[swift-evolution] [Review] SE-0168: Multi-Line String Literals

John Holdsworth mac at johnholdsworth.com
Wed Apr 12 14:07:33 CDT 2017

Finally.. a new Xcode toolchain <http://johnholdsworth.com/swift-LOCAL-2017-04-12-a-osx.tar.gz> is available largely in sync with the proposal as is.
(You need to restart Xcode after selecting the toolchain to restart SourceKit)

I personally am undecided whether to remove the first line if it is empty. The new
rules are more consistent but somehow less practical. A blank initial line is almost
never what a user would want and I would tend towards removing it automatically.
This is almost what a user would it expect it to do.

I’m less sure the same applies to the trailing newline. If this is a syntax for
multi-line strings, I'd argue that they should normally be complete lines -
particularly since the final newline can so easily be escaped.

        let longstring = """\
            Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod \
            tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, \
            quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.\

        print( """\
            Usage: myapp <options>
            Run myapp to do mything
            -myoption - an option
            """ )

(An explicit “\n" in the string should never be stripped btw)

Can we have a straw poll for the three alternatives:

1) Proposal as it stands  - no magic removal of leading/training blank lines.
2) Removal of a leading blank line when indent stripping is being applied.
3) Removal of leading blank line and trailing newline when indent stripping is being applied.

My vote is for the pragmatic path: 2)

(The main intent of this revision was actually removing the link between how the
string started and whether indent stripping was applied which was unnecessary.)

> On 12 Apr 2017, at 17:48, Xiaodi Wu via swift-evolution <swift-evolution at swift.org> wrote:
> Agree. I prefer the new rules over the old, but considering common use cases, stripping the leading and trailing newline makes for a more pleasant experience than not stripping either of them.
> I think that is generally worth prioritizing over a simpler algorithm or even accommodating more styles. Moreover, a user who wants a trailing or leading newline merely types an extra one if there is newline stripping, so no use cases are made difficult, only a very common one is made more ergonomic.

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