Formula

Parse text expression to calculation result.

Installation

npm install @blastz/formula

Examples

List some simple examples for quick start.

prase text expression

import { formula } from "@blastz/formula";

formula("1 + 2"); // 3

get lexer result

import { tokenize } from "@blastz/formula";

tokenize("1 + 2");

// [
//   { image: "1", tokenType: { name: "Number" } },
//   { image: "+", tokenType: { name: "Plus" } },
//   { image: "2", tokenType: { name: "Number" } },
// ];

Get more token detail from Interface IToken

use params

import { formula } from "@blastz/formula";

formula("{Number1} + {Number2}", { Number1: 1, Number2: 2 }); // 3

All Functions And Operators

| Name | Type | Description | | ----------- | ---------------- | ------------------------------------------------------------------------------------------ | | != | Logical operator | Check if one value is not equal to another value. | | = | Logical operator | Compare if one value is equal to another value. | | >= | Logical operator | Compare if one value is greater than, or equal to, another value. | | > | Logical operator | Compare if one value is greater than another value | | <= | Logical operator | Compare if one value is less than, or equal to, another value. | | < | Logical operator | Compare if one value is less than another value. | | + | Numeric operator | Add together two values. | | - | Numeric operator | Subtract two values. | | * | Numeric operator | Multiply two values. | | / | Numeric operator | Divide two values. | | ABS() | Numeric function | Returns the absolute value. | | ROUND() | Numeric function | Rounds the value to the number of decimal places given by precision. | | ROUNDUP() | Numeric function | Rounds the value to the number of decimal places given by precision, always rounding up. | | ROUNDDOWN() | Numeric function | Rounds the value to the number of decimal places given by precision, always rounding down. | | INT() | Numeric function | Returns the greatest integer that is less than or equal to the specified value. | | MAX() | Numeric function | Returns the largest of the given numbers. | | MIN() | Numeric function | Returns the smallest of the given numbers. | | {} | Param operator | reference to a param. |

函数名映射

函数支持以中文方式调用

| 英文函数名 | 中文函数名 | | ----------- | -------------- | | ABS() | 绝对值() | | ROUND() | 四舍五入() | | ROUNDUP() | 向上四舍五入() | | ROUNDDOWN() | 向下四舍五入() | | INT() | 取整 | | MAX() | 最大值 | | MIN() | 最小值 |