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Why is there no `until' in elisp?
From: |
Garreau\, Alexandre |
Subject: |
Why is there no `until' in elisp? |
Date: |
Tue, 16 Oct 2018 19:42:11 +0200 |
User-agent: |
Gnus (5.13), GNU Emacs 25.1.1 (i686-pc-linux-gnu) |
Sometimes I have the strong feeling that the symetric of “while”,
“until” [0], unlike in many languages such as C, exists in elisp. That
happened to me several times, and usually I bug for about an hour before
to realize I do this confusion because it has the symetric of “when”:
“unless”, but not the same for “while”.
However, “until” exists, for instance in bash (which has no “unless”…
maybe because it has no “when” because it has guarded “if”s?), and I
find it pretty handy for making stuff more readable and avoiding making
stuff more complex…
Is there a particular rational or style reason for not using a such
trivial and obvious (both in terms of implementation and
understandement) construct?
If not so, why isn’t it in elisp, aside of `when' and `unless' in
subr.el (if that ought to be the correct file?)?
[0] such as: (defmacro until (test &rest body) (declare (indent 1))
`(while (not ,test) ,@body))