Re: Stop \lyricmode { \skip 1.*3 } from failing. (issue 13256053)

[Janek Warchoł]

2013/9/25  <address@hidden>:
>
>> > On 2013/09/24 07:44:44, janek wrote:
>> >> Hmm. From my point of view, this deserves some comment
>> >> (but i don't insist).
>
> Well, multiple matching regexps are messy and might call for an
> appropriate comment.  But the whole point of the change is not to have
> multiple matching regexps any more.
>
> The original commit message of the commit that failed to do the job was:
>
> commit 38a4081efa4a8ee2f5da780ca0ed2991627afc46
> Author: David Kastrup <address@hidden>
> Date:   Sun Sep 30 02:21:00 2012 +0200
>
>     Issue 2869: Regularize lyrics lexer mode
>
>     That makes lyrics mode rather similar to markup mode regarding how
>     words are formed.  {} are never considered part of words unless
>     enclosed in quotes.  Unquoted words do not contain whitespace,
> braces,
>     quotes, backslashes, numbers or Scheme expressions.  In addition,
> they
>     cannot start with * . = and | since that would mess with duration,
>     assignment and barcheck syntax.  This removes some remaining
>     TeX-oriented cruft in the lexer.  The set of word-non-starters might
>     need revisiting, but at least the regtests seem to pass.
>
> The text that is relevant here is "In addition, [unquoted words] cannot
> start with * . = and | since that would mess with duration, assignment
> and barcheck syntax."
>
> After the fix, the pattern _explicitly_ (rather than implicitly by
> pattern order which did not work) states that unquoted words cannot
> start with * . = and |.  The pattern is now a literal rendition of the
> description.
>
>
>> For me the regex itself required a few moments of thinking to
>> understand.
>
> The problem is that you want a comment describing the problems with
> code/patterns that is no longer there.  I don't think that's helpful.  A
> comment is called for when you use a trick to avoid a problem.  But in
> this case, the problem was avoided by stopping to use a trick and
> instead being boringly explicit in the pattern.
>
> It's quite redundant now to state "this pattern won't match something
> starting with * . = or |" since the pattern explicitly excludes those
> characters in its first position.  My first attempt was to give the
> first single-char pattern priority back by using
> [*.=]/.*
> (a "trailing context" which did not actually work because of technical
> restrictions).  That would both have been fragile _and_ would have
> called for a comment in order to explain its purpose.  But the purpose
> of a pattern
> [^*.=| ...
> is not to match * . = | in the first position of the pattern.  That's
> basic.  Comments can't hope to explain everything that's basic. They
> should tell the story that the code doesn't tell, at least not on its
> most direct surface level.  And the code now tells the story in the most
> blunt way that is possible.  Of course we can add a comment of the "we
> could do this in a trickier way that does not actually work" kind, but
> that's not helpful at all.
>
> It does not belong in the code.  It might belong in the issue tracker,
> perhaps in the commit message.  Just as a record of what went wrong.
> But the code, as it is written, does not offer a temptation of changing
> it back to the buggy previous version.  It was not more elegant or
> obvious or clearer.

Uh, David, thanks for this explanation, but i'm afraid it was not
needed.  If the code doesn't need a comment, just say so.

Now, speaking in general: i don't understand that when Mike submits a
patch, you often complain that it's not commented well enough, but
when I ask you for comments, you usually say "this doesn't need any
comment".

Apparently both you and Mike consider what you write to be self-explanatory.

Maybe you are right that for an experienced developer Mike's code
isn't self-explanatory, and your code is.  All i know is that for me
neither is self-explanatory.  Of course, i'm not an experienced
programmer.  But then, i've been working on LilyPond since 3 years
now, and that seems a pretty long time.

I am sorry that (apparently) you don't care whether i can understand
your patches easily or not.  Also, from my perspective, it seems that
you consider yourself to be always right:
"i think this deserves a regtest" "no, it doesn't"
"i think this deserves a comment" "no, it doesn't"

I suppose that you're not doing this intentionally.  But it drives me
crazy anyway.

Anyway, it seems that when i try to review your patches the first and
foremost result is that we both loose time, so i suppose that i should
stop reviewing your patches :-(

Janek