/
append.go
70 lines (60 loc) · 1.07 KB
/
append.go
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package main
import (
"fmt"
"github.com/mg/i"
"github.com/mg/i/hoi"
"github.com/mg/i/igen"
)
type iappend struct {
itrs []i.Forward
pos int
err error
}
func Append(itrs ...i.Forward) i.Forward {
return &iappend{itrs: itrs}
}
func (i *iappend) AtEnd() bool {
if i.pos < len(i.itrs)-1 {
return false
} else if i.pos >= len(i.itrs) {
return true
}
return i.itrs[i.pos].AtEnd()
}
func (i *iappend) Next() error {
if i.pos >= len(i.itrs) {
i.err = fmt.Errorf("Appending beyond last iterator")
return i.err
}
i.itrs[i.pos].Next()
for i.itrs[i.pos].AtEnd() {
i.pos++
if i.pos >= len(i.itrs) {
return nil
}
}
return nil
}
func (i *iappend) Value() interface{} {
return i.itrs[i.pos].Value()
}
func (i *iappend) Error() error {
if i.err != nil {
return i.err
}
for _, v := range i.itrs {
err := v.Error()
if err != nil {
return err
}
}
return nil
}
func (i *iappend) SetError(err error) {
i.err = err
}
func main() {
for itr := Append(hoi.List(1, 2, 3), igen.Range(10, 20)); !itr.AtEnd(); itr.Next() {
fmt.Println(itr.Value())
}
}