With statememt

Author: ncw

ast/ast.go

@@ -337,7 +337,7 @@ type If struct {
 
 type With struct {
 	StmtBase
-	Items []WithItem
+	Items []*WithItem
 	Body  []Stmt
 }
 

ast/dump.go

@@ -24,6 +24,8 @@ func dumpItem(v interface{}) string {
 		return fmt.Sprintf("'%s'", string(x))
 	case *Keyword:
 		return dump(x, "keyword")
+	case *WithItem:
+		return dump(x, "withitem")
 	case ModBase:
 	case StmtBase:
 	case ExprBase:
@@ -55,6 +57,10 @@ func dump(ast interface{}, name string) string {
 			continue
 		case "exprtype":
 			fname = "type"
+		case "contextexpr":
+			fname = "context_expr"
+		case "optionalvars":
+			fname = "optional_vars"
 		}
 		if fieldValue.Kind() == reflect.Slice && fieldValue.Type().Elem().Kind() != reflect.Uint8 {
 			strs := make([]string, fieldValue.Len())

parser/grammar.y

@@ -67,6 +67,8 @@ func applyTrailers(expr ast.Expr, trailers []ast.Expr) ast.Expr {
 	ifstmt		*ast.If
 	lastif		*ast.If
 	exchandlers	[]*ast.ExceptHandler
+	withitem	*ast.WithItem
+	withitems	[]*ast.WithItem
 }
 
 %type <obj> strings
@@ -88,6 +90,8 @@ func applyTrailers(expr ast.Expr, trailers []ast.Expr) ast.Expr {
 %type <aliases> dotted_as_names import_as_names import_from_arg
 %type <ifstmt> elifs
 %type <exchandlers> except_clauses
+%type <withitem> with_item
+%type <withitems> with_items
 
 %token NEWLINE
 %token ENDMARKER
@@ -1050,27 +1054,30 @@ try_stmt:
 with_items:
 	with_item
 	{
-		// FIXME
+		$$ = nil
+		$$ = append($$, $1)
 	}
 |	with_items ',' with_item
 	{
-		// FIXME
+		$$ = append($$, $3)
 	}
 
 with_stmt:
-	WITH with_items  ':' suite
+	WITH with_items ':' suite
 	{
-		// FIXME
+		$$ = &ast.With{StmtBase: ast.StmtBase{$<pos>$}, Items: $2, Body: $4}
 	}
 
 with_item:
 	test
 	{
-		// FIXME
+		$$ = &ast.WithItem{Pos: $<pos>$, ContextExpr: $1}
 	}
 |	test AS expr
 	{
-		// FIXME
+		v := $3
+		v.(ast.SetCtxer).SetCtx(ast.Store)
+		$$ = &ast.WithItem{Pos: $<pos>$, ContextExpr: $1, OptionalVars: v}
 	}
 
 // NB compile.c makes sure that the default except clause is last

parser/grammar_test.go

@@ -214,6 +214,9 @@ func TestGrammar(t *testing.T) {
 		{"try:\n    pass\nexcept a:\n    break\nexcept:\n    continue\nexcept b as c:\n    break\nelse:\n    pass\n", "exec", "Module(body=[Try(body=[Pass()], handlers=[ExceptHandler(type=Name(id='a', ctx=Load()), name=None, body=[Break()]), ExceptHandler(type=None, name=None, body=[Continue()]), ExceptHandler(type=Name(id='b', ctx=Load()), name='c', body=[Break()])], orelse=[Pass()], finalbody=[])])"},
 		{"try:\n    pass\nexcept:\n    continue\nfinally:\n    pass\n", "exec", "Module(body=[Try(body=[Pass()], handlers=[ExceptHandler(type=None, name=None, body=[Continue()])], orelse=[], finalbody=[Pass()])])"},
 		{"try:\n    pass\nexcept:\n    continue\nelse:\n    break\nfinally:\n    pass\n", "exec", "Module(body=[Try(body=[Pass()], handlers=[ExceptHandler(type=None, name=None, body=[Continue()])], orelse=[Break()], finalbody=[Pass()])])"},
+		{"with x:\n    pass\n", "exec", "Module(body=[With(items=[withitem(context_expr=Name(id='x', ctx=Load()), optional_vars=None)], body=[Pass()])])"},
+		{"with x as y:\n    pass\n", "exec", "Module(body=[With(items=[withitem(context_expr=Name(id='x', ctx=Load()), optional_vars=Name(id='y', ctx=Store()))], body=[Pass()])])"},
+		{"with x as y, a as b, c, d as e:\n    pass\n    continue\n", "exec", "Module(body=[With(items=[withitem(context_expr=Name(id='x', ctx=Load()), optional_vars=Name(id='y', ctx=Store())), withitem(context_expr=Name(id='a', ctx=Load()), optional_vars=Name(id='b', ctx=Store())), withitem(context_expr=Name(id='c', ctx=Load()), optional_vars=None), withitem(context_expr=Name(id='d', ctx=Load()), optional_vars=Name(id='e', ctx=Store()))], body=[Pass(), Continue()])])"},
 		// END TESTS
 	} {
 		Ast, err := ParseString(test.in, test.mode)

parser/make_grammar_test.py

@@ -300,6 +300,20 @@
 finally:
     pass
 """, "exec"),
+
+    ("""\
+with x:
+    pass
+""", "exec"),
+    ("""\
+with x as y:
+    pass
+""", "exec"),
+    ("""\
+with x as y, a as b, c, d as e:
+    pass
+    continue
+""", "exec"),
 ]
 
 def dump(source, mode):