https://github.com/alecthomas/expr

Runtime evaluation of Go-like expressions
https://github.com/alecthomas/expr

Last synced: 16 days ago
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Runtime evaluation of Go-like expressions

• Host: GitHub
• URL: https://github.com/alecthomas/expr
• Owner: alecthomas
• Created: 2014-08-26T23:28:15.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2023-12-02T17:47:41.000Z (12 months ago)
• Last Synced: 2024-10-10T16:07:06.188Z (about 1 month ago)
• Language: Go
• Size: 4.88 KB
• Stars: 4
• Watchers: 4
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Runtime evaluation of Go-like expressions

# What?

eg.

```go

e := expr.MustCompile("a + 1 > 2")

e.Bool(expr.V{"a": 0}) == false

e.Bool(expr.V{"a": 1}) == false

e.Bool(expr.V{"a": 2}) == true

```

and

```go

e = expr.MustCompile("(a + 2) * 10")

n, err := e.Eval(expr.V{"a": 1})

n.(int64) == 30

```

It *does not* support:

- Function calls (though this would be useful).

- Slices or arrays.

It *does* support:

- Truthiness evaluation, ala Python: eg. given `V{"a": 1}`, evaluating `a` will be true.

- Automatic type coercion. eg. `"a" + 10` == `"a10"`

- Nested fields. eg. `A.B == 2`

# Why?

If you want to add simple expression-based filtering or numeric evaluation,

this might fit your needs.

# Where?

## Install

```sh

$ go get github.com/alecthomas/expr

```

## Docs

You can find the API documentation on [godoc](http://godoc.org/github.com/alecthomas/expr).