From 0955bca5bc0a410840430a8afb89f29522d2999e Mon Sep 17 00:00:00 2001
From: Klesti Selimaj <klesti.selimay@icloud.com>
Date: Fri, 5 Jun 2026 12:14:19 +0200
Subject: [PATCH] Updated closures

---
 crates/codegen/src/expr.rs              | 45 +++++++++++++++----------
 crates/parser/src/ast/expr.rs           |  6 +++-
 crates/parser/src/grammar.pest          |  7 ++--
 crates/parser/src/parser/common/expr.rs | 20 +++++------
 4 files changed, 46 insertions(+), 32 deletions(-)

diff --git a/crates/codegen/src/expr.rs b/crates/codegen/src/expr.rs
index 8cdbaca..fc4f41d 100644
--- a/crates/codegen/src/expr.rs
+++ b/crates/codegen/src/expr.rs
@@ -101,6 +101,32 @@ impl GenRust for Expression {
                 cg.add(op);
                 rhs.gen_rust(ctx, cg);
             }
+
+            Expression::Closure {
+                return_type,
+                params,
+                body,
+            } => {
+                cg.add("|");
+                for (i, arg) in params.iter().enumerate() {
+                    if i > 0 {
+                        cg.add(", ");
+                    }
+
+                    arg.gen_rust(ctx, cg);
+                }
+                cg.add("| ");
+
+                if let Some(ty) = return_type {
+                    cg.add("-> ");
+                    cg.add(&ty.get_rust());
+                    cg.add(" ");
+
+                    cg.ensure_brackets_expr(ctx, body);
+                } else {
+                    body.gen_rust(ctx, cg);
+                }
+            }
         }
 
         if ensure_semicolon {
@@ -114,30 +140,13 @@ impl GenRust for Expression {
 }
 
 impl GenRust for Prefix {
-    fn gen_rust(&self, ctx: &mut Context, cg: &mut RustCodegen) {
+    fn gen_rust(&self, _ctx: &mut Context, cg: &mut RustCodegen) {
         match self {
             Self::Deref => cg.add("*"),
             Self::Ref => cg.add("&"),
             Self::RefMut => cg.add("&mut "),
             Self::Not => cg.add("!"),
             Self::Neg => cg.add("-"),
-            Self::Closure(ty, args) => {
-                cg.add("|");
-                for (i, arg) in args.iter().enumerate() {
-                    if i > 0 {
-                        cg.add(", ");
-                    }
-
-                    arg.gen_rust(ctx, cg);
-                }
-                cg.add("| ");
-
-                if let Some(ty) = ty {
-                    cg.add("-> ");
-                    cg.add(&ty.get_rust());
-                    cg.add(" ");
-                }
-            }
         }
     }
 }
diff --git a/crates/parser/src/ast/expr.rs b/crates/parser/src/ast/expr.rs
index 969cf21..2f91ece 100644
--- a/crates/parser/src/ast/expr.rs
+++ b/crates/parser/src/ast/expr.rs
@@ -7,6 +7,11 @@ pub enum Expression {
     Literal(Literal),
     Path(ExprPath),
     Statement(Box<Statement>),
+    Closure {
+        return_type: Option<TypeExpr>,
+        params: Vec<VarDecl>,
+        body: Box<Expression>,
+    },
     Fix {
         initial: Box<Expression>,
         prefixes: Vec<Prefix>,
@@ -72,7 +77,6 @@ pub enum Prefix {
     Deref,
     Not,
     Neg,
-    Closure(Option<TypeExpr>, Vec<VarDecl>),
 }
 
 #[derive(Debug, Clone, Serialize)]
diff --git a/crates/parser/src/grammar.pest b/crates/parser/src/grammar.pest
index e4f748d..ab6daaf 100644
--- a/crates/parser/src/grammar.pest
+++ b/crates/parser/src/grammar.pest
@@ -30,6 +30,7 @@ keyword = {
   | "false"
   | "dyn"
   | "loop"
+  | "fn"
 }
 
 identifier = @{
@@ -448,7 +449,7 @@ match_stmt = {
 // CLOSURES
 // ------------------------------------------------------
 
-closure = { type_expr? ~ "|" ~ param_list ~ "|" }
+closure = { type_expr? ~ "fn" ~ "(" ~ param_list ~ ")" ~ expr }
 
 // ------------------------------------------------------
 // TUPLES & ARRAYS
@@ -490,6 +491,7 @@ expr_path = {
 
 primary = {
     control_flow
+  | closure
   | basic_stmt
   | literal
   | expr_path
@@ -571,8 +573,7 @@ not_px     = { "!" }
 neg_px     = { "-" }
 
 prefix = {
-    closure
-  | deref_px
+    deref_px
   | mut_ref_px
   | ref_px
   | not_px
diff --git a/crates/parser/src/parser/common/expr.rs b/crates/parser/src/parser/common/expr.rs
index b3236d8..3834f1d 100644
--- a/crates/parser/src/parser/common/expr.rs
+++ b/crates/parser/src/parser/common/expr.rs
@@ -75,6 +75,16 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for Expression {
                 ))
             }
 
+            Rule::closure => {
+                ast_expr!(Self::Closure {
+                    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),
+                })
+            }
+
             Rule::primary => pair.into_inner().next().unwrap().try_into(),
             Rule::static_path => ast_expr!(Expression::Path(pair.try_into())),
             Rule::literal => ast_expr!(Expression::Literal(pair.try_into())),
@@ -108,16 +118,6 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for Prefix {
             Rule::ref_px => Self::Ref,
             Rule::not_px => Self::Not,
             Rule::neg_px => Self::Neg,
-            Rule::closure => {
-                let mut inner = pair.into_inner();
-
-                return ast_expr!(Self::Closure(
-                    consume_rule(&mut inner, Rule::type_expr)
-                        .map(TypeExpr::try_from)
-                        .transpose(),
-                    collect_recovered(inner.next().unwrap().into_inner())
-                ));
-            }
 
             _ => return AstError::bug_unimplemented(pair),
         })