ses: Deferred updates
5.1 Deferred updates
====================
To save time by avoiding redundant computations, cells that need
recalculation due to changes in other cells are added to a set. At the
end of the command, each cell in the set is recalculated once. This can
create a new set of cells that need recalculation. The process is
repeated until either the set is empty or it stops changing (due to
circular references among the cells). In extreme cases, you might see
progress messages of the form “Recalculating... (NNN cells left)”. If
you interrupt the calculation using ‘C-g’, the spreadsheet will be left
in an inconsistent state, so use ‘C-_’ or ‘C-c C-l’ to fix it.
To save even more time by avoiding redundant writes, cells that have
changes are added to a set instead of being written immediately to the
data area. Each cell in the set is written once, at the end of the
command. If you change vast quantities of cells, you might see a
progress message of the form “Writing... (NNN cells left)”. These
deferred cell-writes cannot be interrupted by ‘C-g’, so you’ll just have
to wait.
SES uses ‘run-with-idle-timer’ to move the cell underline when Emacs
will be scrolling the buffer after the end of a command, and also to
narrow and underline after ‘C-x C-v’. This is visible as a momentary
glitch after C-x C-v and certain scrolling commands. You can type ahead
without worrying about the glitch.
Info Catalog
ses: For Gurus
ses: Nonrelocatable references