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Re: Adjacent string literals

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Jakob Bohm <jb-usenet@wisemo.com.invalid> writes:

> On 2021-01-26 13:22, Ben Bacarisse wrote:
>> James Kuyper <jameskuyper@alumni.caltech.edu> writes:
>>
>>> I learned a couple of decades ago that adjacent string literals get
>>> concatenated into a single longer literal, even if separated by
>>> arbitrarily large amounts of white-space.
>>>
>>> Yesterday I happened to notice that translation phase 6 says only that
>>> "Adjacent string literal tokens are concatenated.", without saying
>>> anything about white-space. White-space doesn't lose it's significance
>>> until translation phase 7. Therefore, string literals that are separated
>>> by white-space do not qualify as adjacent. There's also no mention of
>>> white-space in the fuller discussion that occurs in 6.4.5p5.
>>>
>>> Am I missing something obvious here? I can imagine someone telling me
>>> that "adjacent" should be understood as "adjacent, ignoring white-space"
>>> - but that doesn't seem obvious to me.
>>
>> Surely it just means "next to", and in the sequence of tokens "a" "b"
>> the two are next to each other.  It happens that string literal tokens
>> are such that they can be adjacent without having any white-space
>> between then, but I suspect that's making you over-think the meaning.
>> Would you say that 'long int x' has no tokens adjacent to any others?
>>
>
> The interesting situation is cases like these:
>
> "a" /* Long comment explaining why b is the next byte */ "b"

By translation phase 6 (when adjacent string literals are concatenated)
this has become

"a"   "b"

> And
>
> #define LEAD_BYTE  "a"
> #define TRAIL_BYTE "b"
>
> LEAD_BYTE TRAIL_BYTE

And this has become

"a" "b"

Am I missing some ambiguity?

-- 
Ben.

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Thread

Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-01-25 10:15 -0500
  Re: Adjacent string literals Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-01-26 12:22 +0000
    Re: Adjacent string literals Jakob Bohm <jb-usenet@wisemo.com.invalid> - 2021-01-26 13:48 +0100
      Re: Adjacent string literals Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-01-26 13:05 -0800
      Re: Adjacent string literals Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-01-26 21:40 +0000
        Re: Adjacent string literals Jakob Bohm <jb-usenet@wisemo.com.invalid> - 2021-01-28 09:53 +0100
          Re: Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-01-28 05:45 -0500
    Re: Adjacent string literals Richard Damon <Richard@Damon-Family.org> - 2021-01-26 07:52 -0500
    Re: Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-01-26 09:29 -0500
      Re: Adjacent string literals Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-01-26 21:46 +0000
        Re: Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-01-26 18:28 -0500
          Re: Adjacent string literals Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-01-27 01:16 +0000
            Re: Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-01-26 22:48 -0500
              Re: Adjacent string literals Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-01-27 15:46 +0000
                Re: Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-01-27 11:20 -0500
                Re: Adjacent string literals Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-01-28 03:05 +0000
  Re: Adjacent string literals Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 08:49 -0700
    Re: Adjacent string literals Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-07-10 14:58 -0700
      Re: Adjacent string literals Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-22 10:29 -0700
    Re: Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-11 11:41 -0700
      Re: Adjacent string literals Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-22 15:26 -0700
        Re: Adjacent string literals James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-22 17:29 -0700
          Re: Adjacent string literals Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-01-17 05:29 -0800

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