On Sun, Apr 01, 2018 at 02:20:16AM +0100, Rob Cliffe via Python-ideas wrote:
New unordered 'd' and 'D' prefixes, for 'dedent', applied to multiline strings only, would multiply the number of alternatives by about 5 and would require another rewrite of all code (Python or not) that parses Python code (such as in syntax colorizers).
I think you're exaggerating the difficulty somewhat. Multiplying the number of alternatives by 5 is not the same thing as increasing the complexity of code to parse it by 5.
Terry didn't say that it would increase the complexity of the code by a factor of five. He said it would multiply the number of alternatives by "about 5". There would be a significant increase in the complexity of the code too, but I wouldn't want to guess how much.
Starting with r and f prefixes, in both upper and lower case, we have:
4 single letter prefixes (plus 2 more, u and U, that don't combine with others) 8 double letter prefixes
making 14 in total. Adding one more prefix, d|D, increases it to:
6 single letter prefixes (plus 2 more, u and U) 24 double letter prefixes 48 triple letter prefixes
making 80 prefixes in total. Terry actually underestimated the explosion in prefixes: it is closer to six times more than five (but who is counting? apart from me wink)
[Aside: if we add a fourth, the total becomes 634 prefixes.]