On Aug 27, 2019, at 01:42, Chris Angelico <ros...@gmail.com> wrote: > > Will these "custom > prefixes" be able to define anything syntactically? If not, why not > just use a function call? And if they can, then you have created an > absolute monster, where a v-string in one context can have completely > different syntactic influence on what follows it than a v-string in > another context.
There is a possibility in between the two extremes of “useless” and “complete monster”: the prefix accepts exactly one token, but can parse that token however it wants. That’s pretty close to what C++ does, and pretty close to the way my hacky proof of concept last time around worked, and I don’t think that only works because those are suffix-only designs. (That being said, if you do allow “really raw” string literals as input to the user prefixes/suffixes to handle the path'C:\' case, then it’s possible to invent cases that would tokenize differently with and without the feature—in fact. I just did—and therefore it _might_ be possible to invent cases that parse validly but differently, in which case the monster is lurking after all. Someone might want to look more carefully at the C++ rules for that?) _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/GLZPVGS5NSWZ64DJMQBPETZFT3TDJEGH/ Code of Conduct: http://python.org/psf/codeofconduct/
