mirror of
https://codeberg.org/forgejo/forgejo.git
synced 2024-12-30 14:09:42 -05:00
a380cfd8e0
* update bleve to master b17287a86f6cac923a5d886e10618df994eeb54b6724eac2e3b8dde89cfbe3a2 * remove unused pkg from dep file * change bleve from master to recent revision
114 lines
2.4 KiB
Go
114 lines
2.4 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package search
|
|
|
|
import (
|
|
"math"
|
|
)
|
|
|
|
func LevenshteinDistance(a, b string) int {
|
|
la := len(a)
|
|
lb := len(b)
|
|
d := make([]int, la+1)
|
|
var lastdiag, olddiag, temp int
|
|
|
|
for i := 1; i <= la; i++ {
|
|
d[i] = i
|
|
}
|
|
for i := 1; i <= lb; i++ {
|
|
d[0] = i
|
|
lastdiag = i - 1
|
|
for j := 1; j <= la; j++ {
|
|
olddiag = d[j]
|
|
min := d[j] + 1
|
|
if (d[j-1] + 1) < min {
|
|
min = d[j-1] + 1
|
|
}
|
|
if a[j-1] == b[i-1] {
|
|
temp = 0
|
|
} else {
|
|
temp = 1
|
|
}
|
|
if (lastdiag + temp) < min {
|
|
min = lastdiag + temp
|
|
}
|
|
d[j] = min
|
|
lastdiag = olddiag
|
|
}
|
|
}
|
|
return d[la]
|
|
}
|
|
|
|
// LevenshteinDistanceMax same as LevenshteinDistance but
|
|
// attempts to bail early once we know the distance
|
|
// will be greater than max
|
|
// in which case the first return val will be the max
|
|
// and the second will be true, indicating max was exceeded
|
|
func LevenshteinDistanceMax(a, b string, max int) (int, bool) {
|
|
v, wasMax, _ := LevenshteinDistanceMaxReuseSlice(a, b, max, nil)
|
|
return v, wasMax
|
|
}
|
|
|
|
func LevenshteinDistanceMaxReuseSlice(a, b string, max int, d []int) (int, bool, []int) {
|
|
la := len(a)
|
|
lb := len(b)
|
|
|
|
ld := int(math.Abs(float64(la - lb)))
|
|
if ld > max {
|
|
return max, true, d
|
|
}
|
|
|
|
if cap(d) < la+1 {
|
|
d = make([]int, la+1)
|
|
}
|
|
d = d[:la+1]
|
|
|
|
var lastdiag, olddiag, temp int
|
|
|
|
for i := 1; i <= la; i++ {
|
|
d[i] = i
|
|
}
|
|
for i := 1; i <= lb; i++ {
|
|
d[0] = i
|
|
lastdiag = i - 1
|
|
rowmin := max + 1
|
|
for j := 1; j <= la; j++ {
|
|
olddiag = d[j]
|
|
min := d[j] + 1
|
|
if (d[j-1] + 1) < min {
|
|
min = d[j-1] + 1
|
|
}
|
|
if a[j-1] == b[i-1] {
|
|
temp = 0
|
|
} else {
|
|
temp = 1
|
|
}
|
|
if (lastdiag + temp) < min {
|
|
min = lastdiag + temp
|
|
}
|
|
if min < rowmin {
|
|
rowmin = min
|
|
}
|
|
d[j] = min
|
|
|
|
lastdiag = olddiag
|
|
}
|
|
// after each row if rowmin isn't less than max stop
|
|
if rowmin > max {
|
|
return max, true, d
|
|
}
|
|
}
|
|
return d[la], false, d
|
|
}
|