@bignum/template
v0.3.2
Published
Write formulas with template literals.
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@bignum/template
Write formulas with template literals.
🚀 Features
- You can write formulas with template literals.
(f`0.3 - 0.1`
is easier to read than a statement likenew Big(0.3).minus(0.1)
.) - Returns exact calculation results using arbitrary-precision arithmetic with BigInt.
(Similar to big.js.) - The calculation engine is customizable.
💿 Installation
npm install @bignum/template
📖 Usage
import { setupEngine } from "@bignum/template";
const f = setupEngine();
const num = 0.1;
const result = f`${num} + 0.1 * 2`;
console.log(result); // 0.3
// Perform exact calculations using the arbitrary-precision arithmetic with BigInt.
console.log(f`${0.2} + ${0.1}`); // 0.3
console.log(0.2 + 0.1); // 0.30000000000000004
🧮 API
setupEngine([context]): BTEngine
Returns the calculation engine.
context
: An object for customizing calculations.
By default, calculations are performed using BigNum.
setupEngine context
TBA
BTEngine
Perform calculations using template literals.
Example:
import { setupEngine } from "@bignum/template";
const f = setupEngine();
console.log(f`${0.1} + 0.2`); // 0.3
The calculation result usually returns a number
, but if the number
loses precision when converted to a string
, it returns a string
with the original precision is returned.
📝 Supported Syntax
Operators
The following operators are supported:
/* Arithmetic Operators */
// add
f`0.1 + 0.2`; // 0.3
// subtract
f`0.3 - 0.1`; // 0.2
// multiply
f`0.07 * 100`; // 7
// divide
f`0.6 / 0.2`; // 3
// modulo
f`0.6 % 0.2`; // 0
// pow / nth root
f`2 ** 3`; // 8
f`4 ** (1/2)`; // 2
f`8 ** (1/3)`; // 2
/* Parentheses */
f`(0.1 + 0.2) * 10`; // 3
f`0.1 + 0.2 * 10`; // 2.1
/* Unary Operators */
f`${0.3} + -${0.1}`; // 0.2
/* Logical Operators (Returns 0/1 for value compatibility) */
f`41 == 41`; // 1
f`41 == 1`; // 0
f`41 != 41`; // 0
f`41 != 1`; // 1
f`1 <= 2`; // 1
f`1 <= 1`; // 1
f`1 <= 0`; // 0
f`1 < 2`; // 1
f`1 < 1`; // 0
f`1 < 1`; // 0
f`2 >= 1`; // 1
f`1 >= 1`; // 1
f`0 >= 1`; // 0
f`2 > 1`; // 1
f`1 > 1`; // 0
f`0 > 1`; // 0
Operand
Either write the numerical value as is in the template, or the template literal substitution is considered as an operand.
f`0.3 + -${0.1}`; // 0.2
Variables
Variables can be accessed using identifiers. The supported variables are:
f`E`; // Same as Math.E
f`LN10`; // Same as Math.LN10
f`LN2`; // Same as Math.LN2
f`LOG2E`; // Same as Math.LOG2E
f`LOG10E`; // Same as Math.LOG10E
f`PI`; // Same as Math.PI
f`SQRT1_2`; // Same as Math.SQRT1_2
f`SQRT2`; // Same as Math.SQRT2
Functions
You can call built-in functions by writing a Call expression.
f`trunc(12.34)`; // Returns the value by truncating the given value.
f`round(12.34)`; // Returns the given value rounded to the nearest integer.
f`floor(12.34)`; // Returns the greatest integer less than or equal to the given value.
f`ceil(12.34)`; // Returns the smallest integer greater than or equal to the given value.
f`abs(-1)`; // Returns the absolute value.
f`sqrt(2)`; // Returns the square root of 2.
🛸 Prior Art
- bigjs-literal
This package is similar to bigjs-literal in that it uses template literals for calculations, but bigjs-literal has a 49kB file for the parser alone.
The JavaScript file for the compiler that@bignum/template
has is 8kB (without minify). (However, there is no ability to compile it in advance.)