Most of the items are marked in the code as well
Grep for TODO and ugh/ugr/urg.
-.* BUGS
-. * junk separate mudela versioning.
-. * PostScript
-. * header for PS enteredby = "bla <bla@bar.com>"
-. * ps/lily.ps see comments.
-. * down tuplet spanner.
-. * didot / big point.
-. * devise standard for functioning of Vertical_align_element.
-. * midi key.
-. * Repeats
-. * input/bugs/rep.ly (moved from test)
-. * unfold broken:
-. * without alternatives: repeat unfold 4 { a b c d }
-. * count > alternatives: repeat unfold 79 { a b c d }
-\alternative { { c c c c } { d d d d } }
-. * kind of 'initial property' iso fold/volta(semi)/unfold strings
-. * fix singleStaffBracket
-. * declare performers in \midi
-. * fix MIDI
-. * \shape 1st dim skipped?
-. * turn slope-damping on/off
-. * tremolo stuff
-. * We need feta-din*.mf files for more sizes than 10.
-. * fix dynamics decently, ie. use kerning & ligatures.
-. * dots & rest collisions?
-. * mudela-book.py
-. * fix \mudelafile{} to have decent functionality
-. * P.P.S. It can be cool in mudela-book to distinguish in
-pre,postMudelaExample, whether MudelaExample is epsed or not: ( if
-this fragment is floating eps, than 1, otherwise 2). say
-preMudelaExample[eps]{}, and change it in document body sometimes.
-. * use less RE's
-. * slurs colllide with lyrics.
-. * Is there any reasonable way to do this: I would like to have one file
-that can generate the same tune in two different modes without having
-to go through and rewrite all the music in the other mode.
-
-Long lyrics don't get a space at the end. They just run right up
-against the next lyric. (I don't think this used to be the case.)
-
-Lyrics and scripts collide.
-
-\key b; \time 4/4; looks bad. The clef and time signature are too close.
-
-restStyle=mensural doesn't seem to work (lots of characters not found
-for rests.fly)
-. * Phrasing: Indicating the textual underlay of a piece, or
-otherwise dividing a piece into phrases.
-
-There are distinct ways of specifying the first two (although at
-present, they're not properly distinguished) but no distinct way to
-specify the third. Should there be?
-. * rest collision minimum dist.
-. * a note with a circle after it, meaning:
-
- note + circle = note + 1/4 of its length
-
- the circle is like a dot that's not filled in. for example, on
- page three, the c-sharp on the second line should be a quarter with
- a circle, not a quarter tied to a sixteenth. is this at all
- possible with lily?
-. * tuplets that are written as "number : note", for example
- "3 : [image of a half note here]". possible?
-. * repeat engraver, gallina.ly
-
-. * Matanya's tips:
-. * spacing for prefatory matter
-. * accidentals closer to note head
-. * to space the staffs/staffgroups contained in the score.
-
-In the orchestscore.ly file, I tried:
-\paper{
- \translator {
- \OrchestralScoreContext
- minVerticalAlign = 3.0*\staffheight;
- }
- \translator {
- \StaffGroupContext
- minVerticalAlign = 3.0*\staffheight;
- }
- \translator {
- \StaffContext
- minVerticalAlign = 3.0*\staffheight;
- }
-}
-. * heavier beams?
-
-.* Cleanups needed
-. * Beam
-. * Stem
-. * Slur
-. * Rhythmic_grouping
-. * Duration
-. * Collision
-. * Rest_collision
-. * clef grav prop's
-. * parser
-
.* TODO before 1.2
-. * Morally pure LilyPond.
-. * Remove mutopia ramblings.
-. * Remove non-free software links.
-. * Remove meta article LilyPond.
-. * break priority setting from SCM.
-. * Gade score
-. * remove [] in favour of auto-beamer
+. * rename 'staff_line_leading' (who is being lead where?) to
+staff_space, interline; (or other meaningful name) and use throughout
+lily
+
+[-> leading are the lead strips between the sticks (lines) of
+typeface. ie. leading is vertical space --hwn]
+. * Rewrite \rhythm to be during interpreting.
+. * move \version check to lexer.ll
+. * junk delayed spanner breaking.
+. * core dump on broken (de)crescendo
+. * align left edge of broken (de)cresc/slur/tie/tuplet/volta
+. * check dangling_scm_sym working.
+. * spacing of accidentals
+. * key restorations & repeats
+. *
+So how do I do what I want to do?
+
+In Caro Mio Ben, bar 8, there's a syllable that starts on a note, and
+ends on a pair of grace notes. Standard practice is to mark this with
+a slur starting on the main note and ending on the grace note, so a
+singer knows where to break the words.
+
+In bar 26, there's a \p marker that should appear below the grace
+note.
+
+In bar 27, there's a crescendo that's supposed to start at the start
+of the grace notes and extend to the note after the grace notes.
+
+How do I specify these?
+. * spanners from grace to normal ctxt
+. * Glen:
+
+5. Sometimes lyrics extend past the right end of the staff. I guess that
+this is a similar problem (if not another symptom of the same problem) as
+one of the spacing bugs mentioned in the TODO.
+. * 4. Lyrics and grace sections don't go too well together.
+ The words are aligned with the main note, not the start of the
+ grace note. This is usually wrong, but is sometimes right.
+. * Auto_beam debugging output (waarom/wanneer heb jij die weggehaald?)
+. * Rename illegal to invalid
+. * Mats:
+
+- The Postscript output is still very experimental
+
+- It is impossible to typeset two textual scripts that are stacked
+ on top of eachother and avoids note collisions and at the same
+ time are typeset with different textStyle. I tried to move around
+ the text_engraver and other engravers between Voice and Thread
+ but the granularity is not fine enough, the scripts have to
+ share the same engraver in order to be get correct vertical
+ position but than they cannot have different style.
+ In my opinion, all scripts that share the same staff, should
+ be stacked vertically, avoiding collisions with the notes
+ in all voices.
+
+- I'd like to change the \repetitions command to Jan's suggested
+ syntax: \repeat "repeatsymbol" 2 {...}, but I'm not sure that
+ I understand the implementation of repeats well enough.
+
+- The paper11/13/26 files have to be updated.
+. * Grace_slur_engraver.
+. * input/star-spangled-banner.ly: fold for lyrics?
+. * don't create $srcdir/share/
+. * Break_req handling is silly (break_forbid () + \break fucks up.)
. * hangOnClef with non-breakable clefs.
-. * Aha, the problem is the new TeX code generation for changing fonts.
-> (The explanation below is mostly intended for Han-Wen and Jan)
-> Before, the font was changed with macros declared separately for
-> pure TeX and LaTeX, but now all the fonts are declared directly in
-> the generated code using the low-level TeX commands. This circumvents
-> the fontencoding mechanism of LaTeX and is a potential source of
-> problems also for us users of the Latin-1 character set.
-> I think it still works since the inputencoding latin1 is
-> declared by ly2dvi, but it still means that e.g. an o with
-> umlaut is typeset as a combination of the two symbols 'o' and
-> 'umlaut' instead of as a single character, as would be the case
-> if fontencoding OT1 had been used. This shouldn't give any
-> difference in layout, though. One of the main argument for using
-> fontencoding OT1 is for the hyphenation mechanism to work, an
-> argument that's clearly irrelevant in our application. Yet we
-> see the problem for August.
-. * Abstraction for engravers:
-. * make "in-between" engraver (Tie, Extender)
-. * make wide_spanner_engraver (line_group_spanne,r staff_symbol)
-. * remove Interval dim_ from Dimension_cache and rename the struct.
-. * do scaled fonts generally
-. * Spacing.
-. * The Lilypond accidental symbols are available through the TeX macros,
-\textflat, \textsharp and \textnatural defined in the init file
-lilyponddefs.tex. All the symbols are defined in the files fetaXX.tex
-where XX corresponds to the size. I don't know where (or even if) they
-are installed but they are generated in the mf/out/ directory during the
-compilation.
-. * make dependencies () a virtual function.
-. * one big ly2dvi input that includes *all* tests.
-. * store req -> element, element -> element causes for warnings
-. * include examples in RPM.
+. * account for accidentals in spacing.
+. * collision of lyrics with span_bars. See star-spangled.
. * fix partial measures in meaningful way.
-. * add scripts to bars eg. |^"bla"
-. * relative mode for mi2mu
+. * relative mode for midi2ly
+. *
+Crescendi/diminuendi that cross a line break lose their vertical
+position and all end up above the top staff line, see the
+following example.
+
+----------------
+\score{
+ \context StaffGroup <
+ \context Staff=s1 \notes\relative c'{
+ c d e f |
+ g f e d | \break %% If this break is removed, it works fine
+ c d e f |}
+ \context Staff=s2 \notes\relative c'{
+ c \< d e f |
+ g f e d |
+ c d e \! f |}
+ >
+}
. * uniformise recent feta contributions.
-. * use SCM and Molecules for {accordeon stuff, }
. * bigger and fatter 4/4 C
. * sort out directory stuff.
. * --prefix option?
. * do --safe for PS output?
. * convert-mudela --output
. * Staff_margin (with a partial measure.)
-. * fix pletvisibility properties:
-. * bracket on/off/no-bracket-when-beam
-. * num on/off/no-num-when-beam
-. * fix: standchen.
-. * junk text{sharp,flat,etc}
. * fix convert-mudela manpage
. * decimal point in \paper {}
-. * { \voiceone <a'4.*2/3 d''4.*2/3 fis''4.*2/3> [g''8 fis'' e''] d''4 |}
- and
- { \voicetwo d'4 d'2.*2/3 } spacing
-. * tied notes for MIDI
-. * sharp / flat on trills (in MIDI ??)
-. * scm-ify \property values.
-. * move class Lookup {} into scm
. * msgfmt -o check?
-. * \breathmark TeX macro
. * add new glyphs to font.ly
. * formatting of input stuff.
-. * \notes{ a \< b \cr } vs \notes{ a \< b \! }
-. * space after bars?
-. * 'hinterfleisch' before bar (e.g. wtk1-fugue2)?
-. * Summary of minor spelling irregularities:
-. * capitalization/use of underscores in property names
-. * fix SkipBars -> skipBars
-. * 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
- portato= \script { "portato" 0 -1 0 1 0 }
-. * ly2dvi
-. * bottomnote for ly2dvi
. * deps for ly2dvi
+. * indent = 0.0 with linewidth=-1.0
+. * collisions & accidentals.
+. * music ending in grace notes.
+. * PostScript
+. * half notes in pfa
+. * didot / big point.
+. * \shape 1st dim skipped?
+. * turn slope-damping on/off
+. * We need feta-din*.mf files for more sizes than 10.
+. * fix dynamics decently, ie. use kerning & ligatures.
+. * behavior of "that the obvious solution
+\lyrics { foo1*4 __ _ }" is unintuitive.
+. * Lyrics and scripts collide.
+. * filenames : junk lily.x
+
+.* Cleanups needed
+. * \$ and $ identifier syntax in examples.
+. * Junk ghost positioning objects eg, Script leans on Staffside
+ leans on Staff.
+
+. * bracket ps code.
+. * Key_engraver, Local_key_item
+. * Think of comprehensive solution for "if (grace_b == self_grace_b_)"
+. * Y dimension units: staffspace vs. Point
+. * Beam
+. * Stem
+. * Rhythmic_column and interaction stem/rhythmic_column/note_head/dots.
+. * Duration
+. * clef engraver
+. * parser
+. * Bezier
+
+.* BUGS
+. * [c8. c16 c16 c16] in 6/8 timesig.
.* STUFF
+. * break priority setting from SCM.
+. * Matanya's tips:
+. * don't shorten stems/staffs closer to each other.
+. * accidentals closer to note head
+. * to space the staffs/staffgroups contained in the score.
+. * heavier beams?
+
+. * tuplets that are written as "number : note", for example
+ "3 : [image of a half note here]". possible?
+. * a note with a circle after it, meaning:
+
+ note + circle = note + 1/4 of its length
+
+ the circle is like a dot that's not filled in. for example, on
+ page three, the c-sharp on the second line should be a quarter with
+ a circle, not a quarter tied to a sixteenth. is this at all
+ possible with lily?
+. * scm-ify \property values.
+. * make dependencies () a virtual function.
+. * Abstraction for engravers:
+. * make "in-between" engraver (Tie, Extender)
+. * make wide_spanner_engraver (line_group_spanner, staff_symbol)
+. * store req -> element, element -> element causes for warnings
. * compulsory hshift
+. *
+My wish list for lyrics. I dream of a time when I will have enough time to
+become familiar enough with the source code to be able to implement some of
+these myself, but I don't know when that will be, so I thought I'd "publish"
+my suggestions in case someone else is in a position to give them some
+priority. Otherwise, perhaps they could go on the todo list?
+
+If any of these are already implemented, please let me what the syntax is to
+use them!
+
+1. Stanza numbering. Numbering at the beginning of a song with the number
+set to the left of the first note. It would also be nice (but not as
+important) to be able to have some form of automatic numbering at the
+beginning of each new line. This would make it easier to follow songs with a
+large number of stanzas.
+
+3. Notes centred above/below lyrics rather than left-aligned.
+
+4. It would be very nice to be able to build some kind of phrasing into the
+lyrics of hymns, etc, so that the first words of a phrase are left aligned
+with each other, the last words are right aligned, and the words in between
+are centred.
+
+5. In a song, with (say) four stanzas and a chorus, it would be nice to be
+able to vertically align the chorus midway between the staves.
+
+6. It would be nice to be able to put vertical brackets either side of a
+repeated section with different words for each repeat.
+
. * Give # lines in linebreaking.
. * arrows on slurs.
. * rewrite context defs using Scheme
. * strip EXEs before installing
. * zip target for binary windows dist (JBR)
. * junking \skip req in lyrics
-. * mi2mu empty staffs.
+. * midi2ly empty staffs.
. * use Fourier transformation for rhythmic quantisation.
. * horizontal centering of dynamics
. * $DEPENDENCIES_OUTPUT support
-. * Xdvi zooming ?! Try to understand GS garbage collection.
-gs: Error: /undefined in draw_beam
-gs: Operand stack:
. * fix vertical alignment and stafflines
. * declaring Performers
. * *.yo: fix pod manpage layout legacy
* { a4 a16 } c <-- duration of c?
* < a4 b8 > c <-- duration of c?
. * \tempo 4. = 90;
-. * fix audio-items (don't use (input) requests, but copy data)
. * make sure all ex's have a mudela-version
. * do rest-collisions for Multi_measure_rests as well.
. * split error/warning in error/warning/non_fatal_error
. * add full cello suites to web site (kom op, Maarten!)
. * add mudela-book-doc source to webstie.
. * Rethink Time_description
-\cadenza , \meter, \grouping should all be \properties
+\cadenza , \meter, should all be \properties
+. * fix singleStaffBracket
. * rename
-. * measure -> bar
-. * abbrev -> tremolo
. * abbreviation-beam -> (measured/unmeasured) tremolo
. * partial -> anacrouse
-. * robustify Beam (in case of no stems, 32nd notes)
. * move paper vars into engraver properties
. * check for groff / troff/ nroff et
. * more intelligent file searching
. * disable spaces in TeX stuff
. * handle ^C for tmp/file creation.
. * make LilyPond RPM fully relocatable
-. * dots & rest collisions.
-. * the warning about the negative slur/tie length appears twice
-which is irritating.
. * better hshift (dots, distance, head dependent)
. * clefs (AG): The "8" should appear closer to the actual clef,
touching it.
. * put errorlevel in Input class
. * junk nesting slurs
-. * integrate midi-elts from mi2mu and lily?
. * distinguish between unset and empty properties.
.* FONT
small sizes.
.* 3RD PARTY BUGS
+. * UMR: Uninitialized memory read
+ This is occurring while in:
+ qst [qsort.c]
+ qsort [libc.so.1]
+ Keyword_table::Keyword_table(Keyword_ent*) [keyword.cc:28]
+ My_lily_lexer::My_lily_lexer() [my-lily-lexer.cc:78]
+ My_lily_parser::parse_file(String,String) [my-lily-parser.cc:54]
+ do_one_file(String,String) [scores.cc:124]
+ Reading 4 bytes from 0xefffeca8 on the stack.
+ Address 0xefffeca8 is 728 bytes below frame pointer in function
. * GNU diff 2.7: diff -rN does not see a new directory with empty file
+. * patch: don't touch timestamp if all patches fail.
+. * mf-to-table -> add space before ; in AFM output. (-> check AFM
+ spec. Is this a bug in afm2tfm?)
. * check out GCC signatures?
. * glibc 2.0:
f = fopen ("/dev/null", "r")
assert (feof (f))
. * tetex: mfplain.mem
-.* 3RD PARTY PROJECTS:
-. * make GCC warn about ctor that leaves member vars uninitialised.
-. * 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
+. * timesig: sometimes bottom digit too high: Xdvi doesn't handle
+ newly created fonts correctly.
+
.* PROJECTS
. * Scripts:
. * stack scripts in chords:
. * 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.
+. * internationalisation for input.
+. * Unicode support? -> man 7 unicode
+. * (The explanation below is mostly intended for Han-Wen and Jan)
+> Before, the font was changed with macros declared separately for
+> pure TeX and LaTeX, but now all the fonts are declared directly in
+> the generated code using the low-level TeX commands. This circumvents
+> the fontencoding mechanism of LaTeX and is a potential source of
+> problems also for us users of the Latin-1 character set.
+> I think it still works since the inputencoding latin1 is
+> declared by ly2dvi, but it still means that e.g. an o with
+> umlaut is typeset as a combination of the two symbols 'o' and
+> 'umlaut' instead of as a single character, as would be the case
+> if fontencoding OT1 had been used. This shouldn't give any
+> difference in layout, though. One of the main argument for using
+> fontencoding OT1 is for the hyphenation mechanism to work, an
+> argument that's clearly irrelevant in our application. Yet we
+> see the problem for August.
. * \header
. * output header info to MIDI too.
. * Debug logs:
. * derive lily_stream, Dstream, texstream from ostream?
. * indentable stream as baseclass for TeX stream, lily stream, Dstream.
-. * use dstream feature in mi2mu
+. * use dstream feature in midi2ly
. * integrate IO checking into stream class
. * input converters
. * SMDL?
. * add to MIDI output:
+. * sharp / flat on trills (in MIDI ??)
. * tempo change
. * ornaments (and trills?)
. * slurs
> Would it be hard to add support for proper dynamics in MIDI output? I
> would really like to have this feature...
-To answer this, I have to give a little background. Please say so if
-I am being obtuse.
-
-Both audio and notation elements are created decentrally, when
-LilyPond says "Interpreting music ... [8][16] etc." After all
-elements are created, they are processed again to calculate all
-parameters. After that is done, they are dumped onto the output (the
-MIDI stream or the TeX file).
-
-The audio and notation elements are created by objects called
-performer and engraver respectively. They work by taking a chunk of
-input (a so-called request), and using the request to create an audio
-or notation element.
-
-After some processing, the engraver sends the created elements to
-its enclosing notation/performance context.
-
-In the case of notation, engravers can also modify existing elements
-created by sibling engravers. Eg. the beam-engraver will modify stems
-when it creates a beam over a couple of stems. This is done in
-Engraver::do_acknowledge_element () and
-Engraver::do_process_acknowledged ().
-
-In the case of audio, there are no mechanisms to modify existing audio
-elements. After the audio elements are created, they are sent directly
-to the enclosing context (an instance of Performer_group_performer),
-through the method Performer::play ()
-
Concretely spoken, for dynamics you have to write a performer
(Dynamics_performer), that will take the input requests. If I
understand correctly, every MIDI note played must have its dynamic
1 supporting dynamic settings in Audio_note
- 2 mimicking the broadcast/acknowledge mechanism of the Engravers in
- the Performers
-
- 3 using that mechanism to write a Dynamics_performer that will modify
+ 2 Write a Dynamics_performer that will modify
any notes it finds to set appropriate strengths.
-You could also kludge this by deriving from Performer_group_performer
-a performer that also sets dynamics within notes, but that is not the
-elegant way to do it.
-
I'd say that the work involved is not hard, but you have to be fluent
with C++ and need some insight into the working of Notation Contexts
and friends. I guess I could do it in a day or so, but if you are not
the MIDI output (I don't even have a soundcard). But I *do* want to help
you or other people with implementing this, so if you need help, don't
hesitate to ask.
-
. * account for rhythmic position in measure
. * etc.
-. * grace notes
-. * make separate class for Grace_*_engravers
- (which is at Voice_gravs level)
-. * make encapsulated spacing problems.
-
-. * accidentals per Voice_group
. * Output class, handles : (smallish)
. * help text /(c) notice?
. * Glissando
. * trill
-. * Rewrite Stem, Beam and Rhythmic_grouping (hairy)
-. * [c8. c32 c32]
-. * doc on Rhythmic_grouping
+. * Rewrite Stem, Beam (hairy)
. * general shaving on Beam and Stem
. * use plet grouping
-. * separate visual from rhythmic info even more
. * beams over bars
. * lines:
. * specify number of lines
.* INPUTLANGUAGE
-. * \rhythms 4 16 16 16 16; c c c c c -> c4 c16 etc.
+. * convention for slurs vs. phrasing marks.
. * Language:
. * \translator -> ?
. * fix \partial
. * \bla {} vs \bla ;
. * mix engraver hacking with music ?
. * \once\property KEY = VAL
-. * \addtranslator, \removetranslator
-. * junk ^ and _ for scripts
-. * junk _ for lyrics.
+. * input property
. * abstract grammar.
. * Figure out semicolons.
-. * c4 4 4 4 for c4 c4 c4 c4?
. * <c f a>4 ?
. * Viola mode?
.* SMALLISH PROJECTS
-. * Faulenzer sign (% repeat). Perhaps also use \repeat syntax?
-
. * fix confusing naming in Engraver vs Engraver_group_engraver (context)
-. * progress when creating MIDI elts.
-
. * A range for context errors (eg. mark both { and }. )
. * lyric in staff (sharpsharp in staff, text below)
-. * half sharps/flats
-
. * write Dynamic_line (to group dynamics horizontally)
. * use Real for all y positions.
. * midi esp.: use I32 iso int where 32 bits are needed (or assumed...)
-. * stafftypes: voice names/ instrument names.
-
. * lily \tempo
. * % toe to bheel four to five
(where "to" is a tiny bow)
. * auxilliary file for caching info.
-
. * Text_crescendo
-. * revise calcideal
-
.* IDEAS
. * Output data structures of Mudela in XML/SGML.
. * create libmudela, or liblily_frontend
. * Spacing_request for manually adjusting spacing
. * caching breakpoints
. * used fixedpoint arithmetic for min. energy.
-. * move towards incremental algorithms.
-. * versioning stuff (cvt mudela, mudela, etc.)
-. * dynamic loading of engravers?
-.* SMOBS
-Han-Wen Nienhuys <hanwen@cs.uu.nl> writes:
-
-> 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,
-
* OUTLINE SETUP
.* .EMACS
(require 'allout)
(outline-init 't)
+