RFC for conditional break, continue, & return statements

Zend/tests/guard_clauses/001.phpt

@@ -0,0 +1,22 @@
+--TEST--
+return if in function
+--FILE--
+<?php
+
+function divide($dividend, $divisor = null) {
+    return if ($divisor === null); // return null void
+
+    return if ($divisor == 0): 0; // explicit return value
+
+    return $dividend / $divisor;
+}
+
+var_dump(divide(10));
+var_dump(divide(10, 0));
+var_dump(divide(10, 5));
+
+?>
+--EXPECT--
+NULL
+int(0)
+int(2)

Zend/tests/guard_clauses/002.phpt

@@ -0,0 +1,37 @@
+--TEST--
+continue if
+--FILE--
+<?php
+
+$x = 0;
+
+for ($i = 0; $i < 10; $i ++) {
+    continue if ($i >= 5);
+
+    $x++;
+}
+
+$y = 0;
+
+for ($j = 0; $j < 10; $j++) {
+    for ($k = 0; $k < 10; $k++) {
+        continue if ($j >= 5): 2;
+
+        $y++;
+    }
+}
+
+var_dump($x);
+var_dump($i);
+var_dump($y);
+var_dump($j);
+var_dump($k);
+
+
+?>
+--EXPECT--
+int(5)
+int(10)
+int(50)
+int(10)
+int(0)

Zend/tests/guard_clauses/003.phpt

@@ -0,0 +1,52 @@
+--TEST--
+break if
+--FILE--
+<?php
+
+$x = 0;
+
+for ($i = 0; $i < 10; $i ++) {
+    break if ($i >= 5);
+
+    $x++;
+}
+
+$y = 0;
+
+for ($j = 0; $j < 10; $j++) {
+    for ($k = 0; $k < 10; $k++) {
+        break if ($j >= 5): 2;
+
+        $y++;
+    }
+}
+
+$output = 'original';
+
+switch (1) {
+    case 1:
+        switch (2) {
+            case 2:
+                break if (true): 2;
+        }
+
+        // never executed
+        $output = 'changed';
+        break;
+}
+
+var_dump($x);
+var_dump($i);
+var_dump($y);
+var_dump($j);
+var_dump($k);
+var_dump($output);
+
+?>
+--EXPECT--
+int(5)
+int(5)
+int(50)
+int(5)
+int(0)
+string(8) "original"

Zend/zend_language_parser.y

@@ -249,7 +249,8 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %type <ast> top_statement_list use_declarations const_list inner_statement_list if_stmt
 %type <ast> alt_if_stmt for_exprs switch_case_list global_var_list static_var_list
 %type <ast> echo_expr_list unset_variables catch_name_list catch_list parameter_list class_statement_list
-%type <ast> implements_list case_list if_stmt_without_else
+%type <ast> implements_list case_list
+%type <ast> break_if_stmt continue_if_stmt return_if_stmt guard_if_optional_return if_stmt_without_else
 %type <ast> non_empty_parameter_list argument_list non_empty_argument_list property_list
 %type <ast> class_const_list class_const_decl class_name_list trait_adaptations method_body non_empty_for_exprs
 %type <ast> ctor_arguments alt_if_stmt_without_else trait_adaptation_list lexical_vars
@@ -428,6 +429,9 @@ inner_statement:
 statement:
 		'{' inner_statement_list '}' { $$ = $2; }
 	|	if_stmt { $$ = $1; }
+	|	continue_if_stmt { $$ = $1; }
+	|	break_if_stmt { $$ = $1; }
+	|	return_if_stmt { $$ = $1; }
 	|	alt_if_stmt { $$ = $1; }
 	|	T_WHILE '(' expr ')' while_statement
 			{ $$ = zend_ast_create(ZEND_AST_WHILE, $3, $5); }
@@ -600,6 +604,31 @@ while_statement:
 	|	':' inner_statement_list T_ENDWHILE ';' { $$ = $2; }
 ;
 
+break_if_stmt:
+		T_BREAK T_IF '(' expr ')' guard_if_optional_return
+			{ $$ = zend_ast_create_list(2, ZEND_AST_IF,
+				zend_ast_create(ZEND_AST_IF_ELEM, $4,
+				zend_ast_create(ZEND_AST_BREAK, $6))); }
+;
+
+continue_if_stmt:
+		T_CONTINUE T_IF '(' expr ')' guard_if_optional_return
+			{ $$ = zend_ast_create_list(2, ZEND_AST_IF,
+				zend_ast_create(ZEND_AST_IF_ELEM, $4,
+				zend_ast_create(ZEND_AST_CONTINUE, $6))); }
+;
+
+return_if_stmt:
+		T_RETURN T_IF '(' expr ')' guard_if_optional_return
+			{ $$ = zend_ast_create_list(2, ZEND_AST_IF,
+				zend_ast_create(ZEND_AST_IF_ELEM, $4,
+				zend_ast_create(ZEND_AST_RETURN, $6))); }
+;
+
+guard_if_optional_return:
+		':' optional_expr ';' { $$ = $2; }
+	|	';' { $$ = NULL; }
+;
 
 if_stmt_without_else:
 		T_IF '(' expr ')' statement