Fifth Release: Types, Safety & Testing

• Type definitions (ADT-lite) to allow specific type tuples {} and list as stack effects.
• New struct and unstruct operators to assemble and disassemble these objects.
• Stack annotations in .Joy are not just documentation but --validate'd too.
• New test framework in libs/test.joy, written entirely in idiomatic joyfl.
• Implementation of Python extension modules: cmd txt and os
• Operators must have new-style Python annotations, they are required to bind.
• Validation supports the checking of outputs of Python operators.
• Rework main to have procedurally-selected sub-commands ('repl', 'one-file', 'one-module', 'dev-mode')
• Formalize and document the ... operator, which allows user to type in code on-the-fly.
• Joy modules are now scoped by MODULE name, error thrown if mismatch with filename.
• The module PRIVATE sections can be linked locally not externally.
• Joy modules are correctly auto-loaded just like the Python ones, also checking JOY_PATH.

Fourth Release: Python API and Package

• Exposing a Python runtime and API, used with "import joyfl.api as J".
• New error types that are Joy specific so they can easily be caught.
• Rework the architecture to break up the single-file script into components.
• Support for "factory" terms that can inject Python object into quotations at comp-time.
• If operators contain a dot namespace, the code auto-imports from corresponding function in libs/_{ns}.py.
• Named-tuple for Stack object, for efficiency, easier print/debug, and better safety.
• Allow for JOY_PATH envvar to load extension modules and the standard library.
• Using uv for build testing, packaging and publishing.
• Improved error handling showing Joy source more consistently.
• Fix for win32 support when using the repl, previously broken.
• Support fraction types when you use the unicode ⁄ separator for numerator and denominator.
• Python-side operators use standard type annotations for ease-of-use, correctness.

Third Release: Usability Improvements

• Stack effects in function definitions, format : (a b -- c)
• Reading commands from stdin and via -c option.
• Dynamic type checking and stack effects (optional) with --validate.
• Display of execution statistics with --stats.
• Assert shows the exact location of the assert.
• Disabling of the ANSI color codes -p or --plain.
• Stack is printed in left-to-right order to match verbose mode.
• Documentation of the standard library.
• Interpreter step is reusable on its own, also can_execute.
• Additions of a few new operators: drop, remove, unary, str-*, etc.
• Dictionary support: words to create, fetch and store.

Second Release: Debug Information

• Better error messages when exceptions are known.
• Callstack display with Joy source code shown.
• Pretty printing in the put! function.
• One extra example about primes, showing iteration.

First Release: Minimum Viable Interpreter

v0.1

FIX: All built-in boolean operators now include '?' as suffix.