Ideas on an alternative notation for key sequences, compilable to XCompose

composeGroup.txt

To write an XCompose file, it is normally necessary to enumerate all the desired
sequences individually. However, there are many sets of related sequences with
common prefixes, as well as ones that differ only in a prefix, but have the same
result. Grouping such sets of sequences together, writing the prefix only once,
could ease both the initial writing and later changes (note that I do not assert
that it actually does).

This document is meant for suggestions on and discussion of both this concept
and possibilities of execution as a text-based notation that can be transformed
back into XCompose sequences.

A group would contain sequence-target pairs, where a sequence is a (possibly
empty) sequence of keystrokes and a target is a group or an output. As a group
could contain the same sequence multiple times or contain sequences that are
prefixes of other sequences in the same group, finding the output of a given
sequence could require following multiple paths at once.

Using the empty string as a sequence is equivalent to including the target in
the current group. Using the same sequence to target two groups is perfectly
sensible if the two groups have disjoint sequence sets.

Groups would probably usually be named, but anonymous inline groups could save
defining a group (and naming it) for just two or three related sequences used
only in one place.

The notation could be realized as a superset of existing XCompose notation,
which would allow simply using an existing XCompose file and converting it bit
by bit as desired.

You’re right, it’s only certain classes of symbols that this helps with … one thing I thought of before was that it would easily be possible to convert from an XCompose file to a state-based notation little by little by translating the state-based things and catting them together. Now I think it would be a good idea to simply use a hybrid format, using the different approaches as appropriate. For example, your ♫s sequences are absolutely unrelated, the ♫& sequences (or whatever you made them into) thematically share almost nothing yet have a meaningful prefix (for changing which a relevant state might have been convenient), and the Greek letters were somewhere defined by ♫* , a thematic prefix. Let me just generalize this out …

Yeah; using this for some parts of the file, making it a tool and not a new way of doing everything, might be useful. Indeed, I have used prefixes more than once, the ♫♫ prefix for "longish things", unrelated (that's what I changed the & into), but also ♫* for Greek, ♫# for musical symbols (♯♭