The Tengo Language

Tengo is a small, dynamic, securely embeddable script language for Go.

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

Try Tengo in Playground

Features

• Similar syntax to Go but much simpler
• Dynamically-typed with type coercions
• First-class functions and closures
• Garbage-collected
• Extensible
• Written in Go (no external deps or CGO)
• Executable as a standalone language / REPL

Benchmark

	fib(35)	fibt(35)	Type
Go	58ms	3ms	Go (native)
Tengo	4,245ms	5ms	VM on Go
Lua	1,739ms	3ms	Lua (native)
go-lua	5,368ms	5ms	Lua VM on Go
GopherLua	5,408ms	5ms	Lua VM on Go
Python	3,176ms	27ms	Python (native)
starlark-go	15,400ms	5ms	Python-like Interpreter on Go
gpython	17,724ms	6ms	Python Interpreter on Go
otto	82,050ms	22ms	JS Interpreter on Go
Anko	98,739ms	31ms	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
• Tengo Objects
• Runtime Types
• Builtin Functions
• Interoperability
• Tengo CLI
• Standard Library (experimental)

Roadmap

v0. (Current)

Things are experimental, and, the focus is on the core language features, stability, basic interoperability, and the performance optimization.

v1. Tengo as a Script Language

This will be the first versioned release, and, the main goal for v1 is to make Tengo as a fast embeddable script language for Go, which means Tengo will be comparable to other Go-based script languages such as Starlark, Lua VMs, and other interpreters.

• Interoperability with Go code
• Sandbox environment
• More language features such as bound methods and switch-case statements

v2. Tengo as a Standalone Language

• Language-level concurrency support
• Tengo Standard Libraries
• Native executables compilation
• More language features