> On Apr 12, 2017, at 5:39 PM, Xiaodi Wu <[email protected]> wrote:
>
> On Wed, Apr 12, 2017 at 5:20 PM, Brent Royal-Gordon <[email protected]
> <mailto:[email protected]>> wrote:
> Wow, maybe I shouldn't have slept.
>
> Okay, let's deal with trailing newline first. I'm *very* confident that
> trailing newlines should be kept by default. This opinion comes from lots of
> practical experience with multiline string features in other languages. In
> practice, if you're generating files in a line-oriented way, you're usually
> generating them a line at a time. It's pretty rare that you want to generate
> half a line and then add more to it in another statement; it's more likely
> you'll interpolate the data. I'm not saying it doesn't happen, of course, but
> it happens a lot less often than you would think just sitting by the fire,
> drinking whiskey and musing over strings.
>
> I know that, if you're pushing for this feature, it's not satisfying to have
> the answer be "trust me, it's not what you want". But trust me, it's not what
> you want.
>
> This is not a very good argument. If you are generating files in a
> line-oriented way, it is the function _emitting_ the string that handles the
> line-orientedness, not the string itself. That is the example set by
> `print()`:
>
> ```
> print("Hello, world!") // Emits "Hello, world!\n"
> ```
You say "this is the example set by `print`", but I don't think anything else
actually *follows* that example. No other I/O operation in Swift behaves this
way. The underlying `TextOutputStream.write(_:)` doesn't; the I/O in Foundation
doesn't; file descriptor I/O doesn't. Concatenation certainly doesn't; nor does
anything else you might do to assemble several multiline string literals into a
whole. So I think `print()` is the exception here, not the rule.
In my opinion, modulo the "newline after leading delimiter" question, if code
like this example:
var xml = """
<?xml version="1.0"?>
<catalog>
"""
for (id, author, title, genre, price) in bookTuples {
xml += """
<book id="bk\(id)">
<author>\(author)</author>
<title>\(title)</title>
<genre>\(genre)</genre>
<price>\(price)</price>
</book>
"""
}
xml += """
</catalog>
"""
Doesn't assemble the kind of string that it's blatantly obvious the user is
trying to assemble, I think the syntax has failed.
`print()` is the outlier. It's an important enough outlier that we should
probably help the user notice when they're about to get it wrong, but an
outlier it is.
--
Brent Royal-Gordon
Architechies
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