I finally wrote a GNU/apl XCompose file that can provide a quick, no
headaches :) alternative to more orthodox methods such as xmodmap or
setxkbmap + a third-level modifier.
This hack may come in handy for new users of GNU/apl who already rely on
a custom keyboard layout where the third-level modifier is used for
other purposes (navigation keypad - arrows, PgDown.. - numpad, special
characters, multimedia keys, exotic scripts)
The layout is meant to reflect the output of the GNU/apl ]KEYB command
(characters & location).
The definitions have been tested in the GNU/apl shell as well as Vim
running on top of an XTerm.
Enabling on GNU/linux:
1. Define a Compose key. Various online articles describe how to do this
depending on your desktop environment.
2. Copy the attached XCompose file as ~/.XCompose to your home
directory.
Limitations:
1. I have not been able to get my custom Compose definitions to work in
GTK apps (firefox, gvim). Search online for possible solutions. They
appear to work in KDE/Qt apps without any customization.
2. Won't work in environments that do not support the X Compose key
mechanism.
In order to avoid conflicts with the standard Compose sequences,
I prepended a <space> prefix to all my definitions. Some may find having
to hit three keys in succession unpractical. Such aspects can easily be
customized to suit your requirements.
CJ