Re: Why is FUNC in cl-callf not allowed to be an expression?

[Stefan Monnier <monnier@iro.umontreal.ca>]

> Sorry that I haven't been clear: I want EXPR to eval to the function to
> be applied, not to the expression to set to.  Like in
>
>   (cl-callf (with (if flag #'1+ #'1-)) my-number)

Note that the gv-modify macro we discussed does not allow that either:
it doesn't funcall the result of an EXPR.

So, what you want can be written

    (cl-callf (lambda (x) (if flag (1+ x) (1- x))) my-number)
or
    (cl-callf (lambda (x) (funcall (if flag #'1+ #'1-) x)) my-number)

Just like you'd have to write

    (gv-modify my-number (if flag (1+ it) (1- it)))
or
    (gv-modify my-number (funcall (if flag #'1+ #'1-) it))


        Stefan