# New Ticket Created by "Carl Mäsak" # Please include the string: [perl #125543] # in the subject line of all future correspondence about this issue. # <URL: https://rt.perl.org/Ticket/Display.html?id=125543 >
<hoelzro> I found some behavior using heredocs, and I'm not really sure what the right thing to do is <hoelzro> https://gist.github.com/hoelzro/3b1ff9951908c9ce5aa4 (Gist shows the following heredoc with a \n in it, which gives a de-indentation warning at compile time.) my $here = qq:to/END_TEXT/; foo\nbar END_TEXT <hoelzro> it's concerning how leading whitespace removal is handled when one has an embedded newline via \n in a heredoc <timotimo> oh, interesting <timotimo> i hadn't considered newlines that are escaped inside heredocs like that when i wrote the new dedenting code <hoelzro> timotimo: I hadn't considered it either until I was converting code that used a single non-heredoc line and came across that =/ <hoelzro> I would file a ticket, but I don't even know if that's a bug. I don't even know what I expect it should do! <lucasb> Is there a way to dedent the heredoc literal text before expanding newline escape sequences? <hoelzro> TimToady may have to weigh in <masak> I'm... not sure I feel that's a bug... <hoelzro> masak: "not sure" is the thing with me too =/ <masak> I can understand the argument that this \n newline is not part of the heredoc's actual newlines, but... <masak> ...I'm also not ready to tear up compiler internals just to fix this one. <masak> but let's see if TimToady has some nice insight about it. <masak> it's kind of related to (but not the same as) http://strangelyconsistent.org/blog/here-be-heredocs under the heading "Indentation, revisited" <colomon> why would you want to embed a \n in a heredoc? <masak> colomon: that's a good, but separate question :) <masak> we're exploring "what happens when you do?" <masak> I don't believe it should be illegal. <hoelzro> colomon, masak: there's no good reason, I just found it interesting <masak> it is interesting. <hoelzro> I was converting a long single double quoted string with multiple embedded newlines into a heredoc while refactoring a program <masak> I mean, from the user's point of view, a \n in a heredoc isn't the same as a hard newline in a heredoc. <hoelzro> right <colomon> what happens if you embed a string with a newline in it? I actually do that quite a bit in my (mostly p5) scripts <masak> colomon: read the blog post I linked. <jnthn> I seem to remember I did it one way in the original herdocs impl in Rakudo, and something was off and got changed (probably what masak++ is referencing) <masak> yes. <TimToady> re \n in heredocs, the dedent should be happening before \n interpolation, just as it happens before $I-contain-a-newline interpolation <TimToady> so re http://irclog.perlgeek.de/perl6/2015-07-03#i_10845432 I'd call it a bug (URL referencing hoelzro's original example at the top of this report) <TimToady> recall that dedent is only for the purposes of establishing a false margin on the literal text, so from the user's perspective it really needs to happen before any kind of string processing <TimToady> I can think of several ways to fix it <TimToady> one is to treat \n interpolation more like $newline interpolation <TimToady> another is to substitute a sentinel character for \n inside heredoc parsing, and only dedent after the sentinel (and replace the sentinel with a real \n) * masak submits TimToady-approved heredoc \n de-indentation rakudobug
