overpass-frontend/src/parseParentheses.js

A JavaScript (NodeJS/Browser) library to easily access data from OpenStreetMap via Overpass API or from an OSM File. The objects can directly be used with LeafletJS or exported to GeoJSON. Data will be cached in the browser memory.

const parseString = require('./parseString')

module.exports = function parseParentheses (str) {
  const openingChrs = '([{'
  const closingChrs = ')]}'
  const stringChrs = '\'"'
  let result = ''
  const chr = str[0]
  str = str.slice(1)

  if (!openingChrs.includes(chr)) {
    throw new Error('parseParentheses(): ' + chr + ' is not a valid opening character')
  }
  const closingChr = closingChrs[openingChrs.indexOf(chr)]

  const regexp = new RegExp('^([^([{\'"\\' + closingChr + ']*)([([{\'"\\' + closingChr + '])')

  do {
    const m = str.match(regexp)
    if (m) {
      if (m[2] === closingChr) {
        result += m[1]
        str = str.slice(m[0].length)
        return [result, str]
      } else if (openingChrs.includes(m[2])) {
        result += m[1]
        str = str.slice(m[1].length)
        const r = parseParentheses(str)
        result += m[2] + r[0] + closingChrs[openingChrs.indexOf(m[2])]
        str = r[1]
      } else if (stringChrs.includes(m[2])) {
        result += m[1]
        str = str.slice(m[1].length)
        const r = parseString(str)
        result += m[2] + r[0] + m[2]
        str = r[1]
      } else {
        throw new Error('haeh?')
      }
    } else {
      throw new Error("Can't parse string from query: " + str)
    }
  } while (str.length)

  throw new Error("Can't parse string, no string end detected!")
}