Expressionrunner

Simple expression engine without external dependencies:

• Standard support for the following operators : / * + - % ** using BODMAS operator precedence
• Support for logic not and bitwise not
• Support for logic operators : && ||
• Support for bitwise operators : & | ^ ~ >> << >>>
• Support for "()" groups
• Support for named variables in expressions
• Support for custom functions
• Support for pre-parsing and reusing the expression tree
• Support for dates using special keyword-functions
• Written in typescript

Getting started

npm install @devhelpr/expressionrunner --save # or yarn add @devhelpr/expressionrunner

import { runExpression } from '@devhelpr/expressionrunner';

const result = runExpression("2+3");
alert(`result : ${result}`);

Named variables

import { runExpression } from '@devhelpr/expressionrunner';

const result = runExpression("a * b", {a:9,b:8});
alert(`result : ${result}`);

TODO

• Better handling of negative numbers like -1 instead of needing (-1)

  • if first key == "-" and following char is a number.. then switch node to number

• aaa=='1' && bbb=='2' should work instead of needing ()

• Support comparisons with strings (' and ") and boolean values

  • Support for specific keywords .. true and false

• Improve performance by only running ExpressionTreeExecuteForOperator for operators that are in the expression

• Refactor ExpressionTreeExecuteForOperator so that the code that executes the actual operator is in its own function and not in a big if statement

• Convert to Rust/Wasm

• Support for more datatypes : datetime, string, boolean

• Support for [] arrays and "in" keyword

• Support for multiple expressions separated by ,

• Support for assignments within expression ?

• Support for libaries of functions (math ...)

• Build function map out of expression tree to execute directly