Created
February 5, 2011 13:14
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EditDistanceMatcher function
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exports.EditDistanceMatcher = function(against, alphabet) { | |
this.against = against; | |
this.alphabet = alphabet || "abcdefghijklmnopqrstuvwxyz"; | |
this.edits1 = function(word) { | |
var n = word.length; | |
var al = this.alphabet.length; | |
var set = new Array(), t; | |
// deletion | |
for (var i=0, len=n; i < len; i++) { | |
t = word.substring(0, i) + word.substring(i+1, n); | |
if (-1 == set.indexOf(t)) | |
set.push(t); | |
} | |
// transposition | |
for (var i=0, len=n - 1; i < len; i++) { | |
t = word.substring(0, i) + word.substr(i+1, 1) + word.substr(i, 1) + word.substring(i+2, n); | |
if (-1 == set.indexOf(t)) | |
set.push(t); | |
} | |
// alteration | |
for (var i=0, len=n; i < len; i++) { | |
for (var j=0, leny=al; j<leny; j++) { | |
t = word.substring(0, i) + this.alphabet.substr(j,1) + word.substring(i+1, n); | |
if (-1 == set.indexOf(t)) | |
set.push(t); | |
} | |
} | |
// insertion | |
for (var i=0, len=n + 1; i < len; i++) { | |
for (var j=0, leny=al; j<leny; j++) { | |
t = word.substring(0, i) + this.alphabet.substr(j,1) + word.substring(i, n); | |
if (-1 == set.indexOf(t)) | |
set.push(t); | |
} | |
} | |
return set; | |
}; | |
}; | |
exports.EditDistanceMatcher.prototype.match = function(word) { | |
var edits1 = this.edits1(word); | |
var set = new Array(); | |
for (var i in edits1) { | |
if (-1 < this.against.indexOf(edits1[i])) { | |
set.push(edits1[i]); | |
} | |
} | |
return set; | |
} | |
exports.EditDistanceMatcher.prototype.is_matched = function(word) { | |
var edits1 = this.edits1(word); | |
for (var i in edits1) { | |
if (-1 < this.against.indexOf(edits1[i])) { | |
return true; | |
} | |
} | |
return false; | |
} |
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