compile: implement yield and yield from

Author: ncw

compile/compile.go

@@ -1515,10 +1515,24 @@ func (c *compiler) Expr(expr ast.Expr) {
 		c.comprehension(expr, node.Generators)
 	case *ast.Yield:
 		// Value Expr
-		panic("FIXME compile: Yield not implemented")
+		if c.SymTable.Type != symtable.FunctionBlock {
+			panic(py.ExceptionNewf(py.SyntaxError, "'yield' outside function"))
+		}
+		if node.Value != nil {
+			c.Expr(node.Value)
+		} else {
+			c.LoadConst(py.None)
+		}
+		c.Op(vm.YIELD_VALUE)
 	case *ast.YieldFrom:
 		// Value Expr
-		panic("FIXME compile: YieldFrom not implemented")
+		if c.SymTable.Type != symtable.FunctionBlock {
+			panic(py.ExceptionNewf(py.SyntaxError, "'yield' outside function"))
+		}
+		c.Expr(node.Value)
+		c.Op(vm.GET_ITER)
+		c.LoadConst(py.None)
+		c.Op(vm.YIELD_FROM)
 	case *ast.Compare:
 		// Left        Expr
 		// Ops         []CmpOp

compile/compile_data_test.go

@@ -3722,4 +3722,106 @@ var compileTestData = []struct {
 		Firstlineno:    1,
 		Lnotab:         "",
 	}, nil, ""},
+	{"yield", "exec", nil, py.SyntaxError, "'yield' outside function"},
+	{"yield potato", "exec", nil, py.SyntaxError, "'yield' outside function"},
+	{"def f():\n    yield\n    ", "exec", &py.Code{
+		Argcount:       0,
+		Kwonlyargcount: 0,
+		Nlocals:        0,
+		Stacksize:      2,
+		Flags:          64,
+		Code:           "\x64\x00\x00\x64\x01\x00\x84\x00\x00\x5a\x00\x00\x64\x02\x00\x53",
+		Consts: []py.Object{&py.Code{
+			Argcount:       0,
+			Kwonlyargcount: 0,
+			Nlocals:        0,
+			Stacksize:      1,
+			Flags:          99,
+			Code:           "\x64\x00\x00\x56\x01\x64\x00\x00\x53",
+			Consts:         []py.Object{py.None},
+			Names:          []string{},
+			Varnames:       []string{},
+			Freevars:       []string{},
+			Cellvars:       []string{},
+			Filename:       "<string>",
+			Name:           "f",
+			Firstlineno:    1,
+			Lnotab:         "\x00\x01",
+		}, py.String("f"), py.None},
+		Names:       []string{"f"},
+		Varnames:    []string{},
+		Freevars:    []string{},
+		Cellvars:    []string{},
+		Filename:    "<string>",
+		Name:        "<module>",
+		Firstlineno: 1,
+		Lnotab:      "",
+	}, nil, ""},
+	{"def f():\n    yield potato\n    ", "exec", &py.Code{
+		Argcount:       0,
+		Kwonlyargcount: 0,
+		Nlocals:        0,
+		Stacksize:      2,
+		Flags:          64,
+		Code:           "\x64\x00\x00\x64\x01\x00\x84\x00\x00\x5a\x00\x00\x64\x02\x00\x53",
+		Consts: []py.Object{&py.Code{
+			Argcount:       0,
+			Kwonlyargcount: 0,
+			Nlocals:        0,
+			Stacksize:      1,
+			Flags:          99,
+			Code:           "\x74\x00\x00\x56\x01\x64\x00\x00\x53",
+			Consts:         []py.Object{py.None},
+			Names:          []string{"potato"},
+			Varnames:       []string{},
+			Freevars:       []string{},
+			Cellvars:       []string{},
+			Filename:       "<string>",
+			Name:           "f",
+			Firstlineno:    1,
+			Lnotab:         "\x00\x01",
+		}, py.String("f"), py.None},
+		Names:       []string{"f"},
+		Varnames:    []string{},
+		Freevars:    []string{},
+		Cellvars:    []string{},
+		Filename:    "<string>",
+		Name:        "<module>",
+		Firstlineno: 1,
+		Lnotab:      "",
+	}, nil, ""},
+	{"yield from range(10)", "exec", nil, py.SyntaxError, "'yield' outside function"},
+	{"def f():\n    yield from range(10)\n    ", "exec", &py.Code{
+		Argcount:       0,
+		Kwonlyargcount: 0,
+		Nlocals:        0,
+		Stacksize:      2,
+		Flags:          64,
+		Code:           "\x64\x00\x00\x64\x01\x00\x84\x00\x00\x5a\x00\x00\x64\x02\x00\x53",
+		Consts: []py.Object{&py.Code{
+			Argcount:       0,
+			Kwonlyargcount: 0,
+			Nlocals:        0,
+			Stacksize:      2,
+			Flags:          99,
+			Code:           "\x74\x00\x00\x64\x01\x00\x83\x01\x00\x44\x64\x00\x00\x48\x01\x64\x00\x00\x53",
+			Consts:         []py.Object{py.None, py.Int(10)},
+			Names:          []string{"range"},
+			Varnames:       []string{},
+			Freevars:       []string{},
+			Cellvars:       []string{},
+			Filename:       "<string>",
+			Name:           "f",
+			Firstlineno:    1,
+			Lnotab:         "\x00\x01",
+		}, py.String("f"), py.None},
+		Names:       []string{"f"},
+		Varnames:    []string{},
+		Freevars:    []string{},
+		Cellvars:    []string{},
+		Filename:    "<string>",
+		Name:        "<module>",
+		Firstlineno: 1,
+		Lnotab:      "",
+	}, nil, ""},
 }

compile/make_compile_test.py

@@ -344,7 +344,23 @@ def method(self, c):
     ('''from mod import a''', "exec"),
     ('''from mod1.mod2.mod3 import *''', "exec"),
     ('''from mod1.mod2.mod3 import a as aa, b as bb, c''', "exec"),
-
+    # yield
+    ('''yield''', "exec", SyntaxError),
+    ('''yield potato''', "exec", SyntaxError),
+    ('''\
+def f():
+    yield
+    ''', "exec"),
+    ('''\
+def f():
+    yield potato
+    ''', "exec"),
+    # yield from
+    ('''yield from range(10)''', "exec", SyntaxError),
+    ('''\
+def f():
+    yield from range(10)
+    ''', "exec"),
 ]
 
 def string(s):