requirebin sketch

index.js

var disolve = require('disolve');
var expr = disolve.Expression;

var string = function(a) {
  return Object.prototype.toString.call(a) === '[object String]';
};

function ineq(exp, op, constant) {
  if (!(this instanceof ineq)) { return new ineq(exp, op, constant) }
	
  this.evaluate = function(knowns) {
    var r = exp.evaluate(knowns);
    if (r && r.evaluate) {
      // compute an interval
      switch (op) {
        case '>' :
          switch (exp.symbols[1].type) {
            case '+':
              return [Number.MIN_VALUE + constant, Infinity]
            break;
            
            case '-':
              // TODO: handle more than one constant
              var cs = exp.symbols.filter(function(a) {
                return !string(a) && !a.type;
              })[0];
              
              return [constant + cs, Infinity];
            break;
          }
        break;
          
        //case '>=': return r <  constant; break;
        //case '<' : return r >= constant; break;
        //case '<=': return r >  constant; break;
      }      
    } else {
      // compare final result
      console.log('r', r);
      switch (op) {
        case '>' : return r <= constant; break;
        case '>=': return r <  constant; break;
        case '<' : return r >= constant; break;
        case '<=': return r >  constant; break;
      }
    }
  }
  
  this.toString = function() {
    return exp.toString() + ' ' + op + ' ' + constant.toString(); 
  }
}

[
  ineq(expr('x', '+', 1), '>', 0),
  ineq(expr('x', '-', 1), '>', 0),
  ineq(expr('x', '-', -1), '>', 0),
].forEach(function(e, i) {
  console.log(e.toString() + ': ', e.evaluate());
});


/*
ex:
	x + 1 > 0
  x = [0, inf] // comes from > 0
  
ex: 
	x + .1 > 0
  x = [0, inf] // comes from > 0

ex:
  x - 1 >= 0
  x = [1, inf] // comes from >= 0
  
ex:
  1 <= x / 2 <= 4
  // [1, 4]
  // [2 * 1, 2 * 4]
  x = [2, 8]
 
 ex:
   x + 1 == 0
   x = [-1, -1]
*/

minified.js

require=function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s}({disolve:[function(require,module,exports){var defined=function(a){return typeof a!=="undefined"};var string=function(a){return Object.prototype.toString.call(a)==="[object String]"};var fn=function(a){return typeof a==="function"};var number=function(a){return Object.prototype.toString.call(a)==="[object Number]"};var array=function(a){return Object.prototype.toString.call(a)==="[object Array]"};function Expression(symbols){var _symbols=symbols;if(!array(symbols)){_symbols=[];Array.prototype.push.apply(_symbols,arguments)}if(!(this instanceof Expression)){return new Expression(_symbols)}for(var i=0;i<_symbols.length;i++){var symbol=_symbols[i];if(Expression.isExpression(symbol)){symbol.parent=this}else if(string(symbol)&&Operator.isOperator(symbol)){_symbols[i]=new Operator(symbol)}}this.symbols=_symbols}Expression.isExpression=function(a){return a&&a.name&&a.name==="expression"};Expression.prototype.constructor=Expression;Expression.prototype.parent=null;Expression.prototype.name="expression";Expression.prototype.toString=function(addParens){return this.symbols.join("")};Expression.prototype.evaluate=function(knowns){knowns=knowns||{};var s=this.symbols.concat();for(var phase=0;phase<=1;phase++){for(var i=0;i<s.length;i++){if(Operator.isOperator(s[i])&&phase===Operator.ops[s[i].type]){var evaluate=true;var p=s[i-1];var c=s[i];var n=s[i+1];if(defined(knowns[p])){p=knowns[p]}else if(Expression.isExpression(p)){p=p.evaluate(knowns)}if(Expression.isExpression(p)||string(p)){evaluate=false}if(defined(knowns[n])){n=knowns[n]}else if(Expression.isExpression(n)){n=n.evaluate(knowns)}if(Expression.isExpression(n)||string(n)){evaluate=false}if(evaluate){s[i-1]=c.perform(p,n);s.splice(i,2);i-=2}else{s[i-1]=p;s[i+1]=n}}}}return s.length>1?new this.constructor(s):s[0]};Expression.prototype.clone=function(){var clone=[],symbols=this.symbols,l=symbols.length;for(var i=0;i<l;i++){if(fn(symbols[i].clone)){clone.push(symbols[i].clone())}else{clone.push(symbols[i])}}return new this.constructor(clone)};Expression.prototype.unknowns=function(knowns,unknowns){unknowns=unknowns||[];var symbols=this.symbols,l=symbols.length;for(var i=0;i<l;i++){var symbol=symbols[i];if(Expression.isExpression(symbol)){symbol.unknowns(knowns,unknowns)}else if(string(symbol)&&!Operator.isOperator(symbol)&&!defined(knowns[symbol])){unknowns.push(symbol)}}return unknowns};function ExpressionFor(variable,expression){if(!(this instanceof ExpressionFor)){return new ExpressionFor(variable,expression)}this.variable=variable;this.expression=expression}ExpressionFor.prototype.evaluate=function(knowns){knowns[this.variable]=this.expression.evaluate(knowns);return knowns[this.variable]};ExpressionFor.prototype.clone=function(){return new ExpressionFor(this.variable,this.expression.clone())};ExpressionFor.prototype.toString=function(){return this.variable+" = "+this.expression.toString()};function ExpressionGroup(symbols){var _symbols=symbols;if(!array(symbols)){_symbols=[];Array.prototype.push.apply(_symbols,arguments)}if(!(this instanceof ExpressionGroup)){return new ExpressionGroup(_symbols)}Expression.call(this,_symbols)}ExpressionGroup.prototype=Object.create(Expression.prototype);ExpressionGroup.prototype.constructor=ExpressionGroup;ExpressionGroup.prototype.toString=function(){return"("+Expression.prototype.toString.call(this)+")"};function ExpressionFunction(fn,expression){if(!(this instanceof ExpressionFunction)){return new ExpressionFunction(fn,expression)}this.fn=fn;this.expression=expression}ExpressionFunction.prototype.evaluate=function(knowns){var fn=Math[this.fn]||this[this.fn];if(Expression.isExpression(this.expression)){return fn(this.expression.evaluate(knowns))}else if(string(this.expression)&&knowns[this.expression]){return fn(knowns[this.expression])}else if(number(this.expression)){return fn(this.expression)}};ExpressionFunction.prototype.unknowns=function(knowns,unknowns){if(Expression.isExpression(this.expression)){return this.expression.unknowns(knowns,unknowns)}};ExpressionFunction.prototype.toString=function(){return this.fn+"("+this.expression.toString()+")"};function Operator(type){if(!(this instanceof Operator)){return new Operator(type)}this.type=type}Operator.prototype.name="operator";Operator.prototype.constructor=Operator;Operator.isOperator=function(a){return a instanceof Operator||defined(Operator.prototype[a])&&a.length===1};Operator.ops={"^":0,"*":0,"/":0,"%":0,"+":1,"-":1};Operator.prototype.sortAgainst=function(op){var ops=Operator.ops;return ops[this.type]>=ops[op.type]};Operator.prototype.clone=function(){return new this.constructor(this.type)};Operator.prototype["+"]=function(a,b){return a+b};Operator.prototype["-"]=function(a,b){return a-b};Operator.prototype["*"]=function(a,b){return a*b};Operator.prototype["/"]=function(a,b){return a/b};Operator.prototype["^"]=function(a,b){return Math.pow(a,b)};Operator.prototype["%"]=function(a,b){return a%b};Operator.prototype.perform=function(a,b){return this[this.type](a,b)};Operator.prototype.toString=function(){if(this.type==="^"){return this.type}return" "+this.type+" "};var disolve=function(val){return new Expression(val)};disolve.Expression=Expression;disolve.ExpressionFor=ExpressionFor;disolve.ExpressionFunction=ExpressionFunction;disolve.ExpressionGroup=ExpressionGroup;disolve.Operator=Operator;if(typeof module!=="undefined"&&typeof module.exports=="object"){module.exports=disolve}if(typeof window!=="undefined"){window.disolve=window.disolve||disolve}},{}]},{},[]);var disolve=require("disolve");var expr=disolve.Expression;var string=function(a){return Object.prototype.toString.call(a)==="[object String]"};function ineq(exp,op,constant){if(!(this instanceof ineq)){return new ineq(exp,op,constant)}this.evaluate=function(knowns){var r=exp.evaluate(knowns);if(r&&r.evaluate){switch(op){case">":switch(exp.symbols[1].type){case"+":return[Number.MIN_VALUE+constant,Infinity];break;case"-":var cs=exp.symbols.filter(function(a){return!string(a)&&!a.type})[0];return[constant+cs,Infinity];break}break}}else{console.log("r",r);switch(op){case">":return r<=constant;break;case">=":return r<constant;break;case"<":return r>=constant;break;case"<=":return r>constant;break}}};this.toString=function(){return exp.toString()+" "+op+" "+constant.toString()}}[ineq(expr("x","+",1),">",0),ineq(expr("x","-",1),">",0),ineq(expr("x","-",-1),">",0)].forEach(function(e,i){console.log(e.toString()+": ",e.evaluate())});

package.json

{
  "name": "requirebin-sketch",
  "version": "1.0.0",
  "dependencies": {
    "disolve": "0.1.0"
  }
}

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