Binary Expression Tree

(This package is a fork of https://github.com/alexkappa/exp)

Package exp implements a binary expression tree which can be used to evaluate arbitrary binary expressions. You can use this package to build your own expressions however a few expressions are provided out of the box.

Installation

$ go get github.com/dedwardstech/exp/...

Usage

import "github.com/dedwardstech/exp"

fmt.Printf("%t\n", exp.Or(exp.And(exp.True, exp.Or(exp.True, exp.False)), exp.Not(exp.False)).Eval(nil)) // true

It is also possible to use text to describe expressions. Warning this feature is not battle tested so use with caution.

import "github.com/dedwardstech/exp"

x, err := exp.Parse(`(foo >= 100.00)`)
if err != nil {
	// handle error
}
x.Eval(exp.Map{"foo": "150.00"}) // true

Currently, only the following operators are supported.

Operator	Symbol	Data Type
And	&&
Or	||
Equal, Eq	==	string, float64
NotEqual, Neq	!=	string, float64
GreaterThan , Gt	>	string, float64
GreaterThanEqual , Gte	>=	string, float64
LessThan , Lt	<	string, float64
LessThanEqual , Lte	<=	string, float64

Documentation

API documentation is available at godoc.