Guards redux

John Rose john.r.rose at oracle.com
Wed Mar 10 22:05:09 UTC 2021


On Mar 10, 2021, at 8:33 AM, Remi Forax <forax at univ-mlv.fr> wrote:
> 
> As i said to Gavin, i'm not at ease with using the symbol '&' in between patterns.

Aren’t patterns inherently sequential and short-circuiting?
Or am I having a failure of imagination?  All of the pattern
syntaxes mimic expression syntaxes, but expressions are
(generally) non-short-circuiting, entailing unconditional
evaluation of subexpressions.  But every subpattern of
a pattern is conditional, which is different from expressions.
Thus, & in pattern-land is short-circuiting.

(What would a non-short-circuiting pattern look like?)



More information about the amber-spec-experts mailing list