website/themes/hugo-theme-wave/static/bower_components/lunr.js/lib/stemmer.js
2020-01-12 23:32:32 +01:00

219 lines
5.1 KiB
JavaScript

/*!
* lunr.stemmer
* Copyright (C) @YEAR Oliver Nightingale
* Includes code from - http://tartarus.org/~martin/PorterStemmer/js.txt
*/
/**
* lunr.stemmer is an english language stemmer, this is a JavaScript
* implementation of the PorterStemmer taken from http://tartarus.org/~martin
*
* @module
* @param {String} str The string to stem
* @returns {String}
* @see lunr.Pipeline
*/
lunr.stemmer = (function(){
var step2list = {
"ational" : "ate",
"tional" : "tion",
"enci" : "ence",
"anci" : "ance",
"izer" : "ize",
"bli" : "ble",
"alli" : "al",
"entli" : "ent",
"eli" : "e",
"ousli" : "ous",
"ization" : "ize",
"ation" : "ate",
"ator" : "ate",
"alism" : "al",
"iveness" : "ive",
"fulness" : "ful",
"ousness" : "ous",
"aliti" : "al",
"iviti" : "ive",
"biliti" : "ble",
"logi" : "log"
},
step3list = {
"icate" : "ic",
"ative" : "",
"alize" : "al",
"iciti" : "ic",
"ical" : "ic",
"ful" : "",
"ness" : ""
},
c = "[^aeiou]", // consonant
v = "[aeiouy]", // vowel
C = c + "[^aeiouy]*", // consonant sequence
V = v + "[aeiou]*", // vowel sequence
mgr0 = "^(" + C + ")?" + V + C, // [C]VC... is m>0
meq1 = "^(" + C + ")?" + V + C + "(" + V + ")?$", // [C]VC[V] is m=1
mgr1 = "^(" + C + ")?" + V + C + V + C, // [C]VCVC... is m>1
s_v = "^(" + C + ")?" + v; // vowel in stem
var re_mgr0 = new RegExp(mgr0);
var re_mgr1 = new RegExp(mgr1);
var re_meq1 = new RegExp(meq1);
var re_s_v = new RegExp(s_v);
var re_1a = /^(.+?)(ss|i)es$/;
var re2_1a = /^(.+?)([^s])s$/;
var re_1b = /^(.+?)eed$/;
var re2_1b = /^(.+?)(ed|ing)$/;
var re_1b_2 = /.$/;
var re2_1b_2 = /(at|bl|iz)$/;
var re3_1b_2 = new RegExp("([^aeiouylsz])\\1$");
var re4_1b_2 = new RegExp("^" + C + v + "[^aeiouwxy]$");
var re_1c = /^(.+?[^aeiou])y$/;
var re_2 = /^(.+?)(ational|tional|enci|anci|izer|bli|alli|entli|eli|ousli|ization|ation|ator|alism|iveness|fulness|ousness|aliti|iviti|biliti|logi)$/;
var re_3 = /^(.+?)(icate|ative|alize|iciti|ical|ful|ness)$/;
var re_4 = /^(.+?)(al|ance|ence|er|ic|able|ible|ant|ement|ment|ent|ou|ism|ate|iti|ous|ive|ize)$/;
var re2_4 = /^(.+?)(s|t)(ion)$/;
var re_5 = /^(.+?)e$/;
var re_5_1 = /ll$/;
var re3_5 = new RegExp("^" + C + v + "[^aeiouwxy]$");
var porterStemmer = function porterStemmer(w) {
var stem,
suffix,
firstch,
re,
re2,
re3,
re4;
if (w.length < 3) { return w; }
firstch = w.substr(0,1);
if (firstch == "y") {
w = firstch.toUpperCase() + w.substr(1);
}
// Step 1a
re = re_1a
re2 = re2_1a;
if (re.test(w)) { w = w.replace(re,"$1$2"); }
else if (re2.test(w)) { w = w.replace(re2,"$1$2"); }
// Step 1b
re = re_1b;
re2 = re2_1b;
if (re.test(w)) {
var fp = re.exec(w);
re = re_mgr0;
if (re.test(fp[1])) {
re = re_1b_2;
w = w.replace(re,"");
}
} else if (re2.test(w)) {
var fp = re2.exec(w);
stem = fp[1];
re2 = re_s_v;
if (re2.test(stem)) {
w = stem;
re2 = re2_1b_2;
re3 = re3_1b_2;
re4 = re4_1b_2;
if (re2.test(w)) { w = w + "e"; }
else if (re3.test(w)) { re = re_1b_2; w = w.replace(re,""); }
else if (re4.test(w)) { w = w + "e"; }
}
}
// Step 1c - replace suffix y or Y by i if preceded by a non-vowel which is not the first letter of the word (so cry -> cri, by -> by, say -> say)
re = re_1c;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
w = stem + "i";
}
// Step 2
re = re_2;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
suffix = fp[2];
re = re_mgr0;
if (re.test(stem)) {
w = stem + step2list[suffix];
}
}
// Step 3
re = re_3;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
suffix = fp[2];
re = re_mgr0;
if (re.test(stem)) {
w = stem + step3list[suffix];
}
}
// Step 4
re = re_4;
re2 = re2_4;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
re = re_mgr1;
if (re.test(stem)) {
w = stem;
}
} else if (re2.test(w)) {
var fp = re2.exec(w);
stem = fp[1] + fp[2];
re2 = re_mgr1;
if (re2.test(stem)) {
w = stem;
}
}
// Step 5
re = re_5;
if (re.test(w)) {
var fp = re.exec(w);
stem = fp[1];
re = re_mgr1;
re2 = re_meq1;
re3 = re3_5;
if (re.test(stem) || (re2.test(stem) && !(re3.test(stem)))) {
w = stem;
}
}
re = re_5_1;
re2 = re_mgr1;
if (re.test(w) && re2.test(w)) {
re = re_1b_2;
w = w.replace(re,"");
}
// and turn initial Y back to y
if (firstch == "y") {
w = firstch.toLowerCase() + w.substr(1);
}
return w;
};
return porterStemmer;
})();
lunr.Pipeline.registerFunction(lunr.stemmer, 'stemmer')