mirror of
https://github.com/dutchcoders/transfer.sh.git
synced 2024-12-05 02:10:18 +01:00
cb6e5cb0c7
* use dep for vendoring * lets encrypt * moved web to transfer.sh-web repo * single command install * added first tests
123 lines
2.8 KiB
Go
123 lines
2.8 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file or at
|
|
// https://developers.google.com/open-source/licenses/bsd.
|
|
|
|
// This file implements the Paice/Husk stemming algorithm.
|
|
// http://www.comp.lancs.ac.uk/computing/research/stemming/Links/paice.htm
|
|
|
|
package database
|
|
|
|
import (
|
|
"bytes"
|
|
"regexp"
|
|
"strconv"
|
|
)
|
|
|
|
const stemRuleText = `
|
|
ai*2. a*1.
|
|
bb1.
|
|
city3s. ci2> cn1t>
|
|
dd1. dei3y> deec2ss. dee1. de2> dooh4>
|
|
e1>
|
|
feil1v. fi2>
|
|
gni3> gai3y. ga2> gg1.
|
|
ht*2. hsiug5ct. hsi3>
|
|
i*1. i1y>
|
|
ji1d. juf1s. ju1d. jo1d. jeh1r. jrev1t. jsim2t. jn1d. j1s.
|
|
lbaifi6. lbai4y. lba3> lbi3. lib2l> lc1. lufi4y. luf3> lu2. lai3> lau3> la2> ll1.
|
|
mui3. mu*2. msi3> mm1.
|
|
nois4j> noix4ct. noi3> nai3> na2> nee0. ne2> nn1.
|
|
pihs4> pp1.
|
|
re2> rae0. ra2. ro2> ru2> rr1. rt1> rei3y>
|
|
sei3y> sis2. si2> ssen4> ss0. suo3> su*2. s*1> s0.
|
|
tacilp4y. ta2> tnem4> tne3> tna3> tpir2b. tpro2b. tcud1. tpmus2. tpec2iv. tulo2v. tsis0. tsi3> tt1.
|
|
uqi3. ugo1.
|
|
vis3j> vie0. vi2>
|
|
ylb1> yli3y> ylp0. yl2> ygo1. yhp1. ymo1. ypo1. yti3> yte3> ytl2. yrtsi5. yra3> yro3> yfi3. ycn2t> yca3>
|
|
zi2> zy1s.
|
|
`
|
|
|
|
type stemRule struct {
|
|
text string
|
|
suffix []byte
|
|
intact bool
|
|
remove int
|
|
append []byte
|
|
more bool
|
|
}
|
|
|
|
func parseStemRules() map[byte][]*stemRule {
|
|
|
|
rules := make(map[byte][]*stemRule)
|
|
for _, m := range regexp.MustCompile(`(?m)(?:^| )([a-zA-Z]*)(\*?)([0-9])([a-zA-z]*)([.>])`).FindAllStringSubmatch(stemRuleText, -1) {
|
|
|
|
suffix := []byte(m[1])
|
|
for i := 0; i < len(suffix)/2; i++ {
|
|
j := len(suffix) - 1 - i
|
|
suffix[i], suffix[j] = suffix[j], suffix[i]
|
|
}
|
|
|
|
remove, _ := strconv.Atoi(m[3])
|
|
r := &stemRule{
|
|
text: m[0],
|
|
suffix: suffix,
|
|
intact: m[2] == "*",
|
|
remove: remove,
|
|
append: []byte(m[4]),
|
|
more: m[5] == ">",
|
|
}
|
|
c := suffix[len(suffix)-1]
|
|
rules[c] = append(rules[c], r)
|
|
}
|
|
return rules
|
|
}
|
|
|
|
var stemRules = parseStemRules()
|
|
|
|
func firstVowel(offset int, p []byte) int {
|
|
for i, b := range p {
|
|
switch b {
|
|
case 'a', 'e', 'i', 'o', 'u':
|
|
return offset + i
|
|
case 'y':
|
|
if offset+i > 0 {
|
|
return offset + i
|
|
}
|
|
}
|
|
}
|
|
return -1
|
|
}
|
|
|
|
func acceptableStem(a, b []byte) bool {
|
|
i := firstVowel(0, a)
|
|
if i < 0 {
|
|
i = firstVowel(len(a), b)
|
|
}
|
|
l := len(a) + len(b)
|
|
if i == 0 {
|
|
return l > 1
|
|
}
|
|
return i >= 0 && l > 2
|
|
}
|
|
|
|
func stem(s string) string {
|
|
stem := bytes.ToLower([]byte(s))
|
|
intact := true
|
|
run := acceptableStem(stem, []byte{})
|
|
for run {
|
|
run = false
|
|
for _, rule := range stemRules[stem[len(stem)-1]] {
|
|
if bytes.HasSuffix(stem, rule.suffix) &&
|
|
(intact || !rule.intact) &&
|
|
acceptableStem(stem[:len(stem)-rule.remove], rule.append) {
|
|
stem = append(stem[:len(stem)-rule.remove], rule.append...)
|
|
intact = false
|
|
run = rule.more
|
|
break
|
|
}
|
|
}
|
|
}
|
|
return string(stem)
|
|
}
|