The Tengo Language

Tengo is a small, dynamic, fast, secure script language for Go.

Tengo is fast and secure because it's compiled/executed as bytecode on stack-based VM that's written in native Go.

/ The Tengo Language /
fmt := import("fmt")
each := func(seq, fn) {     for x in seq { fn(x) } }
sum := func(init, seq) {     each(seq, func(x) { init += x })     return init }
fmt.println(sum(0, [1, 2, 3]))   // "6" fmt.println(sum("", [1, 2, 3]))  // "123"

Test this Tengo code in the

Tengo Playground

Features

• Simple and highly readable

• Securely Embeddable

• Compiler/runtime written in native Go (no external deps or cgo)
• Executable as a

• Use cases: rules engine, state machine,

Benchmark

| | fib(35) | fibt(35) | Language (Type) | | :--- | ---: | ---: | :---: | | Tengo | 2,315ms | 3ms | Tengo (VM) | | go-lua | 4,028ms | 3ms | Lua (VM) | | GopherLua | 4,409ms | 3ms | Lua (VM) | | goja | 5,194ms | 4ms | JavaScript (VM) | | starlark-go | 6,954ms | 3ms | Starlark (Interpreter) | | gpython | 11,324ms | 4ms | Python (Interpreter) | | Yaegi | 11,715ms | 10ms | Yaegi (Interpreter) | | otto | 48,539ms | 6ms | JavaScript (Interpreter) | | Anko | 52,821ms | 6ms | Anko (Interpreter) | | - | - | - | - | | Go | 47ms | 2ms | Go (Native) | | Lua | 756ms | 2ms | Lua (Native) | | Python | 1,907ms | 14ms | Python2 (Native) |

* fib(35): Fibonacci(35)_ * fibt(35): tail-call version of Fibonacci(35)_ * Go does not read the source code from file, while all other cases do * See here for commands/codes used_

go get github.com/d5/tengo/v2

package main
import ( 	"context" 	"fmt"
"github.com/d5/tengo/v2" )
func main() { 	// create a new Script instance 	script := tengo.NewScript([]byte( each := func(seq, fn) {     for x in seq { fn(x) } }

sum := 0 mul := 1 each([a, b, c, d], func(x) {     sum += x     mul *= x })))
// set values 	_ = script.Add("a", 1) 	_ = script.Add("b", 9) 	_ = script.Add("c", 8) 	_ = script.Add("d", 4)
// run the script 	compiled, err := script.RunContext(context.Background()) 	if err != nil { 		panic(err) 	}
// retrieve values 	sum := compiled.Get("sum") 	mul := compiled.Get("mul") 	fmt.Println(sum, mul) // "22 288" }

res, err := tengo.Eval(ctx,
	input ? "success" : "fail",
	map[string]interface{}{"input": 1})
if err != nil {
	panic(err)
}
fmt.Println(res) // "success"