expr/iter-list.go

71 lines
1.4 KiB
Go

// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.
// iter-list.go
package expr
import "io"
type ListIterator struct {
a *ListType
index int
}
func NewListIterator(list *ListType) *ListIterator {
return &ListIterator{a: list, index: 0}
}
func NewArrayIterator(array []any) *ListIterator {
return &ListIterator{a: (*ListType)(&array), index: 0}
}
func NewAnyIterator(value any) (it *ListIterator) {
if value == nil {
it = NewArrayIterator([]any{})
} else if list, ok := value.(*ListType); ok {
it = NewListIterator(list)
} else if array, ok := value.([]any); ok {
it = NewArrayIterator(array)
} else if it1, ok := value.(*ListIterator); ok {
it = it1
} else {
it = NewArrayIterator([]any{value})
}
return
}
func (it *ListIterator) HasOperation(name string) bool {
return false
}
func (it *ListIterator) CallOperation(name string, args []any) (any, error) {
return nil, errNoOperation(name)
}
func (it *ListIterator) Current() (item any, err error) {
a := *(it.a)
if it.index >= 0 && it.index < len(a) {
item = a[it.index]
} else {
err = io.EOF
}
return
}
func (it *ListIterator) Next() (item any, err error) {
if item, err = it.Current(); err != io.EOF {
it.index++
}
// if it.index < len(it.a) {
// item = it.a[it.index]
// it.index++
// } else {
// err = io.EOF
// }
return
}
func (it *ListIterator) Index() int {
return it.index - 1
}