I have a defcustom with :type variable,
and I would like to constrain the variable name to comply to a pattern.
How would I do that?
for instance let say I want the custom to only accept a variable name starting with some prefix.
Don't use type variable. Use type restricted-sexp.
The predicate checks for a symbolp that is boundp (i.e., a variable) and whose symbol-name is matched by your chosen prefix.
See the Elisp manual, node Composite Types.
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Thanks Drew. I tried your solution, but for a strange reason the validating function is being called with nil except for the initial value. Besides the
sethandler is also called! Any idea why? – AdrieanKhisbe Sep 21 '17 at 21:11 -
Here is the code in question: gist.github.com/AdrieanKhisbe/81dbd538b6b8cca0b2dadd33ac24a6ed – AdrieanKhisbe Sep 21 '17 at 21:12
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Looks like you accidentally used
fboundp' in one place, instead ofboundp'. – Drew Sep 21 '17 at 23:11 -
