Introduction

Goblin is a dynamically typed language with Go-style braces and a compact, Python-like feel. It is useful for experimenting with programs and for learning how interpreters, runtimes, and code generation fit together.

This book assumes that you can use a command line and already know the basic ideas of variables, functions, and control flow. Its aim is not to catalogue every API, but to get you comfortably reading and writing Goblin programs.

Goblin has two ways to run a program:

• goblin run interprets a source file directly. Use it while developing and experimenting.
• goblin build-exe transpiles source to Go and compiles a native executable. Use it when you want a standalone program.

Both paths parse the same language and run semantic checks before executing. During development, start with goblin run; use build-exe when you need an executable without the Goblin CLI. The generated executable still uses the Goblin runtime, so the language behavior is intended to be the same.

Here is a complete Goblin program:

func greet(name) {
    print("Hello,", name)
}

for name in ["world", "Goblin"] {
    greet(name)
}

Source files use the .goblin extension. Comments start with #. When you are ready, continue with Installation.

What this book covers

The chapters first cover values and control flow, then functions and collections, followed by custom types, modules, and errors. The examples are complete fragments that can be pasted into a .goblin file. The Book focuses on the language and its standard runtime; see the repository's examples/ directory for larger executable programs.

For the current implementation boundaries and features deliberately absent from the language, see Language model and limits.