Re: Concern around use of eval

[Tassilo Horn]

Joost Kremers <joost.m.kremers@gmail.com> writes:

> Why not do it at the top level directly? E.g.:
>
> ,----
> | (defvar lh/labels '("label1" "label2" "label3"))
> | 
> | (defmacro lh/gen-predicate (label)
> |   `(defun ,(intern (concat "lh/" label "-p")) ()
> |      (member ,label *lh/system-label-store*)))
> | 
> | (mapc (lambda (label)
> |         (lh/gen-predicate label))
> |       lh/labels)
> `----

That won't work because.  When reading the mapc form, emacs sees that
`lh/gen-predicate' is a macro and tries to expand it with the symbol
label as argument.  The macroexpansion takes place before the actual
execution of the code.

Bye,
Tassilo