@fav/arith

Calculates an arithmetical expression acculately.

"fav" is an abbreviation of "favorite" and also the acronym of "for all versions". This package is intended to support all Node.js versions and many browsers as possible. At least, this package supports Node.js >= v0.10 and major Web browsers: Chrome, Firefox, IE11, Edge, Vivaldi and Safari.

Install

To install from npm:

$ npm install --save @fav/arith

NOTE: npm < 2.7.0 does not support scoped package, but old version Node.js supports it. So when you use such older npm, you should download this package from github.com, and move it in node_modules/@fav/arith/ directory manually.

Usage

For Node.js:

var arithmetic = require('@fav/arith');

var a0 = arithmetic(1.23);
// => ArithNumber { numerator: 123, denominator: 1, exponent: -2 }
a0.toApproximateString();
// => '1.23'

var a1 = arithmetic(1.23, '+', 4.56, '*', 7.89);
// => ArithNumber { numerator: 372084, denominator: 1, exponent: -4 }
a1.toApproximateString();
// => '37.2084'

var a1 = arithmetic([1.23, '+', 4.56, '*', 7.89]);
// => ArithNumber { numerator: 372084, denominator: 1, exponent: -4 }
a1.toApproximateString();
// => '37.2084'

var a2 = arithmetic([[1.23, '+', 4.56], '*', 7.89]);
// => ArithNumber { numerator: 456831, denominator: 1, exponent: -4 }
a2.toApproximateString();
// => '45.6831'

var a = arithmetic('1')   // => ArithNumber { numerator: 1, denominator: 1, exponent: 0 }
  .add(2)                 // => ArithNumber { numerator: 3, denominator: 1, exponent: 0 }
  .subtract(-3)           // => ArithNumber { numerator: 6, denominator: 1, exponent: 0 }
  .multiply(4)            // => ArithNumber { numerator: 24, denominator: 1, exponent: 0 }
  .divide(5)              // => ArithNumber { numerator: 24, denominator: 5, exponent: 0 }
  .toApproximteString()   // => '4.8'

For Web browsers:

<script src="fav.arith.min.js"></script>
<script>
var arithmetic = fav.arith;

var a1 = arithmetic(1.23, '+', 4.56, '*', 7.89);
// => ArithNumber { numerator: 372084, denominator: 1, exponent: -4 }
a1.toApproximateString();
// => '37.2084'

var a = arithmetic('1')   // => ArithNumber { numerator: 1, denominator: 1, exponent: 0 }
  .add(2)                 // => ArithNumber { numerator: 3, denominator: 1, exponent: 0 }
  .subtract(-3)           // => ArithNumber { numerator: 6, denominator: 1, exponent: 0 }
  .multiply(4)            // => ArithNumber { numerator: 24, denominator: 1, exponent: 0 }
  .divide(5)              // => ArithNumber { numerator: 24, denominator: 5, exponent: 0 }
  .toApproximteString()   // => '4.8'
</script>

API

arithmetic(expression, ...) : ArithNumber

Calculate an expression, which is an Array parameter or a set of parameters. An expression consists of terms, operators and nested arrays. A term can be a number, a string or an ArithNumber object. An operator is a string which is one of '+', '-', '*', '/'.

ArithNumber is for representing a number value as accurately as possible by using three integers: numerator, denominator and exponent; a number = (numerator / denominator) * 10^exponent .

Parameters:

Parameter	Type	Description
expression	Array | number | string | ArithNumber	An expression to be calculated.

Returns:

An ArithNumber object which represents an number value.

Type: ArithNumber

Operators:

Operator	Description
'+'	Addition
'-'	Subtraction
'*'	Multiplication
'/'	Division

Checked

Node.js (11〜)

Platform	11
macOS	◯
Windows10	◯
Linux	◯

Node.js (4〜10)

Platform	4	5	6	7	8	9	10
macOS	◯	◯	◯	◯	◯	◯	◯
Windows10	◯	◯	◯	◯	◯	◯	◯
Linux	◯	◯	◯	◯	◯	◯	◯

io.js (1〜3)

Platform	1	2	3
macOS	◯	◯	◯
Windows10	◯	◯	◯
Linux	◯	◯	◯

Node.js (〜0.12)

Platform	0.8	0.9	0.10	0.11	0.12
macOS	◯	◯	◯	◯	◯
Windows10	◯	◯	◯	◯	◯
Linux	◯	◯	◯	◯	◯

Web browsers

Platform	Chrome	Firefox	Vivaldi	Safari	Edge	IE11
macOS	◯	◯	◯	◯	--	--
Windows10	◯	◯	◯	--	◯	◯
Linux	◯	◯	◯	--	--	--

License

Copyright (C) 2018 Takayuki Sato

This program is free software under MIT License. See the file LICENSE in this distribution for more details.