Re: GrandStaff vertical distance

[Thomas Morley]

Am Mi., 17. Okt. 2018 um 15:43 Uhr schrieb Thomas Morley
<address@hidden>:

> I'd like to propose the code below.
>
> It stores the info in a string, which is converted to a nested list
> suitable for 'systemStartDelimiterHierarchy'. It can be nested in
> arbitrary depth.
>
> I used the following signs:
> [] indicating start/end of SystemStartBracket
> {} indicating start/end of SystemStartBrace
> <> indicating start/end of SystemStartSquare
> () indicating start/end of SystemStartBar
> Other elements should be of string-length 1
>
> I'm not that happy with the ones for SystemStartSquare and
> SystemStartBar. Though I looked for signs mirroring each others and
> not hard to type.
> After adding the definition for 'remove-whitespace' from 2.19.xx and
> 'parser'/'location' as the default arguments for a music-function it
> works in 2.18.2 as well.
>
>
> What do you think?
>
> Cheers,
>   Harm
>
>
> \version "2.18.2"
>
> %% build in since 2.19.xx, c/p here to make it work with 2.18.2
> #(define (remove-whitespace strg)
> "Remove characters satisfying @code{char-whitespace?} from string @var{strg}"
>   (if (guile-v2)
>       (string-delete char-whitespace? strg)
>       (string-delete strg char-whitespace?)))
>
> #(define (string->raw-system-start-hierarchy-list strg)
> "Takes the string @var{strg} which may contain {}[]<>().
> Those are transformed according to the local 'ref-list' and are returned as
> pairs where the cdr is the nesting-level.
> Other elements are supposed to be of string-length 1 and are transformed to 
> #f.
> Both will build a list.
> The finally returned result is a pair, containing the final list and the
> greatest nesting level.
> Example:
> \"-[--]-\"
> ->
> ((#f (SystemStartBracket . 1) SystemStartBracket #f #f (#t . 1) #f) . 1)
> "
>   (let* ((cleared-strg (remove-whitespace strg))
>          (ref-list
>            '((#\{ . SystemStartBrace)
>              (#\[ . SystemStartBracket)
>              (#\( . SystemStartBar)
>              (#\< . SystemStartSquare)
>              (#\} . #t)
>              (#\] . #t)
>              (#\) . #t)
>              (#\> . #t)
>              ))
>          (nest-lvl 0)
>          (max-nest-lvl 0)
>          (ready-list
>            (append-map
>              (lambda (x)
>                ;; Look into 'ref-list'
>                ;;   (a) - if a symbol is returned, return it as pair with its
>                ;;         'nest-lvl'
>                ;;       - increase 'nest-lvl'
>                ;;       - probably increse 'max-nest-lvl' as well
>                ;;   (b) - if it returns #t, return it as pair with its
>                ;;         'nest-lvl'
>                ;;       - decrease 'nest-lvl'
>                ;;   (c) if it returns #f, return it
>                ;; All are wrapped into a list to make outer append-map work
>                (let* ((el (assoc-get x ref-list)))
>                  (cond ((symbol? el)
>                           (set! nest-lvl (1+ nest-lvl))
>                           (if (> nest-lvl max-nest-lvl)
>                               (set! max-nest-lvl nest-lvl))
>                           ;; Urgh, adding another 'el' is a ugly hack to make
>                           ;; 'split-list-by-separator' work later
>                           (list (cons el nest-lvl) el))
>                        (el
>                          (set! nest-lvl (1- nest-lvl))
>                          (list (cons el (1+ nest-lvl))))
>                        (else
>                          (list el)))))
>             (string->list cleared-strg))))
>     (cons ready-list max-nest-lvl)))
>
> #(define (helper l nest-lvl)
> "Creates a nested list relying on whether the given list 'l' contains
> pairs and the there stored nesting level.
> Starting with the given 'nest-lvl', which is supposed to be the
> maximum nesting level for the most inner of the resulting sub-list(s).
> 'l' should be supplied by 'string->raw-system-start-hierarchy-list'."
>   (if (zero? nest-lvl)

To match the default behaviour, please replace:
>       l
with:
      ;; unnest one lvl if cdr is '()
      (if (and (pair? l) (null? (cdr l)))
          (car l)
          l)

Cheers,
  Harm

>       (let* ((splitted-ls
>                 (split-list-by-separator
>                   l
>                   (lambda (x) (and (pair? x) (eq? (cdr x) nest-lvl)))))
>              (result
>                (append-map
>                  (lambda (el)
>                    (if (and (pair? el) (symbol? (car el)))
>                        (list el)
>                        el))
>                  splitted-ls)))
>         (helper result (1- nest-lvl)))))
>
> #(define (system-start-hierarchy-list strg)
>   (let ((lst (string->raw-system-start-hierarchy-list strg)))
>     (helper (car lst) (cdr lst))))
>
> %% For conveniance
> setSystemStartDelimiterHierarchy =
> #(define-music-function (parser location strg) (string?)
> "Derived from @var{strg} a nested list suitable for setting
> @code{systemStartDelimiterHierarchy} is created and applied there.
>
> @var{strg} may contain:
> [] indicating start/end of SystemStartBracket
> {} indicating start/end of SystemStartBrace
> <> indicating start/end of SystemStartSquare
> () indicating start/end of SystemStartBar
> Other elements should be of string-length 1.
> Not properly nested brackets/braces/squares/bars like [xx<x]x> will not error,
> but cause strange results.
> "
>   #{
>      \set systemStartDelimiterHierarchy = #(system-start-hierarchy-list strg)
>   #})
>
>
> \new Score
>   \with {
>       \setSystemStartDelimiterHierarchy "-[-{-<<->>-}-]-[[--]]-"
>     \override SystemStartSquare.collapse-height = 1
>   }
>   <<
>     $@(make-list 10 #{ \new Staff R1 #})
>   >>
>
>
> <<
>   \new Staff R1
>   \new StaffGroup
>     \with {
>       \setSystemStartDelimiterHierarchy "-{---}[<<<{[--]}>>>]--"
>       %% Added for better viewing
>       \override SystemStartBar.color = #red
>       \offset X-offset -1 SystemStartBar
>       \override SystemStartSquare.collapse-height = 1
>     }
>     <<
>       $@(make-list 10 #{ \new Staff R1 #})
>     >>
>   \new Staff R1
> >>
>
> %% Not properly nested
> \new Score
>   \with {
>     \setSystemStartDelimiterHierarchy "{[1 <2 3] [4 5> 6]"
>   }
>   <<
>     $@(make-list 6 #{ \new Staff R1 #})
>   >>