From 1e7e32aff264702d74c607877aa18a58b47fb656 Mon Sep 17 00:00:00 2001
From: Shylock Hg <tcath2s@icloud.com>
Date: Sat, 15 Feb 2025 11:21:06 +0800
Subject: [PATCH] fix: remove decl from Ast.

---
 tigerc/src/ast.rs            | 10 ++--------
 tigerc/src/escape.rs         | 13 ++++---------
 tigerc/src/parser.rs         | 12 ++++--------
 tigerc/src/type_inference.rs |  5 +----
 4 files changed, 11 insertions(+), 29 deletions(-)

diff --git a/tigerc/src/ast.rs b/tigerc/src/ast.rs
index 476122e..ad5478f 100644
--- a/tigerc/src/ast.rs
+++ b/tigerc/src/ast.rs
@@ -5,17 +5,11 @@ use std::rc::Rc;
 use crate::ident_pool::Symbol;
 
 #[derive(Debug, PartialEq, Eq)]
-pub enum Ast {
-    Decl(Decl),
-    Expr(Expr),
-}
+pub struct Ast(pub Expr);
 
 impl Display for Ast {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Ast::Decl(decl) => write!(f, "{}", decl),
-            Ast::Expr(expr) => write!(f, "{}", expr),
-        }
+        write!(f, "{}", self.0)
     }
 }
 
diff --git a/tigerc/src/escape.rs b/tigerc/src/escape.rs
index 7da9cc8..531ca74 100644
--- a/tigerc/src/escape.rs
+++ b/tigerc/src/escape.rs
@@ -16,12 +16,7 @@ impl Escape {
 
     // mark escape parameters/local variables
     pub fn escape(&mut self, ast: &mut ast::Ast) {
-        match ast {
-            ast::Ast::Expr(expr) => {
-                self.escape_expr(expr, 0, 0, &None);
-            }
-            _ => unreachable!(),
-        }
+        self.escape_expr(&mut ast.0, 0, 0, &None);
     }
 
     // depth of nested function
@@ -185,7 +180,7 @@ mod tests {
         let it = tokenize(doc);
         let mut parser = Parser::new(Box::new(it));
         let mut ast = parser.parse();
-        let expected = ast::Ast::Expr(ast::Expr::Let(ast::Let {
+        let expected = ast::Ast(ast::Expr::Let(ast::Let {
             decls: vec![
                 ast::Decl::Type(ast::TypeDecl {
                     type_name: ident_pool::symbol("r1"),
@@ -239,7 +234,7 @@ mod tests {
         let mut ast = parser.parse();
         Escape::new().escape(&mut ast);
         let escape = match ast {
-            ast::Ast::Expr(ast::Expr::Let(ast::Let { decls, .. })) => {
+            ast::Ast(ast::Expr::Let(ast::Let { decls, .. })) => {
                 let decl = decls.get(1).unwrap();
                 match decl {
                     ast::Decl::Var(v) => *v.escape.borrow(),
@@ -268,7 +263,7 @@ mod tests {
         let mut ast = parser.parse();
         Escape::new().escape(&mut ast);
         let escape = match ast {
-            ast::Ast::Expr(ast::Expr::Let(ast::Let { decls, .. })) => {
+            ast::Ast(ast::Expr::Let(ast::Let { decls, .. })) => {
                 let decl = decls.get(2).unwrap();
                 match decl {
                     ast::Decl::Func(f) => *f.args[0].escape.borrow(),
diff --git a/tigerc/src/parser.rs b/tigerc/src/parser.rs
index c0aab48..8ba4be3 100644
--- a/tigerc/src/parser.rs
+++ b/tigerc/src/parser.rs
@@ -65,11 +65,7 @@ impl<'a> Parser<'a> {
     }
 
     pub fn parse(&mut self) -> ast::Ast {
-        if let Ok(decl) = self.parse_decl() {
-            ast::Ast::Decl(decl)
-        } else {
-            ast::Ast::Expr(self.parse_expr())
-        }
+        ast::Ast(self.parse_expr())
     }
 
     fn bump(&mut self) -> Option<Posed<Token>> {
@@ -635,7 +631,7 @@ mod tests {
         let it = tokenize(doc);
         let mut parser = Parser::new(Box::new(it));
         let ast = parser.parse();
-        assert_eq!(ast, ast::Ast::Expr(ast::Expr::Literal(ast::Value::Nil)));
+        assert_eq!(ast, ast::Ast(ast::Expr::Literal(ast::Value::Nil)));
     }
 
     #[test]
@@ -646,7 +642,7 @@ mod tests {
         let it = tokenize(doc);
         let mut parser = Parser::new(Box::new(it));
         let ast = parser.parse();
-        assert_eq!(ast, ast::Ast::Expr(ast::Expr::Literal(ast::Value::Nothing)));
+        assert_eq!(ast, ast::Ast(ast::Expr::Literal(ast::Value::Nothing)));
     }
 
     #[test]
@@ -659,7 +655,7 @@ mod tests {
         let ast = parser.parse();
         assert_eq!(
             ast,
-            ast::Ast::Expr(ast::Expr::Binary(ast::Binary::Ne(
+            ast::Ast(ast::Expr::Binary(ast::Binary::Ne(
                 Box::new(ast::Expr::Literal(ast::Value::Int(1))),
                 Box::new(ast::Expr::Literal(ast::Value::Int(2))),
             )))
diff --git a/tigerc/src/type_inference.rs b/tigerc/src/type_inference.rs
index 0b2e10a..7c1c172 100644
--- a/tigerc/src/type_inference.rs
+++ b/tigerc/src/type_inference.rs
@@ -193,10 +193,7 @@ impl TypeInference {
     }
 
     pub fn infer(&mut self, ast: &ast::Ast) -> Result<type_ast::TypeAst> {
-        match ast {
-            ast::Ast::Decl(decl) => Ok(type_ast::TypeAst::TypeDecl(self.infer_decl(decl)?)),
-            ast::Ast::Expr(expr) => Ok(type_ast::TypeAst::TypeExpr(self.infer_expr(expr)?)),
-        }
+        Ok(type_ast::TypeAst::TypeExpr(self.infer_expr(&ast.0)?))
     }
 
     // TODO maybe return void