github-pages-deploy-action/node_modules/damerau-levenshtein/index.js
2020-03-06 22:45:40 -05:00

73 lines
1.9 KiB
JavaScript

// TheSpanishInquisition
// Cache the matrix. Note that if you not pass a limit this implementation will use a dynamically calculate one.
module.exports = function(__this, that, limit) {
var thisLength = __this.length,
thatLength = that.length,
matrix = [];
// If the limit is not defined it will be calculate from this and that args.
limit = (limit || ((thatLength > thisLength ? thatLength : thisLength)))+1;
for (var i = 0; i < limit; i++) {
matrix[i] = [i];
matrix[i].length = limit;
}
for (i = 0; i < limit; i++) {
matrix[0][i] = i;
}
if (Math.abs(thisLength - thatLength) > (limit || 100)){
return prepare (limit || 100);
}
if (thisLength === 0){
return prepare (thatLength);
}
if (thatLength === 0){
return prepare (thisLength);
}
// Calculate matrix.
var j, this_i, that_j, cost, min, t;
for (i = 1; i <= thisLength; ++i) {
this_i = __this[i-1];
// Step 4
for (j = 1; j <= thatLength; ++j) {
// Check the jagged ld total so far
if (i === j && matrix[i][j] > 4) return prepare (thisLength);
that_j = that[j-1];
cost = (this_i === that_j) ? 0 : 1; // Step 5
// Calculate the minimum (much faster than Math.min(...)).
min = matrix[i - 1][j ] + 1; // Deletion.
if ((t = matrix[i ][j - 1] + 1 ) < min) min = t; // Insertion.
if ((t = matrix[i - 1][j - 1] + cost) < min) min = t; // Substitution.
// Update matrix.
matrix[i][j] = (i > 1 && j > 1 && this_i === that[j-2] && __this[i-2] === that_j && (t = matrix[i-2][j-2]+cost) < min) ? t : min; // Transposition.
}
}
return prepare (matrix[thisLength][thatLength]);
/**
*
*/
function prepare(steps) {
var length = Math.max(thisLength, thatLength)
var relative = length === 0
? 0
: (steps / length);
var similarity = 1 - relative
return {
steps: steps,
relative: relative,
similarity: similarity
};
}
};