phoe

GOOPS has GFs which can have a variable number of arguments while still permitting the programmer to specialize on them. This is a quick draft of a CL version that I've done recently and decided to share for fun and profit.

The main issue here is to avoid the fact that methods which agree on parameter specializers and qualifiers as per CLHS 7.6.3 are gonna get overwritten, and we don't want that. GOOPS-like dispatch must mean a maximum of 0 required arguments in defmethod, which means that we get to specialize on exactly 0 arguments, which means that, trivially, 7.6.3 points 1 and 2 are always going to be true.

Hence, only 7.6.3 point 3 is left for us - and that means qualifiers. I (ab)use those in this example, by using a lax method combination (to still have :before/:after/:around) and passing class names this way. It also means that all method lambda lists are effectively (&rest args) or something similar, since we have no req

raiph

Then mathematical neatness became a goal and led to pruning some features from the core of the language.

— John McCarthy, History of Lisp

If you prefer programming languages with a tidy and tiny core, you're in for a treat. This article drills down to the singleton primitive at the heart of Raku's metamodel ("model of a model") of a model of computation ("how units of computations, memories, and communications are organized")¹.

The reason I've written this article

It began with u/faiface's reddit post/thread "I'm impressed with Raku"². One of their sentences in particular stood out for me:

yang-wei

Should be work with 0.18

Destructuring(or pattern matching) is a way used to extract data from a data structure(tuple, list, record) that mirros the construction. Compare to other languages, Elm support much less destructuring but let's see what it got !

Tuple

myTuple = ("A", "B", "C")
myNestedTuple = ("A", "B", "C", ("X", "Y", "Z"))