diff --git a/src/parser/ast_node/ast_node.rs b/src/parser/ast_node/ast_node.rs
index 4a585ce..4e2a2e4 100644
--- a/src/parser/ast_node/ast_node.rs
+++ b/src/parser/ast_node/ast_node.rs
@@ -1,47 +1,47 @@
 // #[derive(Debug)]
-use super::ast_node_concat::ASTNodeConcat;
-use super::ast_node_group::ASTNodeGroup;
-use super::ast_node_literal::ASTNodeLiteral;
-use super::ast_node_optional::ASTNodeOptional;
-use super::ast_node_plus::ASTNodePlus;
-use super::ast_node_star::ASTNodeStar;
-use super::ast_node_union::ASTNodeUnion;
+use super::ast_node_concat::AstNodeConcat;
+use super::ast_node_group::AstNodeGroup;
+use super::ast_node_literal::AstNodeLiteral;
+use super::ast_node_optional::AstNodeOptional;
+use super::ast_node_plus::AstNodePlus;
+use super::ast_node_star::AstNodeStar;
+use super::ast_node_union::AstNodeUnion;
 
-pub(crate) enum ASTNode {
-    Literal(ASTNodeLiteral),   // Single character literal
-    Concat(ASTNodeConcat),     // Concatenation of two expressions
-    Union(ASTNodeUnion),       // Union of two expressions
-    Star(ASTNodeStar),         // Kleene Star (zero or more)
-    Plus(ASTNodePlus),         // One or more
-    Optional(ASTNodeOptional), // Zero or one (optional)
-    Group(ASTNodeGroup),       // Capturing group
+pub(crate) enum AstNode {
+    Literal(AstNodeLiteral),   // Single character literal
+    Concat(AstNodeConcat),     // Concatenation of two expressions
+    Union(AstNodeUnion),       // Union of two expressions
+    Star(AstNodeStar),         // Kleene Star (zero or more)
+    Plus(AstNodePlus),         // One or more
+    Optional(AstNodeOptional), // Zero or one (optional)
+    Group(AstNodeGroup),       // Capturing group
 }
 
-impl PartialEq for ASTNode {
+impl PartialEq for AstNode {
     fn eq(&self, other: &Self) -> bool {
         match (self, other) {
-            (ASTNode::Literal(l1), ASTNode::Literal(l2)) => l1 == l2,
-            (ASTNode::Concat(c1), ASTNode::Concat(c2)) => c1 == c2,
-            (ASTNode::Union(u1), ASTNode::Union(u2)) => u1 == u2,
-            (ASTNode::Star(s1), ASTNode::Star(s2)) => s1 == s2,
-            (ASTNode::Plus(p1), ASTNode::Plus(p2)) => p1 == p2,
-            (ASTNode::Optional(o1), ASTNode::Optional(o2)) => o1 == o2,
-            (ASTNode::Group(g1), ASTNode::Group(g2)) => g1 == g2,
+            (AstNode::Literal(l1), AstNode::Literal(l2)) => l1 == l2,
+            (AstNode::Concat(c1), AstNode::Concat(c2)) => c1 == c2,
+            (AstNode::Union(u1), AstNode::Union(u2)) => u1 == u2,
+            (AstNode::Star(s1), AstNode::Star(s2)) => s1 == s2,
+            (AstNode::Plus(p1), AstNode::Plus(p2)) => p1 == p2,
+            (AstNode::Optional(o1), AstNode::Optional(o2)) => o1 == o2,
+            (AstNode::Group(g1), AstNode::Group(g2)) => g1 == g2,
             _ => false,
         }
     }
 }
 
-impl std::fmt::Debug for ASTNode {
+impl std::fmt::Debug for AstNode {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            ASTNode::Literal(l) => write!(f, "Literal({:?})", l),
-            ASTNode::Concat(c) => write!(f, "Concat({:?})", c),
-            ASTNode::Union(u) => write!(f, "Union({:?})", u),
-            ASTNode::Star(s) => write!(f, "Star({:?})", s),
-            ASTNode::Plus(p) => write!(f, "Plus({:?})", p),
-            ASTNode::Optional(o) => write!(f, "Optional({:?})", o),
-            ASTNode::Group(g) => write!(f, "Group({:?})", g),
+            AstNode::Literal(l) => write!(f, "Literal({:?})", l),
+            AstNode::Concat(c) => write!(f, "Concat({:?})", c),
+            AstNode::Union(u) => write!(f, "Union({:?})", u),
+            AstNode::Star(s) => write!(f, "Star({:?})", s),
+            AstNode::Plus(p) => write!(f, "Plus({:?})", p),
+            AstNode::Optional(o) => write!(f, "Optional({:?})", o),
+            AstNode::Group(g) => write!(f, "Group({:?})", g),
         }
     }
 }
diff --git a/src/parser/ast_node/ast_node_concat.rs b/src/parser/ast_node/ast_node_concat.rs
index 034d160..b247755 100644
--- a/src/parser/ast_node/ast_node_concat.rs
+++ b/src/parser/ast_node/ast_node_concat.rs
@@ -1,12 +1,12 @@
-use crate::parser::ast_node::ast_node::ASTNode;
+use crate::parser::ast_node::ast_node::AstNode;
 
 #[derive(Debug)]
-pub(crate) struct ASTNodeConcat {
-    m_op1: Box<ASTNode>,
-    m_op2: Box<ASTNode>,
+pub(crate) struct AstNodeConcat {
+    m_op1: Box<AstNode>,
+    m_op2: Box<AstNode>,
 }
 
-impl PartialEq for ASTNodeConcat {
+impl PartialEq for AstNodeConcat {
     fn eq(&self, other: &Self) -> bool {
         self.m_op1 == other.m_op1 && self.m_op2 == other.m_op2
     }
diff --git a/src/parser/ast_node/ast_node_group.rs b/src/parser/ast_node/ast_node_group.rs
index 7da6798..8c2ee95 100644
--- a/src/parser/ast_node/ast_node_group.rs
+++ b/src/parser/ast_node/ast_node_group.rs
@@ -1,11 +1,11 @@
-use crate::parser::ast_node::ast_node::ASTNode;
+use crate::parser::ast_node::ast_node::AstNode;
 
 #[derive(Debug)]
-pub(crate) struct ASTNodeGroup {
-    m_op1: Box<ASTNode>,
+pub(crate) struct AstNodeGroup {
+    m_op1: Box<AstNode>,
 }
 
-impl PartialEq for ASTNodeGroup {
+impl PartialEq for AstNodeGroup {
     fn eq(&self, other: &Self) -> bool {
         self.m_op1 == other.m_op1
     }
diff --git a/src/parser/ast_node/ast_node_literal.rs b/src/parser/ast_node/ast_node_literal.rs
index cc05a6f..ffbdbc2 100644
--- a/src/parser/ast_node/ast_node_literal.rs
+++ b/src/parser/ast_node/ast_node_literal.rs
@@ -1,9 +1,9 @@
 #[derive(Debug)]
-pub(crate) struct ASTNodeLiteral {
+pub(crate) struct AstNodeLiteral {
     m_value: char,
 }
 
-impl PartialEq for ASTNodeLiteral {
+impl PartialEq for AstNodeLiteral {
     fn eq(&self, other: &Self) -> bool {
         self.m_value == other.m_value
     }
diff --git a/src/parser/ast_node/ast_node_optional.rs b/src/parser/ast_node/ast_node_optional.rs
index a283423..f73a7d7 100644
--- a/src/parser/ast_node/ast_node_optional.rs
+++ b/src/parser/ast_node/ast_node_optional.rs
@@ -1,11 +1,11 @@
-use crate::parser::ast_node::ast_node::ASTNode;
+use crate::parser::ast_node::ast_node::AstNode;
 
 #[derive(Debug)]
-pub(crate) struct ASTNodeOptional {
-    m_op1: Box<ASTNode>,
+pub(crate) struct AstNodeOptional {
+    m_op1: Box<AstNode>,
 }
 
-impl PartialEq for ASTNodeOptional {
+impl PartialEq for AstNodeOptional {
     fn eq(&self, other: &Self) -> bool {
         self.m_op1 == other.m_op1
     }
diff --git a/src/parser/ast_node/ast_node_plus.rs b/src/parser/ast_node/ast_node_plus.rs
index d7b62ab..fcc97cb 100644
--- a/src/parser/ast_node/ast_node_plus.rs
+++ b/src/parser/ast_node/ast_node_plus.rs
@@ -1,11 +1,11 @@
-use crate::parser::ast_node::ast_node::ASTNode;
+use crate::parser::ast_node::ast_node::AstNode;
 
 #[derive(Debug)]
-pub(crate) struct ASTNodePlus {
-    m_op1: Box<ASTNode>,
+pub(crate) struct AstNodePlus {
+    m_op1: Box<AstNode>,
 }
 
-impl PartialEq for ASTNodePlus {
+impl PartialEq for AstNodePlus {
     fn eq(&self, other: &Self) -> bool {
         self.m_op1 == other.m_op1
     }
diff --git a/src/parser/ast_node/ast_node_star.rs b/src/parser/ast_node/ast_node_star.rs
index 4b00590..3a29618 100644
--- a/src/parser/ast_node/ast_node_star.rs
+++ b/src/parser/ast_node/ast_node_star.rs
@@ -1,11 +1,11 @@
-use crate::parser::ast_node::ast_node::ASTNode;
+use crate::parser::ast_node::ast_node::AstNode;
 
 #[derive(Debug)]
-pub(crate) struct ASTNodeStar {
-    m_op1: Box<ASTNode>,
+pub(crate) struct AstNodeStar {
+    m_op1: Box<AstNode>,
 }
 
-impl PartialEq for ASTNodeStar {
+impl PartialEq for AstNodeStar {
     fn eq(&self, other: &Self) -> bool {
         self.m_op1 == other.m_op1
     }
diff --git a/src/parser/ast_node/ast_node_union.rs b/src/parser/ast_node/ast_node_union.rs
index 8f39f2b..4e1b9b3 100644
--- a/src/parser/ast_node/ast_node_union.rs
+++ b/src/parser/ast_node/ast_node_union.rs
@@ -1,12 +1,12 @@
-use crate::parser::ast_node::ast_node::ASTNode;
+use crate::parser::ast_node::ast_node::AstNode;
 
 #[derive(Debug)]
-pub(crate) struct ASTNodeUnion {
-    m_op1: Box<ASTNode>,
-    m_op2: Box<ASTNode>,
+pub(crate) struct AstNodeUnion {
+    m_op1: Box<AstNode>,
+    m_op2: Box<AstNode>,
 }
 
-impl PartialEq for ASTNodeUnion {
+impl PartialEq for AstNodeUnion {
     fn eq(&self, other: &Self) -> bool {
         self.m_op1 == other.m_op1 && self.m_op2 == other.m_op2
     }
diff --git a/src/parser/parser.rs b/src/parser/parser.rs
index bc43f16..edcf039 100644
--- a/src/parser/parser.rs
+++ b/src/parser/parser.rs
@@ -1,4 +1,4 @@
-use super::ast_node::ast_node::ASTNode;
+use super::ast_node::ast_node::AstNode;
 use super::token::Token;
 
 pub struct ParserStream {
@@ -30,7 +30,7 @@ impl ParserStream {
 }
 
 impl ParserStream {
-    fn parse_regex(&mut self) -> Option<ASTNode> {
+    fn parse_regex(&mut self) -> Option<AstNode> {
         None
     }
 }