[Mike Miller] >> - How are other modern languages solving this issue?
[Greg Ewing <greg.ew...@canterbury.ac.nz>] > In all the languages I can think of that allow assignments in > expressions, there is only one assignment operator -- a stand > alone assignment is just a bare assignment expression. Pretty much so, but I don't know what "modern" means to Mike. The R language may set a record for, umm, innovation here: """ There are three different assignment operators: two of them have leftwards and rightwards forms.[1] """ So there are 5 assignment operator spellings in R: = <- -> <<- ->> Note that the link doesn't tell the whole story either; e.g., they don't all have the same precedence level. And, in addition to the 5 infix spellings shown above, there are also prefix (looks like a 2-argument function call) spellings. Back on Earth ;-) , I think it's worth it to point out that only languages (with assignment expressions) aping C use "=" for assignment and "==" for equality. That was a Really Bad Idea that all other (not aping C) languages I know of avoided. But I'm not sure any of this is relevant to what Mike meant by "this issue". > But those languages were all designed that way from the start. > I'm not aware of any that began by forbidding assignment in > expressions and then added it later. Me neither. It's certainly the case that Guido would not have designed a language that aped C's poor decision here. At its very start, Python used "=" for both assignment and equality testing (and == was a syntax error). So I think it's evident that, at the time, he didn't envision ever adding assignment expressions. [1] https://www.rdocumentation.org/packages/base/versions/3.5.0/topics/assignOps _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
