ReadonlyaccentsHow the system spells a single added accent, each spelling a sequence of its expression types: a latched system turns a valve on and off again, a held one holds one perforation for the accent.
ReadonlyareasThe blocks of positions, from the bass edge upwards.
ReadonlyexpressionThe expression types the bar reads, each a term of the system.
ReadonlyidNames the reproducing system in the type vocabulary:
the system is https://w3id.org/reo/type/system/<id> and its
expression types live under https://w3id.org/reo/type/<id>/.
ReadonlynameOptional ReadonlypaperThe paper speed the system runs its rolls at, where the literature states one. A system whose rolls each carry a tempo of their own, as the Licensee's do, states none.
ReadonlyrewindThe position carrying the rewind perforation, which runs at the very end of a roll and is the usual landmark for calibrating a scan against the bar.
ReadonlytrackNumber of positions on the bar. Tracks run from 1 to this.
ReadonlywidthWidth of the roll the bar reads.
Where the roll's own content ends, from its perforations alone, or
undefined where nothing on the paper says. A copy that reads
undefined runs to the end of whatever was scanned, which is a fact
about the scan rather than about the roll and should be reported as one.
Takes anything with a place and a position, so a reader can ask it of a copy's features before there are symbols, and a collation can ask it of the symbols afterwards.
undefined for a position the bar does not read. A measured place
is snapped to the nearest position: perforations sit on the grid and
measurements of them scatter around it.
What the bar reads off a feature, which may lie across more than one
position. A perforation lifts every valve whose bar hole it uncovers,
so an opening across two positions reads as two commands; one on a
single position reads as the one meaningOf gives, and one on
positions the bar does not read as none at all.
What the expression type operates, or undefined for one the bar
does not read or whose function has no counterpart in another scale.
meaningOf inverted: the position this bar reads the meaning on,
or undefined where it does not read it at all. A symbol's track
is this rather than anything measured, since a note of one pitch
sits on exactly one position of a given bar.
Describes a tracker bar. Track numbers are 1-based and count from the bass edge of the roll, which is the numbering used throughout the edition: a feature's
vertical.fromis a track in this sense.This is the only place where track numbers are given a meaning. Anything that needs to know where the note block ends, which side an expression belongs to, or how a track maps to a pitch, should ask the tracker bar rather than repeat the boundaries.