Provide framework for deprecation warnings
In !1961 (merged), @eble asks the following:
Is there a simple way to print the warning only once per
lilypond
process, no matter how many times the feature is used (in this case, the number of times the file is included)? That would be kind.[...] We might want to implement deprecation warnings as a separate category with a separate option to disable or ignore them, which we would do by default in regression tests but might re-enable explicitly so that we can make sure they work.
Ideally, we would be able warn about a deprecated feature with similar ease in C++ and Scheme.
Candidates for warnings:
barCheckSynchronize = ##t
\include "gregorian.ly"
-
voltaSpannerDuration
: suggest\override Score.VoltaBracket.musical-length
whichBar
Edited by Dan Eble