-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
- * scales.ly
+ * *.yo: fix pod manpage layout legacy
- * standchen triool beam up/down
-
- * (where are the) gcc compile warnings on linux
-
-SEVERELY LACKING:
+ * text-items clash with stems/beams
- * SPEED!
+ * --include, -I option for ly2dvi (pass on to lily)
- * grace notes
+ * fix placement of beam-less abbrev
+ * \meter 3/4;
+ <{\voiceone cis4. cis8 cis4 | cis4 cis cis | r1 }
+ {\voicetwo cis,4 r r | r2. | r1 }> |
+ }
-FURTHER FOR ORCHESTRAL SCORE:
+ * try to use template<Type> iso MACRO(Type)
- * multibar rests
+ - 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?
- * barnumbers, markers
+ * \tempo 4. = 90;
- * abbreviations c4=16
+ * fix audio-items (don't use (input) requests, but copy data)
-INPUTLANGUAGE
+ * junk My_lily_parser::abbrev_beam_type_i_
- * c4 4 4 4 for c4 c4 c4 c4?
+ * make sure all ex's have a mudela-version
- * neatly (and readably) expressing concurrent
- voices
+ * do rest-collisions for Multi_measure_rests as well.
- * <c f a>4 ?
+ * split error/warning in error/warning/non_fatal_error
- * should have \require{package.ly} to read req'd packages.
+ * add a Duration_convert member to Duration_iter to set parameters.
+ Junk global duration settings.
+
+ * deps for ly2dvi
- * Viola mode?
+ * clean up abbrev/plet/beam/abbrevbeam/duration mess in parser.
- @c c g e g
- for
- c g es g,
+ * minimum length second part broken tie
+
+ * en-,discouraged linebreaking:
+ - handle DISALLOW < penalty > FORCE
+ - discourage breaking of slurs
- @A c g e g
- for
- cis gis e gis
+ * multibar rest
+ - symbol(s)
- * relative mode for pitch entering
+ * fix variable define/lookup parser global<->paper
- * bracket (bracketplets)
+ * fix title/instrument placements; see input/test/title.ly
- * \duration 8; e*2/3
+ * <\voiceone c4. \voicetwo c4>
- * configure pitch_byte
+ * add full cello suites to web site (kom op, Maarten!)
- * figured bass?
+ * Rethink Time_description
+ * \cadenza , \meter, \grouping should all be \properties
- * rest name configurable
+ * rename
+ - measure -> bar
+ - abbrev -> tremolo
+ - abbreviation-beam -> (measured/unmeasured) tremolo
+ - partial -> anacrouse
- * Raw request syntax
+ * shared lib
- * subtime with Subtle_reqs
+ * robustify Beam (in case of no stems, 32nd notes)
-PROJECTS
+ * decentralised spring factory
- * Do RTTI i.s.o. static_name(), name() and request-junk.
+ * move paper vars into engraver properties
-SMALLISH PROJECTS
+ * check for groff / troff/ nroff et
- * A range for context errors (eg. mark both { and }. )
+ * more intelligent file searching
+ - make LilyPond RPM fully relocatable
- * text in staff (sharpsharp in staff, text below)
+ * nicen examples:
+ - break-up heavily-nested score blocks
- * fix Egler definitions ( see tex/eglerdefs.tex )
+ * disable spaces in TeX stuff
+
+ * handle ^C for tmp/file creation.
- * replace Score_elem member access by get()/set() methods, to enable
- future embedded code.
+
+ * dots & rest collisions.
- * --fast/--draft: leave out constraints
+ * documentation
+ - introduction?
+ - info?
+ - LaTeX?
+ - more manpages?
- * write Dynamic_line (to group dynamics horizontally)
+ * versioning for Feta
- * write Rest_collision
+ * the warning about the negative slur/tie length appears twice
+ which is irritating.
- * use Real for y positions.
+ * The `3' in the meter key is a one or two pixels too thin (at 600dpi)
+ in the middle:
- * shared lib on Solaris too.
+ * the bracket is ugly (wings are too parabolic, should be more circular)
- * bugreport to doc++ devel: struct not in class hier; public
- virtual baseclasses
+ * better hshift (dots, distance, head dependent)
- * get rid of init_end;
+ * clefs (AG): The "8" should appear closer to the actual clef,
+ touching it.
- * cleanup lily-proto.hh and proto.hh
+ * put errorlevel in Input class
- * half-sharps, half-flats
+ * junk nesting slurs
- * adaptive accidental spacing.
+ * integrate midi-elts from mi2mu and lily?
- * unix style paths for LILYINCLUDE env
+ * 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...
- * indentable stream as baseclass for TeX stream, lily stream, Dstream.
- * handle EOF graciously in error messages.
+3RD PARTY BUGS:
- * caching Item/spanner dimensions.
+ * make GCC warn about ctor that leaves member vars uninitialised.
- * centered whole rest
+ * redhat (v?) graphical install bomb-out?
- * caching breakpoints / saving them.
+ * GNU diff 2.7: diff -rN does not see a new directory with empty file
- * use dstream feature in mi2mu
+ * 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.
- * qtor, btor, mtor-> tor( QUIET_ver ), tor( DEBUG_ver ), etc.
- - use tors feature in lily (?)
+ * glibc 2.0:
- * declare symtab
+ f = fopen ("/dev/null", "r")
+ assert (feof (f))
- * declare notenametab?
+3RD PARTY PROJECTS:
- * midi esp.: use I32 iso int where 32 bits are needed (or assumed...)
+ * GNU indent: handle C++
- * parshape
+ * 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
- * read from mmap directly: bugreport to flex developers->
- yy_scan_buffer in C++..
+PROJECTS
- * binsearch/hash for identifiers
+ * 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.
- * stafftypes: voice names/ instrument names.
+ * grace notes
+ - make separate class for Grace_*_engravers
+ (which is at Voice_gravs level)
+ - make encapsulated spacing problems.
- * Decent TeX titledefs (\tempo, \metron, etc. )
+ * accidentals per Voice_group
- * C meter iso 4/4, idem for alla breve, etc.
+ * 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
- * textspanner: center position
+ * piano staff
- * script-spacing
+ * elaborate Staff_side baseclass:
+ - scripts
+ - text
+ - slur start/end
- * Brackets
+ * PS
+ - speed up PS code.
+ - PS lines to .eps files
+ - write custom prolog
-
- * use (char *) iso. String for communication between lexer and
- parser.
- * configure idealspacing: arithmetic spacing
+ * Output an output format independent (ofi) typeset file; and
+ make ofi2 TeX, MusiXTex, Display PostScript, PostScript,
+ Ascii... interpreters. (difficult)
- * LilyPond .deb. Other packaging methods?
+ - NIFF ?
+ - Common Music Notation
+ - PostScript output (esp. Beams, Slurs, etc)
+ - Move all Score_elems, into libmutype.a
+ - SGML
- * detect -pipe
+ * Documentation
+ - Doc (C) stuff of sheet music
+ - a better format? SGML? TeX? Info?
+ - a better tutorial
-DOC
- * Score_elem structure.
+ * more spanners (smallish)
+ - Glissando
+ - trill
- * all errors
-
- * config of TeX macros
+ * 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
- * a test suite
+ * 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)
- * hacking-HOWTO
+ * Collisions
+ - left/right note balls should be handled by Collision:
+ < \multi 2; { \stem 1; <b c> } { <f as b> } >
-FUTURE
+ * Keys:
+ - merge key{item} & localkey{item}?
+ - spacing, national styles?
- * auxilliary file for caching info.
+ * Support for TAB
+ - redo Notehead to allow digits as heads
+ - add a \tablature {} lexer mode for easy entering
- * Reg_configure_request
+ * should adjust stemlength for flag number.
- * slur parts as a script
-
- * mixed fontsizes
+ * breaking:
+ - caching breakpoints
+ - saving them
+ - specify number of lines
- * put scripts on bars
+ * markers
- * guitar chord
+INPUTLANGUAGE
- * better beamslope calculation: QLP for beams?
+ * c4 4 4 4 for c4 c4 c4 c4?
- * Text_crescendo
+ * neatly (and readably) expressing concurrent
+ voices
- * clean solution for staffsize in items.
+ * <c f a>4 ?
- * revise calcideal
+ * Viola mode?
- * volta
+ @c c g e g
+ for
+ c g es g,
-IDEAS
- * check out CORBA for Score_elems?
+ @A c g e g
+ for
+ cis gis e gis
+
+ * relative mode for pitch entering
+
+ * configure pitch_byte
- * derive PCol from Score_elem? More in Score_elems? Spacing?
+ * rest name configurable
- * scoping in Lexer: do general id- assignments in mudela.
+SMALLISH PROJECTS
- ID '=' EXPR;
+ * limit memory usage; the full coriolan takes up too much resources.
- * create libmudela, or liblily_frontend
+ * fix confusing naming in Engraver vs Engraver_group_engraver (context)
- * move MIDI stuff (including Quantization) to a ANSI C libmidi library.
+ * progress when creating MIDI elts.
- * use an embedded language: Python
- for:
- - Score_elems
- - Registers
- - Complex mudela?
+ * A range for context errors (eg. mark both { and }. )
- * y -dims in internote?
+ * lyric in staff (sharpsharp in staff, text below)
- * merge Atom and Symbol?
+ * half sharps/flats
- * merge common code of Item, Atom/Molecule
+ * write Dynamic_line (to group dynamics horizontally)
- * Spacing_request for manually adjusting spacing
+ * use Real for all y positions.
+ - use translate_axis( .. ,Y_AXIS) iso separate variables.
-
- * caching breakpoints
+ * half-sharps, half-flats
+
+ * adaptive accidental spacing.
- * #c <-> cis
+ * handle EOF graciously in error messages.
- * breath marks
+ * centered whole rest
- * used fixedpoint arithmetic for min. energy.
+ * declare notenametab?
- * default convert mudela-file.ly -> mudela-file.tex
- - rename {standchen,scsii-menuetto,...}.tex
+ * midi esp.: use I32 iso int where 32 bits are needed (or assumed...)
- * stack scripts in chords:
- % fingering: footing:
- < a-4 c-2 g-1 > < c-\ltoe e-\lheel >
+ * Flower types:
+ - A decent scalar type
+
+ * stafftypes: voice names/ instrument names.
- * parameterised scripts for fingering and footing:
+ * lily \tempo
- % toe to bheel four to five
+ * 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