emacs lisp if function's grammar
Emacs Lisp's “if” function has a annoying form.
One would expect it to take 3 arguments, no more and no less, like this:
(if ‹test› ‹expression for true› ‹expression for false› )
But it's actually takes many more args. From the 3rd args onward are all expressions for false. Like this:
(if ‹test› ‹expression for true› ‹expression for false› ‹expression for false 2› ‹expression for false 3› … )
Here's a test code you can check:
(if nil (message "false") (message "true") (message "so true") (message "yes really") )
You can run the code by selecting it, then call “eval-region” 【Alt+x】. You can switch to the “*Messages*” buffer by 【Ctrl+h e】.
Is Common Lisp and Scheme Lisp the same way?
I think i'd prefer the simpler, logical, form:
(if test true false).