I agree that backslash string wrapping is obscure.
I do use it a lot, but I would not be sad to see it go.
The same is true for \a, \b, \f, \v, \EM, \DC1, etc.
We do need \&, though.
On Tue, Oct 2, 2012 at 10:17 PM, Evan Laforge
The backslash string wrapping feature is a fairly obscure part of haskell syntax, and some tools don't handle it properly (e.g. the built in 'lex' function won't lex such strings properly). It's also not as useful as e.g. python's triple quotes, because you have to suffix and prefix every line with a backslash. As long as you are have to add suffixes and prefixes (i.e. straight cut and paste no longer works), you might as well write it out with (++). In other words, as long as you're applying ('\\':) . (++"\\") you might as well apply ("++ \""++) . (++"\""). And it seems to me that "string literal" ++ "another string" is an easy thing for a compiler to optimize, ghc-core says ghc unsurprisingly has no trouble with it.
So it's probably not helpful for performance. IMO it's not very useful for it's intended purpose (embedding multiline strings) because of the \s everywhere. It doesn't seem very widely used, and it adds a little bit of a hassle to parsing. And 'lex' doesn't support it.
Any interest in getting rid of it?
I would actually be in favor of triple quotes (yeah, I know it can be done with quasi-quotes, but still...), but that's a different issue.
Also, it's hardly a big deal, but do we really need \a, \b, \f, and \v? The one time I used one (it was \v) it was a typo and I would have preferred the parse error, instead I got weird output that I didn't notice for a long time. If I really want to, say, ring the terminal bell or do a vertical tab or perhaps send a telegraph, I would be using some library that handles terminal type stuff in a higher level way. Similarly, the \EM, \DC1, etc. codes are probably not pulling their weight. The '70s were 40 years ago! And there's that weird \& thing. Surely cursor control library authors have better ways to construct their magic codes.
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