easeeval's Introduction

EaseEval

EaseEval is a simple text eval tool, built on DSL, written in Go.

Note: To not reinvent the wheel, please use https://github.com/Knetic/govaluate

Quick Start

Install

go get github.com/samanhappy/easeeval

Example

// use jq to extract value from json, v should be 7(int64)
v, err = easeeval.Eval(`1 + jq(".key") * 3`, `{"key":"2"}`)

// use time functions, v should be true(bool)
v, err = easeeval.Eval(`unixTime(jq(".time")) < now()`, `{"time":"2022-08-01T12:00:00"}`)

Overview

EaseEval is designed to extract values from text and evaluate expressions using a DSL, which contains Function, Typecast and Compute.

Function

Function is very useful in many scenarios, we plan to supply different kind of functions.

Extract Function

Extract functions extract target values from source text in many types: plain text, json, html, xml, etc.

Name	Description	Usage
jq	extract values from json format text using https://github.com/savaki/jq	jq(".key")
regex	extract values from text using regex	(to be implemented)

Time Function

Time functions supply ways to get unix time from string or for now.

Name	Description	Usage
unixTime	return unix time seconds in int64 for any format string using https://github.com/araddon/dateparse	unixTime("2022-08-01T12:00:00")
now	return unix time seconds in int64 for now	now()

Typecast

Typecast auto converts values on demand to specific types like string, number, date, etc. We support types below.

Name	Description
bool	bool type can be used in assertions
int64	int64 is the only int type supported, other int type like int8,int32 and int strings will auto be converted to int64
Time	Time type will be converted to int64 for compute