Flex - new line unrecognized

Question

I am doing a project with a Pascal subset. My code looks like:

NLINE       [\n]
BRACKET     ['('|')']

%%

{BRACKET} {
  std::cout << "Found BRACKET symbol " << yytext[0] << std::endl;
  return yytext[0];
}

{NLINE} {
  std::cout << "Found NEWLINE symbol " << yytext[0] << std::endl;
  yylineno++;
}

...

. { // anything is exactly before EOF
    std::cout << "Found ANYTHING " << yytext[0] << std::endl;
    yylval = NONE;
    return yytext[0];
}

I tried many ways to deal with that, also just \n instead of [\n] or [ \n] but without the expected results. Below is the output:

...
Found BRACKET symbol )
Found ANYTHING ;
Found ANYTHING  << where in code should be \n

I know that this is \n issue, because when I push the code without that it works like a charm!

Will appreciate every constructive answer.

The correct pattern to match ( or ) is [()]. Your pattern will match a parenthesis, an apostrophe, or a vertical bar. — rici
Also, I have no idea what you mean by "when I push the code without that". — rici
I mean when I cut all \n from input file. All just in one line, which is not highly comfortable. Sorry, I didn't express myself clearly enough. — Kris

Kris Kris · Accepted Answer · 2017-09-09T19:35:16

The problem seemed to be the carriage return symbol. In case you will have similar issue, if this won't help, you should check other nonprintable characters.

In my case helped:

DELIM       [ \t\r]

DELIM is "eated" in my solution so no rule is applied.

Flex - new line unrecognized

1 Answers