base on Expression language and expression evaluation for Go <h1><a href="https://expr-lang.org"><img src="https://expr-lang.org/img/logo.png" alt="Zx logo" height="48"align="right"></a> Expr</h1> [](https://github.com/expr-lang/expr/actions/workflows/test.yml) [](https://goreportcard.com/report/github.com/expr-lang/expr) [](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:expr) [](https://godoc.org/github.com/expr-lang/expr) **Expr** is a Go-centric expression language designed to deliver dynamic configurations with unparalleled accuracy, safety, and speed. **Expr** combines simple [syntax](https://expr-lang.org/docs/language-definition) with powerful features for ease of use: ```js // Allow only admins and moderators to moderate comments. user.Group in ["admin", "moderator"] || user.Id == comment.UserId ``` ```js // Determine whether the request is in the permitted time window. request.Time - resource.Age < duration("24h") ``` ```js // Ensure all tweets are less than 240 characters. all(tweets, len(.Content) <= 240) ``` ## Features **Expr** is a safe, fast, and intuitive expression evaluator optimized for the Go language. Here are its standout features: ### Safety and Isolation * **Memory-Safe**: Expr is designed with a focus on safety, ensuring that programs do not access unrelated memory or introduce memory vulnerabilities. * **Side-Effect-Free**: Expressions evaluated in Expr only compute outputs from their inputs, ensuring no side-effects that can change state or produce unintended results. * **Always Terminating**: Expr is designed to prevent infinite loops, ensuring that every program will conclude in a reasonable amount of time. ### Go Integration * **Seamless with Go**: Integrate Expr into your Go projects without the need to redefine types. ### Static Typing * Ensures type correctness and prevents runtime type errors. ```go out, err := expr.Compile(`name + age`) // err: invalid operation + (mismatched types string and int) // | name + age // | .....^ ``` ### User-Friendly * Provides user-friendly error messages to assist with debugging and development. ### Flexibility and Utility * **Rich Operators**: Offers a reasonable set of basic operators for a variety of applications. * **Built-in Functions**: Functions like `all`, `none`, `any`, `one`, `filter`, and `map` are provided out-of-the-box. ### Performance * **Optimized for Speed**: Expr stands out in its performance, utilizing an optimizing compiler and a bytecode virtual machine. Check out these [benchmarks](https://github.com/antonmedv/golang-expression-evaluation-comparison#readme) for more details. ## Install ``` go get github.com/expr-lang/expr ``` ## Documentation * See [Getting Started](https://expr-lang.org/docs/Getting-Started) page for developer documentation. * See [Language Definition](https://expr-lang.org/docs/language-definition) page to learn the syntax. ## Examples [Play Online](https://go.dev/play/p/XCoNXEjm3TS) ```go package main import ( "fmt" "github.com/expr-lang/expr" ) func main() { env := map[string]interface{}{ "greet": "Hello, %v!", "names": []string{"world", "you"}, "sprintf": fmt.Sprintf, } code := `sprintf(greet, names[0])` program, err := expr.Compile(code, expr.Env(env)) if err != nil { panic(err) } output, err := expr.Run(program, env) if err != nil { panic(err) } fmt.Println(output) } ``` [Play Online](https://go.dev/play/p/tz-ZneBfSuw) ```go package main import ( "fmt" "github.com/expr-lang/expr" ) type Tweet struct { Len int } type Env struct { Tweets []Tweet } func main() { code := `all(Tweets, {.Len <= 240})` program, err := expr.Compile(code, expr.Env(Env{})) if err != nil { panic(err) } env := Env{ Tweets: []Tweet{{42}, {98}, {69}}, } output, err := expr.Run(program, env) if err != nil { panic(err) } fmt.Println(output) } ``` ## Who uses Expr? * [Google](https://google.com) uses Expr as one of its expression languages on the [Google Cloud Platform](https://cloud.google.com). * [Uber](https://uber.com) uses Expr to allow customization of its Uber Eats marketplace. * [GoDaddy](https://godaddy.com) employs Expr for the customization of its GoDaddy Pro product. * [ByteDance](https://bytedance.com) incorporates Expr into its internal business rule engine. * [Aviasales](https://aviasales.ru) utilizes Expr as a business rule engine for its flight search engine. * [Alibaba](https://alibaba.com) uses Expr in a web framework for building recommendation services. * [Argo](https://argoproj.github.io) integrates Expr into Argo Rollouts and Argo Workflows for Kubernetes. * [Wish.com](https://www.wish.com) employs Expr in its decision-making rule engine for the Wish Assistant. * [OpenTelemetry](https://opentelemetry.io) integrates Expr into the OpenTelemetry Collector. * [Philips Labs](https://github.com/philips-labs/tabia) employs Expr in Tabia, a tool designed to collect insights on their code bases. * [CrowdSec](https://crowdsec.net) incorporates Expr into its security automation tool. * [CoreDNS](https://coredns.io) uses Expr in CoreDNS, which is a DNS server. * [qiniu](https://www.qiniu.com) implements Expr in its trade systems. * [Junglee Games](https://www.jungleegames.com/) uses Expr for its in-house marketing retention tool, Project Audience. * [Faceit](https://www.faceit.com) uses Expr to enhance customization of its eSports matchmaking algorithm. * [Chaos Mesh](https://chaos-mesh.org) incorporates Expr into Chaos Mesh, a cloud-native Chaos Engineering platform. * [Visually.io](https://visually.io) employs Expr as a business rule engine for its personalization targeting algorithm. * [Akvorado](https://github.com/akvorado/akvorado) utilizes Expr to classify exporters and interfaces in network flows. * [keda.sh](https://keda.sh) uses Expr to allow customization of its Kubernetes-based event-driven autoscaling. * [Span Digital](https://spandigital.com/) uses Expr in its Knowledge Management products. * [Xiaohongshu](https://www.xiaohongshu.com/) combining yaml with Expr for dynamically policies delivery. * [Melrōse](https://melrōse.org) uses Expr to implement its music programming language. * [Tork](https://www.tork.run/) integrates Expr into its workflow execution. * [Critical Moments](https://criticalmoments.io) uses Expr for its mobile realtime conditional targeting system. * [WoodpeckerCI](https://woodpecker-ci.org) uses Expr for [filtering workflows/steps](https://woodpecker-ci.org/docs/usage/workflow-syntax#evaluate). * [FastSchema](https://github.com/fastschema/fastschema) - A BaaS leveraging Expr for its customizable and dynamic Access Control system. * [WunderGraph Cosmo](https://github.com/wundergraph/cosmo) - GraphQL Federeration Router uses Expr to customize Middleware behaviour * [SOLO](https://solo.one) uses Expr interally to allow dynamic code execution with custom defined functions. * [Naoma.AI](https://www.naoma.ai) uses Expr as a part of its call scoring engine. [Add your company too](https://github.com/expr-lang/expr/edit/master/README.md) ## License [MIT](https://github.com/expr-lang/expr/blob/master/LICENSE) <p align="center"><img src="https://expr-lang.org/img/gopher-small.png" width="150" /></p> ", Assign "at most 3 tags" to the expected json: {"id":"3521","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"