@dtable/formula/README.md

dtable-formula

<h1 align="center">Welcome to @dtable/formula 👋</h1>
<p>
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    <img alt="Version" src="https://img.shields.io/npm/v/@dtable/formula.svg">
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    <img alt="License: ISC" src="https://img.shields.io/badge/License-ISC-yellow.svg" />
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> dtable-formula

## Install

```sh
npm install --save @dtable/formula
```

## Run tests

```sh
npm run test
```

## Examples

List some simple examples for quick start.

### prase text expression

```ts
import { formula } from "@dtable/formula";

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

### get lexer result

```ts
import { tokenize } from "@dtable/formula";

tokenize("1 + 2");

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

### use params

```ts
import { formula } from "@dtable/formula";

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

## All Functions And Operators


| Name              | Type             | Description                                                                                |
|-------------------|------------------|--------------------------------------------------------------------------------------------|
| {}                | Param operator   | reference to a param.                                                                      |
| !=                | 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.                                           |
| IF()              | Logical function | It allows you to make logical comparisons between a value and what you expect              |
| +                 | 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.                                                 |
| &                 | Strings operator | Concatenate strings.                                                                       |
| CONCATENATE()     | Strings function | Concatenate strings.                                                                       |
| REPT()            | Strings function | Repeats text a given number of times.                                                      |
| LEN()             | Strings function | Get the length of the string                                                               |
| DATETIME_FORMAT() | Date function    | Reformat the data from the date-type field into a string of your specifications            |
| SET_TIMEZONE()    | Date function    | Set the time zone for the date                                                             |

## Author

👤 **zhangchao1997**

* Github: [@little-thing](https://github.com/little-thing)