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Improved the search by including a levenshtein distance calculation w…
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…hich enables the docs search function to be more forgiving for spelling mistakes
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@jroweboy
jroweboy committed Jul 3, 2014
1 parent eda75bc commit 6b21087
Showing 1 changed file with 86 additions and 44 deletions.
130 changes: 86 additions & 44 deletions src/librustdoc/html/static/main.js
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Expand Up @@ -58,7 +58,7 @@
}
$('#' + from)[0].scrollIntoView();
$('.line-numbers span').removeClass('line-highlighted');
for (i = from; i <= to; i += 1) {
for (i = from; i <= to; ++i) {
$('#' + i).addClass('line-highlighted');
}
}
Expand Down Expand Up @@ -99,7 +99,7 @@
stripped = '',
len = rootPath.match(/\.\.\//g).length + 1;

for (i = 0; i < len; i += 1) {
for (i = 0; i < len; ++i) {
match = url.match(/\/[^\/]*$/);
if (i < len - 1) {
stripped = match[0] + stripped;
Expand All @@ -111,9 +111,44 @@

document.location.href = url;
});
/**
* Code from Stackoverflow to compute the Levenshtein distance between two strings
* Written by Marco de Wit at http://stackoverflow.com/a/18514751/745719
*/
var levenshtein = (function() {
var row2 = [];
return function(s1, s2) {
if (s1 === s2) {
return 0;
} else {
var s1_len = s1.length, s2_len = s2.length;
if (s1_len && s2_len) {
var i1 = 0, i2 = 0, a, b, c, c2, row = row2;
while (i1 < s1_len)
row[i1] = ++i1;
while (i2 < s2_len) {
c2 = s2.charCodeAt(i2);
a = i2;
++i2;
b = i2;
for (i1 = 0; i1 < s1_len; ++i1) {
c = a + (s1.charCodeAt(i1) !== c2 ? 1 : 0);
a = row[i1];
b = b < a ? (b < c ? b + 1 : c) : (a < c ? a + 1 : c);
row[i1] = b;
}
}
return b;
} else {
return s1_len + s2_len;
}
}
};
})();

function initSearch(rawSearchIndex) {
var currentResults, index, searchIndex;
var MAX_LEV_DISTANCE = 3;
var params = getQueryStringParams();

// Populate search bar with query string search term when provided,
Expand All @@ -140,7 +175,7 @@
split = valLower.split("::");

//remove empty keywords
for (var j = 0; j < split.length; j++) {
for (var j = 0; j < split.length; ++j) {
split[j].toLowerCase();
if (split[j] === "") {
split.splice(j, 1);
Expand All @@ -153,7 +188,7 @@
val.charAt(val.length - 1) === val.charAt(0))
{
val = val.substr(1, val.length - 2);
for (var i = 0; i < nSearchWords; i += 1) {
for (var i = 0; i < nSearchWords; ++i) {
if (searchWords[i] === val) {
// filter type: ... queries
if (typeFilter < 0 || typeFilter === searchIndex[i].ty) {
Expand All @@ -167,15 +202,31 @@
} else {
// gather matching search results up to a certain maximum
val = val.replace(/\_/g, "");
for (var i = 0; i < split.length; i++) {
for (var j = 0; j < nSearchWords; j += 1) {
for (var i = 0; i < split.length; ++i) {
for (var j = 0; j < nSearchWords; ++j) {
var lev_distance;
if (searchWords[j].indexOf(split[i]) > -1 ||
searchWords[j].indexOf(val) > -1 ||
searchWords[j].replace(/_/g, "").indexOf(val) > -1)
{
// filter type: ... queries
if (typeFilter < 0 || typeFilter === searchIndex[j].ty) {
results.push({id: j, index: searchWords[j].replace(/_/g, "").indexOf(val)});
results.push({
id: j,
index: searchWords[j].replace(/_/g, "").indexOf(val),
lev: 0,
});
}
} else if (
(lev_distance = levenshtein(searchWords[j], val)) <=
MAX_LEV_DISTANCE) {
if (typeFilter < 0 || typeFilter === searchIndex[j].ty) {
results.push({
id: j,
index: 0,
// we want lev results to go lower than others
lev: lev_distance,
});
}
}
if (results.length === max) {
Expand All @@ -186,7 +237,7 @@
}

var nresults = results.length;
for (var i = 0; i < nresults; i += 1) {
for (var i = 0; i < nresults; ++i) {
results[i].word = searchWords[results[i].id];
results[i].item = searchIndex[results[i].id] || {};
}
Expand All @@ -198,6 +249,12 @@
results.sort(function(aaa, bbb) {
var a, b;

// Sort by non levenshtein results and then levenshtein results by the distance
// (less changes required to match means higher rankings)
a = (aaa.lev);
b = (bbb.lev);
if (a !== b) return a - b;

// sort by crate (non-current crate goes later)
a = (aaa.item.crate !== window.currentCrate);
b = (bbb.item.crate !== window.currentCrate);
Expand Down Expand Up @@ -255,7 +312,7 @@
results[i].id = -1;
}
}
for (var i = 0; i < results.length; i++) {
for (var i = 0; i < results.length; ++i) {
var result = results[i],
name = result.item.name.toLowerCase(),
path = result.item.path.toLowerCase(),
Expand Down Expand Up @@ -285,38 +342,23 @@
* @return {[boolean]} [Whether the result is valid or not]
*/
function validateResult(name, path, keys, parent) {
//initially valid
var validate = true;
//if there is a parent, then validate against parent
if (parent !== undefined) {
for (var i = 0; i < keys.length; i++) {
// if previous keys are valid and current key is in the
// path, name or parent
if ((validate) &&
(name.toLowerCase().indexOf(keys[i]) > -1 ||
path.toLowerCase().indexOf(keys[i]) > -1 ||
parent.name.toLowerCase().indexOf(keys[i]) > -1))
{
validate = true;
} else {
validate = false;
}
}
} else {
for (var i = 0; i < keys.length; i++) {
// if previous keys are valid and current key is in the
// path, name
if ((validate) &&
(name.toLowerCase().indexOf(keys[i]) > -1 ||
path.toLowerCase().indexOf(keys[i]) > -1))
{
validate = true;
} else {
validate = false;
}
for (var i=0; i < keys.length; ++i) {
// each check is for validation so we negate the conditions and invalidate
if (!(
// check for an exact name match
name.toLowerCase().indexOf(keys[i]) > -1 ||
// then an exact path match
path.toLowerCase().indexOf(keys[i]) > -1 ||
// next if there is a parent, check for exact parent match
(parent !== undefined &&
parent.name.toLowerCase().indexOf(keys[i]) > -1) ||
// lastly check to see if the name was a levenshtein match
levenshtein(name.toLowerCase(), keys[i]) <=
MAX_LEV_DISTANCE)) {
return false;
}
}
return validate;
return true;
}

function getQuery() {
Expand Down Expand Up @@ -496,7 +538,7 @@

resultIndex = execQuery(query, 20000, index);
len = resultIndex.length;
for (i = 0; i < len; i += 1) {
for (i = 0; i < len; ++i) {
if (resultIndex[i].id > -1) {
obj = searchIndex[resultIndex[i].id];
filterdata.push([obj.name, obj.ty, obj.path, obj.desc]);
Expand Down Expand Up @@ -568,7 +610,7 @@
// faster analysis operations
var len = items.length;
var lastPath = "";
for (var i = 0; i < len; i += 1) {
for (var i = 0; i < len; ++i) {
var rawRow = items[i];
var row = {crate: crate, ty: rawRow[0], name: rawRow[1],
path: rawRow[2] || lastPath, desc: rawRow[3],
Expand Down Expand Up @@ -640,7 +682,7 @@
crates.push(crate);
}
crates.sort();
for (var i = 0; i < crates.length; i++) {
for (var i = 0; i < crates.length; ++i) {
var klass = 'crate';
if (crates[i] == window.currentCrate) {
klass += ' current';
Expand All @@ -657,10 +699,10 @@
window.register_implementors = function(imp) {
var list = $('#implementors-list');
var libs = Object.getOwnPropertyNames(imp);
for (var i = 0; i < libs.length; i++) {
for (var i = 0; i < libs.length; ++i) {
if (libs[i] == currentCrate) continue;
var structs = imp[libs[i]];
for (var j = 0; j < structs.length; j++) {
for (var j = 0; j < structs.length; ++j) {
var code = $('<code>').append(structs[j]);
$.each(code.find('a'), function(idx, a) {
var href = $(a).attr('href');
Expand Down

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