70 lines
1.2 KiB
Go
70 lines
1.2 KiB
Go
package iter
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import "github.com/anacrolix/missinggo/slices"
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type Iterator interface {
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// Advances to the next value. Returns false if there are no more values.
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// Must be called before the first value.
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Next() bool
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// Returns the current value. Should panic when the iterator is in an
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// invalid state.
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Value() interface{}
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// Ceases iteration prematurely. This should occur implicitly if Next
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// returns false.
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Stop()
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}
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func ToFunc(it Iterator) Func {
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return func(cb Callback) {
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defer it.Stop()
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for it.Next() {
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if !cb(it.Value()) {
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break
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}
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}
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}
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}
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type sliceIterator struct {
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slice []interface{}
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value interface{}
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ok bool
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}
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func (me *sliceIterator) Next() bool {
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if len(me.slice) == 0 {
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return false
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}
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me.value = me.slice[0]
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me.slice = me.slice[1:]
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me.ok = true
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return true
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}
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func (me *sliceIterator) Value() interface{} {
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if !me.ok {
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panic("no value; call Next")
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}
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return me.value
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}
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func (me *sliceIterator) Stop() {}
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func Slice(a []interface{}) Iterator {
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return &sliceIterator{
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slice: a,
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}
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}
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func StringIterator(a string) Iterator {
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return Slice(slices.ToEmptyInterface(a))
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}
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func ToSlice(f Func) (ret []interface{}) {
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f(func(v interface{}) bool {
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ret = append(ret, v)
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return true
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})
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return
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}
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