Add parser support for constraint type

Author: Girgias

Zend/tests/type_declarations/associated/associated_type_with_constraint.phpt

@@ -0,0 +1,32 @@
+--TEST--
+Associated type with a constraint
+--FILE--
+<?php
+
+interface I {
+    type T : int|string;
+    public function foo(T $param): T;
+}
+
+class CS implements I {
+    public function foo(string $param): string {
+        return $param . '!';
+    }
+}
+
+class CI implements I {
+    public function foo(int $param): int {
+        return $param + 42;
+    }
+}
+
+$cs = new CS();
+var_dump($cs->foo("Hello"));
+
+$ci = new CI();
+var_dump($ci->foo(5));
+
+?>
+--EXPECT--
+string(6) "Hello!"
+int(47)

Zend/tests/type_declarations/associated/associated_type_with_constraint_failed.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Associated type with a constraint that is not satisfied
+--FILE--
+<?php
+
+interface I {
+    type T : int|string;
+    public function foo(T $param): T;
+}
+
+class C implements I {
+    public function foo(float $param): float {}
+}
+
+?>
+--EXPECT--

Zend/zend_ast.c

@@ -2377,10 +2377,6 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 			APPEND_NODE_1("break");
 		case ZEND_AST_CONTINUE:
 			APPEND_NODE_1("continue");
-		case ZEND_AST_ASSOCIATED_TYPE:
-			smart_str_appends(str, "type ");
-			zend_ast_export_name(str, ast->child[0], 0, indent);
-			break;
 
 		/* 2 child nodes */
 		case ZEND_AST_DIM:
@@ -2703,6 +2699,16 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 			smart_str_appends(str, ": ");
 			ast = ast->child[1];
 			goto tail_call;
+		case ZEND_AST_ASSOCIATED_TYPE:
+			smart_str_appends(str, "type ");
+			zend_ast_export_name(str, ast->child[0], 0, indent);
+			if (ast->child[1]) {
+				smart_str_appends(str, " : ");
+				smart_str_appends(str, " : ");
+				zend_ast_export_type(str, ast->child[1], indent);
+			}
+			smart_str_appendc(str, ';');
+		break;
 
 		/* 3 child nodes */
 		case ZEND_AST_METHOD_CALL:

Zend/zend_ast.h

@@ -99,7 +99,6 @@ enum _zend_ast_kind {
 	ZEND_AST_POST_DEC,
 	ZEND_AST_YIELD_FROM,
 	ZEND_AST_CLASS_NAME,
-	ZEND_AST_ASSOCIATED_TYPE,
 
 	ZEND_AST_GLOBAL,
 	ZEND_AST_UNSET,
@@ -155,6 +154,7 @@ enum _zend_ast_kind {
 	ZEND_AST_MATCH_ARM,
 	ZEND_AST_NAMED_ARG,
 	ZEND_AST_PARENT_PROPERTY_HOOK_CALL,
+	ZEND_AST_ASSOCIATED_TYPE,
 
 	/* 3 child nodes */
 	ZEND_AST_METHOD_CALL = 3 << ZEND_AST_NUM_CHILDREN_SHIFT,

Zend/zend_language_parser.y

@@ -664,8 +664,10 @@ enum_case_expr:
 ;
 
 associated_type:
-        T_TYPE name ';'
-			{ $$ = zend_ast_create(ZEND_AST_ASSOCIATED_TYPE, $2); }
+        T_TYPE name ':' type_expr_without_static ';'
+			{ $$ = zend_ast_create(ZEND_AST_ASSOCIATED_TYPE, $2, $4); }
+	|	T_TYPE name ';'
+			{ $$ = zend_ast_create(ZEND_AST_ASSOCIATED_TYPE, $2, NULL); }
 ;
 
 extends_from: