Polymorphism ideas

[chrisosaurus]

As of #37 we now have contains?, array-contains?, string-contains?.

I see a few ways of handling this:

1. don't, many lisps never handle this, so leave it be.
2. have the contains? method test it's argument and dispatch to list-contains?, array-contains?, string-contains? - this works for builtin types but cannot be user extended.
3. have contains operate via an interface that supports all the builtin types that can also be extended - I am unsure if Carp currently has the capability for this.

What are your thoughts?

[chrisosaurus]

hmm on second-thought maybe option (2) is actually user-extendible if functions/macros are powerful enough

maybe (contains? foo) could dispatch to (typeof(foo)-contains? foo)

this would require something being able to get a typeof string, append "-contains?" (or arbitrary function names) and then call it (via eval I presume?)

[eriksvedang]

Yes, this is very interesting. My hope is to implement something like this eventually, and your solution is nice and simple. The first 0.1 release of carp won't have it though, I want to sort out some bigger things (like modules) first!

[porky11]

the reason why other lisps don't handle it, is that they are dynamically typed.
another low level lisp already handles this: dale