Lobashov_Ivan_PIBD-21_IP/Lab3/node_modules/balanced-match/index.js
2024-01-10 22:39:31 +04:00

63 lines
1.2 KiB
JavaScript

'use strict';
module.exports = balanced;
function balanced(a, b, str) {
if (a instanceof RegExp) a = maybeMatch(a, str);
if (b instanceof RegExp) b = maybeMatch(b, str);
var r = range(a, b, str);
return r && {
start: r[0],
end: r[1],
pre: str.slice(0, r[0]),
body: str.slice(r[0] + a.length, r[1]),
post: str.slice(r[1] + b.length)
};
}
function maybeMatch(reg, str) {
var m = str.match(reg);
return m ? m[0] : null;
}
balanced.range = range;
function range(a, b, str) {
var begs, beg, left, right, result;
var ai = str.indexOf(a);
var bi = str.indexOf(b, ai + 1);
var i = ai;
if (ai >= 0 && bi > 0) {
if(a===b) {
return [ai, bi];
}
begs = [];
left = str.length;
while (i >= 0 && !result) {
if (i == ai) {
begs.push(i);
ai = str.indexOf(a, i + 1);
} else if (begs.length == 1) {
result = [ begs.pop(), bi ];
} else {
beg = begs.pop();
if (beg < left) {
left = beg;
right = bi;
}
bi = str.indexOf(b, i + 1);
}
i = ai < bi && ai >= 0 ? ai : bi;
}
if (begs.length) {
result = [ left, right ];
}
}
return result;
}