[ANTSANTS]

> Generally I think it is a slight mistake to use specific data types in arglists - basically mixing syntax and data types.

That's kinda what alists and plists do! They mix up the abstract "map" or "table" data structure (something that maps keys to values) with some concrete implementation of it. '((key . value) (key . value)) and '(key value key value) are literal representations of two particular map-like data structures, whereas {key: value} or {key = value} could have any concrete representation that the language implementer desires.

Maybe I should have dropped the "hash" from "hash table" in my above posts, so that it was clear that I was interested in the syntactic benefit of using one syntax for mapping names to values, and not some imagined efficiency gains from having (read keyword-function-call) include a hash table instead of an alist.

[lispm]

    (defun foo (&key foo) ...)

In Common Lisp an implementation can implement a call like (foo :bar 10) how it wants. There is nothing said about lists, hash tables, property lists or assoc lists.

Whereas having a syntax for hash table {} and using this syntax in definitions/calls clearly indicates a conflict. What is it? Coincidence? Purpose?