Effect-free forms such as if/then/else for Emacs Lisp.
(require 'syntactic-sugar)
(if t
(then (message "true"))
(else (message "false")))
(unwind-protect
(protected
(error "Error"))
(unwind
(message "cleanup")))
This library offers absolutely no functionality! The following
macros are provided as synonyms for progn
:
then
else
protected
unwind
These macros can be used to clarify if
or unwind-protect
forms.
Note that as synonyms for progn
, these forms have no useful
effects, and no additional syntax check is done, so nothing
prevents you from writing obfuscatory expressions such as
(if t (else 1) (then 2)) ; same as (if t (progn 1) (progn 2))
or idiotic expressions such as
(if t
(protected 1)
(unwind 2))
So, think of these macros as glorified comments. And realize that if you are tempted to use them, if in fact you have even read the documentation to this point, you are hopelessly impure at heart.
To use syntactic-sugar, place the syntactic-sugar.el
library somewhere
Emacs can find it, and add the following to your ~/.emacs
file:
(require 'syntactic-sugar)
When this library is loaded, the provided forms are registered as
keywords in font-lock. This may be disabled via customize
.
The included macros are intentionally not autoloaded, because they are outside the package namespace.
GNU Emacs version 24.4-devel : yes, at the time of writing
GNU Emacs version 24.3 : yes
GNU Emacs version 23.3 : yes
GNU Emacs version 22.2 : yes
GNU Emacs version 21.x and lower : unknown
No external dependencies