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//
// DISCLAIMER
//
// Copyright 2017 ArangoDB GmbH, Cologne, Germany
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Copyright holder is ArangoDB GmbH, Cologne, Germany
//
// Author Ewout Prangsma
//
package velocypack
type ArrayIterator struct {
s Slice
position ValueLength
size ValueLength
current Slice
}
// NewArrayIterator initializes an iterator at position 0 of the given object slice.
func NewArrayIterator(s Slice) (*ArrayIterator, error) {
if !s.IsArray() {
return nil, InvalidTypeError{"Expected Array slice"}
}
size, err := s.Length()
if err != nil {
return nil, WithStack(err)
}
i := &ArrayIterator{
s: s,
position: 0,
size: size,
}
if size > 0 {
i.current, err = s.At(0)
if err != nil {
return nil, WithStack(err)
}
}
return i, nil
}
// IsValid returns true if the given position of the iterator is valid.
func (i *ArrayIterator) IsValid() bool {
return i.position < i.size
}
// IsFirst returns true if the current position is 0.
func (i *ArrayIterator) IsFirst() bool {
return i.position == 0
}
// Value returns the value of the current position of the iterator
func (i *ArrayIterator) Value() (Slice, error) {
if i.position >= i.size {
return nil, WithStack(IndexOutOfBoundsError)
}
if current := i.current; current != nil {
return current, nil
}
value, err := i.s.At(i.position)
return value, WithStack(err)
}
// Next moves to the next position.
func (i *ArrayIterator) Next() error {
i.position++
if i.position < i.size && i.current != nil {
var err error
// skip over entry
i.current, err = i.current.Next()
if err != nil {
return WithStack(err)
}
} else {
i.current = nil
}
return nil
}