Cast values during array destructuring

UPGRADING

@@ -427,6 +427,8 @@ PHP 8.0 UPGRADE NOTES
     RFC: https://wiki.php.net/rfc/variable_syntax_tweaks
   . Added Stringable.
     RFC: https://wiki.php.net/rfc/stringable
+  . Added type casting in array destructuring expressions.
+    RFC: https://wiki.php.net/rfc/typecast_array_desctructuring
 
 - Date:
   . Added DateTime::createFromInterface() and

Zend/tests/list/list_casting_001.phpt

@@ -0,0 +1,21 @@
+--TEST--
+"Cast during unpacking - general" list()
+--FILE--
+<?php
+$arr = [1, 2, 3, 4];
+
+list((string) $a, (bool) $b, (float) $c, $d) = $arr;
+var_dump($a, $b, $c, $d);
+
+[(string) $a, (bool) $b, (float) $c, $d] = $arr;
+var_dump($a, $b, $c, $d);
+?>
+--EXPECT--
+string(1) "1"
+bool(true)
+float(3)
+int(4)
+string(1) "1"
+bool(true)
+float(3)
+int(4)

Zend/tests/list/list_casting_002.phpt

@@ -0,0 +1,21 @@
+--TEST--
+"Cast during unpacking - non existing values" list()
+--FILE--
+<?php
+$arr = [];
+
+@list((string) $a, (bool) $b, (float) $c, $d) = $arr;
+var_dump($a, $b, $c, $d);
+
+@[(string) $a, (bool) $b, (float) $c, $d] = $arr;
+var_dump($a, $b, $c, $d);
+?>
+--EXPECT--
+string(0) ""
+bool(false)
+float(0)
+NULL
+string(0) ""
+bool(false)
+float(0)
+NULL

Zend/tests/list/list_casting_003.phpt

@@ -0,0 +1,21 @@
+--TEST--
+"Cast during unpacking - nested unpacking" list()
+--FILE--
+<?php
+$arr = [1, [2, 3], 4];
+
+list((string) $a, list((bool) $b, (float) $c), $d) = $arr;
+var_dump($a, $b, $c, $d);
+
+[(string) $a, [(bool) $b, (float) $c], $d] = $arr;
+var_dump($a, $b, $c, $d);
+?>
+--EXPECT--
+string(1) "1"
+bool(true)
+float(3)
+int(4)
+string(1) "1"
+bool(true)
+float(3)
+int(4)

Zend/tests/list/list_casting_004.phpt

@@ -0,0 +1,21 @@
+--TEST--
+"Cast during unpacking - associative unpacking" list()
+--FILE--
+<?php
+$arr = ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4];
+
+list('a' => (string) $a, 'b' => (bool) $b, 'c' => (float) $c, 'd' => $d) = $arr;
+var_dump($a, $b, $c, $d);
+
+['a' => (string) $a, 'b' => (bool) $b, 'c' => (float) $c, 'd' => $d] = $arr;
+var_dump($a, $b, $c, $d);
+?>
+--EXPECT--
+string(1) "1"
+bool(true)
+float(3)
+int(4)
+string(1) "1"
+bool(true)
+float(3)
+int(4)

Zend/tests/list/list_casting_005.phpt

@@ -0,0 +1,21 @@
+--TEST--
+"Cast during unpacking - nested associative unpacking" list()
+--FILE--
+<?php
+$arr = ['a' => 1, 'b' => ['b1' => 2, 'b2' => 3], 'c' => 4];
+
+list('a' => (string) $a, 'b' => list('b1' => (bool) $b, 'b2' => (float) $c), 'c' => $d) = $arr;
+var_dump($a, $b, $c, $d);
+
+['a' => (string) $a, 'b' => ['b1' => (bool) $b, 'b2' => (float) $c], 'c' => $d] = $arr;
+var_dump($a, $b, $c, $d);
+?>
+--EXPECT--
+string(1) "1"
+bool(true)
+float(3)
+int(4)
+string(1) "1"
+bool(true)
+float(3)
+int(4)

Zend/tests/list/list_casting_006.phpt

@@ -0,0 +1,27 @@
+--TEST--
+"Cast during unpacking - foreach loop" list()
+--FILE--
+<?php
+$arr = [[1, 2, 3], [4, 5, 6]];
+
+foreach ($arr as list((string) $a, (bool) $b, $c)) {
+    var_dump($a, $b, $c);
+}
+
+foreach ($arr as [(string) $a, (bool) $b, $c]) {
+    var_dump($a, $b, $c);
+}
+?>
+--EXPECT--
+string(1) "1"
+bool(true)
+int(3)
+string(1) "4"
+bool(true)
+int(6)
+string(1) "1"
+bool(true)
+int(3)
+string(1) "4"
+bool(true)
+int(6)

Zend/zend_compile.c

@@ -2809,6 +2809,25 @@ static zend_bool zend_propagate_list_refs(zend_ast *ast) { /* {{{ */
 }
 /* }}} */
 
+void zend_compile_cast(znode *result, zend_ast *ast) /* {{{ */
+{
+	zend_ast *expr_ast = ast->child[0];
+	znode expr_node;
+	zend_op *opline;
+
+	zend_compile_expr(&expr_node, expr_ast);
+
+	if (ast->attr == _IS_BOOL) {
+		opline = zend_emit_op_tmp(result, ZEND_BOOL, &expr_node, NULL);
+	} else if (ast->attr == IS_NULL) {
+		zend_error(E_COMPILE_ERROR, "The (unset) cast is no longer supported");
+	} else {
+		opline = zend_emit_op_tmp(result, ZEND_CAST, &expr_node, NULL);
+		opline->extended_value = ast->attr;
+	}
+}
+/* }}} */
+
 static void zend_compile_list_assign(
 		znode *result, zend_ast *ast, znode *expr_node, zend_bool old_style) /* {{{ */
 {
@@ -2824,6 +2843,7 @@ static void zend_compile_list_assign(
 
 	for (i = 0; i < list->children; ++i) {
 		zend_ast *elem_ast = list->child[i];
+		zend_ast *cast_ast = NULL;
 		zend_ast *var_ast, *key_ast;
 		znode fetch_result, dim_node;
 		zend_op *opline;
@@ -2867,6 +2887,11 @@ static void zend_compile_list_assign(
 			Z_TRY_ADDREF(expr_node->u.constant);
 		}
 
+		if (var_ast->kind == ZEND_AST_CAST) {
+			cast_ast = var_ast;
+			var_ast = var_ast->child[0];
+		}
+
 		zend_verify_list_assign_target(var_ast, old_style);
 
 		opline = zend_emit_op(&fetch_result,
@@ -2886,6 +2911,11 @@ static void zend_compile_list_assign(
 		} else {
 			zend_emit_assign_znode(var_ast, &fetch_result);
 		}
+
+		if (cast_ast) {
+			zend_compile_cast(&fetch_result, cast_ast);
+			zend_emit_assign_znode(var_ast, &fetch_result);
+		}
 	}
 
 	if (has_elems == 0) {
@@ -7694,25 +7724,6 @@ void zend_compile_pre_incdec(znode *result, zend_ast *ast) /* {{{ */
 }
 /* }}} */
 
-void zend_compile_cast(znode *result, zend_ast *ast) /* {{{ */
-{
-	zend_ast *expr_ast = ast->child[0];
-	znode expr_node;
-	zend_op *opline;
-
-	zend_compile_expr(&expr_node, expr_ast);
-
-	if (ast->attr == _IS_BOOL) {
-		opline = zend_emit_op_tmp(result, ZEND_BOOL, &expr_node, NULL);
-	} else if (ast->attr == IS_NULL) {
-		zend_error(E_COMPILE_ERROR, "The (unset) cast is no longer supported");
-	} else {
-		opline = zend_emit_op_tmp(result, ZEND_CAST, &expr_node, NULL);
-		opline->extended_value = ast->attr;
-	}
-}
-/* }}} */
-
 static void zend_compile_shorthand_conditional(znode *result, zend_ast *ast) /* {{{ */
 {
 	zend_ast *cond_ast = ast->child[0];