diff --git a/src/abstract_tree/yield.rs b/src/abstract_tree/yield.rs
index 9657196..a8e718b 100644
--- a/src/abstract_tree/yield.rs
+++ b/src/abstract_tree/yield.rs
@@ -3,7 +3,7 @@ use serde::{Deserialize, Serialize};
 use crate::{
     error::{RuntimeError, SyntaxError, ValidationError},
     function_expression::FunctionExpression,
-    AbstractTree, Error, Expression, Format, FunctionCall, Map, SyntaxNode, Type, Value,
+    AbstractTree, Expression, Format, FunctionCall, Map, SyntaxNode, Type, Value,
 };
 
 /// Abstract representation of a yield expression.
@@ -16,7 +16,7 @@ pub struct Yield {
 
 impl AbstractTree for Yield {
     fn from_syntax(node: SyntaxNode, source: &str, context: &Map) -> Result<Self, SyntaxError> {
-        Error::expect_syntax_node(source, "yield", node)?;
+        SyntaxError::expect_syntax_node(source, "yield", node)?;
 
         let input_node = node.child(0).unwrap();
         let input = Expression::from_syntax(input_node, source, context)?;
diff --git a/src/error/mod.rs b/src/error/mod.rs
index 369bacc..13fbcba 100644
--- a/src/error/mod.rs
+++ b/src/error/mod.rs
@@ -11,12 +11,11 @@ pub use runtime_error::RuntimeError;
 pub use syntax_error::SyntaxError;
 pub use validation_error::ValidationError;
 
-use tree_sitter::{LanguageError, Node, Point};
-
-use crate::{SourcePosition};
+use tree_sitter::{LanguageError, Point};
 
 use std::fmt::{self, Formatter};
 
+#[derive(PartialEq)]
 pub enum Error {
     Syntax(SyntaxError),
 
@@ -29,32 +28,6 @@ pub enum Error {
     Language(LanguageError),
 }
 
-impl Error {
-    pub fn expect_syntax_node(
-        source: &str,
-        expected: &str,
-        actual: Node,
-    ) -> Result<(), SyntaxError> {
-        log::info!("Converting {} to abstract node", actual.kind());
-
-        if expected == actual.kind() {
-            Ok(())
-        } else if actual.is_error() {
-            Err(SyntaxError::InvalidSource {
-                source: source[actual.byte_range()].to_string(),
-                position: SourcePosition::from(actual.range()),
-            })
-        } else {
-            Err(SyntaxError::UnexpectedSyntaxNode {
-                expected: expected.to_string(),
-                actual: actual.kind().to_string(),
-                location: actual.start_position(),
-                relevant_source: source[actual.byte_range()].to_string(),
-            })
-        }
-    }
-}
-
 impl From<SyntaxError> for Error {
     fn from(error: SyntaxError) -> Self {
         Error::Syntax(error)
diff --git a/src/error/runtime_error.rs b/src/error/runtime_error.rs
index 9e9e3cc..a813c0f 100644
--- a/src/error/runtime_error.rs
+++ b/src/error/runtime_error.rs
@@ -3,23 +3,24 @@ use std::{
     io,
     num::ParseFloatError,
     string::FromUtf8Error,
-    time::{self, SystemTimeError},
+    time,
 };
 
-use crate::{Value};
+use crate::Value;
 
 use super::rw_lock_error::RwLockError;
 
+#[derive(PartialEq)]
 pub enum RuntimeError {
-    Csv(csv::Error),
+    Csv(String),
 
-    Io(io::Error),
+    Io(String),
 
-    Reqwest(reqwest::Error),
+    Reqwest(String),
 
-    Json(serde_json::Error),
+    Json(String),
 
-    SystemTime(SystemTimeError),
+    SystemTime(String),
 
     Toml(toml::de::Error),
 
@@ -128,31 +129,31 @@ impl RuntimeError {
 
 impl From<csv::Error> for RuntimeError {
     fn from(error: csv::Error) -> Self {
-        RuntimeError::Csv(error)
+        RuntimeError::Csv(error.to_string())
     }
 }
 
 impl From<io::Error> for RuntimeError {
     fn from(error: std::io::Error) -> Self {
-        RuntimeError::Io(error)
+        RuntimeError::Io(error.to_string())
     }
 }
 
 impl From<reqwest::Error> for RuntimeError {
     fn from(error: reqwest::Error) -> Self {
-        RuntimeError::Reqwest(error)
+        RuntimeError::Reqwest(error.to_string())
     }
 }
 
 impl From<serde_json::Error> for RuntimeError {
     fn from(error: serde_json::Error) -> Self {
-        RuntimeError::Json(error)
+        RuntimeError::Json(error.to_string())
     }
 }
 
 impl From<time::SystemTimeError> for RuntimeError {
     fn from(error: time::SystemTimeError) -> Self {
-        RuntimeError::SystemTime(error)
+        RuntimeError::SystemTime(error.to_string())
     }
 }
 
diff --git a/src/error/syntax_error.rs b/src/error/syntax_error.rs
index dfb35d6..a0a7df8 100644
--- a/src/error/syntax_error.rs
+++ b/src/error/syntax_error.rs
@@ -1,5 +1,5 @@
 use serde::{Deserialize, Serialize};
-use tree_sitter::Point;
+use tree_sitter::{Node as SyntaxNode, Point};
 
 use crate::SourcePosition;
 
@@ -26,6 +26,32 @@ pub enum SyntaxError {
     },
 }
 
+impl SyntaxError {
+    pub fn expect_syntax_node(
+        source: &str,
+        expected: &str,
+        actual: SyntaxNode,
+    ) -> Result<(), SyntaxError> {
+        log::info!("Converting {} to abstract node", actual.kind());
+
+        if expected == actual.kind() {
+            Ok(())
+        } else if actual.is_error() {
+            Err(SyntaxError::InvalidSource {
+                source: source[actual.byte_range()].to_string(),
+                position: SourcePosition::from(actual.range()),
+            })
+        } else {
+            Err(SyntaxError::UnexpectedSyntaxNode {
+                expected: expected.to_string(),
+                actual: actual.kind().to_string(),
+                location: actual.start_position(),
+                relevant_source: source[actual.byte_range()].to_string(),
+            })
+        }
+    }
+}
+
 impl From<RwLockError> for SyntaxError {
     fn from(error: RwLockError) -> Self {
         SyntaxError::RwLock(error)
diff --git a/tests/assignment.rs b/tests/assignment.rs
index 1ff91a0..6df7f82 100644
--- a/tests/assignment.rs
+++ b/tests/assignment.rs
@@ -1,4 +1,4 @@
-use dust_lang::*;
+use dust_lang::{error::ValidationError, *};
 
 #[test]
 fn simple_assignment() {
@@ -39,8 +39,19 @@ fn list_add_wrong_type() {
             ",
     );
 
-    assert!(result.unwrap_err().is_error(&Error::TypeCheck {
-        expected: Type::String,
-        actual: Type::Integer
-    }))
+    assert_eq!(
+        Err(Error::Validation(ValidationError::TypeCheck {
+            expected: Type::String,
+            actual: Type::Integer,
+            position: SourcePosition {
+                start_byte: 0,
+                end_byte: 0,
+                start_row: 0,
+                start_column: 0,
+                end_row: 0,
+                end_column: 0
+            }
+        })),
+        result
+    );
 }
diff --git a/tests/functions.rs b/tests/functions.rs
index 25b8067..3734ae6 100644
--- a/tests/functions.rs
+++ b/tests/functions.rs
@@ -1,4 +1,4 @@
-use dust_lang::*;
+use dust_lang::{error::ValidationError, *};
 
 #[test]
 fn function_call() {
@@ -48,14 +48,18 @@ fn built_in_function_call() {
 
 #[test]
 fn function_context_does_not_capture_normal_values() {
-    assert!(interpret(
-        "
+    assert_eq!(
+        interpret(
+            "
             x = 1
 
             foo = () <any> { x }
             "
-    )
-    .is_err_and(|error| error.is_error(&Error::VariableIdentifierNotFound("x".to_string()))));
+        ),
+        Err(Error::Validation(
+            ValidationError::VariableIdentifierNotFound(Identifier::new("x".to_string()))
+        ))
+    );
 
     assert_eq!(
         interpret(
diff --git a/tests/types.rs b/tests/types.rs
index 6afade9..3caed77 100644
--- a/tests/types.rs
+++ b/tests/types.rs
@@ -1,13 +1,24 @@
-use dust_lang::*;
+use dust_lang::{error::ValidationError, *};
 
 #[test]
 fn simple_type_check() {
     let result = interpret("x <bool> = 1");
 
-    assert!(result.unwrap_err().is_error(&Error::TypeCheck {
-        expected: Type::Boolean,
-        actual: Type::Integer
-    }));
+    assert_eq!(
+        Err(Error::Validation(ValidationError::TypeCheck {
+            expected: Type::Boolean,
+            actual: Type::Integer,
+            position: SourcePosition {
+                start_byte: 0,
+                end_byte: 0,
+                start_row: 0,
+                start_column: 0,
+                end_row: 0,
+                end_column: 0,
+            }
+        })),
+        result
+    );
 }
 
 #[test]
@@ -37,14 +48,25 @@ fn callback_type_check() {
             ",
     );
 
-    assert!(result.unwrap_err().is_error(&Error::TypeCheck {
-        expected: Type::Function {
-            parameter_types: vec![],
-            return_type: Box::new(Type::Boolean),
-        },
-        actual: Type::Function {
-            parameter_types: vec![],
-            return_type: Box::new(Type::Integer),
-        },
-    }));
+    assert_eq!(
+        Err(Error::Validation(ValidationError::TypeCheck {
+            expected: Type::Function {
+                parameter_types: vec![],
+                return_type: Box::new(Type::Boolean),
+            },
+            actual: Type::Function {
+                parameter_types: vec![],
+                return_type: Box::new(Type::Integer),
+            },
+            position: SourcePosition {
+                start_byte: 0,
+                end_byte: 0,
+                start_row: 0,
+                start_column: 0,
+                end_row: 0,
+                end_column: 0
+            }
+        })),
+        result
+    );
 }
diff --git a/tests/value.rs b/tests/value.rs
index beced42..f1bc814 100644
--- a/tests/value.rs
+++ b/tests/value.rs
@@ -99,12 +99,21 @@ fn map_types() {
 
 #[test]
 fn map_type_errors() {
-    assert!(interpret("{ foo <bool> = 'bar' }")
-        .unwrap_err()
-        .is_error(&Error::TypeCheck {
+    assert_eq!(
+        interpret("{ foo <bool> = 'bar' }"),
+        Err(Error::Validation(error::ValidationError::TypeCheck {
             expected: Type::Boolean,
-            actual: Type::String
+            actual: Type::String,
+            position: SourcePosition {
+                start_byte: 0,
+                end_byte: 0,
+                start_row: 0,
+                start_column: 0,
+                end_row: 0,
+                end_column: 0
+            }
         }))
+    );
 }
 
 #[test]