Introduction

Implemented

GSET (Generic Syntax Extension Tool) is a single-binary Go transpiler. It reads a .gset source file, parses it into an abstract syntax tree, and emits a complete, runnable file for one of five targets: Python, JavaScript, Go, Java, and Ruby.

Version: 2.2.1. License: CC BY-NC 4.0.

What GSET actually does

1. Lexes your source into tokens (lexer/lexer.go).
2. Parses tokens into an AST (parser/parser.go, nodes in ast/ast.go).
3. Emits a complete file for your chosen target (transpiler/transpiler.go, per-target backends in transpiler/emit.go).
4. Runs the output with the target's toolchain — python3, node, go run, java, or ruby — or just prints it with gset transpile.

There is no VM. The output is real source code in the target language, executed by the target's own runtime.

What GSET is not

• It is not a compiler that turns GSET into a low-level language. Go is the default intermediate representation, and even there the shared subset is narrow (untyped assignments do not compile under go run).
• It is not a universal "write Python, run Java" tool. It is a small common-subset language with per-target backends. Each construct transpiles best to the targets where it is native.
• It is not a magic config that adds new languages. Adding a language requires writing a new emitter.

Where the idea came from

The original vision was broader: "any-language syntax, mapped via config, executed anywhere." The repo's gset.conf still carries keyword sections for C, C++, C#, Rust, PHP, and others. Today's reality is more focused — five emitters, config-driven keyword aliases, and the Go IR as the default. Pages in this guide carry an Implemented or Planned badge so you always know which part of the original vision is real.

Core features

Implemented

• Five working code generators: go, python, javascript, java, ruby
• gset run <file> [--target <lang>] [--keep] — transpile and execute
• gset transpile <file> [--target <lang>] [-o outfile] — print or save one target's output
• Variables (var, val, let, const), arrays, maps, index access, foreach
• if/elif/else, while, do-while, for, for … in
• function/fn/def functions with return
• try/catch/finally, throw/raise
• match/case/default (and switch)
• List comprehensions [x * x for x in items]
• Global and per-extension keyword aliases from gset.conf (say, shout, echo, …)
• gset run hello.gset works out of the box (.gset defaults to the Go target with a proper wrapper)

Planned

• More targets (C, C++, C#, Rust, PHP, Swift, Kotlin, TypeScript backends already have config stubs)
• Real type inference so Go/Java output compiles for typed code
• Classes for the Go target and richer class support everywhere
• File-header key=value keyword blocks
• A proper semantic analyzer (scope/type checking)

Next steps

• Install GSET
• Quick Start
• The language
• Per-target behavior