63 lines
998 B
Go
63 lines
998 B
Go
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package segments
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type Int = int64
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type Length = Int
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func min(i Int, rest ...Int) Int {
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ret := i
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for _, i := range rest {
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if i < ret {
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ret = i
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}
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}
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return ret
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}
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type Extent struct {
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Start, Length Int
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}
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func (e Extent) End() Int {
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return e.Start + e.Length
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}
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type (
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Callback = func(int, Extent) bool
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LengthIter = func() (Length, bool)
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)
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func Scan(haystack func() (Length, bool), needle Extent, callback Callback) {
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i := 0
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for needle.Length != 0 {
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l, ok := haystack()
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if !ok {
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return
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}
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if needle.Start < l || needle.Start == l && l == 0 {
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e1 := Extent{
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Start: needle.Start,
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Length: min(l, needle.End()) - needle.Start,
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}
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if e1.Length >= 0 {
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if !callback(i, e1) {
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return
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}
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needle.Start -= e1.Length
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needle.Length -= e1.Length
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}
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} else {
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needle.Start -= l
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}
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i++
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}
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}
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func LocaterFromLengthIter(li LengthIter) Locater {
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return func(e Extent, c Callback) {
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Scan(li, e, c)
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}
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}
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type Locater func(Extent, Callback)
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