Range.js

composable("composites.Range", function (require, global) {


  "use strict";


  require("environment_extended_introspective_core");


  var
    environment               = require("environment"),

    environment_introspective = environment.introspective,
    environment_helpers       = environment.helpers,


    Object          = global.Object,
    String          = global.String,
    Number          = global.Number,
    Math            = global.Math,

    isFinite        = global.isFinite,

    isObject        = environment_introspective.isObject,
    isFunction      = environment_introspective.isFunction,
    isBoolean       = environment_introspective.isBoolean,
    isNumber        = environment_introspective.isNumber,
    isString        = environment_introspective.isString,

    compareTypes    = environment_helpers.compareTypes,

    object_keys     = Object.keys,
    object_isEqual  = Object.isEqual,

    isPrototypeOf   = Object.isPrototypeOf,

    fromCharCode    = String.fromCharCode,

    floor           = Math.floor,


    INTEGER_MINIMUM = Math.pow(-2, 53), //  (Math.pow(-2, 53) - 1) === (Math.pow(-2, 53)) // true // (Math.pow(-2, 53) + 1) === (Math.pow(-2, 53)) // false
    INTEGER_MAXIMUM = Math.pow(2, 53),  //  - see [http://blog.vjeux.com/2010/javascript/javascript-max_int-number-limits.html]
                                        //  - via [http://stackoverflow.com/questions/307179/what-is-javascripts-max-int-whats-the-highest-integer-value-a-number-can-go-to#answer-4375743]
    UNDEFINED_VALUE,

    REGX_RANGELIKE  = (/\[[^.]+\.{2}[^.]+\]/),


    getSanitizedInteger = function (type) {
      return (isFinite(type = Number(type)) && ((type = floor(type)) <= INTEGER_MAXIMUM) && (type >= INTEGER_MINIMUM)) ? type : UNDEFINED_VALUE;
    },


    isEqualType = function (typeA, typeB) {
      var
        isEqual = false
      ;
      if (isFunction(typeA.equals)) {

        isEqual = typeA.equals(typeB);

      } else if (isFunction(typeB.equals)) {

        isEqual = typeB.equals(typeA);
      }
      if (!isEqual) {

        isEqual = object_isEqual(typeA, typeB);
      }
      return isEqual;
    },


    isIteratorItemLike = function (type) {
      return (
          ('value' in type)
          && (isBoolean(type.done))
          && (object_keys(type).length === 2)
      );
    }
  ;


  function compareNumbers(a, b) {
    return (a - b);
  }
  function compareStrings(a, b) {
    return (((a < b) && -1) || ((a > b) && 1) || 0);
  }


  function getNextInteger(int) {
    var
      currVal = getSanitizedInteger(int),
      nextVal = (currVal + 1)
    ;
  //Math.pow(2, 53) === Math.pow(2, 53)     //  true
  //Math.pow(2, 53) + 1 === Math.pow(2, 53) //  true
  //Math.pow(2, 53) + 2 === Math.pow(2, 53) //  false

    return ((isFinite(nextVal) && (nextVal !== currVal)) ? nextVal : UNDEFINED_VALUE);
  }
  function getNextIntegerInRange(int, intEnd) {
    return {
      value : (int = getNextInteger(int)),
      done  : ((int === UNDEFINED_VALUE) || (compareNumbers(int, intEnd) >= 0))
    };
  }


  function getNextCharacter(char) {
    var
      currVal = ("" + char),
      nextVal
    ;
    if (currVal.length == 1) { // this definitely is a character.
      /**
       *  as for >> (currVal === "") << ...
       *  ... there is nothing like a "next" character
       *  that could be a successor of an empty string.
       */
      nextVal = fromCharCode(currVal.charCodeAt(0) + 1);
      /*
       *  either "nextVal" gets assigned a valid character ...
       *  ... or assignement of "nextVal" falls back again to the [undefined] value.
       */
      nextVal = ((nextVal !== "") && (nextVal !== currVal)) ? nextVal : UNDEFINED_VALUE;
    }
    return nextVal;
  }
  function getNextCharacterInRange(char, charEnd) {
    return {
      value : (char = getNextCharacter(char)),
      done  : ((char === UNDEFINED_VALUE) || (compareStrings(char, charEnd) >= 0))
    };
  }


  function hasNextGenericItemInRange(typeA, typeB) { // fallback via build in default comparison.
    return (
         (compareTypes(typeA, typeB) < 0)
      || (!isEqualType(typeA, typeB))
    );
  }


  function getNextGenericItemInRange(type, typeEnd, hasNext) {
    var
      tupel
    ;
    type  = type.next();

    if (isIteratorItemLike(type)) {

      tupel = type;

    } else {

      tupel = {
        value : type,
        done  : !hasNext(type, typeEnd)
      }
    }
    return tupel;
  }


  function toString(type, typeEnd, tupel) {
    return [

      '{[ '
      , type
      , ' .. '
      , typeEnd
      , ' ], { value: '
      , tupel.value
      , ', done: '
      , tupel.done
      , ' }}'

    ].join("");
  }
  function toValue(tupel) {
    return {
      value : tupel.value,
      done  : tupel.done
    };
  }


  function isRangeLike(type) {
    return (
         isFunction(type.next)
      && REGX_RANGELIKE.test(type.toString())
    );
  }
  function isRange(type) {
    return ((type instanceof Range) || isRangeLike(type));
  }


  function Range(type, typeEnd, hasNext, getNext, isInitiallyDone) {  // Constructor.
    var
      tupel = {
        value : type,
        done  : !!isInitiallyDone
      },
      range = this
    ;

    range.next = function () {
      if (!tupel.done) {
        tupel = getNext(tupel.value, typeEnd, hasNext);
      }
      return tupel;
    };

    range.toString = function () {
      return toString(type, typeEnd, tupel);
    };
    range.valueOf = function () {
      return toValue(tupel);
    };
  }


  function createRange(config) {                                      // Factory.
    var
      typeBegin = config.begin,
      typeEnd   = config.end,

      compare   = config.compare,             // custom.
      equals    = config.equals,              // custom.

      hasNext   = hasNextGenericItemInRange,  // default.

      range
    ;
    if (isObject(typeBegin) && isObject(typeEnd)) {
      if (
           isFunction(typeBegin.next)
        && isFunction(typeEnd.next)
        && (isPrototypeOf(typeBegin) === isPrototypeOf(typeEnd))
      ) {
        if (isFunction(compare)) {

          hasNext = (function (compare) {
            return function (typeA, typeB) {

              return (compare(typeA, typeB) < 0);
            };
          }(compare));

        } else if (isFunction(equals)) {

          hasNext = (function (equals) {
            return function (typeA, typeB) {

              return (!equals(typeA, typeB));
            };
          }(equals));

        }
        range = (new Range(typeBegin, typeEnd, hasNext, getNextGenericItemInRange));
      }
    } else if (
         isString(typeBegin)
      && (typeBegin.length === 1)
      && ((typeEnd = ("" + typeEnd)) && (typeEnd.length === 1))
      && (compareStrings(typeBegin, typeEnd) < 0)
    ) {
      range = (new Range(typeBegin, typeEnd, hasNext, getNextCharacterInRange));

    } else if (
           isNumber(typeBegin)
        && ((typeBegin = getSanitizedInteger(typeBegin)) !== UNDEFINED_VALUE)
        && ((typeEnd = getSanitizedInteger(typeEnd)) !== UNDEFINED_VALUE)
        && (compareNumbers(typeBegin, typeEnd) < 0)
    ) {
      range = (new Range(typeBegin, typeEnd, hasNext, getNextIntegerInRange));

    }
    return (range || (new Range(typeBegin, typeEnd, hasNext, getNextGenericItemInRange, true)));
  }


  return {                                                            // (Factory) Module.
    create  : createRange,
    isRange : isRange
  };


});



/*


  [http://closure-compiler.appspot.com/home]


- Simple          -  1716 byte
composable("composites.Range",function(r,k){function y(a,c){var b=n(a),d=b+1;return{value:a=t(d)&&d!==b?d:g,done:a===g||0<=a-c}}function z(a,c){var b=""+a,d;1==b.length&&(d=A(b.charCodeAt(0)+1),d=""!==d&&d!==b?d:g);return{value:a=d,done:a===g||0<=(a<c&&-1||a>c&&1||0)}}function B(a,c){var b;(b=0>C(a,c))||(b=!1,h(a.equals)?b=a.equals(c):h(c.equals)&&(b=c.equals(a)),b||(b=D(a,c)),b=!b);return b}function u(a,c,b){var d=a=a.next();return"value"in d&&E(d.done)&&2===F(d).length?a:{value:a,done:!b(a,c)}}function l(a,c,b,d,f){var e={value:a,done:!!f};this.next=function(){e.done||(e=d(e.value,c,b));return e};this.toString=function(){return["{[ ",a," .. ",c," ], { value: ",e.value,", done: ",e.done," }}"].join("")};this.valueOf=function(){return{value:e.value,done:e.done}}}r("environment_extended_introspective_core");var v=r("environment"),m=v.introspective,p=k.Object,G=k.Number,q=k.Math,t=k.isFinite,w=m.isObject,h=m.isFunction,E=m.isBoolean,H=m.isNumber,I=m.isString,C=v.helpers.compareTypes,F=p.keys,D=p.isEqual,x=p.isPrototypeOf,A=k.String.fromCharCode,J=q.floor,K=q.pow(-2,53),L=q.pow(2,53),g,M=/\[[^.]+\.{2}[^.]+\]/,n=function(a){return t(a=G(a))&&(a=J(a))<=L&&a>=K?a:g};return{create:function(a){var c=a.begin,b=a.end,d=a.compare;a=a.equals;var f=B,e;w(c)&&w(b)?h(c.next)&&h(b.next)&&x(c)===x(b)&&(h(d)?f=function(a){return function(b,c){return 0>a(b,c)}}(d):h(a)&&(f=function(a){return function(b,c){return!a(b,c)}}(a)),e=new l(c,b,f,u)):I(c)&&1===c.length&&(b=""+b)&&1===b.length&&0>(c<b&&-1||c>b&&1||0)?e=new l(c,b,f,z):H(c)&&(c=n(c))!==g&&(b=n(b))!==g&&0>c-b&&(e=new l(c,b,f,y));return e||new l(c,b,f,u,!0)},isRange:function(a){var c;(c=a instanceof l)||(c=h(a.next)&&M.test(a.toString()));return c}}});


*/



/*


var
  r, o,
  TypeRange = composable.require("composites.Range")
;


r = TypeRange.create({begin: 1, end: 0});
while(!(o = r.next()).done) {
  console.log("[1 .. 0].next() : ", o);
}
console.log("[1 .. 0].next() : ", o);

r = TypeRange.create({begin: 4, end: 20});
while(!(o = r.next()).done) {
  console.log("[4 .. 20].next() : ", o);
}
console.log("[4 .. 20].next() : ", o);

r = TypeRange.create({begin: -4, end: "12"});
while(!(o = r.next()).done) {
  console.log("[-4 .. '12'].next() : ", o);
}
console.log("[-4 .. '12'].next() : ", o);


r = TypeRange.create({begin: "_", end: "N"});
while(!(o = r.next()).done) {
  console.log("['_' .. 'N'].next() : ", o);
}
console.log("['_' .. 'N'].next() : ", o);

r = TypeRange.create({begin: "N", end: "_"});
while(!(o = r.next()).done) {
  console.log("['N' .. '_'].next() : ", o);
}
console.log("['N' .. '_'].next() : ", o);


*/