Change space to basic-distance in spacing alists.

[lilypond.git] / scm / define-grob-properties.scm

diff --git a/scm/define-grob-properties.scm b/scm/define-grob-properties.scm
index 2816cb6fa8b19cc083918de4da0b2838822c0cfc..497f8f08af0798485d535eca88a5201735cbe39d 100644 (file)
--- a/scm/define-grob-properties.scm
+++ b/scm/define-grob-properties.scm
@@ -1,9 +1,20 @@
-;;;; define-grob-properties.scm -- part of generated backend documentation
+;;;; This file is part of LilyPond, the GNU music typesetter.

 ;;;;
 ;;;;

-;;;;  source file of the GNU LilyPond music typesetter
-;;;;
-;;;; (c) 1998--2009  Han-Wen Nienhuys <hanwen@xs4all.nl>
+;;;; Copyright (C) 1998--2010  Han-Wen Nienhuys <hanwen@xs4all.nl>

 ;;;;                 Jan Nieuwenhuizen <janneke@gnu.org>
 ;;;;                 Jan Nieuwenhuizen <janneke@gnu.org>

+;;;;
+;;;; LilyPond is free software: you can redistribute it and/or modify
+;;;; it under the terms of the GNU General Public License as published by
+;;;; the Free Software Foundation, either version 3 of the License, or
+;;;; (at your option) any later version.
+;;;;
+;;;; LilyPond is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;;; GNU General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU General Public License
+;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.

 
 (define (define-grob-property symbol type? description)
   (if (not (equal? (object-property symbol 'backend-doc) #f))
 
 (define (define-grob-property symbol type? description)
   (if (not (equal? (object-property symbol 'backend-doc) #f))


@@ -95,10 +106,10 @@ beamlet, as a proportion of the distance between two adjacent stems.")
      (before-line-breaking ,boolean? "Dummy property, used to trigger
 a callback function.")
      (between-cols ,pair? "Where to attach a loose column to.")
      (before-line-breaking ,boolean? "Dummy property, used to trigger
 a callback function.")
      (between-cols ,pair? "Where to attach a loose column to.")

-     (bound-padding ,number? "The amount of padding to insert around
-spanner bounds.")

      (bound-details ,list? "An alist of properties for determining
 attachments of spanners to edges.")
      (bound-details ,list? "An alist of properties for determining
 attachments of spanners to edges.")

+     (bound-padding ,number? "The amount of padding to insert around
+spanner bounds.")

      (bracket-flare ,number-pair? "A pair of numbers specifying how
 much edges of brackets should slant outward.  Value @code{0.0} means
 straight edges.")
      (bracket-flare ,number-pair? "A pair of numbers specifying how
 much edges of brackets should slant outward.  Value @code{0.0} means
 straight edges.")


@@ -114,12 +125,6 @@ center of the bar line.")
      (break-align-anchor-alignment ,number? "Read by
 @code{ly:break-aligned-interface::calc-extent-aligned-anchor} for
 aligning an anchor to a grob's extent.")
      (break-align-anchor-alignment ,number? "Read by
 @code{ly:break-aligned-interface::calc-extent-aligned-anchor} for
 aligning an anchor to a grob's extent.")

-     (break-align-symbol ,symbol? "This key is used for aligning and
-spacing breakable items.")
-     (break-align-symbols ,list? "A list of symbols that determine
-which break-aligned grobs to align this to.  If the grob selected by
-the first symbol in the list is invisible due to break-visibility, we
-will align to the next grob (and so on).")

      (break-align-orders ,vector? "Defines the order in which
 prefatory matter (clefs, key signatures) appears.  The format is a
 vector of length@tie{}3, where each element is one order for
      (break-align-orders ,vector? "Defines the order in which
 prefatory matter (clefs, key signatures) appears.  The format is a
 vector of length@tie{}3, where each element is one order for


@@ -137,6 +142,15 @@ For example, clefs are put after key signatures by setting
                     clef
                     time-signature))
 @end example")
                     clef
                     time-signature))
 @end example")

+     (break-align-symbol ,symbol? "This key is used for aligning and
+spacing breakable items.")
+     (break-align-symbols ,list? "A list of symbols that determine
+which break-aligned grobs to align this to.  If the grob selected by
+the first symbol in the list is invisible due to break-visibility, we
+will align to the next grob (and so on).  Choices are @code{left-edge},
+@code{ambitus}, @code{breathing-sign}, @code{clef}, @code{staff-bar},
+@code{key-cancellation}, @code{key-signature}, @code{time-signature},
+and @code{custos}.")

      (break-overshoot ,number-pair? "How much does a broken spanner
 stick out of its bounds?")
      (break-visibility ,vector? "A vector of 3@tie{}booleans,
      (break-overshoot ,number-pair? "How much does a broken spanner
 stick out of its bounds?")
      (break-visibility ,vector? "A vector of 3@tie{}booleans,


@@ -175,7 +189,7 @@ this should list the control points of a third-order B@'ezier curve.")
 ;; d
 ;;
      (damping ,number? "Amount of beam slope damping.")
 ;; d
 ;;
      (damping ,number? "Amount of beam slope damping.")

-     (dash-definition ,pair? "List of @code{dash-elements} defining the 
+     (dash-definition ,pair? "List of @code{dash-elements} defining the

 dash structure.  Each @code{dash-element} has a starting t value,
 an ending t-value, a @code{dash-fraction}, and a @code{dash-period}.")
      (dash-fraction ,number? "Size of the dashes, relative to
 dash structure.  Each @code{dash-element} has a starting t value,
 an ending t-value, a @code{dash-fraction}, and a @code{dash-period}.")
      (dash-fraction ,number? "Size of the dashes, relative to


@@ -185,11 +199,16 @@ an ending t-value, a @code{dash-fraction}, and a @code{dash-period}.")
 whitespace.  If negative, no line is drawn at all.")
      (default-direction ,ly:dir? "Direction determined by note head
 positions.")
 whitespace.  If negative, no line is drawn at all.")
      (default-direction ,ly:dir? "Direction determined by note head
 positions.")

+     (default-staff-staff-spacing ,list? "The settings to use for
+@code{staff-staff-spacing} when it is unset, for ungrouped staves
+and for grouped staves that do not have the relevant
+@code{StaffGrouper} property set (@code{staff-staff-spacing} or
+@code{staffgroup-staff-spacing}).")

      (details ,list? "Alist of parameters for detailed grob behavior.
      (details ,list? "Alist of parameters for detailed grob behavior.

-More information on the allowed parameters for a grob can be found by 
+More information on the allowed parameters for a grob can be found by

 looking at the top of the Internals Reference page for each interface
 having a @code{details} property.")
 looking at the top of the Internals Reference page for each interface
 having a @code{details} property.")

-     (digit-names ,vector "Names for string finger digits.")
+     (digit-names ,vector? "Names for string finger digits.")

      (direction ,ly:dir? "If @code{side-axis} is @code{0} (or
 @code{#X}), then this property determines whether the object is placed
 @code{#LEFT}, @code{#CENTER} or @code{#RIGHT} with respect to the
      (direction ,ly:dir? "If @code{side-axis} is @code{0} (or
 @code{#X}), then this property determines whether the object is placed
 @code{#LEFT}, @code{#CENTER} or @code{#RIGHT} with respect to the


@@ -220,10 +239,6 @@ the vertical edges: @code{(@var{left-height} . @var{right-height})}.")
 edges: @code{(@var{left-text} . @var{right-text})}.")
      (expand-limit ,integer? "Maximum number of measures expanded in
 church rests.")
 edges: @code{(@var{left-text} . @var{right-text})}.")
      (expand-limit ,integer? "Maximum number of measures expanded in
 church rests.")

-     (extra-X-extent ,number-pair? "A grob is enlarged in
-X@tie{}dimension by this much.")
-     (extra-Y-extent ,number-pair? "A grob is enlarged in
-Y@tie{}dimension by this much.")

      ;; remove me?
      (extra-dy ,number? "Slope glissandi this much extra.")
      (extra-offset ,number-pair? "A pair representing an offset.  This
      ;; remove me?
      (extra-dy ,number? "Slope glissandi this much extra.")
      (extra-offset ,number-pair? "A pair representing an offset.  This


@@ -241,6 +256,10 @@ problem, we pad each item by this amount (by adding the @q{car} on the
 left side of the item and adding the @q{cdr} on the right side of the
 item).  In order to make a grob take up no horizontal space at all,
 set this to @code{(+inf.0 . -inf.0)}.")
 left side of the item and adding the @q{cdr} on the right side of the
 item).  In order to make a grob take up no horizontal space at all,
 set this to @code{(+inf.0 . -inf.0)}.")

+     (extra-X-extent ,number-pair? "A grob is enlarged in
+X@tie{}dimension by this much.")
+     (extra-Y-extent ,number-pair? "A grob is enlarged in
+Y@tie{}dimension by this much.")

 
 
 ;;
 
 
 ;;


@@ -259,9 +278,9 @@ for standard flags, @code{'mensural} and @code{'no-flag}, which
 switches off the flag.")
      (font-encoding ,symbol? "The font encoding is the broadest
 category for selecting a font.  Currently, only lilypond's system
 switches off the flag.")
      (font-encoding ,symbol? "The font encoding is the broadest
 category for selecting a font.  Currently, only lilypond's system

-fonts (Emmentaler and Aybabtu) are using this property.  Available
-values are @code{fetaMusic} (Emmentaler), @code{fetaBraces} (Aybabtu),
-@code{fetaNumber} (Emmentaler), and @code{fetaDynamic} (Emmentaler).")
+fonts (Emmentaler) are using this property.  Available
+values are @code{fetaMusic} (Emmentaler), @code{fetaBraces},
+@code{fetaText} (Emmentaler).")

      (font-family ,symbol? "The font family is the broadest category
 for selecting text fonts.  Options include: @code{sans},
 @code{roman}.")
      (font-family ,symbol? "The font family is the broadest category
 for selecting text fonts.  Options include: @code{sans},
 @code{roman}.")


@@ -383,7 +402,9 @@ read from the NonMusicalPaperColumn that begins the measure.")
      (glyph ,string? "A string determining what @q{style} of glyph is
 typeset.  Valid choices depend on the function that is reading this
 property.")
      (glyph ,string? "A string determining what @q{style} of glyph is
 typeset.  Valid choices depend on the function that is reading this
 property.")

+     (glyph-name ,string? "The glyph name within the font.")

      (glyph-name-alist ,list? "An alist of key-string pairs.")
      (glyph-name-alist ,list? "An alist of key-string pairs.")

+     (graphical ,boolean? "Display in graphical (vs. text) form.")

      (grow-direction ,ly:dir? "Crescendo or decrescendo?")
 
 
      (grow-direction ,ly:dir? "Crescendo or decrescendo?")
 
 


@@ -452,9 +473,6 @@ slur quants to this position, and print the respective scores.")
 ;;
 ;; k
 ;;
 ;;
 ;; k
 ;;

-     (keep-fixed-while-stretching ,boolean? "A grob with this property
-set to true is fixed relative to the staff above it when systems are
-stretched.")

      (keep-inside-line ,boolean? "If set, this column cannot have
 objects sticking into the margin.")
      (kern ,ly:dimension? "Amount of extra white space to add.  For
      (keep-inside-line ,boolean? "If set, this column cannot have
 objects sticking into the margin.")
      (kern ,ly:dimension? "Amount of extra white space to add.  For


@@ -469,9 +487,11 @@ correction and @code{1} for full correction.")
 ;; l
 ;;
      (labels ,list? "List of labels (symbols) placed on a column.")
 ;; l
 ;;
      (labels ,list? "List of labels (symbols) placed on a column.")

-     (layer ,integer? "The output layer (a value between 0
-and@tie{}2): Layers define the order of printing objects.  Objects in
-lower layers are overprinted by objects in higher layers.")
+     (layer ,integer? "An integer which determines the order of printing
+objects.  Objects with the lowest value of layer are drawn first, then
+objects with progressively higher values are drawn, so objects with
+higher values overwrite objects with lower values.  By default most
+objects are assigned a layer value of 1.")

      (ledger-line-thickness ,number-pair? "The thickness of ledger
 lines.  It is the sum of 2@tie{}numbers: The first is the factor for
 line thickness, and the second for staff space.  Both contributions
      (ledger-line-thickness ,number-pair? "The thickness of ledger
 lines.  It is the sum of 2@tie{}numbers: The first is the factor for
 line thickness, and the second for staff space.  Both contributions


@@ -479,7 +499,7 @@ are added.")
      (left-bound-info ,list? "An alist of properties for determining
 attachments of spanners to edges.")
      (left-padding ,ly:dimension? "The amount of space that is put
      (left-bound-info ,list? "An alist of properties for determining
 attachments of spanners to edges.")
      (left-padding ,ly:dimension? "The amount of space that is put

-left to an object (e.g., a group of accidentals).")
+left to an object (e.g., a lyric extender).")

      (length ,ly:dimension? "User override for the stem length of
 unbeamed stems.")
      (length-fraction ,number? "Multiplier for lengths.  Used for
      (length ,ly:dimension? "User override for the stem length of
 unbeamed stems.")
      (length-fraction ,number? "Multiplier for lengths.  Used for


@@ -526,10 +546,6 @@ guitar notation.  The value of this setting is used by
 
 @code{merge-differently-headed} only applies to opposing stem
 directions (i.e., voice 1 &@tie{}2).")
 
 @code{merge-differently-headed} only applies to opposing stem
 directions (i.e., voice 1 &@tie{}2).")

-     (minimum-X-extent ,number-pair? "Minimum size of an object in
-X@tie{}dimension, measured in @code{staff-space} units.")
-     (minimum-Y-extent ,number-pair? "Minimum size of an object in
-Y@tie{}dimension, measured in @code{staff-space} units.")

      (minimum-distance ,ly:dimension? "Minimum distance between rest
 and notes or beam.")
      (minimum-length ,ly:dimension? "Try to make a spanner at least
      (minimum-distance ,ly:dimension? "Minimum distance between rest
 and notes or beam.")
      (minimum-length ,ly:dimension? "Try to make a spanner at least


@@ -541,6 +557,10 @@ noteheads.")
 as fraction of note head size.")
      (minimum-space ,ly:dimension? "Minimum distance that the victim
 should move (after padding).")
 as fraction of note head size.")
      (minimum-space ,ly:dimension? "Minimum distance that the victim
 should move (after padding).")

+     (minimum-X-extent ,number-pair? "Minimum size of an object in
+X@tie{}dimension, measured in @code{staff-space} units.")
+     (minimum-Y-extent ,number-pair? "Minimum size of an object in
+Y@tie{}dimension, measured in @code{staff-space} units.")

 
 
 ;;
 
 
 ;;


@@ -559,9 +579,36 @@ syllable following an extender).")
 object.")
      (no-stem-extend ,boolean? "If set, notes with ledger lines do not
 get stems extending to the middle staff line.")
 object.")
      (no-stem-extend ,boolean? "If set, notes with ledger lines do not
 get stems extending to the middle staff line.")

+     (non-break-align-symbols ,list? "A list of symbols that determine
+which NON-break-aligned interfaces to align this to.")

      (non-default ,boolean? "Set for manually specified clefs.")
      (non-musical ,boolean? "True if the grob belongs to a
 @code{NonMusicalPaperColumn}.")
      (non-default ,boolean? "Set for manually specified clefs.")
      (non-musical ,boolean? "True if the grob belongs to a
 @code{NonMusicalPaperColumn}.")

+     (nonstaff-nonstaff-spacing ,list? "The spacing alist
+controlling the distance between the current non-staff line and
+the next non-staff line in the direction of @code{staff-affinity},
+if both are on the same side of the related staff, and
+@code{staff-affinity} is either @code{UP} or @code{DOWN}.  See
+@code{staff-staff-spacing} for a description of the alist
+structure.")
+     (nonstaff-relatedstaff-spacing ,list? "The spacing alist
+controlling the distance between the current non-staff line and
+the nearest staff in the direction of @code{staff-affinity}, if
+there are no non-staff lines between the two, and
+@code{staff-affinity} is either @code{UP} or @code{DOWN}.  If
+@code{staff-affinity} is @code{CENTER}, then
+@code{nonstaff-relatedstaff-spacing} is used for the nearest
+staves on @emph{both} sides, even if other non-staff lines appear
+between the current one and either of the staves.  See
+@code{staff-staff-spacing} for a description of the alist
+structure.")
+     (nonstaff-unrelatedstaff-spacing ,list? "The spacing alist
+controlling the distance between the current non-staff line and
+the nearest staff in the opposite direction from
+@code{staff-affinity}, if there are no other non-staff lines
+between the two, and @code{staff-affinity} is either @code{UP} or
+@code{DOWN}.  See @code{staff-staff-spacing} for a description of
+the alist structure.")

      (note-names ,vector? "Vector of strings containing names for
 easy-notation note heads.")
 
      (note-names ,vector? "Vector of strings containing names for
 easy-notation note heads.")
 


@@ -653,11 +700,6 @@ value @code{-1} means left aligned, @code{0}@tie{}centered, and
 values may also be specified.")
      (self-alignment-Y ,number? "Like @code{self-alignment-X} but for
 the Y@tie{}axis.")
 values may also be specified.")
      (self-alignment-Y ,number? "Like @code{self-alignment-X} but for
 the Y@tie{}axis.")

-     (toward-stem-shift ,number? "Amount by which scripts are shifted
-toward the stem if their direction coincides with the stem direction.
-@code{0.0} means keep the default position (centered on the note
-head), @code{1.0} means centered on the stem.  Interpolated values are
-possible.")

      (shorten-pair ,number-pair? "The lengths to shorten a
 text-spanner on both sides, for example a pedal bracket.  Positive
 values shorten the text-spanner, while negative values lengthen it.")
      (shorten-pair ,number-pair? "The lengths to shorten a
 text-spanner on both sides, for example a pedal bracket.  Positive
 values shorten the text-spanner, while negative values lengthen it.")


@@ -701,9 +743,27 @@ there.")
      (spacing-increment ,number? "Add this much space for a doubled
 duration.  Typically, the width of a note head.  See also
 @rinternals{spacing-spanner-interface}.")
      (spacing-increment ,number? "Add this much space for a doubled
 duration.  Typically, the width of a note head.  See also
 @rinternals{spacing-spanner-interface}.")

+     (spacing-pair ,pair? "A pair of alignment symbols which set an object's
+spacing relative to its left and right @code{BreakAlignment}s.
+
+For example, a @code{MultiMeasureRest} will ignore prefatory items at its
+bounds (i.e., clefs, key signatures and time signatures) using the following
+override:
+
+@example
+\\override MultiMeasureRest #'spacing-pair = #'(staff-bar . staff-bar)
+@end example")

      (springs-and-rods ,boolean? "Dummy variable for triggering
 spacing routines.")
      (stacking-dir ,ly:dir? "Stack objects in which direction?")
      (springs-and-rods ,boolean? "Dummy variable for triggering
 spacing routines.")
      (stacking-dir ,ly:dir? "Stack objects in which direction?")

+     (staff-affinity ,ly:dir? "The direction of the staff to use
+for spacing the current non-staff line.  Choices are @code{UP},
+@code{DOWN}, and @code{CENTER}.  If @code{CENTER}, the non-staff
+line will be placed equidistant between the two nearest staves on
+either side, unless collisions or other spacing constraints
+prevent this.  Setting @code{staff-affinity} for a staff causes it
+to be treated as a non-staff line.  Setting @code{staff-affinity}
+to @code{#f} causes a non-staff line to be treated as a staff.")

      (staff-padding ,ly:dimension? "Maintain this much space between
 reference points and the staff.  Its effect is to align objects of
 differing sizes (like the dynamics @b{p} and @b{f}) on their
      (staff-padding ,ly:dimension? "Maintain this much space between
 reference points and the staff.  Its effect is to align objects of
 differing sizes (like the dynamics @b{p} and @b{f}) on their


@@ -712,6 +772,38 @@ baselines.")
 staff spaces, counted from the middle line.")
      (staff-space ,ly:dimension? "Amount of space between staff lines,
 expressed in global @code{staff-space}.")
 staff spaces, counted from the middle line.")
      (staff-space ,ly:dimension? "Amount of space between staff lines,
 expressed in global @code{staff-space}.")

+     (staff-staff-spacing ,list? "When applied to a staff-group's
+@code{StaffGrouper} grob, this spacing alist controls the distance
+between consecutive staves within the staff-group.  When applied
+to a staff's @code{VerticalAxisGroup} grob, it controls the
+distance between the staff and the nearest staff below it in the
+same system, replacing any settings inherited from the
+@code{StaffGrouper} grob of the containing staff-group, if there
+is one.  This property remains in effect even when non-staff lines
+appear between staves.  The alist can contain the following keys:
+@itemize
+@item @code{padding} -- the minimum required amount of
+unobstructed vertical whitespace between the two items, measured
+in staff-spaces.
+@item @code{basic-distance} -- the vertical distance, measured in
+staff-spaces, between the reference points of the two items when
+no collisions would result, and no stretching or compressing is in
+effect.
+@item @code{minimum-distance} -- the smallest allowable vertical
+distance, measured in staff-spaces, between the reference points
+of the two items, when compressing is in effect.
+@item @code{stretchability} -- a unitless measure of the
+dimension's relative propensity to stretch.  If zero, the distance
+will not stretch (unless collisions would result).
+@end itemize")
+     (staffgroup-staff-spacing ,list? "The spacing alist
+controlling the distance between the last staff of the current
+staff-group and the staff just below it in the same system, even
+if one or more non-staff lines exist between the two staves.  If
+the @code{staff-staff-spacing} property of the staff's
+@code{VerticalAxisGroup} grob is set, that is used instead.  See
+@code{staff-staff-spacing} for a description of the alist
+structure.")

      (stem-attachment ,number-pair? "An @code{(@var{x} . @var{y})}
 pair where the stem attaches to the notehead.")
      (stem-end-position ,number? "Where does the stem end (the end is
      (stem-attachment ,number-pair? "An @code{(@var{x} . @var{y})}
 pair where the stem attaches to the notehead.")
      (stem-end-position ,number? "Where does the stem end (the end is


@@ -752,8 +844,6 @@ should use @code{LEFT}.")
      (thickness ,number? "Line thickness, generally measured in
 @code{line-thickness}.")
      (thin-kern ,number? "The space after a hair-line in a bar line.")
      (thickness ,number? "Line thickness, generally measured in
 @code{line-thickness}.")
      (thin-kern ,number? "The space after a hair-line in a bar line.")

-     (threshold ,number-pair? "@code{(@var{min} . @var{max})}, where
-@var{min} and @var{max} are dimensions in staff space.")

      (tie-configuration ,list? "List of @code{(@var{position} .
 @var{dir})} pairs, indicating the desired tie configuration, where
 @var{position} is the offset from the center of the staff in staff
      (tie-configuration ,list? "List of @code{(@var{position} .
 @var{dir})} pairs, indicating the desired tie configuration, where
 @var{position} is the offset from the center of the staff in staff


@@ -763,6 +853,11 @@ in the list causes the corresponding tie to be formatted
 automatically.")
      (to-barline ,boolean? "If true, the spanner will stop at the bar
 line just before it would otherwise stop.")
 automatically.")
      (to-barline ,boolean? "If true, the spanner will stop at the bar
 line just before it would otherwise stop.")

+     (toward-stem-shift ,number? "Amount by which scripts are shifted
+toward the stem if their direction coincides with the stem direction.
+@code{0.0} means keep the default position (centered on the note
+head), @code{1.0} means centered on the stem.  Interpolated values are
+possible.")

      (transparent ,boolean? "This makes the grob invisible.")
 
 
      (transparent ,boolean? "This makes the grob invisible.")
 
 


@@ -788,6 +883,9 @@ one below this grob.")
 ;;
      (when ,ly:moment? "Global time step associated with this column
 happen?")
 ;;
      (when ,ly:moment? "Global time step associated with this column
 happen?")

+     (whiteout ,boolean? "If true, the grob is printed over a white
+background to white-out underlying material, if the grob is visible.
+ Usually #f by default.")

      (width ,ly:dimension? "The width of a grob measured in staff
 space.")
      (word-space ,ly:dimension? "Space to insert between words in
      (width ,ly:dimension? "The width of a grob measured in staff
 space.")
      (word-space ,ly:dimension? "Space to insert between words in


@@ -840,132 +938,131 @@ constructed from a whole number of squiggles.")
    `(
      ;;;;;;;;;;;;;;;;
      ;; grobs & grob arrays.  (alphabetical)
    `(
      ;;;;;;;;;;;;;;;;
      ;; grobs & grob arrays.  (alphabetical)

-     (X-common ,ly:grob? "Common reference point for axis group.")
-
-     (Y-common ,ly:grob? "See @code{X-common}.")
-

      (accidental-grob ,ly:grob? "The accidental for this note.")
      (accidental-grobs ,list? "An alist with @code{(@var{notename} .
 @var{groblist})} entries.")
      (accidental-grob ,ly:grob? "The accidental for this note.")
      (accidental-grobs ,list? "An alist with @code{(@var{notename} .
 @var{groblist})} entries.")

-     (adjacent-pure-heights ,pair? "A pair of vectors.  Used by a
-@code{VerticalAxisGroup} to cache the @code{Y-extent}s of different column
-ranges.")
-     (adjacent-hairpins ,ly:grob-array? "A list of directly neighboring
-hairpins.")
-     (all-elements ,ly:grob-array? "A list of all grobs in this line.  Its
+     (adjacent-spanners ,ly:grob-array? "An array of directly neighboring
+dynamic spanners.")
+     (all-elements ,ly:grob-array? "An array of all grobs in this line.  Its

 function is to protect objects from being garbage collected.")
      (arpeggio ,ly:grob? "A pointer to an @code{Arpeggio} object.")
      (axis-group-parent-X ,ly:grob? "Containing X@tie{}axis group.")
      (axis-group-parent-Y ,ly:grob? "Containing Y@tie{}axis group.")
 
 function is to protect objects from being garbage collected.")
      (arpeggio ,ly:grob? "A pointer to an @code{Arpeggio} object.")
      (axis-group-parent-X ,ly:grob? "Containing X@tie{}axis group.")
      (axis-group-parent-Y ,ly:grob? "Containing Y@tie{}axis group.")
 

-     (bar-extent ,number-pair? "The Y-extent of the actual bar line.
-This may differ from @code{Y-extent} because it does not include the dots in
-a repeat bar line.")
-     (bars ,ly:grob-array? "A list of bar line pointers.")
+     (bars ,ly:grob-array? "An array of bar line pointers.")

      (beam ,ly:grob? "A pointer to the beam, if applicable.")
      (beam ,ly:grob? "A pointer to the beam, if applicable.")

-     (bounded-by-me ,ly:grob-array? "A list of spanners that have this
+     (bounded-by-me ,ly:grob-array? "An array of spanners that have this

 column as start/begin point.  Only columns that have grobs or act as
 bounds are spaced.")
      (bracket ,ly:grob? "The bracket for a number.")
 
 column as start/begin point.  Only columns that have grobs or act as
 bounds are spaced.")
      (bracket ,ly:grob? "The bracket for a number.")
 

-     (columns ,ly:grob-array? "A list of grobs, typically containing
+     (columns ,ly:grob-array? "An array of grobs, typically containing

 @code{PaperColumn} or @code{NoteColumn} objects.")
      (conditional-elements ,ly:grob-array? "Internal use only.")
 @code{PaperColumn} or @code{NoteColumn} objects.")
      (conditional-elements ,ly:grob-array? "Internal use only.")

-     (cross-staff ,boolean? "For a beam or a stem, this is true if we
-depend on inter-staff spacing.")

 
      (direction-source ,ly:grob? "In case @code{side-relative-direction} is
 set, which grob to get the direction from.")
 
      (direction-source ,ly:grob? "In case @code{side-relative-direction} is
 set, which grob to get the direction from.")

+     (display-cautionary ,boolean? "Should the grob be displayed as a cautionary grob?")

      (dot ,ly:grob? "A reference to a @code{Dots} object.")
      (dots ,ly:grob-array? "Multiple @code{Dots} objects.")
 
      (dot ,ly:grob? "A reference to a @code{Dots} object.")
      (dots ,ly:grob-array? "Multiple @code{Dots} objects.")
 

-     (elements ,ly:grob-array? "A list of grobs; the type is depending on
+     (elements ,ly:grob-array? "An array of grobs; the type is depending on

 the grob where this is set in.")
      (encompass-objects ,ly:grob-array? "Objects that a slur should avoid
 in addition to notes and stems.")
 
      (figures ,ly:grob-array? "Figured bass objects for continuation line.")
 the grob where this is set in.")
      (encompass-objects ,ly:grob-array? "Objects that a slur should avoid
 in addition to notes and stems.")
 
      (figures ,ly:grob-array? "Figured bass objects for continuation line.")

-     (forced ,boolean? "Manually forced accidental.")

 
 

-     (glyph-name ,string? "The glyph name within the font.")

      (grace-spacing ,ly:grob? "A run of grace notes.")
 
      (grace-spacing ,ly:grob? "A run of grace notes.")
 

-     (heads ,ly:grob-array? "A list of note heads.")
+     (heads ,ly:grob-array? "An array of note heads.")

 
 

-     (important-column-ranks ,vector? "A cache of columns that contain
-@code{items-worth-living} data.")
-     (items-worth-living ,ly:grob-array? "A list of interesting items.  If
+     (items-worth-living ,ly:grob-array? "An array of interesting items.  If

 empty in a particular staff, then that staff is erased.")
 
 empty in a particular staff, then that staff is erased.")
 

-     (left-items ,ly:grob-array? "DOCME")
-     (left-neighbors ,ly:grob-array? "A list of @code{spacing-wishes} grobs
-that are close to the current column.
+     (keep-alive-with ,ly:grob-array? "An array of other
+@code{VerticalAxisGroup}s.  If any of them are alive, then we will stay alive.")

 
 

-The closest @code{spacing-wishes} determine the actual distances between the
-columns.")
+     (left-items ,ly:grob-array? "DOCME")
+     (left-neighbor ,ly:grob? "The right-most column that has a spacing-wish
+for this column.")

 
      (normal-stems ,ly:grob-array? "An array of visible stems.")
 
      (normal-stems ,ly:grob-array? "An array of visible stems.")

-     (note-columns ,pair? "A list of @code{NoteColumn} grobs.")
+     (note-columns ,ly:grob-array? "An array of @code{NoteColumn} grobs.")

      (note-head ,ly:grob? "A single note head.")
      (note-head ,ly:grob? "A single note head.")

-     (note-heads ,ly:grob-array? "A list of note head grobs.")
+     (note-heads ,ly:grob-array? "An array of note head grobs.")

      (pedal-text ,ly:grob? "A pointer to the text of a mixed-style piano
 pedal.")
      (pedal-text ,ly:grob? "A pointer to the text of a mixed-style piano
 pedal.")

-     (pure-Y-common ,ly:grob? "A cache of the
-@code{common_refpoint_of_array} of the @code{elements} grob set.")
-     (pure-Y-offset-in-progress ,boolean? "A debugging aid for catching
-cyclic dependencies.")
+     (pure-relevant-grobs ,ly:grob-array? "All the grobs (items and spanners)
+that are relevant for finding the @code{pure-Y-extent}")

      (pure-relevant-items ,ly:grob-array? "A subset of elements that are
 relevant for finding the @code{pure-Y-extent}.")
      (pure-relevant-spanners ,ly:grob-array? "A subset of elements that are
 relevant for finding the @code{pure-Y-extent}.")
      (pure-relevant-items ,ly:grob-array? "A subset of elements that are
 relevant for finding the @code{pure-Y-extent}.")
      (pure-relevant-spanners ,ly:grob-array? "A subset of elements that are
 relevant for finding the @code{pure-Y-extent}.")

+     (pure-Y-common ,ly:grob? "A cache of the
+@code{common_refpoint_of_array} of the @code{elements} grob set.")

 
      (rest ,ly:grob? "A pointer to a @code{Rest} object.")
      (rest-collision ,ly:grob? "A rest collision that a rest is in.")
 
      (rest ,ly:grob? "A pointer to a @code{Rest} object.")
      (rest-collision ,ly:grob? "A rest collision that a rest is in.")

-     (rests ,ly:grob-array? "A list of rest objects.")
+     (rests ,ly:grob-array? "An array of rest objects.")

      (right-items ,ly:grob-array? "DOCME")
      (right-items ,ly:grob-array? "DOCME")

-     (right-neighbors ,ly:grob-array? "See @code{left-neighbors}.")
+     (right-neighbor ,ly:grob? "See @code{left-neighbor}.")

 
 

-     (separation-item ,ly:grob? "A separation item.")
-     (side-support-elements ,ly:grob-array? "The side support, a list of
+     (side-support-elements ,ly:grob-array? "The side support, an array of

 grobs.")
      (slur ,ly:grob? "A pointer to a @code{Slur} object.")
 grobs.")
      (slur ,ly:grob? "A pointer to a @code{Slur} object.")

-     (spaceable-staves ,ly:grob-array? "Objects to be spaced during page
-layout.")

      (spacing ,ly:grob? "The spacing spanner governing this section.")
      (spacing ,ly:grob? "The spacing spanner governing this section.")

-     (spacing-wishes ,ly:grob-array? "List of note spacing or staff spacing
+     (spacing-wishes ,ly:grob-array? "An array of note spacing or staff spacing

 objects.")
 objects.")

+     (span-start ,boolean? "Is the note head at the start of a spanner?")
+     (staff-grouper ,ly:grob? "The staff grouper we belong to.")

      (staff-symbol ,ly:grob? "The staff symbol grob that we are in.")
      (stem ,ly:grob? "A pointer to a @code{Stem} object.")
      (staff-symbol ,ly:grob? "The staff symbol grob that we are in.")
      (stem ,ly:grob? "A pointer to a @code{Stem} object.")

-     (stems ,ly:grob-array? "A list of stem objects, corresponding to the
-notes that the arpeggio has to be before.")
+     (stems ,ly:grob-array? "An array of stem objects.")

 
      (tie ,ly:grob? "A pointer to a @code{Tie} object.")
      (tremolo-flag ,ly:grob? "The tremolo object on a stem.")
      (tuplet-number ,ly:grob? "The number for a bracket.")
 
      (tie ,ly:grob? "A pointer to a @code{Tie} object.")
      (tremolo-flag ,ly:grob? "The tremolo object on a stem.")
      (tuplet-number ,ly:grob? "The number for a bracket.")

-     (tuplets ,ly:grob-array? "A list of smaller tuplet brackets.")
+     (tuplets ,ly:grob-array? "An array of smaller tuplet brackets.")
+     (X-common ,ly:grob? "Common reference point for axis group.")
+     (Y-common ,ly:grob? "See @code{X-common}.")

 
      ;;;;;;;;;;;;;;;;
      ;; other
 
      ;;;;;;;;;;;;;;;;
      ;; other

-     (begin-of-line-visible ,boolean? "Set to make @code{ChordName} or 
-@code{FretBoard} be visible only at beginning of line or at 
+     (adjacent-pure-heights ,pair? "A pair of vectors.  Used by a
+@code{VerticalAxisGroup} to cache the @code{Y-extent}s of different column
+ranges.")
+
+     (bar-extent ,number-pair? "The Y-extent of the actual bar line.
+This may differ from @code{Y-extent} because it does not include the dots in
+a repeat bar line.")
+     (begin-of-line-visible ,boolean? "Set to make @code{ChordName} or
+@code{FretBoard} be visible only at beginning of line or at

 chord changes.")
 
      (cause ,scheme? "Any kind of causation objects (i.e., music, or perhaps
 translator) that was the cause for this grob.")
 chord changes.")
 
      (cause ,scheme? "Any kind of causation objects (i.e., music, or perhaps
 translator) that was the cause for this grob.")

+     (cross-staff ,boolean? "For a beam or a stem, this is true if we
+depend on inter-staff spacing.")

 
      (delta-position ,number? "The vertical position difference.")
 
      (font ,ly:font-metric? "A cached font metric object.")
 
      (delta-position ,number? "The vertical position difference.")
 
      (font ,ly:font-metric? "A cached font metric object.")

+     (forced ,boolean? "Manually forced accidental.")

 
      (head-width ,ly:dimension? "The width of this ligature head.")
 
      (ideal-distances ,list? "@code{(@var{obj} . (@var{dist} .
 @var{strength}))} pairs.")
 
      (head-width ,ly:dimension? "The width of this ligature head.")
 
      (ideal-distances ,list? "@code{(@var{obj} . (@var{dist} .
 @var{strength}))} pairs.")

+     (important-column-ranks ,vector? "A cache of columns that contain
+@code{items-worth-living} data.")

      (interfaces ,list? "A list of symbols indicating the interfaces
 supported by this object.  It is initialized from the @code{meta} field.")
 
      (least-squares-dy ,number? "The ideal beam slope, without damping.")
 
      (interfaces ,list? "A list of symbols indicating the interfaces
 supported by this object.  It is initialized from the @code{meta} field.")
 
      (least-squares-dy ,number? "The ideal beam slope, without damping.")
 

+     (maybe-loose ,boolean? "Used to mark a breakable column that is
+loose if and only if it is in the middle of a line.")

      (meta ,list? "Provide meta information.  It is an alist with the
 entries @code{name} and @code{interfaces}.")
      (minimum-distances ,list? "A list of rods that have the format
      (meta ,list? "Provide meta information.  It is an alist with the
 entries @code{name} and @code{interfaces}.")
      (minimum-distances ,list? "A list of rods that have the format


@@ -974,6 +1071,8 @@ entries @code{name} and @code{interfaces}.")
      (positioning-done ,boolean? "Used to signal that a positioning element
 did its job.  This ensures that a positioning is only done once.")
      (pure-Y-extent ,number-pair? "The estimated height of a system.")
      (positioning-done ,boolean? "Used to signal that a positioning element
 did its job.  This ensures that a positioning is only done once.")
      (pure-Y-extent ,number-pair? "The estimated height of a system.")

+     (pure-Y-offset-in-progress ,boolean? "A debugging aid for catching
+cyclic dependencies.")

 
      (quant-score ,string? "The beam quanting score; stored for
 debugging.")
 
      (quant-score ,string? "The beam quanting score; stored for
 debugging.")


@@ -986,9 +1085,9 @@ quanting.")
 acts as an index for looking up a @code{Stencil} object.")
      (shorten ,ly:dimension? "The amount of space that a stem is shortened.
 Internally used to distribute beam shortening over stems.")
 acts as an index for looking up a @code{Stencil} object.")
      (shorten ,ly:dimension? "The amount of space that a stem is shortened.
 Internally used to distribute beam shortening over stems.")

-     (skyline-distance ,number? "The distance between this staff and the
-next one, as determined by a skyline algorithm.")

      (stem-info ,pair? "A cache of stem parameters.")
      (stem-info ,pair? "A cache of stem parameters.")

+     (system-Y-offset ,number? "The Y-offset (relative to the bottom of the
+top-margin of the page) of the system to which this staff belongs.")

 
      (use-breve-rest ,boolean? "Use breve rests for measures longer
 than a whole rest.")
 
      (use-breve-rest ,boolean? "Use breve rests for measures longer
 than a whole rest.")


@@ -1021,8 +1120,8 @@ a head may be affected by the left and/or right neighbour head.
 @code{context-info} holds for each head such information about the left and
 right neighbour, encoded as a bit mask.")
 
 @code{context-info} holds for each head such information about the left and
 right neighbour, encoded as a bit mask.")
 

-     (descendens ,boolean? "Is this neume of descendent type?")

      (deminutum ,boolean? "Is this neume deminished?")
      (deminutum ,boolean? "Is this neume deminished?")

+     (descendens ,boolean? "Is this neume of descendent type?")

 
      (flexa-height ,ly:dimension? "The height of a flexa shape in a ligature
 grob (in @code{staff-space} units).")
 
      (flexa-height ,ly:dimension? "The height of a flexa shape in a ligature
 grob (in @code{staff-space} units).")


@@ -1031,9 +1130,8 @@ ligature grob in (in @code{staff-space} units).")
 
      (inclinatum ,boolean? "Is this neume an inclinatum?")
 
 
      (inclinatum ,boolean? "Is this neume an inclinatum?")
 

-     (join-heads ,boolean? "Whether to join the note heads of an ambitus
-grob with a vertical line.")
-     (join-right-amount ,number? "DOCME")
+     (join-right-amount ,number? "A length used for calculating the
+Y-extent of mensural ligatures.")

 
      (linea ,boolean? "Attach vertical lines to this neume?")
 
 
      (linea ,boolean? "Attach vertical lines to this neume?")