Antlr-calculator NPM

antlr-calculator

This calculator is using the ANTLR4 TypeScript target to calculate results from formulas that are passed in as string. Both JavaScript and TypeScript are supported.

Whenever a calculation is performed, a CalculationResult is returned with the following properties:

Property	Type
isValid	boolean	`true` if the formula could be parsed and calculated, else `false`
errorPosition	number	Position of the offending symbol in the line, 0 based index, for invalid results, else null
errorMessage	string	ANTLR error message for invalid formulas, else null
result	number	`NaN` for invalid formulas, else the actual result

You can check out the live demo here!

Installation

Clone this repository or just go with npm install antlr-calculator.

JavaScript

Just reference dist/bundle.js and the global variable antlrCalc is available.

var result = antlrCalc.Calculator.calculate('4*5');
console.log(JSON.stringify(result, null, 2));

//  {
//    "isValid": true,
//    "errorPosition": null,
//    "errorMessage": null,
//    "result": 20
//  }

TypeScript

Import the Calculator class and use the static calculate(formula: string) method to evaluate formulas.

import { Calculator } from 'antlr-calculator';

var result = Calculator.calculate('4*5');
console.log(JSON.stringify(result, null, 2));

//  {
//    "isValid": true,
//    "errorPosition": null,
//    "errorMessage": null,
//    "result": 20
//  }

Supported functions

Expression
`FLOOR expression`	Round down to zero accuracy
`CEIL expression`	Round up to zero accuracy
`ABS expression`	Absolute value
`ROUNDK '(' expression ';' expression ')'`	Round expr_1 with expr_2 accuracy
`ROUND expression`	Round with zero accuracy
`TRUNC expression`	Trim decimal digits
`SIN expression`	Sinus
`COS expression`	Cosinus
`TAN expression`	Tangens
`COT expression`	Cotangens
`SINH expression`	Sinus Hypererbolicus
`COSH expression`	Cosinus Hyperbolicus
`TANH expression`	Tangens Hyperbolicus
`ARCSIN expression`	Inverse Sinus
`ARCCOS expression`	Inverse Cosinus
`ARCTAN expression`	Inverse Tangens
`ARCTAN2 '(' expression ';' expression ')'`	Atan2
`ARCCOT expression`	Inverse Cotangens
`EXP expression`	e ^ expr
`LN expression`	Logarithm to e
`EEX expression`	10 ^ expr
`LOG expression`	Logarithm to 10
`RAD expression`	Angle to radians (360° base)
`DEG expression`	Radians to angle (360° base)
`SQRT expression`	Square root
`SQR expression`	Square product
`expression op = ('^'\|'**') expression`	expr_1 to the expr_2 th power
`expression (MOD \| '%' ) expression`	Modulo
`expression DIV expression`	Whole part of division rest
`expression op = ('~'\|'//') expression`	expr_1 nth root of expr_2
`expression op = ('*'\|'/') expression`	Multiplication or division
`expression op = ('+'\|'-') expression`	Addition or subtraction
`NUMBER`	Single integer or float number
`'(' expression ')'`	Expression within parentheses
`PI '()'?`	Mathematical constant pi = 3,141593
`expression E+ expression`	Exponent, e.g. 10e+43
`expression E- expression`	Inverted Exponent, e.g. 10e-43
`EULER`	Mathematical constant e = 2,718282
`'-' expression`	Unary minus sign (negative numbers)
`'+' expression`	Unary plus sign (positive numbers)
`'(' expression ')' expression`	Expressions without multiplication sign, e.g. `2(3)` -> `2*(3)`
`expression '(' expression ')'`	Expressions without multiplication sign, e.g. `2(3)` -> `2*(3)`