From 2f12f5ac53f531f8ddda80b89beecaf3c021910c Mon Sep 17 00:00:00 2001
From: Klesti Selimaj <klesti.selimay@icloud.com>
Date: Tue, 23 Jun 2026 17:41:49 +0200
Subject: [PATCH] Updated closure syntax

---
 crates/parser/src/grammar.pest          | 12 ++++++------
 crates/parser/src/parser/common/expr.rs |  2 +-
 mist-test/src/common/expr_test.mist     |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/crates/parser/src/grammar.pest b/crates/parser/src/grammar.pest
index d4f09b7..c254af8 100644
--- a/crates/parser/src/grammar.pest
+++ b/crates/parser/src/grammar.pest
@@ -30,7 +30,6 @@ keyword = {
   | "false"
   | "dyn"
   | "loop"
-  | "fn"
   | "unsafe"
   | "override"
 }
@@ -200,8 +199,8 @@ attributes = {
 // DECLARATION HELPERS
 // ======================================================
 var_decl = {
-    ("let" ~ pattern) |
-    type_expr ~ (!tuple_pattern ~ pattern)
+    ("let" ~ pattern)
+  | type_expr ~ (!tuple_pattern ~ pattern)
 }
 
 field = {
@@ -343,7 +342,8 @@ function_decl = {
 // ======================================================
 
 top_level = {
-    mod_attribute | (attributes ~ (import | impl_for_decl | impl_decl | trait_decl | struct_decl | enum_decl | class_decl | declare_module | function_decl))
+    mod_attribute
+  | (attributes ~ (import | impl_for_decl | impl_decl | trait_decl | struct_decl | enum_decl | class_decl | declare_module | function_decl))
 }
 
 // ======================================================
@@ -466,8 +466,8 @@ match_stmt = {
 // ------------------------------------------------------
 
 closure = {
-    "fn" ~ "(" ~ param_list ~ ")" ~ type_expr? ~ block
-  | "fn" ~ "(" ~ param_list ~ ")" ~ type_expr? ~ "->" ~ expr
+    ("(" ~ param_list ~ ")" ~ "=>" ~ expr)
+    | (type_expr ~ "(" ~ param_list ~ ")" ~ "=>" ~ expr)
 }
 
 // ------------------------------------------------------
diff --git a/crates/parser/src/parser/common/expr.rs b/crates/parser/src/parser/common/expr.rs
index 01ae58b..5f4afa6 100644
--- a/crates/parser/src/parser/common/expr.rs
+++ b/crates/parser/src/parser/common/expr.rs
@@ -77,10 +77,10 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for Expression {
 
             Rule::closure => {
                 ast_expr!(Expression::Closure {
-                    params: collect_recovered(inner.next().unwrap().into_inner()),
                     return_type: consume_rule(&mut inner, Rule::type_expr)
                         .map(TypeExpr::try_from)
                         .transpose(),
+                    params: collect_recovered(inner.next().unwrap().into_inner()),
                     body: Expression::try_from(inner.next().unwrap()).map(Box::new),
                 })
             }
diff --git a/mist-test/src/common/expr_test.mist b/mist-test/src/common/expr_test.mist
index 888447b..c344a00 100644
--- a/mist-test/src/common/expr_test.mist
+++ b/mist-test/src/common/expr_test.mist
@@ -88,7 +88,7 @@ pub void test_as_cast() {
 }
 
 pub void test_closure() {
-    let add = fn(a, b) -> a + b;
+    let add = (a, b) => a + b;
     assert_eq!(add(2, 3), 5);
 }