Including a file only once - Revision history

Lemzwerg: New category

2025-11-21T23:20:52Z

New category

← Older revision		Revision as of 23:20, 21 November 2025
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	[[Category:Version-specific]]		[[Category:Version-specific]]
	[[Category:Preparing parts]][[Category:Snippet]]		[[Category:Preparing parts]]
			[[Category:Snippet]]

Lemzwerg at 22:54, 21 November 2025

2025-11-21T22:54:52Z

← Older revision		Revision as of 22:54, 21 November 2025
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	[[Category:Version-specific]]		[[Category:Version-specific]]
	[[Category:Preparing parts]]		[[Category:Preparing parts]][[Category:Snippet]]

Jean Abou Samra: Replace version="2.24.0" with version="2.24" now that the LilyWiki extension supports auto-selecting the latest release in a stable series

2025-11-16T18:56:58Z

Replace version="2.24.0" with version="2.24" now that the LilyWiki extension supports auto-selecting the latest release in a stable series

← Older revision		Revision as of 18:56, 16 November 2025
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	Some files of definitions should be included only once in a project, but they need to be mentioned by all of the files that require them. I defined \includeIfAbsent to include a file if and only if it has not already been included by \includeIfAbsent. It works in a different scope from \include, so definitions in the included file need to be made global with define-public-toplevel in order to be effective.		Some files of definitions should be included only once in a project, but they need to be mentioned by all of the files that require them. I defined \includeIfAbsent to include a file if and only if it has not already been included by \includeIfAbsent. It works in a different scope from \include, so definitions in the included file need to be made global with define-public-toplevel in order to be effective.

	<lilypond version="2.24.0">		<lilypond version="2.24">
	%% http://lsr.di.unimi.it/LSR/Item?id=657		%% http://lsr.di.unimi.it/LSR/Item?id=657

Jean Abou Samra: Import snippet from LSR

2025-10-26T22:44:48Z

Import snippet from LSR

New page

Some files of definitions should be included only once in a project, but they need to be mentioned by all of the files that require them. I defined \includeIfAbsent to include a file if and only if it has not already been included by \includeIfAbsent. It works in a different scope from \include, so definitions in the included file need to be made global with define-public-toplevel in order to be effective.

<lilypond version="2.24.0">
%% http://lsr.di.unimi.it/LSR/Item?id=657

% Will not work in 2.13 or later since define-public-toplevel has been removed

% Updating-remark: reinserted the relevant files from 2.12.3

% Updaring-remark: works now for 2.18 (Feb. 2014)

% Include a file unless it has already been included. This executes
% in a cloned parser, so all definitions in the included file need to
% be made global with define-public-toplevel. Include seems to be
% implemented in the lexical analyzer, and I don't see how to do it
% properly at a higher level. Executing in the main parser appears to
% have the right effect, and produce all desired output, but LilyPond
% ends with a segmentation fault.

%
% In the included file, do lilypond variable defintion
%
% var = <stuff>
% as
% #(define-public-toplevel var #{ <stuff> #} )
%
% music function definition
%
% fname = #(define-music-function <stuff>)
% as
% #(define-public-toplevel fname (define-music-function <stuff>))
%
% markup definition
%
% var = \markup { <stuff> }
% as
% #(define-public-toplevel var (markup <translated-stuff>))
%
% Using the translation described in the LilyPond Notation Manual
% section Markup-construction-in-Scheme
%

#(define-public toplevel-module-define-public! #f)
#(define-public toplevel-module-ref #f)
#(let ((toplevel-module (current-module)))
(set! toplevel-module-define-public!
(lambda (symbol value)
(module-define! toplevel-module symbol value)
(module-export! toplevel-module (list symbol))))
(set! toplevel-module-ref
(lambda (symbol)
(module-ref toplevel-module symbol))))

#(defmacro-public define-public-toplevel
(first-arg . rest)
"Define a public variable or function in the toplevel module:
(define-public-toplevel variable-name value)
or:
(define-public-toplevel (function-name . args)
..body..)"
(if (symbol? first-arg)
;; (define-public-toplevel symbol value)
(let ((symbol first-arg)
(value (car rest)))
`(toplevel-module-define-public! ',symbol ,value))
;; (define-public-toplevel (function-name . args) . body)
(let ((function-name (car first-arg))
(arg-list (cdr first-arg))
(body rest))
`(toplevel-module-define-public!
',function-name
(let ((proc (lambda ,arg-list
,@body)))
(set-procedure-property! proc
'name
',function-name)
proc)))))

#(if (not (defined? 'includeIfAbsent))
(define-public-toplevel includeIfAbsent(define-music-function (fileName) (string?)

(let ((guardName (string-append "Already Got " fileName)))

(if (not (defined? (string->symbol guardName)))
(begin

(primitive-eval (list 'define (string->symbol guardName) #t))

(ly:parser-parse-string (ly:parser-clone) (string-concatenate (list "\\include \"" fileName "\"")))

(make-music 'SequentialMusic 'void #t))

(make-music 'SequentialMusic 'void #t))))))

\markup {
Pointless markup to avoid LSR rejecting the snippet for lack of output
}
</lilypond>

[[Category:Version-specific]]
[[Category:Preparing parts]]