Re: How to handle operator of undefined associativity

On Sun, 02 May 2010 15:58:06 -0400, Chris F Clark
<cfc@shell01.TheWorld.com> wrote:


>Associativity is a concept of binary operators, unary operators do not
>have (or need) associativity. They always associate inner-most to
>outer-most.


Hmmm...


In the expression "not not x", you might first evaluate "not not" -
presumably giving the identity operation - then apply the identity to
"x". That is, the "not" operator might be semantically a first-class
functional value.


Then again, is this the application of a unary operator, or of an
implicit binary operator? Despite superficial appearances, maybe the
latter - depends whether the word "not" is a grammatically a keyword
in a rule or a value identifier, I suppose, which may be independent
of the semantics.


Not really a real-world issue, I suspect.
[There are languages in which you can invent operators by composing existing
operators, but they have their own issues. -John]

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