The Algorithms logo
The Algorithms
AboutDonate

Parse Nested Brackets

P
/**
 * @function parseNestedBrackets
 * @description Parse nested brackets algorithm for a string.
 * @param {string} text - text to parse
 * @param {string} openBrackets - open brackets
 * @param {string} closingBrackets - closing brackets
 * @returns {string[]} - array of the tags
 * @example parseNestedBrackets(`<MAIN hoge><MAIN2 fuga>`) => [ '<MAIN hoge>', '<MAIN2 fuga>' ]
 * @example parseNestedBrackets(
 *  `THIS IS SAMPLE TEXT(MAIN hoge 0.1 fuga(ITEM fuga hoge)hoge(ITEM2 nogami(ABBR)))`,
 *  { openBrackets: '(', closingBrackets: ')' }) => 
 *  [
      '(MAIN hoge 0.1 fuga(ITEM fuga hoge)hoge(ITEM2 nogami(ABBR)))',
      '(ITEM fuga hoge)',
      '(ITEM2 nogami(ABBR))',
      '(ABBR)'
    ]
 */
 export const parseNestedBrackets = (
   text: string,
   openBrackets = "<",
   closingBrackets = ">"
 ) => {
   let array: string[] = []; // The array of the tags in this present floor.
   let prFloor = 0; // The present floor.
   let begin = 0, // The begin index of the tag.
     end = 0; // The end index of the tag.
   for (let i = 0; i < text.length; i++) {
     if (text[i] === openBrackets) {
       prFloor++;
       if (prFloor === 1) begin = i;
     } else if (text[i] === closingBrackets) {
       if (prFloor === 1) {
         end = i;
         const tag = text.slice(begin + 1, end);
         // push the tag in this present floor.
         array.push(`${openBrackets}${tag}${closingBrackets}`);
         // push the array of the tags in the next floor.
         array = array.concat(
           parseNestedBrackets(tag, openBrackets, closingBrackets)
         );
       }
       prFloor--;
     }
   }
   return array;
 };