UExL (Universal Expression Language) in Golang

Introduction

UExL (Universal Expression Language) is an embeddable platform independent expression evaluation engine. It is a simple language that can be used to evaluate expressions in various formats. UExL is designed to be used in applications where the expression to be evaluated is not known at compile time. Or to make the application more flexible by allowing the user to define expressions through the configuration file or database.

, is a . Designed for efficiency and simplicity, UExL offers an intuitive approach to handling and evaluating expressions in various formats.

Table of Contents

• UExL (Universal Expression Language) in Golang
  • Introduction
  • Table of Contents
  • Installation
    • Installing UExL
  • Getting Started
    • Importing the Library
    • Basic Usage
  • Features
  • Operator Precedence
  • Examples

Installation

UExL is not yet released and ready for use. However, whenever it is, you can install it using the following instructions.

Installing UExL

To install UExL, run the following command in your terminal:

go get github.com/maniartech/uexl-go

This command downloads and installs the UExL package along with its dependencies.

---

Getting Started

Importing the Library

First, include UExL in your Go project by importing it:

import "github.com/maniartech/uexl-go"

Basic Usage

Here’s how you can quickly start using UExL to evaluate an expression:

package main

import (
    "fmt"
    "github.com/maniartech/uexl-go"
    "log"
)

func main() {
    // Evaluating a simple expression
    result, err := uexl.Eval("10 + 20")
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("Result: %v\n", result) // Output: Result: 30

    // Using pipe operator in expression
    result, err = uexl.Eval("10 + 20 |: $1 * 2")
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("Result: %v\n", result) // Output: Result: 60
}

This basic example demonstrates how to use UExL to evaluate simple arithmetic expressions.

Features

(List the key features of UExL.)

Operator Precedence

Operators	Type	Associativity
( )	Parentheses	Left to Right
.	Dot	Left to Right
%	Modulus	Left to Right
* /	Multiplicative	Left to Right
+ -	Additive	Left to Right
<< >>	Bitwise Shift	Left to Right
< > <= >=	Comparison	Left to Right
== !=	Equality	Left to Right
& | ^	Bitwise	Left to Right
&& ||	Logical	Left to Right
|:	Pipe	Left to Right

Examples

result, err := uexl.Eval("10 + 20 |: $1 * 2") // Returns 60