Double char is a way to insert two different string. One is inserted when you hit the char twice fast enough.
typically on azerty keybord you can do:
(defdoublechar great "<" ">") (global-set-key (kbd "<") 'double-char---great)
Then type “<<” in less than 0.3 second to get “>” Or “<<” if it exceed 0.3 second. In that example it will permit to skip the use of the modifier Shift (azerty keyborad).
Change the ‘double-char-delay to change the delay (0.3 second as default).
Notice that ‘(defdoublechar silly “12” “abc”) work as well. It will produce a function named
double-char---silly
.