overpass-frontend/src/evaluator/ternary.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 evaluatorExport = require('../evaluatorExport')
const EvaluatorOperator = require('../EvaluatorOperator')
const EvaluatorValue = require('../EvaluatorValue')

module.exports = class EvaluatorOperatorTernary extends EvaluatorOperator {
  constructor (op, condition, left, right) {
    super()
    this.op = op
    this.condition = condition
    this.left = left
    this.right = right
  }

  eval (context) {
    const condition = this.condition.eval(context)
    if (condition) {
      return this.left.eval(context)
    } else {
      return this.right.eval(context)
    }
  }

  toValue () {
    const condition = this.condition.toValue()
    if (condition === null) {
      return null
    }
    if (condition) {
      return this.left.toValue()
    } else {
      return this.right.toValue()
    }
  }

  toJSON () {
    const result = super.toJSON()
    result.condition = evaluatorExport(this.condition)
    return result
  }

  toString (options) {
    return this.condition.toString(options) + '?' + this.left.toString(options) + ':' + this.right.toString(options)
  }

  priority () {
    return 8
  }

  isSupersetOf (other) {
    const r = super.isSupersetOf(other)
    if (r !== undefined) {
      return r
    }

    if (this.left.isSupersetOf(other) && this.right.isSupersetOf(other)) {
      return true
    }
  }

  cacheDescriptors (descriptors) {
    const copyLeft = JSON.parse(JSON.stringify(descriptors))
    const copyRight = JSON.parse(JSON.stringify(descriptors))
    this.condition.cacheDescriptors(descriptors)
    this.left.cacheDescriptors(copyLeft)
    this.right.cacheDescriptors(copyRight)
    descriptors.push(...copyLeft)
    descriptors.push(...copyRight)
  }

  simplify () {
    const v = this.toValue()
    if (v !== null) {
      return new EvaluatorValue(v, this.master)
    }
    const condition = this.condition.simplify()
    const left = this.left.simplify()
    const right = this.right.simplify()
    return new EvaluatorOperatorTernary(this.op, condition, left, right)
  }
}