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 */

each := func(seq, fn) {
    for x in seq { fn(x) }
}

sum := func(init, seq) {
    each(seq, func(x) { init += x })
    return init
}

n := sum(0, [1, 2, 3])   // == 6
s := sum("", [1, 2, 3])  // == "123"

Run this code in the Playground

Features

• Simple and highly readable Syntax
  • Dynamic typing with type coercion
  • Higher-order functions and closures
  • Immutable values
  • Garbage collection
• Securely Embeddable and Extensible
• Compiler/runtime written in native Go (no external deps or cgo)
• Executable as a standalone language / REPL

Benchmark

	fib(35)	fibt(35)	Type
Go	58ms	4ms	Go (native)
Tengo	4,180ms	5ms	VM on Go
Lua	1,695ms	3ms	Lua (native)
go-lua	5,163ms	5ms	Lua VM on Go
GopherLua	5,525ms	5ms	Lua VM on Go
Python	3,097ms	27ms	Python (native)
starlark-go	15,307ms	5ms	Python-like Interpreter on Go
gpython	17,656ms	5ms	Python Interpreter on Go
goja	6,876ms	5ms	JS VM on Go
otto	81,886ms	12ms	JS Interpreter on Go
Anko	97,517ms	14ms	Interpreter on Go

* 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

References

• Language Syntax
• Object Types
• Runtime Types
• Builtin Functions
• Interoperability
• Tengo CLI
• Standard Library