realloc/src/JSONPathCompiler.js

Observable and Immutable State Manager Base On JSONPath For Javascript Applications

import {
  stackProcess,
  range,
  isPlainObject,
  isArray,
  hasOwnProperty
} from './utils'
import lexers from './lexers'


const argsRegExpr = /\{([^\{]*)\}/g
const isArgIndexRegExpr = /^\[\d+\]/


export function parseJSONPath(expr){
  return stackProcess(expr, lexers)
}
function _parseExpr(expr, lv, isLast){
  if('..' === expr){
    return [
      (input,ctx) => {
        return input +
        '\n((function(){\n' +
            'var stop = false;var breakFn = function(){stop = true};\n' +
          '\nreturn function recurfn'+lv+'(visit, parentCur, pwd, key){\n' +
              'visit(parentCur, key, pwd, breakFn);\n' +
            '\nif(stop === false && (isPlainObject(parentCur)||isArray(parentCur))){\n' +
              '\nvar newPwd = key === null ? pwd : pwd.concat([key]);\n' +
              '\nvar parentCurKeys;\n'+
              '\nif(isArray(parentCur)){\n'+
                'parentCurKeys = range(parentCur.length);'+
              '\n}else{\n'+
                'parentCurKeys = [];'+
                '\nfor(var k in parentCur){\n'+
                  '\nif(hasOwnProperty.call(parentCur,k)){\n'+
                    'parentCurKeys.push(k);\n'+
                  '\n}\n'+
                '\n}\n'+
              '\n}\n'+
              '\nfor(var i = 0; i < parentCurKeys.length; i++){\n' +
                '\nif(stop === false ){\n' +
                  'recurfn'+lv+'(visit, parentCur[parentCurKeys[i]], newPwd, parentCurKeys[i]);' +
                '\n}\n' +
              '}\n' +
            '}\n' +
          '}\n' +
        '}())(function(recur, key, pwd, breakFn){\n' +
          'var $'+lv+' = recur;\n' +
          '\nif(isPlainObject($'+lv+')){\n'+
          (isLast?(
          'matches.push({' +
            'pwd: key === null && $' + lv + ' !== $0 ? pwd.slice(0, pwd.length - 1) : pwd,' +
            'name: key === null && $' + lv + ' !== $0 ? pwd[pwd.length - 1] : key,'+
            'value: $' + lv +
          '});\n'
          ):(
          'var pwd' + lv + ' = key === null ? pwd : pwd.concat([key]);\n'
          ))
      },
      (input, ctx) => {
        return input +
            ('\n}\n')+
          '\n},$'+(lv - 1)+', pwd'+(lv - 1)+', null))\n'
      }
    ]
  }else if('*' === expr){
    return [
      (input,ctx) => {
        return input +
              '\nvar $$'+(lv - 1)+';\n'+
              '\nif(isArray($'+(lv - 1)+')){\n'+
                '$$'+(lv - 1)+' = range($'+(lv - 1)+'.length);'+
              '\n}else{\n'+
                '$$'+(lv - 1)+' = [];'+
                '\nfor(var k'+lv+' in $'+(lv - 1)+'){\n'+
                  '\nif(hasOwnProperty.call($'+(lv - 1)+',k'+lv+')){\n'+
                    '$$'+(lv - 1)+'.push(k'+lv+');\n'+
                  '\n}\n'+
                '\n}\n'+
              '\n}\n'+
              '\nfor(var i'+lv+' = 0;i'+lv+' < $$'+(lv-1)+'.length;i'+lv+'++){\n'+
                  'var $' + lv + ' = $'+(lv - 1)+'[$$'+(lv-1)+'[i'+lv+']];\n' +
                  (isLast?(
                  'matches.push({' +
                    'pwd: pwd' + (lv - 1) + ',' +
                    'name: $$'+(lv - 1)+'[i'+lv+'],'+
                    'value: $' + lv +
                  '});\n'
                  ):(
                  '\nif(isPlainObject($'+lv+')||isArray($'+lv+')){\n'+
                  'var pwd' + lv + ' = pwd'+(lv - 1)+'.concat([$$'+(lv - 1)+'[i'+lv+']]);\n'
                  ))
      },
      (input, ctx) => {
        return input +
                (isLast?'':'\n}\n')+
              '\n}\n'
      }
    ]
  }else if(/^\d+(,\d+)*$/.test(expr)){
    return [
      (input,ctx) => {
        return input +
              '\nvar k'+lv+' = ['+expr+'];\n'+
              '\nfor(var i'+lv+' = 0; i'+lv+' < k'+lv+'.length; i'+lv+'++){\n'+
                  'var $' + lv + ' = $'+(lv - 1)+'[k'+lv+'[i'+lv+']];\n' +
                  (isLast?(
                  'matches.push({' +
                    'pwd: pwd' + (lv - 1) + ',' +
                    'name: k'+lv+'[i'+lv+'],'+
                    'value: $' + lv +
                  '});\n'
                  ):(
                  '\nif(isPlainObject($'+lv+')||isArray($'+lv+')){\n'+
                  'var pwd' + lv + ' = pwd'+(lv - 1)+'.concat([k' + lv +'[i'+lv+']]);\n'
                  ))
      },
      (input, ctx) => {
        return input +
              (isLast?'':'\n}\n')+
              '\n}\n'
      }
    ]
  }else if(/^\d+(:\d+){0,2}$/.test(expr)){
    return [
      (input,ctx) => {
        var indexes = range.apply(null, expr.split(':').map((i) => parseInt(i)))
        return input +
              '\nvar k'+lv+' = ['+indexes.join(', ')+'];\n'+
              '\nfor(var i'+lv+' = 0; i'+lv+' < k'+lv+'.length; i'+lv+'++){\n'+
                  'var $' + lv + ' = $'+(lv - 1)+'[k'+lv+'[i'+lv+']];\n' +
                  (isLast?(
                  'matches.push({' +
                    'pwd: pwd' + (lv - 1) + ',' +
                    'name: k'+lv+'[i'+lv+'],'+
                    'value: $' + lv +
                  '});\n'
                  ):(
                  '\nif(isPlainObject($'+lv+')||isArray($'+lv+')){\n'+
                  'var pwd' + lv + ' = pwd'+(lv - 1)+'.concat([k' + lv +'[i'+lv+']]);\n'
                  ))
      },
      (input, ctx) => {
        return input +
              (isLast?'':'\n}\n')+
              '\n}\n'
      }
    ]
  }else if(/^\?\(.*\)$/.test(expr)){
    return [
      (input, ctx) => {
        return input +
              '\nfor(var i'+lv+' = 0; i' + lv + ' < $' + (lv - 1) + '.length; i'+lv+'++){\n' +
                  'if(' +
                    expr.substring(1).replace(/@/g, '$'+(lv - 1)+'[i'+lv+']') +
                  '){\n'+
                    'var $' + lv + ' = $'+(lv - 1)+'[i'+lv+'];\n' +
                    (isLast?(
                    'matches.push({' +
                      'pwd: pwd' + (lv - 1) + ',' +
                      'name: i'+lv+','+
                      'value: $' + lv +
                    '});\n'
                    ):(
                    '\nif(isPlainObject($'+lv+')||isArray($'+lv+')){\n'+
                    'var pwd' + lv + ' = pwd'+(lv - 1)+'.concat([i' + lv +']);\n'
                    ))
      },
      (input, ctx) => {
        return input +
                (isLast?'':'\n}\n')+
                '\n}\n'+
              '\n}\n'
      }
    ]
  }else if(/^\(.*\)$/.test(expr)){
    return [
      (input, ctx) => {
        return input +
              'var k'+lv+ ' = ' + expr.replace(/@/g, '$' + (lv - 1)) + ';\n' +
              'var $' + lv + ' = $' + (lv - 1) + '[k' + lv + '];\n' +
              (isLast?(
              'matches.push({' +
                'pwd: pwd' + (lv - 1) + ',' +
                'name: k'+lv+',' +
                'value: $' + lv +
              '});\n'
              ):(
              '\nif(isPlainObject($'+lv+')||isArray($'+lv+')){\n'+
              'var pwd' + lv + ' = pwd'+(lv - 1)+'.concat([k' + lv +']);;\n'
              ))
      },
      (input, ctx) => {
        return input +
              (isLast?'':'\n}\n')+
              ''
      }
    ]
  }else if(/^\[.+\]$/.test(expr)){
    return [
      (input, ctx) => {
        var key = expr.substring(1, expr.length - 1)
        return input +
              'var k'+lv+' = ' + key + ';\n' +
              'var $' + lv + ' = $' + (lv - 1) + expr +';\n' +
              (isLast?(
              'matches.push({' +
                'pwd: pwd' + (lv - 1) + ', ' +
                'name: k'+lv+', ' +
                'value: $' + lv +
              '});\n'
              ):(
              '\nif(isPlainObject($'+lv+')||isArray($'+lv+')){\n'+
              'var pwd' + lv + ' = pwd'+(lv - 1)+'.concat([k' + lv +']);\n'
              ))
      },
      (input, ctx) => {
        return input +
              (isLast?'':'\n}\n')+
              ''
      }
    ]
  }else{
    // istanbul ignore next
    throw new Error('unexpected expression: '+expr+'')
  }
}
export function createJSONPathMatcher(expr){
  const normalizedExprArray = parseJSONPath(expr)
    .map((token) =>
            token.replace(argsRegExpr, ($0, $1) =>
              'args' + (isArgIndexRegExpr.test($1) ? '' : '[0]') + $1))
  const lastIndex = normalizedExprArray.length - 1
  const body = stackProcess('', normalizedExprArray.map((expr, i) => {
    if(i === 0){
      return [
        (input, ctx) => {
          return input +
                'var matches = [], $0 = $, pwd0 = ["$"];\n' +
                (i === lastIndex?(
                'matches.push({' +
                  'pwd: pwd0, ' +
                  'name: null, ' +
                  'value: $0' +
                '});\n'
                ):'')
        },
        (input, ctx) => {
          return input +
                'return matches;'
        }
      ]
    }else{
      return _parseExpr(expr, i, i === lastIndex)
    }
  }))
  try{
    var fn = new Function('isPlainObject', 'isArray', 'hasOwnProperty', 'range', '$', 'args', body)
    return function matcher($, args){
      return fn(isPlainObject, isArray, hasOwnProperty, range, $, args)
    }
  }catch(e){
    // istanbul ignore next
    throw new Error(e + '\nfunction matcher($, args){\n' + body + '\n}')
  }
}

export function JSONPath(source, expr, options = {}){
  let resultType = (options.resultType||'value').toUpperCase()
  let getResult
  if(resultType === 'VALUE'){
    getResult = (v) => v.value
  }else if(resultType === 'PATH'){
    getResult = (v) => v.pwd.concat([v.name])
  }
  return createJSONPathMatcher(expr)(source).map(getResult)
}