Re: How do I match empty lines with Flex?

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From	Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid>
Newsgroups	comp.compilers
Subject	Re: How do I match empty lines with Flex?
Date	Sat, 5 Oct 2019 22:29:46 +0800
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On 05/10/2019 12:55 am, Kaz Kylheku wrote:
> On 2019-10-04, Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> wrote:
>> Dear comp.compilers,
>>
>> The following program matches lines in a text file, but ignores empty
>> lines.  Is there any way I can alter it so it returns something on empty
>> lines?
>
> How about:
>
> .+\n { num_lines++; return NONEMPTY_LINE; }
> \n   { num_lines++; return EMPTY_LINE; }
> .+   { num_lines++; return MISSING_LAST_NEWLINE; }

Thank you, that indeed does the trick.  With %option yylineno the count
is off by one; the first line is numbered 2 for some reason.  With my
own count, it's correct.

--
Johann | email: invalid -> com | www.myrkraverk.com/blog/
I'm not from the Internet, I just work there. | twitter: @myrkraverk
[Flex starts yylineno at 1, so if you increment it in the pattern
that matches .+\n you'll see the first line as line 2.  -John]

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How do I match empty lines with Flex? Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2019-10-04 22:01 +0800
  Re: How do I match empty lines with Flex? Kaz Kylheku <847-115-0292@kylheku.com> - 2019-10-04 16:55 +0000
    Re: How do I match empty lines with Flex? Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2019-10-05 22:29 +0800

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