Add __new__ function and property of slice

builtin/builtin.go

@@ -88,7 +88,7 @@ func init(){
  "range": py.RangeType,
  // "reversed": py.ReversedType,
  "set": py.SetType,
-// "slice": py.SliceType,
+ "slice": py.SliceType,
  "staticmethod": py.StaticMethodType,
  "str": py.StringType,
  // "super": py.SuperType,

py/slice.go

@@ -13,11 +13,11 @@ type Slice struct{
  Step Object
 }
 
-var SliceType = NewType("slice", `slice(stop) -> slice object
+var SliceType = NewTypeX("slice", `slice(stop) -> slice object
 "slice(stop)
 slice(start, stop[, step])
 
-Create a slice object. This is used for extended slicing (e.g. a[0:10:2]).`)
+Create a slice object. This is used for extended slicing (e.g. a[0:10:2]).`, SliceNew, nil)
 
 // Type of this object
 func (o *Slice) Type() *Type{
@@ -151,4 +151,25 @@ func (r *Slice) GetIndices(length int) (start, stop, step, slicelength int, err
  return
 }
 
+func init(){
+ SliceType.Dict["start"] = &Property{
+ Fget: func(self Object) (Object, error){
+ selfSlice := self.(*Slice)
+ return selfSlice.Start, nil
+ },
+ }
+ SliceType.Dict["stop"] = &Property{
+ Fget: func(self Object) (Object, error){
+ selfSlice := self.(*Slice)
+ return selfSlice.Stop, nil
+ },
+ }
+ SliceType.Dict["step"] = &Property{
+ Fget: func(self Object) (Object, error){
+ selfSlice := self.(*Slice)
+ return selfSlice.Step, nil
+ },
+ }
+}
+
 // Check interface is satisfied

py/tests/slice.py

@@ -0,0 +1,16 @@
+# Copyright 2019 The go-python Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+doc="slice"
+a = slice(10)
+assert a.start == None
+assert a.stop == 10
+assert a.step == None
+
+a = slice(0, 10, 1)
+assert a.start == 0
+assert a.stop == 10
+assert a.step == 1
+
+doc="finished"