Rye is a Pythonic scripting language for the Go ecosystem. Rye translates a rigid subset of old-school Python into Go.

Why Go?

• the Go runtime rules
• Go libraries rule
• Go concurrency rules

Why Python?

• I love Single Inheritance.
• I love exceptions.
• I love duck typing. (Yeah, those all have their problems, but for some projects, they're the problems I choose.)

Types

• None, bool, int, float. (All ints are int64; there is no long. Use Go's math/big if you need big ints.)
• str, byt. (byt corresponds to []byte in Go. It converts to/from str, but also to/from a list of int.)
• tuple, list, dict, set. Iterators on them.
• object (ultimate superclass of all user-defined classes).
• Various callable things: named functions, lambda exprs, class constructors, uncalled instance methods.
• Reflective references to Go objects (passed in and out of Go functions).

Goroutines

• go fn(x, y, z, ...) is an expression, returning a promise, running in background. You can Wait() for the result.
• Generator functions (those using yield) run in their own goroutine, when iterated in a "for" loop.
• Go libaries (like net/http) also create goroutines, which can call back into Rye functions.

Rye Modules

• Each source .py file defines 1 module (not each directory, as in go).

Imports

• Import statements: - from . import stuff # where stuff.py is another Rye module - from go import net/http # Go standard library - from go import github.com/russross/blackfriday # Other Go packages - import re # A small amount of python library emulation is available.

Limitations

• All ints are int64. No longs.
• No monkey-patching.
• No module reflection (yet).
• Many builtins and methods on builtin types are missing.
• No python libraries. Use go libraries.
• No nested classes. No class methods.
• Dictionary keys are converted to strings (as in javascript).
• No code blocks after ":" on same line with "if", "for", etc., statements.
• Continued lines (due to unclosed parens, etc.) should indent but not outdent.
• Lack of meaningful error messages due to unclosed parens, etc. (Obscured by "continued line" logic.)
• More limitations.
• Also bugs.

Compile & Run

• python .../rye/compiler/rye.py build src.py (creates a binary).
• python .../rye/compiler/rye.py run src.py arg1 arg2...

Interpreter (not working any more)

• python .../rye/rye.py interp src.py
• Commands /b ; /g ; /l ; (builtins; globals; locals)
• work in progress.

Demos

• tests/ directory.
• The compiler is written in rye (actually, the common subset of python and rye).
• See also "strickyak/aphid" github for lots of Rye code.