/**
* @module editor/mathpath
* @private
*/
define([],
function() {
/**
*
* @memberof module:editor/mathpath
* @param {Object} path
* @param {number} extent
* @return {string}
* @private
*/
function pathToString(path, extent) {
let result = '';
for (const segment of path) {
result += segment.relation + ':' + segment.offset + '/';
}
if (extent) {
result += '#' + extent;
}
return result;
}
/**
*
* @memberof module:editor/mathpath
* @param {string} string
* @return {Object}
* @private
*/
function pathFromString(string) {
// Reset the path
const result = {path: [], extent: 0};
// Parse the selection extent, if present
const components = string.split('#');
if (components.length > 1) {
result.extent = parseInt(components[1]);
}
// Parse the segments
const segments = components[0].split('/');
for (const segment of segments) {
const m2 = segment.match(/([^:]*):(.*)/);
if (m2) {
result.path.push({
relation: m2[1],
offset: parseInt(m2[2])
});
}
}
return result;
}
/**
* Given two paths, return a path representing their common ancestor.
*
* @param {Array.<string>} p
* @param {Array.<string>} q
* @return {Array.<string>}
* @memberof module:editor/mathpath
* @private
*/
function pathCommonAncestor(p, q) {
const result = [];
const maxIndex = Math.min(p.length - 1, q.length - 1);
let i = 0;
while ( i <= maxIndex &&
p[i].relation === q[i].relation &&
p[i].offset === q[i].offset) {
result.push(p[i]);
i += 1;
}
return result;
}
/**
*
* @param {Array.<string>} p
* @param {Array.<string>} q
* @return {number} 0 if the paths are identical
* - 1 if they are siblings
* - >1 if they are not siblings
* @memberof module:editor/mathpath
* @private
*/
function pathDistance(p, q) {
let result = 0;
let i = -1;
let done = false;
while (!done) {
i += 1;
done = i >= p.length || i >= q.length;
done = done ||
!(p[i].relation === q[i].relation &&
p[i].offset === q[i].offset);
}
if (i === p.length && i === q.length) {
// They're identical
result = 0;
} else if (i + 1 === p.length && i + 1 === q.length &&
p[i].relation === q[i].relation ) {
// They're siblings
result = 1;
} else {
result = 2;
}
return result;
}
function clone(path) {
return pathFromString(pathToString(path)).path;
}
return {
pathFromString,
pathToString,
pathDistance,
pathCommonAncestor,
clone
}
})
