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Re: SRFI 105: Curly-infix-expressions

This page is part of the web mail archives of SRFI 105 from before July 7th, 2015. The new archives for SRFI 105 contain all messages, not just those from before July 7th, 2015.

David A. Wheeler scripsit:

> Regarding "nfx": The reader returns a list with the "nfx" symbol in
> the front.  The user then decides what to do.  There's *NO* requirement
> that the result *EVER* be passed to eval, by the way; the user might
> have a completely different process for handling the result from read.
> This adds flexibility at little cost.

Quite so.  It should be mentioned that R6RS and R7RS systems cannot
reliably implement "nfx" as a procedure, because (in a rampant case of
ML-envy) there are no equality relations between procedures in those
standards.  Thus a procedure like this is not portable:

(define (test-plus f)
  (if (eqv? f +) "plus" "not plus"))

(test-plus +) => undefined

I Hope, Sir, that we are not                    John Cowan
mutually Un-friended by this                    cowan@xxxxxxxx
Difference which hath happened                  http://www.ccil.org/~cowan
betwixt us.     --Thomas Fuller, Appeal of Injured Innocence (1659)