Re: Bar lines

[Thomas Morley]

2013/3/6 David Kastrup <address@hidden>:
> Thomas Morley <address@hidden> writes:

>> You mentioned your concerns before (can't find it right now), though,
>> personally I see no _coding-problem_.
>
> Good.

Probably a little misunderstanding here, because I explained myself badly.
I wanted to say, that the current discussion is not about any
mal-coding, rather _what_ should be coded and _how_ in order not to
puzzle the user but to get user-accessable custom-barlines.
No clue if it would be easy to change the current code - I didn't proof it.

[...]
> You are assuming that the average user is aware of the visual
> composition of repeat signs.  But that's LilyPond's responsibility.
>
> We use "|." for the end bar not because of its _visual_ properties, but
> because of a _logical_ property, ending a piece.  WYSIWYG would be "I"
> or "|I" or "|]" instead (again, it is not really the job of the user to
> remember that a thick bar line is always accompanied by a thin one, so
> he writes something akin to "give me a bar line fit for ending a
> piece").
>
> "." is in no way a thicker bar line than "|" is.  So the whole "WYSIWYG"
> analogy/principle is a rather strained one, and that means that nobody
> will understand it without getting a thorough explanation.

Well, I thought of myself being an experienced user, but I never, I
mean _never_, understood any logic with the old barlines (2.16 and
before).
So far about being intuitive.
After reading and rereading your explanations above, it's the _first_
time I understand your concerns.
Up to now I regarded the old barline-naming as the desperate try to
distingish between similiar barlines without bloating the amount and
sort of used strings.

I had a look at the 2.16.-barlines searching them for some logic
and/or assuming "." being a WYSIWYG-sign for a thick-bar. Below the
shortened list with remarks.

;; How should a bar line behave at a break?
;; the following alist has the form
;; ( unbroken-bar-glyph . ( bar-glyph-at-end-of-line .
bar-glyph-at-begin-of-line ))

(define bar-glyph-alist
  '((":|.|:" . (":|" . "|:"))   ok
    (":|.:" . (":|" . "|:"))    ok
    ("|." . ("|." . ()))        ok

    (".|" . ("|" . ".|"))       ok and WYSIWYG

    (".|." . (".|." . ()))      a double thick-bar not logical, not WYSIWYG
    ("|.|" . ("|.|" . ()))      WYSIWYG
    ("." . ("." . ()))          WYSIWYG

    ;; segno bar lines
    ("|S" . ("|" . "S"))        should be than ("|.S" . ("|" . "S"))
    ("S|" . ("S" . ()))         should be than ("S|" . ("S" . ()))
    (":|S" . (":|" . "S"))      should be than (":|.S" . (":|" . "S"))
    (":|S." . (":|S" . ()))     ok
    ("S|:" . ("S" . "|:"))      should be than ("S.|:" . ("S" . "|:"))
    (".S|:" . ("|" . "S|:"))    ok
    (":|S|:" . (":|" . "S|:"))  should be than (":|.S|:" . (":|" . "S|:"))
    (":|S.|:" . (":|S" . "|:")) ok
))

Summary: Sometime this, sometimes that. There's no real consequent
coding-style, imho.
Especially for complex barlines.

>
>> What do other users/developers think?
>
> My guess would be that they trust the programmers to have good reasons
> for doing things like they do.
>
> I am also pretty sure that in a "frequently asked questions" list for
> LilyPond, this one will end up occupying a rather high place.  And I
> don't think that is warranted.
>
>> Can we reach a consensus?
>
> Well, I am a doomsayer faced with optimists.  The easiest way to reach
> consensus is to just wait.

lol

> I have enjoyed working on the Bach solo partitas and sonatas.

Btw, great stuff. I played some of them on the guitar.

[...]

> That's a lot of verbiage for a small issue.  It will be easier to
> convince you once you have answered the respective user mails for a year
> or so.

I'm already tired answering user-questions omitting any code and/or
version or questions where it's clear that the requester has probably
read the title of the Manual, probably not ...
And sometimes, well, sometimes I'm _very_ tired ...

-Harm