README
¶
CEL Engine · 表达式引擎
基于 cel-go 的 Google 通用表达式语言引擎
概述
CEL 引擎使用 Google 的 cel-go 库，提供 CEL (Common Expression Language) 表达式的编译与求值。CEL 是非图灵完备的表达式语言，专为简洁、安全和快速求值设计。每个"脚本"求值一个独立表达式，支持编译时类型检查。
引擎特性
| 特性 | 说明 |
|---|---|
| 底层库 | github.com/google/cel-go v0.22.1 |
| 语言 | CEL 规范（非图灵完备表达式语言） |
| 类型推断 | 通过反射自动推断 Go 值的 CEL 类型 |
| 环境重建 | 注册全局变量/函数时自动重建 CEL 环境 |
| 线程安全 | 双锁模式（RWMutex + execMutex） |
| 热更新 | 支持 StartWatch / StopWatch |
| 类型常量 | scriptEngine.CELType |
安装
go get github.com/tx7do/go-scripts/cel
快速开始
package main
import (
"context"
"fmt"
"log"
scriptEngine "github.com/tx7do/go-scripts"
_ "github.com/tx7do/go-scripts/cel" // 注册 CEL 引擎
)
func main() {
eng, _ := scriptEngine.NewScriptEngine(scriptEngine.CELType)
defer eng.Close()
ctx := context.Background()
eng.Init(ctx)
// 注入变量
_ = eng.RegisterGlobal("name", "world")
_ = eng.RegisterGlobal("age", 25)
// 注册自定义函数
_ = eng.RegisterFunction("isAdult", func(age int) bool {
return age >= 18
})
// 求值表达式
result, _ := eng.ExecuteString(ctx, "check", `isAdult(age) && name == "world"`)
fmt.Println(result) // true
}
API 参考
| 方法 | 说明 |
|---|---|
Init(ctx) |
创建 CEL 环境 |
Close() |
释放引擎资源 |
LoadString(ctx, name, code) |
编译 CEL 表达式并加入队列 |
Execute(ctx) |
顺序求值队列中所有表达式，返回最后一个结果 |
ExecuteString(ctx, name, code) |
编译并立即求值内联 CEL 表达式 |
RegisterGlobal(name, value) |
注册全局变量，自动推断 CEL 类型 |
RegisterFunction(name, fn) |
注册 Go 函数，参数/返回值类型通过反射推断 |
CallFunction(ctx, name, args...) |
命令式调用已注册的宿主函数 |
RegisterModule(name, module) |
注册模块（键映射为 模块名_键名 全局变量） |
StartWatch(ctx, key) |
启动表达式热更新监听 |
StopWatch(key) |
停止热更新监听 |
测试
cd cel && go test -v ./...
相关文档
License
Documentation
¶
Overview ¶
Package cel provides a script engine implementation using Google's CEL-Go (Common Expression Language — https://github.com/google/cel-go). CEL is a non-Turing-complete expression language designed for simplicity, safety, and fast evaluation. Unlike full scripting languages, CEL evaluates a single expression per "script" and supports compile-time type checking.
Construction:
eng, _ := cel.New(ctx)
eng.Init(ctx)
eng.RegisterGlobal("name", "world")
result, _ := eng.ExecuteString(ctx, "greet", `"Hello " + name`)
The engine supports hot-reload via StartWatch/StopWatch when the bound Source implements the Watcher interface.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrCELEngineNotInitialized is returned when an operation is invoked // before Init or after Close. ErrCELEngineNotInitialized = errors.New("cel engine not initialized") // ErrCELEngineAlreadyInitialized is returned when Init is called on an // already-initialized engine. ErrCELEngineAlreadyInitialized = errors.New("cel engine already initialized") // ErrCLEEnvNotInitialized is returned when the underlying cel-go Env is nil. ErrCLEEnvNotInitialized = errors.New("cel env not initialized") // ErrCELCompileFailed is returned when compiling a CEL expression fails. ErrCELCompileFailed = errors.New("cel compile failed") // ErrCELNoExpressionLoaded is returned when Execute is called but no // expression has been loaded. ErrCELNoExpressionLoaded = errors.New("cel no expression loaded") // ErrCELEvalFailed is returned when evaluating a CEL expression fails. ErrCELEvalFailed = errors.New("cel eval failed") // ErrCELFunctionNotFound is returned when CallFunction cannot find the // named function. ErrCELFunctionNotFound = errors.New("cel function not found") // ErrCELGlobalNotFound is returned when GetGlobal cannot find the named // variable. ErrCELGlobalNotFound = errors.New("cel global not found") )
Sentinel errors returned by the CEL engine.
Functions ¶
This section is empty.
Types ¶
This section is empty.
Source Files