Rubysyn: Clarifying Ruby's Syntax and Semantics

Rubysyn: Clarifying Ruby's Syntax and Semantics(github.com)

72 points by petalmind 46 days ago | 16 comments

I prefer the postcard ;-) https://richardeng.medium.com/syntax-on-a-post-card-cb6d85fa...

amomchilov 42 days ago | |

I never understood the appeal of this talking point. It’s just an accounting trick that moves the complexity to the standard library.

For example, SmallTalk is a class based OO system, yet this postcard doesn’t slow you how to create a class.

petalmind 42 days ago | | |

Yeah, I was also going to say that conflating trivial syntax and "supremely easy to learn" is a very weak flex.

The first Smalltalk-80 book you randomly find is 560 pages.

Also, there is a weird bargaining with "but not block temporaries" and "not an instance variable". Why not? Half of the postcard is basically empty. Also, "except primitives" — how many primitives are there?

pansa2 42 days ago | |

Yes, Smalltalk's syntax fits on a postcard - and it's possible to go even more minimal than that, e.g. Lisp or Forth.

OTOH Ruby doesn't need a postcard, it needs a full poster.

SeriousM 42 days ago |

> This is an experiment in clarifying some aspects of Ruby syntax and semantics. For that we're going to introduce an alternative Lisp-based syntax for Ruby, preserving Ruby semantics.

Lisp? Then I would use Lisp...

> The goal is to define a comprehensive, trivially-parsable and sugar-free syntax.

Ruby has syntax sugar, no need to remove the funny parts.

petalmind 42 days ago | |

> Ruby has syntax sugar, no need to remove the funny parts.

This is just an intermediate representation, it's not meant to be used directly (even though you can do that, of course).

petalmind 42 days ago | |

> Lisp? Then I would use Lisp...

Lisp has completely different runtime semantics. Even the lexical scope in Ruby is extremely peculiar. One of the hard parts of writing this document was to remove the intuitive influence of Lisp because it just doesn't make sense for Ruby.

lifthrasiir 42 days ago | |

S-expression is a standard representation for syntax-free semantics. For example, PLT Redex [1] is a DSL for programming language semantics and built on top of Racket which uses S-expressions.

[1] https://redex.racket-lang.org/

petalmind 42 days ago | | |

Do you know if Redex could be a tool that would be useful in my situation?

Claude suggests it, but I need to learn a lot of Redex to understand how to apply it.

I have a general understanding of what operational semantics is. Or maybe, are there any Redex implementations for common programming languages? \lambda_v is a bit too abstract.

petalmind 42 days ago | | |

Even Ruby `parser` gem uses S-expressions in their documentation: https://github.com/whitequark/parser/blob/master/doc/AST_FOR...