Re: How do I match empty lines with Flex?

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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