From 316e60eedbea54a06676070f58de65d14580fb03 Mon Sep 17 00:00:00 2001
From: Toni <antpiasecki@gmail.com>
Date: Tue, 10 Mar 2026 18:32:58 +0100
Subject: [PATCH] add Stmt::Struct and Expr::New

---
 src/analyzer.rs       |  2 ++
 src/codegen_x86_64.rs | 12 +++++++++---
 src/parser.rs         | 40 +++++++++++++++++++++++++++++++++++++++-
 src/tokenizer.rs      |  4 ++++
 4 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/src/analyzer.rs b/src/analyzer.rs
index 1b33d95..44f5020 100644
--- a/src/analyzer.rs
+++ b/src/analyzer.rs
@@ -117,6 +117,7 @@ impl Analyzer {
                 }
                 self.functions.insert(name.lexeme.clone(), -1);
             }
+            Stmt::Struct { name: _, fields: _ } => todo!(),
         }
         Ok(())
     }
@@ -188,6 +189,7 @@ impl Analyzer {
             Expr::AddrOf { op: _, expr } => {
                 self.analyze_expr(expr)?;
             }
+            Expr::New(_) => {}
         }
         Ok(())
     }
diff --git a/src/codegen_x86_64.rs b/src/codegen_x86_64.rs
index 40040a7..dcd54ab 100644
--- a/src/codegen_x86_64.rs
+++ b/src/codegen_x86_64.rs
@@ -6,8 +6,9 @@ use crate::{
     tokenizer::{TokenType, ZernError, error},
 };
 
-pub struct Var {
+struct Var {
     pub stack_offset: usize,
+    pub var_type: String,
 }
 
 pub struct Env {
@@ -37,19 +38,20 @@ impl Env {
         self.scopes.pop();
     }
 
-    pub fn define_var(&mut self, name: String, _var_type: String) -> usize {
+    pub fn define_var(&mut self, name: String, var_type: String) -> usize {
         let offset = self.next_offset;
         self.next_offset += 8;
         self.scopes.last_mut().unwrap().insert(
             name,
             Var {
                 stack_offset: offset,
+                var_type,
             },
         );
         offset
     }
 
-    pub fn get_var(&self, name: &str) -> Option<&Var> {
+    fn get_var(&self, name: &str) -> Option<&Var> {
         for scope in self.scopes.iter().rev() {
             if let Some(var) = scope.get(name) {
                 return Some(var);
@@ -315,6 +317,9 @@ _builtin_environ:
             Stmt::Extern(name) => {
                 emit!(&mut self.output, "extern {}", name.lexeme);
             }
+            Stmt::Struct { name: _, fields: _ } => {
+                // handled in the analyzer
+            }
         }
         Ok(())
     }
@@ -622,6 +627,7 @@ _builtin_environ:
                     return error!(&op.loc, "can only take address of variables and functions");
                 }
             },
+            Expr::New(_) => todo!(),
         }
         Ok(())
     }
diff --git a/src/parser.rs b/src/parser.rs
index 8135faa..b25849b 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -45,6 +45,10 @@ pub enum Stmt {
     Break,
     Continue,
     Extern(Token),
+    Struct {
+        name: Token,
+        fields: Vec<Param>,
+    },
 }
 
 #[derive(Debug, Clone)]
@@ -84,6 +88,7 @@ pub enum Expr {
         op: Token,
         expr: Box<Expr>,
     },
+    New(Token),
 }
 
 // TODO: currently they are all just 64 bit values
@@ -127,6 +132,9 @@ impl Parser {
             if self.match_token(&[TokenType::KeywordConst]) {
                 return self.const_declaration();
             }
+            if self.match_token(&[TokenType::KeywordStruct]) {
+                return self.struct_declaration();
+            }
             return error!(
                 self.peek().loc,
                 "statements not allowed outside function body"
@@ -182,6 +190,29 @@ impl Parser {
         })
     }
 
+    fn struct_declaration(&mut self) -> Result<Stmt, ZernError> {
+        let name = self.consume(TokenType::Identifier, "expected struct name")?;
+
+        self.consume(TokenType::Indent, "expected indent after struct name")?;
+
+        let mut fields = vec![];
+        while !self.eof() && !self.check(&TokenType::Dedent) {
+            let var_name = self.consume(TokenType::Identifier, "expected field name")?;
+            self.consume(TokenType::Colon, "expected ':' after field name")?;
+
+            let var_type = self.consume(TokenType::Identifier, "expected field type")?;
+            if !TYPES.contains(&var_type.lexeme.as_str()) {
+                return error!(&name.loc, format!("unknown type: {}", var_type.lexeme));
+            }
+
+            fields.push(Param { var_type, var_name });
+        }
+
+        self.consume(TokenType::Dedent, "expected dedent after the struct fields")?;
+
+        Ok(Stmt::Struct { name, fields })
+    }
+
     fn let_declaration(&mut self) -> Result<Stmt, ZernError> {
         let name = self.consume(TokenType::Identifier, "expected variable name")?;
 
@@ -524,10 +555,17 @@ impl Parser {
             self.consume(TokenType::RightBracket, "expected ']' after values")?;
 
             Ok(Expr::ArrayLiteral(xs))
+        } else if self.match_token(&[TokenType::KeywordNew]) {
+            let struct_name =
+                self.consume(TokenType::Identifier, "expected struct name after 'new'")?;
+            Ok(Expr::New(struct_name))
         } else if self.match_token(&[TokenType::Identifier]) {
             Ok(Expr::Variable(self.previous().clone()))
         } else {
-            error!(self.peek().loc, "expected expression")
+            error!(
+                self.peek().loc,
+                format!("expected expression, got '{}'", self.peek().lexeme)
+            )
         }
     }
 
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index 441db72..9dacccf 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -52,6 +52,8 @@ pub enum TokenType {
     KeywordContinue,
     KeywordExtern,
     KeywordExport,
+    KeywordStruct,
+    KeywordNew,
 
     Indent,
     Dedent,
@@ -347,6 +349,8 @@ impl Tokenizer {
             "continue" => TokenType::KeywordContinue,
             "extern" => TokenType::KeywordExtern,
             "export" => TokenType::KeywordExport,
+            "struct" => TokenType::KeywordStruct,
+            "new" => TokenType::KeywordNew,
             "true" => TokenType::True,
             "false" => TokenType::False,
             _ => TokenType::Identifier,