From c0bdb4a47b2a9f61683281f9b7fff5ce19a5da41 Mon Sep 17 00:00:00 2001
From: Swastik Baranwal <swstkbaranwal@gmail.com>
Date: Sun, 8 Jun 2025 15:21:29 +0530
Subject: [PATCH] v: implement `expr.remove_para` (#24669)

---
 vlib/v/ast/ast.v           | 11 ++++++++++-
 vlib/v/checker/assign.v    |  9 ++-------
 vlib/v/checker/checker.v   |  5 +----
 vlib/v/checker/fn.v        |  4 +---
 vlib/v/fmt/fmt.v           |  8 ++------
 vlib/v/gen/golang/golang.v |  8 ++------
 vlib/v/parser/expr.v       |  4 +---
 7 files changed, 19 insertions(+), 30 deletions(-)

diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index 943e661be9..18ae4d85c4 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -1571,7 +1571,7 @@ pub:
 	has_len       bool
 	has_cap       bool
 	has_init      bool
-	has_index     bool // true if temp variable index is used	
+	has_index     bool // true if temp variable index is used
 pub mut:
 	exprs        []Expr // `[expr, expr]` or `[expr]Type{}` for fixed array
 	len_expr     Expr   // len: expr
@@ -2728,6 +2728,15 @@ pub fn (expr Expr) is_reference() bool {
 	}
 }
 
+// remove_par removes all parenthesis and gets the innermost Expr
+pub fn (mut expr Expr) remove_par() Expr {
+	mut e := expr
+	for mut e is ParExpr {
+		e = e.expr
+	}
+	return e
+}
+
 // is `expr` a literal, i.e. it does not depend on any other declarations (C compile time constant)
 pub fn (expr Expr) is_literal() bool {
 	return match expr {
diff --git a/vlib/v/checker/assign.v b/vlib/v/checker/assign.v
index d11f5955d0..94b5302fb6 100644
--- a/vlib/v/checker/assign.v
+++ b/vlib/v/checker/assign.v
@@ -339,10 +339,7 @@ fn (mut c Checker) assign_stmt(mut node ast.AssignStmt) {
 		if left is ast.ParExpr && is_decl {
 			c.error('parentheses are not supported on the left side of `:=`', left.pos())
 		}
-
-		for left is ast.ParExpr {
-			left = (left as ast.ParExpr).expr
-		}
+		left = left.remove_par()
 		is_assign := node.op in [.assign, .decl_assign]
 		match mut left {
 			ast.Ident {
@@ -943,9 +940,7 @@ or use an explicit `unsafe{ a[..] }`, if you do not want a copy of the slice.',
 			c.inside_ref_lit = old_inside_ref_lit
 			if right_node.op == .amp {
 				mut expr := right_node.right
-				for mut expr is ast.ParExpr {
-					expr = expr.expr
-				}
+				expr = expr.remove_par()
 				if mut expr is ast.Ident {
 					if mut expr.obj is ast.Var {
 						v := expr.obj
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index a18225b3e9..eca69b8ccc 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -4767,10 +4767,7 @@ fn (mut c Checker) prefix_expr(mut node ast.PrefixExpr) ast.Type {
 	c.inside_ref_lit = old_inside_ref_lit
 	node.right_type = right_type
 	mut expr := node.right
-	// if ParExpr get the innermost expr
-	for mut expr is ast.ParExpr {
-		expr = expr.expr
-	}
+	expr = expr.remove_par()
 	if node.op == .amp {
 		if expr is ast.Nil {
 			c.error('invalid operation: cannot take address of nil', expr.pos())
diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index bbc8a23fc8..3f05551496 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -1983,9 +1983,7 @@ fn (mut c Checker) check_type_and_visibility(name string, type_idx int, expected
 fn (mut c Checker) method_call(mut node ast.CallExpr, mut continue_check &bool) ast.Type {
 	// `(if true { 'foo.bar' } else { 'foo.bar.baz' }).all_after('foo.')`
 	mut left_expr := node.left
-	for mut left_expr is ast.ParExpr {
-		left_expr = left_expr.expr
-	}
+	left_expr = left_expr.remove_par()
 	if mut left_expr is ast.IfExpr {
 		if left_expr.branches.len > 0 && left_expr.has_else {
 			mut last_stmt := left_expr.branches[0].stmts.last()
diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index 850af93b78..00e6a0bd9d 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -856,9 +856,7 @@ fn expr_is_single_line(expr ast.Expr) bool {
 pub fn (mut f Fmt) assert_stmt(node ast.AssertStmt) {
 	f.write('assert ')
 	mut expr := node.expr
-	for mut expr is ast.ParExpr {
-		expr = expr.expr
-	}
+	expr = expr.remove_par()
 	f.expr(expr)
 	if node.extra !is ast.EmptyExpr {
 		f.write(', ')
@@ -2935,9 +2933,7 @@ pub fn (mut f Fmt) or_expr(node ast.OrExpr) {
 
 pub fn (mut f Fmt) par_expr(node ast.ParExpr) {
 	mut expr := node.expr
-	for mut expr is ast.ParExpr {
-		expr = expr.expr
-	}
+	expr = expr.remove_par()
 	requires_paren := expr !is ast.Ident || node.comments.len > 0
 	if requires_paren {
 		f.par_level++
diff --git a/vlib/v/gen/golang/golang.v b/vlib/v/gen/golang/golang.v
index aba2c7e15b..52c6891a0f 100644
--- a/vlib/v/gen/golang/golang.v
+++ b/vlib/v/gen/golang/golang.v
@@ -729,9 +729,7 @@ fn expr_is_single_line(expr ast.Expr) bool {
 pub fn (mut f Gen) assert_stmt(node ast.AssertStmt) {
 	f.write('assert ')
 	mut expr := node.expr
-	for mut expr is ast.ParExpr {
-		expr = expr.expr
-	}
+	expr = expr.remove_par()
 	f.expr(expr)
 	f.writeln('')
 }
@@ -2058,9 +2056,7 @@ pub fn (mut f Gen) par_expr(node ast.ParExpr) {
 		f.write('(')
 	}
 	mut expr := node.expr
-	for mut expr is ast.ParExpr {
-		expr = expr.expr
-	}
+	expr = expr.remove_par()
 	f.expr(expr)
 	if requires_paren {
 		f.par_level--
diff --git a/vlib/v/parser/expr.v b/vlib/v/parser/expr.v
index 707b6e3d5b..a7cc6832d6 100644
--- a/vlib/v/parser/expr.v
+++ b/vlib/v/parser/expr.v
@@ -790,9 +790,7 @@ fn (mut p Parser) infix_expr(left ast.Expr) ast.Expr {
 	p.inside_assign_rhs = old_assign_rhs
 	if op in [.plus, .minus, .mul, .div, .mod, .lt, .eq] && mut right is ast.PrefixExpr {
 		mut right_expr := right.right
-		for mut right_expr is ast.ParExpr {
-			right_expr = right_expr.expr
-		}
+		right_expr = right_expr.remove_par()
 		if right.op in [.plus, .minus, .mul, .div, .mod, .lt, .eq] && right_expr.is_pure_literal() {
 			p.error_with_pos('invalid expression: unexpected token `${op}`', right_op_pos)
 		}