[q-lang-users] A proposal to adopt Python tuple syntax

[John.Cowan <jc...@re...>]

Representing tuples as parenthesized expressions separated by commas is
a Good Thing, but 1-tuples (in languages where they are not the same as
non-tuples) are always a syntactic wart.

(wart: n.  A small, crocky feature that sticks out of an otherwise
clean design.  Something conspicuous for localized ugliness, especially
a special-case exception to a general rule.)

The current Q solution to this wart is to interpret a parenthesized
expression as a 1-tuple only in certain circumstances: as noted in the
manual, "(99)" is a tuple but "(-99)" is not.

I propose that the Python syntax be adopted instead.  A Python tuple
is expressed in the same way as a Q one, except that there may be a
terminating comma after the last expression.  In particular, "(expr,)"
is unambiguously a 1-tuple, allowing "(expr)" and "((expr))" to be merely
parenthesized expressions.  The Python printer prints a terminating
comma only for 1-tuples.

This syntax could be permitted in an early release, and then the old
interpretation of excess parentheses deprecated later on.

-- 
John Cowan  www.ccil.org/~cowan  www.reutershealth.com  jc...@re...
All "isms" should be "wasms".   --Abbie