replace singular statement ++/-- with += 1/-= 1 for integer variables

[dduan]

I busted out sed and replaced all the one-line ++ and -- statements in Swift files, then filtered out the results gradually until all tests passed in "check-swift-all".

Please let me know if breaking this up to multiple commit/PR is more desirable.

[gribozavr]

This part does not compile on Linux:

swift/stdlib/private/StdlibUnittest/StdlibCoreExtras.swift:60:20: error: binary operator '+=' cannot be applied to operands of type 'String.UnicodeScalarView.Index' and 'Int'

[gribozavr]

@dduan Could you fix the compilation issue on Linux? Just omitting that part of the patch should be fine. Please squash patches after that fix.

@nadavrot I have reviewed the patch, and it only affects variables typed as integers. Do you have performance concerns with this kind of change?

[dabrahams]

When advancing something that is primarily an index, x = x.successor() may be more appropriate than x += 1 even when you happen to know it's an integer. Please consider each case carefully; thanks.

[dduan]

@gribozavr done.

[dduan]

@dabrahams Ahah! It just happens so that after sed, I had to leave a lot of ++/-- statement unchanged because they are for Index types, which can't be operand of +=/-=. You just give me an idea for the next patch :P

[nadavrot]

@gribozavr Thanks for checking with me. We'll track the performance of this change after it lands. I don't have any objections for committing this patch.

[falcon03]

Is there any reason for the removal of these (extremely handy) operators, other than the (extremely debatable IMHO) ones exposed at

https://github.com/apple/swift-evolution/blob/master/proposals/0004-remove-pre-post-inc-decrement.md

Not to mention the fact that we’re not sure wether
let x = 1
x += 1

can have the same performance as
let x = 1
x++

(and the same applies for the — operator)

If discussion can still be reopened I’d like to share my opinions on the “disadvantages” exposed in the previously linked change proposal.

Il giorno 16 dic 2015, alle ore 02:40, Dmitri Gribenko [email protected] ha scritto:

Merged #556 #556.

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Reply to this email directly or view it on GitHub #556 (comment).

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[gribozavr]

@falcon03 You are welcome to send your arguments to [email protected].