Hi, On Sat, 15 Oct 2016 00:05:56 +0200 Ricardo Wurmus <rek...@elephly.net> wrote: > Would it be desirable to change “substitute*” (or replace it) such that > it throws an error or returns a value if substitution failed? This > might be helpful for the more complex packages with many substitutions. > If we make it return a value (#f for error) it would also make our build > phases a little prettier, I think. (Now we forcefully return #t in any > case and that seems wrong.)
While it's a big change I am for substitute* throwing an error if it can't find one of the patterns - and #t otherwise. It's true that these substitutions that are necessary but cannot be found would not be noticed in a long time otherwise. I'm against it returning a value #f in the error case - it should just unwind. If you don't want it to unwind (in a few cases) you can always protect against it manually.
