FormulaParser : Formula string parser working in pure JavaScript

Special lovers ❤️

• rhyscitlema.com
• Precedence climbing

👏 Example

See demo

📦 Installation

git

$ git clone [email protected]:KennethanCeyer/metric-parser.git

npm

$ npm install metric-parser

yarn

$ yarn add metric-parser

📃 Getting started

Javascript (Web)

<script src="~/dist/metric.parser.umd.js"></script> <script> // { data: {tree object}, code: 0 } const result = metricParser.convert('1 + (2 + 3)');  // { data: [ 1, '+', 2, '+', 3 ], code: 0 } <= bracket will be optimized const expression = metricParser.convert(result.data);  // true | false <= true means valid const valid = metricParser.valid(result.data); </script>

Typescript

import { convert, valid } from 'metric-parser';  // { data: {tree object}, code: 0 } const result: ParserGeneralResult = convert('1 + (2 + 3)');  // { data: [ 1, '+', 2, '+', 3 ], code: 0 } <= bracket will be optimized const expression: string[] = convert(result.data);  // true | false <= true means valid const valid: boolean = valid(result.data);

NodeJS

const parser = require('metric-parser');  // { data: {tree object}, code: 0 } const result = parser.convert('1 + (2 + 3)');  // { data: [ 1, '+', 2, '+', 3 ], code: 0 } <= bracket will be optimized const expression = parser.convert(result.data);  // true | false <= true means valid const valid = parser.valid(result.data);

⚡️ Type

Tree

Tree is a simple object that converted from AST.

const result = convert('1 + (2 + 3)'); const tree: Tree = result.data;

{   operator: '+',   operand1: { value: { type: 'unit', unit: 1 } },   operand2: {     operator: '+',     operand1: { value: { type: 'unit', unit: 2 } },     operand1: { value: { type: 'unit', unit: 3 } }   } }

AST (AbstractSyntaxTree)

AST is the most important object that contains the structure of a formula.

const ast = convert('1 + (2 + 3)', true); 

{   AbstractSyntaxTree {     type: 1, // operator     value: '+',     leftNode: AbstractSyntaxTree {       type: 2, // value       value: 1     },     rightNode: AbstractSyntaxTree {       type: 1, // operator       value: '+',       leftNode: AbstractSyntaxTree {         type: 1, // value         value: 2       },       rightNode: AbstractSyntaxTree {         type: 1, // value,         value: 3       }     }   } }

🚩 Roadmap

v0.0.1

• support typescript
• support UMD and ES5 module
• support automated test environment
• support custom value (custom object as value)
• support implicit patterns (multiplication omitted, operator aliases)
• support reference docs
• improve parser logic based AST
• improve validation error (parserStack, codes)
• add unit test with coverage rate over 90%
• support validation for many cases

v0.1.0

• guidelines for developers
• guidelines for contributors

v0.2.0

• function expression IF(), SUM(), AVG(), _CUSTOM_NAMED_FUNC_()
• support custom tree model declaration

v0.3.0

• declare variable (operator and value type)

🔍 License

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.