github.com/grumpyhome/grumpy@v0.3.1-0.20201208125205-7b775405bdf1/grumpy-runtime-src/runtime/callableiter.go (about)

     1  // Copyright 2018 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package grumpy
    16  
    17  import (
    18  	"reflect"
    19  	"sync"
    20  )
    21  
    22  var (
    23  	callableIteratorType = newBasisType("callable-iterator", reflect.TypeOf(callableIterator{}), toCallableIteratorUnsafe, ObjectType)
    24  )
    25  
    26  type callableIterator struct {
    27  	Object
    28  	callable *Object
    29  	sentinel *Object
    30  	mutex    sync.Mutex
    31  }
    32  
    33  func newCallableIterator(callable *Object, sentinel *Object) *Object {
    34  	iter := &callableIterator{Object: Object{typ: callableIteratorType}, callable: callable, sentinel: sentinel}
    35  	return &iter.Object
    36  }
    37  
    38  func toCallableIteratorUnsafe(o *Object) *callableIterator {
    39  	return (*callableIterator)(o.toPointer())
    40  }
    41  
    42  func callableIteratorIter(f *Frame, o *Object) (*Object, *BaseException) {
    43  	return o, nil
    44  }
    45  
    46  func callableIteratorNext(f *Frame, o *Object) (item *Object, raised *BaseException) {
    47  	i := toCallableIteratorUnsafe(o)
    48  	i.mutex.Lock()
    49  	defer i.mutex.Unlock()
    50  	if i.callable == nil {
    51  		raised = f.Raise(StopIterationType.ToObject(), nil, nil)
    52  	} else if item, raised = i.callable.Call(f, Args{}, nil); raised == nil {
    53  		var eq *Object
    54  		if eq, raised = Eq(f, item, i.sentinel); raised == nil && eq == True.ToObject() {
    55  			i.callable = nil
    56  			item = nil
    57  			raised = f.Raise(StopIterationType.ToObject(), nil, nil)
    58  		}
    59  	}
    60  	return item, raised
    61  }
    62  
    63  func initCallableIteratorType(map[string]*Object) {
    64  	callableIteratorType.flags &= ^(typeFlagBasetype | typeFlagInstantiable)
    65  	callableIteratorType.slots.Iter = &unaryOpSlot{callableIteratorIter}
    66  	callableIteratorType.slots.Next = &unaryOpSlot{callableIteratorNext}
    67  }