diff --git a/crates/codegen/src/class_decl.rs b/crates/codegen/src/class_decl.rs
new file mode 100644
index 0000000..9a19e0e
--- /dev/null
+++ b/crates/codegen/src/class_decl.rs
@@ -0,0 +1,223 @@
+use mist_parser::ast::*;
+
+use crate::Context;
+
+use crate::{GenRust, GetRust, RustCodegen};
+
+pub fn class_decl(
+    ctx: &mut Context,
+    cg: &mut RustCodegen,
+
+    visibility: &Visibility,
+    name: &Identifier,
+    generics: &GenericsDecl,
+    inherits: &Option<TypeExpr>,
+    fields: &Vec<Spanned<FieldDeclStmt>>,
+    constructor: &Spanned<ClassConstructor>,
+    items: &Vec<ClassItem>,
+) {
+    // Struct decl
+    cg.addln(&format!(
+        "{}struct {}{} {{",
+        visibility.get_rust(),
+        name.clone().get_rust(),
+        generics.clone().get_rust()
+    ));
+    cg.indent += 1;
+
+    if let Some(inherits) = inherits {
+        cg.add_indented("pub _super: ");
+        cg.add(&inherits.get_rust());
+        cg.addln(",");
+    }
+
+    for field in fields.clone() {
+        cg.add_indentedln(&field.get_comment());
+        cg.add_indentedln(&field.item.decl.get_rust());
+    }
+
+    cg.indent -= 1;
+    cg.addln("}\n");
+
+    // Constructor
+    cg.addln(&format!(
+        "impl{} {}{} {{",
+        generics.clone().get_rust(),
+        name.clone().get_rust(),
+        format!(
+            "<{}>",
+            generics
+                .clone()
+                .0
+                .into_iter()
+                .map(|v| Generic::from(v).get_rust())
+                .collect::<Vec<_>>()
+                .join(", ")
+        )
+    ));
+    cg.indent += 1;
+
+    let constructor_comment = constructor.get_comment();
+
+    cg.add_indentedln("#[allow(invalid_value)]");
+    cg.add_indentedln(&constructor_comment);
+
+    (fields, constructor).gen_rust(ctx, cg);
+
+    for item in items.clone() {
+        match item {
+            ClassItem::ImplDecl(_) => {}
+            ClassItem::Method(method) => method.gen_rust(ctx, cg),
+        }
+    }
+
+    cg.indent -= 1;
+    cg.addln("}\n");
+
+    for item in items {
+        match item {
+            ClassItem::ImplDecl(impl_) => {
+                let mut impl_ = impl_.clone();
+
+                impl_.item.trait_ = Some(impl_.item.target);
+                impl_.item.target = TypeExpr::Path(Path(vec![name.clone()]), None);
+
+                impl_.gen_rust(ctx, cg);
+            }
+            ClassItem::Method(_) => {}
+        }
+    }
+
+    if let Some(inherits) = inherits {
+        cg.add("impl std::ops::Deref for ");
+        cg.add(&name.get_rust());
+
+        cg.addln(" {");
+        cg.indent += 1;
+
+        cg.add_indented("type Target = ");
+        cg.add(&inherits.get_rust());
+        cg.addln(";");
+
+        cg.add_indentedln("fn deref(&self) -> &Self::Target {&self._super}");
+
+        cg.indent -= 1;
+        cg.addln("}");
+
+        // Mut
+
+        cg.add("impl std::ops::DerefMut for ");
+        cg.add(&name.get_rust());
+
+        cg.addln(" {");
+        cg.indent += 1;
+
+        cg.add_indentedln("fn deref_mut(&mut self) -> &mut Self::Target {&mut self._super}");
+
+        cg.indent -= 1;
+        cg.addln("}");
+    }
+}
+
+impl GenRust for (&Vec<Spanned<FieldDeclStmt>>, &Spanned<ClassConstructor>) {
+    fn gen_rust(&self, ctx: &mut Context, cg: &mut RustCodegen) {
+        cg.add_indented(&format!(
+            "{}fn new{}(",
+            self.1.item.visibility.get_rust(),
+            self.1.item.generics.get_rust()
+        ));
+
+        let params = self
+            .1
+            .item
+            .params
+            .0
+            .clone()
+            .into_iter()
+            .enumerate()
+            .map(|(idx, mut v)| {
+                v.name = construct_pattern(&v.name, idx);
+                (idx, v)
+            })
+            .collect::<Vec<_>>();
+
+        for (i, param) in &params {
+            if *i > 0 {
+                cg.add(", ");
+            }
+
+            param.gen_rust(ctx, cg);
+        }
+
+        cg.addln(") -> Self {");
+        cg.indent += 1;
+
+        cg.add_indentedln("let mut this: Self = unsafe { std::mem::MaybeUninit::<Self>::zeroed().assume_init() };");
+
+        for field in self.0 {
+            let comment = field.get_comment();
+
+            if let Some(init) = &field.item.init {
+                cg.add_indentedln(&comment);
+
+                cg.add_indentedln(&format!("this.{} = ", field.item.decl.name.get_rust()));
+
+                init.gen_rust(ctx, cg);
+            }
+        }
+
+        cg.add_indented(&format!("this.constructor("));
+
+        for (i, param) in params {
+            if i > 0 {
+                cg.add(", ");
+            }
+
+            ctx.expr_ensure_semicolon = false;
+            param.name.gen_rust(ctx, cg);
+        }
+
+        cg.addln(");");
+
+        cg.add_indentedln("this");
+
+        cg.indent -= 1;
+        cg.add_indentedln("}\n");
+
+        let mut constructor_params = vec![VarDecl {
+            name: Pattern::Path(false, Path(vec![Identifier(String::from("self"))])),
+            type_: Some(TypeExpr::Ref {
+                lifetime: None,
+                mutable: true,
+                ty: Box::new(TypeExpr::Path(
+                    Path(vec![Identifier(String::from("Self"))]),
+                    None,
+                )),
+            }),
+        }];
+
+        constructor_params.append(&mut self.1.item.params.0.clone());
+
+        Spanned {
+            line: self.1.line,
+            column: self.1.column,
+            item: FunctionDecl {
+                visibility: self.1.item.visibility.clone(),
+                name: Identifier(String::from("constructor")),
+                generics: self.1.item.generics.clone(),
+                params: ParamList(constructor_params),
+                return_type: Some(TypeExpr::Tuple(Vec::new())),
+                body: Some(self.1.item.body.clone()),
+            },
+        }
+        .gen_rust(ctx, cg);
+    }
+}
+
+fn construct_pattern(pat: &Pattern, idx: usize) -> Pattern {
+    match pat {
+        Pattern::Literal(v) => Pattern::Literal(v.clone()),
+        Pattern::Path(is_mut, v) => Pattern::Path(*is_mut, v.clone().into()),
+        _ => Pattern::Path(false, Path(vec![Identifier(format!("_{idx}"))])),
+    }
+}
diff --git a/crates/codegen/src/lib.rs b/crates/codegen/src/lib.rs
index 168b0af..2a14d0e 100644
--- a/crates/codegen/src/lib.rs
+++ b/crates/codegen/src/lib.rs
@@ -1,3 +1,4 @@
+pub mod class_decl;
 pub mod expr;
 pub mod statement;
 pub mod top_level;
diff --git a/crates/codegen/src/top_level.rs b/crates/codegen/src/top_level.rs
index 94073c5..1b2ff11 100644
--- a/crates/codegen/src/top_level.rs
+++ b/crates/codegen/src/top_level.rs
@@ -1,6 +1,6 @@
 use mist_parser::ast::*;
 
-use crate::Context;
+use crate::{Context, class_decl};
 
 use crate::{GenRust, GetRust, RustCodegen};
 
@@ -170,109 +170,6 @@ impl GenRust for TopLevel {
     }
 }
 
-impl GenRust for (&Vec<Spanned<FieldDeclStmt>>, &Spanned<ClassConstructor>) {
-    fn gen_rust(&self, ctx: &mut Context, cg: &mut RustCodegen) {
-        cg.add_indented(&format!(
-            "{}fn new{}(",
-            self.1.item.visibility.get_rust(),
-            self.1.item.generics.get_rust()
-        ));
-
-        let params = self
-            .1
-            .item
-            .params
-            .0
-            .clone()
-            .into_iter()
-            .enumerate()
-            .map(|(idx, mut v)| {
-                v.name = construct_pattern(&v.name, idx);
-                (idx, v)
-            })
-            .collect::<Vec<_>>();
-
-        for (i, param) in &params {
-            if *i > 0 {
-                cg.add(", ");
-            }
-
-            param.gen_rust(ctx, cg);
-        }
-
-        cg.addln(") -> Self {");
-        cg.indent += 1;
-
-        cg.add_indentedln("let mut this: Self = unsafe { std::mem::MaybeUninit::<Self>::zeroed().assume_init() };");
-
-        for field in self.0 {
-            let comment = field.get_comment();
-
-            if let Some(init) = &field.item.init {
-                cg.add_indentedln(&comment);
-
-                cg.add_indentedln(&format!("this.{} = ", field.item.decl.name.get_rust()));
-
-                init.gen_rust(ctx, cg);
-            }
-        }
-
-        cg.add_indented(&format!("this.constructor("));
-
-        for (i, param) in params {
-            if i > 0 {
-                cg.add(", ");
-            }
-
-            ctx.expr_ensure_semicolon = false;
-            param.name.gen_rust(ctx, cg);
-        }
-
-        cg.addln(");");
-
-        cg.add_indentedln("this");
-
-        cg.indent -= 1;
-        cg.add_indentedln("}\n");
-
-        let mut constructor_params = vec![VarDecl {
-            name: Pattern::Path(false, Path(vec![Identifier(String::from("self"))])),
-            type_: Some(TypeExpr::Ref {
-                lifetime: None,
-                mutable: true,
-                ty: Box::new(TypeExpr::Path(
-                    Path(vec![Identifier(String::from("Self"))]),
-                    None,
-                )),
-            }),
-        }];
-
-        constructor_params.append(&mut self.1.item.params.0.clone());
-
-        Spanned {
-            line: self.1.line,
-            column: self.1.column,
-            item: FunctionDecl {
-                visibility: self.1.item.visibility.clone(),
-                name: Identifier(String::from("constructor")),
-                generics: self.1.item.generics.clone(),
-                params: ParamList(constructor_params),
-                return_type: Some(TypeExpr::Tuple(Vec::new())),
-                body: Some(self.1.item.body.clone()),
-            },
-        }
-        .gen_rust(ctx, cg);
-    }
-}
-
-fn construct_pattern(pat: &Pattern, idx: usize) -> Pattern {
-    match pat {
-        Pattern::Literal(v) => Pattern::Literal(v.clone()),
-        Pattern::Path(is_mut, v) => Pattern::Path(*is_mut, v.clone().into()),
-        _ => Pattern::Path(false, Path(vec![Identifier(format!("_{idx}"))])),
-    }
-}
-
 impl GenRust for TopLevelKind {
     fn gen_rust(&self, ctx: &mut Context, cg: &mut RustCodegen) {
         match self {
@@ -365,111 +262,17 @@ impl GenRust for TopLevelKind {
                 fields,
                 constructor,
                 items,
-            } => {
-                // Struct decl
-                cg.addln(&format!(
-                    "{}struct {}{} {{",
-                    visibility.get_rust(),
-                    name.clone().get_rust(),
-                    generics.clone().get_rust()
-                ));
-                cg.indent += 1;
-
-                if let Some(inherits) = inherits {
-                    cg.add_indented("pub _super: ");
-                    cg.add(&inherits.get_rust());
-                    cg.addln(",");
-                }
-
-                for field in fields.clone() {
-                    cg.add_indentedln(&field.get_comment());
-                    cg.add_indentedln(&field.item.decl.get_rust());
-                }
-
-                cg.indent -= 1;
-                cg.addln("}\n");
-
-                // Constructor
-                cg.addln(&format!(
-                    "impl{} {}{} {{",
-                    generics.clone().get_rust(),
-                    name.clone().get_rust(),
-                    format!(
-                        "<{}>",
-                        generics
-                            .clone()
-                            .0
-                            .into_iter()
-                            .map(|v| Generic::from(v).get_rust())
-                            .collect::<Vec<_>>()
-                            .join(", ")
-                    )
-                ));
-                cg.indent += 1;
-
-                let constructor_comment = constructor.get_comment();
-
-                cg.add_indentedln("#[allow(invalid_value)]");
-                cg.add_indentedln(&constructor_comment);
-
-                (fields, constructor).gen_rust(ctx, cg);
-
-                for item in items.clone() {
-                    match item {
-                        ClassItem::ImplDecl(_) => {}
-                        ClassItem::Method(method) => method.gen_rust(ctx, cg),
-                    }
-                }
-
-                cg.indent -= 1;
-                cg.addln("}\n");
-
-                for item in items {
-                    match item {
-                        ClassItem::ImplDecl(impl_) => {
-                            let mut impl_ = impl_.clone();
-
-                            impl_.item.trait_ = Some(impl_.item.target);
-                            impl_.item.target = TypeExpr::Path(Path(vec![name.clone()]), None);
-
-                            impl_.gen_rust(ctx, cg);
-                        }
-                        ClassItem::Method(_) => {}
-                    }
-                }
-
-                if let Some(inherits) = inherits {
-                    cg.add("impl std::ops::Deref for ");
-                    cg.add(&name.get_rust());
-
-                    cg.addln(" {");
-                    cg.indent += 1;
-
-                    cg.add_indented("type Target = ");
-                    cg.add(&inherits.get_rust());
-                    cg.addln(";");
-
-                    cg.add_indentedln("fn deref(&self) -> &Self::Target {&self._super}");
-
-                    cg.indent -= 1;
-                    cg.addln("}");
-
-                    // Mut
-
-                    cg.add("impl std::ops::DerefMut for ");
-                    cg.add(&name.get_rust());
-
-                    cg.addln(" {");
-                    cg.indent += 1;
-
-                    cg.add_indentedln(
-                        "fn deref_mut(&mut self) -> &mut Self::Target {&mut self._super}",
-                    );
-
-                    cg.indent -= 1;
-                    cg.addln("}");
-                }
-            }
+            } => class_decl::class_decl(
+                ctx,
+                cg,
+                visibility,
+                name,
+                generics,
+                inherits,
+                fields,
+                constructor,
+                items,
+            ),
         }
     }
 }