Make argument validation routine of a method an object
Ruby methods have their acceptable argument configurations specified by special syntax. As argument fields has gotten more complex, simple
#arity is no longer enough to capture the type of the argument field. I suggest making this argument validation routine (so far defined by special syntax) introspectible, and reusable for the purposes of metaprogramming. One possibility would be to have eg.
UnboundArgumentValidator objects just like we have method and unbound method objects. Then eg.
Proc#argity would return that
UnboundArgumentValidator. The purpose of this post is not to suggest the final solution, but to bring attention to the problem of non-oo nature of built-in argument validation and the growing need to do something about that.
Updated by Anonymous about 6 years ago
It is my fault that I was not aware of
Method#parameters when writing this post. Too bad I did not participate in its naming, I would push for calling it
Method#arguments. This method resolves the main reasons that led me to writing this post. It remains worthy of consideration to make
#parameters method return a special object rather than just
Array, but this thread can be closed without harm. Contrary to what I thought, the pressing part of the problem has already been tackled.