-Features you cannot find in the doco as working, should be mentioned her.
+Features you cannot find in the doco as working, should be mentioned here.
This is an assorted collection of stuff that will be done, might be
done, or is an idea that I want to think about
Most of the items are marked in the code as well, with full explanation.
-grep for TODO and ugh/ugr
+grep for TODO and ugh/ugr/urg
-bugs introduced in pl68:
-
- * lyrics broken,
+BUGS:
+ * c4 \! \> c4
- * midi broken
+ * tremolo stuff
- * scripts broken
+ * gallina barlines.
-IMPORTANT
+ * fix height of / collisions with lyrics (chords),
+ see input/test/vertical-text.ly
- * piano staff
+ * repeat/volta:
+ - one volta spanner per score
+ - repeat bars span staffs
+ - placement alternative number
- * decent spacing
-
- * implement better breaking algorithm
+ * who is trying to print too (small/big) piano braces all the time?
+ warning: piano brace too small (16.000pt)
+
+ * latex bla.tex broken (titles / \lilyfooter stuff?)
+
+ * msgfmt -o check?
+
+ * \breathmark TeX macro
+
+ * configure error if GUILE 1.3 not found
+
+ * configure error if no rtti (gcc 2.8 or egcs-1.1)
+
+ * catch GUILE errors?
+
+ * add new glyphs to font.ly
+
+ * formatting of input stuff.
+
+ * \notes{ a \< b \cr } vs \notes{ a \< b \! }
+
+ * if possible, it might be nice for a warning to appear if someone does
+ \translator with no name and without assigning it to an
+ identifier.
- * update 20 pt table
+ * space after bars?
+
+ * \type Voice \times 2/3 { [c8 c16 c16 c16 c16] }
+
+ * fix singleStaffBracket
+
+ * repeat bars: need distance after ":|" and before "|:"
+
+ * The time signature warnings still remain, will be fixed later.
+
+ Summary of minor spelling irregularities:
+ - capitalization/use of underscores in property names
+
+ * fix SkipBars -> skipBars
+
+ * \shape 1st dim skipped?
+
+ * fix marks/barnumbers/marginal notes
+
+ * broken scripts:
+ lbheel = \script { "bheel" 0 0 -1 0 0 }
+ rbheel = \script { "bheel" 0 0 1 0 0 }
+ lbtoe = \script { "btoe" 0 0 -1 0 0 }
+ rbtoe = \script { "btoe" 0 0 1 0 0 }
+ lfheel = \script { "fheel" 0 0 -1 0 0 }
+ rfheel = \script { "fheel" 0 0 1 0 0 }
+ lftoe = \script { "ftoe" 0 0 -1 0 0 }
+ rftoe = \script { "ftoe" 0 0 1 0 0 }
+
+ and also
- * use Hungarian throughout code
+ portato= \script { "portato" 0 -1 0 1 0 }
- * decent TeX page layout
+STUFF
+ * uniformise recent feta contributions.
- * script priority
+ * check out legal/(c) matters for scores.
- * a Hands on tutorial [HKN]
+ * check out GCC signatures?
-PROJECTS
+ * Align_element::padding ?
- * Convert all ref/bib stuff into BibTeX.
+ * uniformise property names.
- * Output class, handles : (smallish)
- - help text /(c) notice?
- - version line
- - warning /errors/progress
- - abort on error/warning; exit status
- - quiet/ignore-version options
- - logfile output
+ * ydirection <-> yDirection
- * elaborate Staff_side baseclass:
- - scripts
- - text
- - slur start/end
+ * typo checks on property names?
- * Output an output format independent (ofi) typeset file; and
- make ofi2 TeX, MusixTex, PostScript, Ascii... interpreters. (difficult)
- - poor man's ascii output possible?
- - MusixTeX output possible? (would have to be done before break calc.)
- - NIFF ?
- - Common Music Notation
- - PostScript output (esp. Beams, Slurs, etc)
- - Move PScore, Items, Spanners etc. into libmutype.a
+ * use streambufs and iostream
+ to provide IO handling for TeX stream, mudela stream, data-file.
+ * seriously buffer TeX output (do profile of writing .5 mb TeX file.)
- * separate Score_elem settings in user-settable (properties
- .. ) and non-user-settable part. Maybe use something like X-resources:
- "Staff=oboe*dir: 0", "Staff=*.Voice_group=solo*dir: 1"
+ * strip EXEs before installing
- * TeX spanners , use texbeam.cc as an example (smallish)
- - Glissando
- - trill
- - bracket
+ * zip target for binary windows dist (JBR)
- * Rewrite Stem, Beam and Rhythmic_grouping (hairy)
- - [c8. c32 c32]
- - interbeam height
- - doc on Rhythmic_grouping
- - general shaving on Beam and Stem
- - use plet grouping
- - abbreviations [c2 c2]1/2
- - separate visual from rhythmic info even more
- - beams over bars
+ * junking \skip req in lyrics
- * Redo MIDI output to use Registers: (Difficult)
- - remember more horizontal info than melodics:
- - tempo change
- - repeat
- - slurs
- - dynamics etc.
+ * Language:
+ - \type -> \context ?
+ - \translator -> ?
+ - fix \partial
+ - \bla {} vs \bla ;
+ - mix engraver hacking with music ?
+ - \once\property KEY = VAL
+ - \addtranslator, \removetranslator
+ - junk ^ and _ for scripts
+ - junk _ for lyrics.
+ - abstract grammar.
+ * percussion note heads
- * Redo font support
- - use GSharp fonts?
- - rename mf fonts to avoid conflicts with musixtex
- - check (c) issues
- - use own fonts/update musixtex fonts/find older (c)-less fonts
- - hack up mf sources for decent spacing info (and then
- read AFM/TFM directly, for text too)
+ * mi2mu empty staffs.
+ * midi_instrument -> midiInstrument
- * lines:
- - Ledger lines, should be separate item: Ledger_lines, Ledger_lines_reg
- - set different line sizes / thicknesses
- - stem down too far right
- - beam stem showthrough, inter beam sizes (french vs german style)
+ * horizontal centering of dynamics
- * Collisions
- - bring Collision::do_pre_processing to haircutter
- - left/right note balls should be handled by Collision:
- < \multivoice { \stem 1; <b c> } { <f as b> } >
+ * \font\fontA=feta20.afm (.afm?)
- * Keys:
- - merge key{item} & localkey{item}?
- - do conventional keys (C G A, F B E, a e fis, d as des, etc ),
- besides lists of flats/sharps, possibly via declaration
- - key transposition.
- - key undo: \key bes; .. . \key; should print natural
- - special key: \key 'b bes bis';
- - spacing, national styles?
+ * gzip RH manpage
-PARSER
- * Duration -> Musical_duration, typedef Rational Duration?
+ * stable make/config stuff
-HKN buglist:
+ * $DEPENDENCIES_OUTPUT support
-tekst staat erg ver van notenbalken af
+ * fix BUGs
-waarom geen ; achter dingen in \paper? (\textwidth 180\mm)
-(sowieso: wanneer wel en geen ; ?)
+ * fix weird behaviour when .AFMs/.SCMs not found.
-Onduidelijk wanneer wel en geen \ voor een woord. Maak liever
-verplichte regels
+ * Xdvi zooming ?! Try to understand GS garbage collection.
+ gs: Error: /undefined in draw_beam
+ gs: Operand stack:
+ * run texhash after installing .tex
-BUGS
- * spurious Weird stem size warnings
+ * fix vertical alignment and stafflines
- * staccato dot positions.
+ * GrandStaff needs more work -- I want a single word
+ `harpsichord' to the left of the grandstaff, not one on each
+ stave. (Organ staff -- with separate pedal -- but common
+ properties may be something to think about. Of course for
+ organ you want to be able to give stop indications on the way
+ through, so the \property Voice.Instrument would be a stop,
+ and \property GrandStaff.instrument would be PipeOrgan...)
- * stacked scripts.
+ * make Tie_req a "command" { <c g> ~ <c g> }
- * should adjust stemlength for flag number.
+ * revise the Score_priority_align_engraver concept. It sucks.
- * lilypond - -> crash
+ * make new VoiceOne, VoiceTwo, VoiceThree contexts with
+ydirection and hshift preset
- * standchen triool beam up/down
-
- * (where are the) gcc compile warnings on linux
-
-SEVERELY LACKING:
+ * *.yo: fix pod manpage layout legacy
- * SPEED!
+ * text-items clash with stems/beams
- * grace notes
+ * --include, -I option for ly2dvi (pass on to lily)
+ * fix placement of beam-less abbrev
-FURTHER FOR ORCHESTRAL SCORE:
+ * \meter 3/4;
+ <{\voiceone cis4. cis8 cis4 | cis4 cis cis | r1 }
+ {\voicetwo cis,4 r r | r2. | r1 }> |
+ }
- * multibar rests
+ * try to use template<Type> iso MACRO(Type)
- * barnumbers, markers
+ - NEWS: ... Musical_pitch (analogous to Duration and Rhythmic_req)
+ think about, analogous to pitch:
+ * { a4 a16 } c <-- duration of c?
+ * <a4 b8> c <-- duration of c?
- * abbreviations c4=16
+ * \tempo 4. = 90;
-INPUTLANGUAGE
+ * fix audio-items (don't use (input) requests, but copy data)
- * c4 4 4 4 for c4 c4 c4 c4?
+ * junk My_lily_parser::abbrev_beam_type_i_
- * neatly (and readably) expressing concurrent
- voices
+ * make sure all ex's have a mudela-version
- * <c f a>4 ?
+ * do rest-collisions for Multi_measure_rests as well.
- * should have \require{package.ly} to read req'd packages.
+ * split error/warning in error/warning/non_fatal_error
- * Viola mode?
+ * add a Duration_convert member to Duration_iter to set parameters.
+ Junk global duration settings.
+
+ * deps for ly2dvi
- @c c g e g
- for
- c g es g,
+ * clean up abbrev/plet/beam/abbrevbeam/duration mess in parser.
- @A c g e g
- for
- cis gis e gis
+ * minimum length second part broken tie
+
+ * en-,discouraged linebreaking:
+ - handle DISALLOW < penalty > FORCE
+ - discourage breaking of slurs
- * relative mode for pitch entering
+ * multibar rest
+ - symbol(s)
- * bracket (bracketplets)
+ * fix variable define/lookup parser global<->paper
- * \duration 8; e*2/3
+ * fix title/instrument placements; see input/test/title.ly
- * configure pitch_byte
+ * <\voiceone c4. \voicetwo c4>
- * figured bass?
+ * add full cello suites to web site (kom op, Maarten!)
- * rest name configurable
+ * Rethink Time_description
+ * \cadenza , \meter, \grouping should all be \properties
- * Raw request syntax
+ * rename
+ - measure -> bar
+ - abbrev -> tremolo
+ - abbreviation-beam -> (measured/unmeasured) tremolo
+ - partial -> anacrouse
- * subtime with Subtle_reqs
+ * shared lib
-PROJECTS
+ * robustify Beam (in case of no stems, 32nd notes)
- * Do RTTI i.s.o. static_name(), name() and request-junk.
+ * decentralised spring factory
-SMALLISH PROJECTS
+ * move paper vars into engraver properties
- * A range for context errors (eg. mark both { and }. )
+ * check for groff / troff/ nroff et
- * text in staff (sharpsharp in staff, text below)
+ * more intelligent file searching
+ - make LilyPond RPM fully relocatable
- * fix Egler definitions ( see tex/eglerdefs.tex )
+ * nicen examples:
+ - break-up heavily-nested score blocks
- * replace Score_elem member access by get()/set() methods, to enable
- future embedded code.
+ * disable spaces in TeX stuff
+
+ * handle ^C for tmp/file creation.
- * --fast/--draft: leave out constraints
+
+ * dots & rest collisions.
- * write Dynamic_line (to group dynamics horizontally)
+ * documentation
+ - introduction?
+ - info?
+ - LaTeX?
+ - more manpages?
- * write Rest_collision
+ * versioning for Feta
- * use Real for y positions.
+ * the warning about the negative slur/tie length appears twice
+ which is irritating.
- * shared lib on Solaris too.
+ * The `3' in the meter key is a one or two pixels too thin (at 600dpi)
+ in the middle:
- * bugreport to doc++ devel: struct not in class hier; public
- virtual baseclasses
+ * the bracket is ugly (wings are too parabolic, should be more circular)
- * get rid of init_end;
+ * better hshift (dots, distance, head dependent)
- * cleanup lily-proto.hh and proto.hh
+ * clefs (AG): The "8" should appear closer to the actual clef,
+ touching it.
- * half-sharps, half-flats
+ * put errorlevel in Input class
- * adaptive accidental spacing.
+ * junk nesting slurs
- * unix style paths for LILYINCLUDE env
+ * integrate midi-elts from mi2mu and lily?
- * indentable stream as baseclass for TeX stream, lily stream, Dstream.
+ * score-bar-scripts
+ FMR: Free memory read:
+ * This is occurring while in:
+ Bar_column::do_substitute_dependency(Score_element*,Score_element*) [bar
+ -column.cc:29]
+ Score_element::unlink() [score-elem.cc:383]
+ Paper_score::set_breaking(const Array<Column_x_positions>&) [p-score.cc:
+ 150]
+ Paper_score::calc_breaking() [p-score.cc:189]
+ Paper_score::process() [p-score.cc:203]
+ Score::run_translator(Music_output_def*) [score.cc:117]
+ * Reading 4 bytes from 0x65d3a0 in the heap.
+ * Address 0x65d3a0 is 160 bytes into a freed block at 0x65d300 of 208 bytes.
+ * This block was allocated from:
+ malloc [rtlib.o]
+ __builtin_new [libgcc.a]
+ Span_score_bar::clone()const [span-score-bar.hh:20]
+ Item::copy_breakable_items() [item.cc:69]
+ Item::do_breakable_col_processing() [item.cc:89]
+ Score_element::calcalute_dependencies(int,int,void(Score_element::*)()*)
+ [score-elem.cc:171]
+ * There have been 22 frees since this block was freed from:
+ free [rtlib.o]
+ __builtin_delete [libgcc.a]
+ Span_score_bar::~Span_score_bar() [span-score-bar.hh:18]
+ Paper_score::set_breaking(const Array<Column_x_positions>&) [p-score.cc:
+ 156]
+ Paper_score::calc_breaking() [p-score.cc:189]
+ Paper_score::process() [p-score.cc:203]
+ Postprocessing elements...
+ TeX output to score-bar-scripts.tex...
- * handle EOF graciously in error messages.
- * caching Item/spanner dimensions.
+3RD PARTY BUGS:
- * centered whole rest
+ * make GCC warn about ctor that leaves member vars uninitialised.
- * caching breakpoints / saving them.
+ * redhat (v?) graphical install bomb-out?
- * use dstream feature in mi2mu
+ * GNU diff 2.7: diff -rN does not see a new directory with empty file
- * qtor, btor, mtor-> tor( QUIET_ver ), tor( DEBUG_ver ), etc.
- - use tors feature in lily (?)
+ * GNU patch 2.1: <must find simple example> if patch chokes on a
+ hunk, or on allegedly unsorted hunks in a diff, it may stop
+ without a trace of failure (create .rej file, print error or
+ dump core) and just ignore any further diffs.
- * declare symtab
+ * glibc 2.0:
- * declare notenametab?
+ f = fopen ("/dev/null", "r")
+ assert (feof (f))
- * midi esp.: use I32 iso int where 32 bits are needed (or assumed...)
+3RD PARTY PROJECTS:
- * parshape
+ * GNU indent: handle C++
- * read from mmap directly: bugreport to flex developers->
- yy_scan_buffer in C++..
+ * GNU patch
+ - 'double-fix' mode: ignore identical fix, rather than suggest
+ to revert patch direction when (more or less? exactly) the same
+ thing is fixed
- * binsearch/hash for identifiers
+PROJECTS
- * stafftypes: voice names/ instrument names.
+ * Scripts:
+ - fix position of bar number
+ - stack scripts in chords:
+ % fingering: footing:
+ < a-4 c-2 g-1 > < c-\ltoe e-\lheel >
+ - script-spacing
+ - slur parts as a script
+ - stack parameterised scripts for fingering and footing:
+
+ * convert-mudela:
+ - automatically add a \version if not present.
+ - better parsing
+ - make smarter
+ - convert-mudela -e empty.ly
+
+ * emacs mudela-mode
+ - should handle block comments too.
+ - handle lexer modes (\header, \melodic, \lyric) etc.
+ - indentation
+ - notenames?
+ - fontlock: \melodic \melodic
+
+ * use properties for:
+ - plet?
+ - Staff_sym size
+ - default tempo.
+ - font size
+ - bartypes (get rid of derived Span_bar_engravers)
+ - cadenza mode?
+
+ * page handling:
+ - PS output
+ - optimal pagebreaking.
+
+ * Unicode support? -> man 7 unicode
+ - 16 bit Strings
+ - -u switch
+ - detect of 16/8 bit files
+ - examples to go with it.
+
+ * Spring_spacer:
+ - write a faster Spring_spacer (without matrices if possible)
+ - relate energybound to linelen unitspace fontsize etc.
+ - used fixed point fp?
+
+ * \header
+ - output header info to MIDI too.
+
+ * a musical dictionary. See Documentation/vocabulary-*, other
+ languages:
+ - explanations
+ - italian
+ - german
+ - dutch
+ - swedish
+ .. ?
+
+ * chords
+ - jazz style inversions C/E => <e g c>
+ - guitar chords (fret diagrams)
+ - other chord name styles (american(?) style)
+ - basso continuo
+ - MIDI output?
+
+ * Debug logs:
+ - derive lily_stream, Dstream, texstream from ostream?
+ - indentable stream as baseclass for TeX stream, lily stream, Dstream.
+ - use dstream feature in mi2mu
+ - integrate IO checking into stream class
+
+ * input converters
+ - NIFF?
+ - ABC?
+ - SMDL?
+
+ * add to MIDI output:
+ - tempo change
+ - ornaments (and trills?)
+ - repeat/volta
+ - slurs
+ - accents
+ - dynamics
+ - account for rhythmic position in measure
+ - etc.
- * Decent TeX titledefs (\tempo, \metron, etc. )
+ * grace notes
+ - make separate class for Grace_*_engravers
+ (which is at Voice_gravs level)
+ - make encapsulated spacing problems.
- * C meter iso 4/4, idem for alla breve, etc.
+ * accidentals per Voice_group
- * textspanner: center position
+ * Output class, handles : (smallish)
+ - help text /(c) notice?
+ - version line
+ - warning /errors/progress
+ - abort on error/warning; exit status
+ - quiet/ignore-version options
+ - logfile output
- * script-spacing
+ * piano staff
- * Brackets
+ * elaborate Staff_side baseclass:
+ - scripts
+ - text
+ - slur start/end
-
- * use (char *) iso. String for communication between lexer and
- parser.
+ * PS
+ - speed up PS code.
+ - PS lines to .eps files
+ - write custom prolog
- * configure idealspacing: arithmetic spacing
- * LilyPond .deb. Other packaging methods?
+ * Output an output format independent (ofi) typeset file; and
+ make ofi2 TeX, MusiXTex, Display PostScript, PostScript,
+ Ascii... interpreters. (difficult)
- * detect -pipe
+ - NIFF ?
+ - Common Music Notation
+ - PostScript output (esp. Beams, Slurs, etc)
+ - Move all Score_elems, into libmutype.a
+ - SGML
-DOC
- * Score_elem structure.
+ * Documentation
+ - Doc (C) stuff of sheet music
+ - a better format? SGML? TeX? Info?
+ - a better tutorial
- * all errors
-
- * config of TeX macros
+ * more spanners (smallish)
+ - Glissando
+ - trill
- * a test suite
+ * Rewrite Stem, Beam and Rhythmic_grouping (hairy)
+ - [c8. c32 c32]
+ - doc on Rhythmic_grouping
+ - general shaving on Beam and Stem
+ - use plet grouping
+ - separate visual from rhythmic info even more
+ - beams over bars
- * hacking-HOWTO
+ * lines:
+ - Ledger lines, should be separate item: Ledger_lines, Ledger_lines
+ - set different line sizes / thicknesses
+ - beam stem showthrough, inter beam sizes (french vs german style)
-FUTURE
+ * Collisions
+ - left/right note balls should be handled by Collision:
+ < \multi 2; { \stem 1; <b c> } { <f as b> } >
- * auxilliary file for caching info.
+ * Keys:
+ - merge key{item} & localkey{item}?
+ - spacing, national styles?
- * Reg_configure_request
+ * Support for TAB
+ - redo Notehead to allow digits as heads
+ - add a \tablature {} lexer mode for easy entering
- * slur parts as a script
-
- * mixed fontsizes
+ * should adjust stemlength for flag number.
- * put scripts on bars
+ * breaking:
+ - caching breakpoints
+ - saving them
+ - specify number of lines
- * guitar chord
+ * markers
- * better beamslope calculation: QLP for beams?
+INPUTLANGUAGE
- * Text_crescendo
+ * c4 4 4 4 for c4 c4 c4 c4?
- * clean solution for staffsize in items.
+ * neatly (and readably) expressing concurrent
+ voices
- * revise calcideal
+ * <c f a>4 ?
- * volta
+ * Viola mode?
-IDEAS
- * check out CORBA for Score_elems?
+ @c c g e g
+ for
+ c g es g,
- * derive PCol from Score_elem? More in Score_elems? Spacing?
+ @A c g e g
+ for
+ cis gis e gis
- * scoping in Lexer: do general id- assignments in mudela.
+ * relative mode for pitch entering
- ID '=' EXPR;
+ * configure pitch_byte
- * create libmudela, or liblily_frontend
+ * rest name configurable
- * move MIDI stuff (including Quantization) to a ANSI C libmidi library.
+SMALLISH PROJECTS
- * use an embedded language: Python
- for:
- - Score_elems
- - Registers
- - Complex mudela?
+ * limit memory usage; the full coriolan takes up too much resources.
- * y -dims in internote?
+ * fix confusing naming in Engraver vs Engraver_group_engraver (context)
- * merge Atom and Symbol?
+ * progress when creating MIDI elts.
- * merge common code of Item, Atom/Molecule
+ * A range for context errors (eg. mark both { and }. )
- * Spacing_request for manually adjusting spacing
+ * lyric in staff (sharpsharp in staff, text below)
-
- * caching breakpoints
+ * half sharps/flats
- * #c <-> cis
+ * write Dynamic_line (to group dynamics horizontally)
- * breath marks
+ * use Real for all y positions.
+ - use translate_axis( .. ,Y_AXIS) iso separate variables.
- * used fixedpoint arithmetic for min. energy.
+ * half-sharps, half-flats
- * default convert mudela-file.ly -> mudela-file.tex
- - rename {standchen,scsii-menuetto,...}.tex
+ * adaptive accidental spacing.
- * stack scripts in chords:
- % fingering: footing:
- < a-4 c-2 g-1 > < c-\ltoe e-\lheel >
+ * handle EOF graciously in error messages.
+
+ * centered whole rest
+
+ * declare notenametab?
+
+ * midi esp.: use I32 iso int where 32 bits are needed (or assumed...)
- * parameterised scripts for fingering and footing:
+ * Flower types:
+ - A decent scalar type
- % toe to bheel four to five
+ * stafftypes: voice names/ instrument names.
+
+ * lily \tempo
+
+ * C meter iso 4/4, idem for alla breve, etc.
+
+ * textspanner: center position
+
+ * % toe to bheel four to five
% ^_u 4_5
% -
% --|x-- --|x--
% --|--- --|---
(where "to" is a tiny bow)
+ * auxilliary file for caching info.
+
+ * Text_crescendo
+
+ * clean solution for staffsize in items.
+
+ * revise calcideal
+
+IDEAS
+
+ * Output data structures of Mudela in XML/SGML.
+
+ * create libmudela, or liblily_frontend
+
+ * move MIDI stuff (including Quantization) to a ANSI C libmidi library.
+
+ * use an embedded language: Python, Scheme
+ for:
+ - Score_elems
+ - Translators
+
+ * y -dims in internote? Staff-space? X-dimensions?
+
+ * Spacing_request for manually adjusting spacing
+
+ * caching breakpoints
+
+ * used fixedpoint arithmetic for min. energy.
+
* move towards incremental algorithms.
+ * far fetched language ideas
+ - design meta-language like TeX and Metafont
+ - programming/macros input
+
+ * versioning stuff (cvt mudela, mudela, etc.)
+
+ * Klavarskribo?
+
+ * dynamic loading of engravers?
+
+SMOBS:
+
+****************************************
+Han-Wen Nienhuys <hanwen@cs.uu.nl> writes:
+
+> mcmanus@IDT.NET writes:
+> > > I want different C++ objects (with scheme embedded) to be linked by
+> > > C++ pointers. I want to access these other objects from the Scheme
+> > > code, and I want access to these pointers from C++.
+> >
+> > You can do this with a combination of smob's and primitive functions,
+> > though it may not be be exactly what you wanted. You would have one
+> > smob for each class in your application, and then you would write a
+> > primitive function that would return the objects that are linked to a
+> > base object.
+>
+> And the smob and the C++ class are interlinked? Like
+>
+> class Foo_class {
+> Foo_smob *smob_ptr_;
+> }
+>
+> struct Foo_smob {
+> Foo_class *class_ptr_
+> }
+
+Usually you can get away without having this interlinked structure.
+One piece of information you need when exporting objects to scheme is
+the smob tag for your class. You might store this value (a long) into
+a class static variable, or a file static variable. I'll use a class
+static variable in this example.
+
+I typically use code that works like this (untested code ahead):
+
+class Foo_class {
+ static long *Foo_smob_tag;
+ SCM obj; // representation as a scheme object, description comes later
+}
+
+// call this once on startup
+void init_Foo_class {
+ static scm_smobfuns type_rec;
+
+ type_rec.mark = foo_mark;
+ type_rec.free = foo_free;
+ type_rec.print = foo_display;
+ type_rec.equalp = 0;
+ Foo_class::Foo_smob_tag = new int(scm_new_smob(type_rec));
+}
+
+When you want to export an object to scheme, you put a pointer to the
+object itself in the cdr of the cell, and the tag in the car of the
+cell. The code looks like this:
+
+// Is this a Foo?
+static int
+foo_p(SCM obj)
+{
+ return(SCM_NIMP(obj) && SCM_CAR(obj) == Foo_class::Foo_smob_tag);
+}
+
+// given a Scheme representation, return, a C++ representation
+static Foo_class *
+foo_unbox(SCM obj)
+{
+ return((Foo_class*)SCM_CDR(obj));
+}
+
+// the SCM representation of the object is stored inside itself
+// this will become useful when destructor gets called
+static SCM
+foo_box(Foo_class *foo)
+{
+ SCM_DEFER_INTS;
+ SCM_NEWCELL(foo->obj);
+ SCM_SETCAR(foo->obj, Foo_class::Foo_smob_tag);
+ SCM_SETCDR(foo->obj, (SCM)foo);
+ SCM_ALLOW_INTS;
+ return foo->obj;
+}
+
+> C++ determines life time, so what is the strategy?
+
+What happens now when the destructor gets called? Lets set the cdr to
+NULL, and then check for that in all of the primitive functions that
+use your smob. We'll call this notion 'live'; a scheme object is
+'live' if the C++ representation still exists, it's dead if the C++
+object is gone. You can still have references to dead objects in
+scheme code; it's just an error to use them. This idea is stolen from
+Emacs's handling of buffers ('buffer-live-p' and friends).
+
+Add another function, foo_live_p:
+
+static int
+foo_live_p(SCM obj)
+{
+ return(foo_p(obj) && SCM_CDR(obj) != NULL);
+}
+
+In you destructor, you need to do:
+
+~Foo_class()
+{
+ SCM_CDR(this->obj, NULL);
+}
+
+When writing new primitives, now just check foo_live_p().
+
+I hope the above helps,
+
+-russ
+
+
+--
+"Even if you are on the right track, you'll get run over
+if you just sit there."
+ --Will Rogers (1879-1935)
+
+***************************
projects / lilypond.git / blobdiff