39 lines
798 B
Go
39 lines
798 B
Go
// For more tutorials: https://blog.learngoprogramming.com
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//
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// Copyright © 2018 Inanc Gumus
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// Learn Go Programming Course
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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//
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package pipe
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import "fmt"
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// logCount counts the yielded records.
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type logCount struct {
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Iterator
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n int
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}
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// Each yields to the inner iterator while counting the records.
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// Reports the record number on an error.
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func (lc *logCount) Each(yield func(Record) error) error {
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count := func(r Record) error {
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lc.n++
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return yield(r)
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}
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err := lc.Iterator.Each(count)
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if err != nil {
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// lc.n+1: iterator.each won't call yield on err
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return fmt.Errorf("record %d: %v", lc.n+1, err)
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}
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return nil
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}
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// count returns the last read record number.
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func (lc *logCount) count() int {
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return lc.n
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}
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