Hi Axel, > I suppose you mean that you want to arrange syntax in a complex > manner, then evaluate it and you are concerned about the cost of > rearranging every time the function/macro is called. Suppose also that > this rearranging can be done as soon as you know the code inside the > macro form, in CL language after definition time but before runtime. > In this case you cannot use Alexander's suggestion of using reader > macros at definition time. Here is a solution: > > (de defmacro "F" > (let (@Name (car "F") > @Fun (cdr "F") > @Arg (pack "X") > @Id (pack "WILL EVAL:") ) > (macro > (de @Name @Arg > (unless (== (car @Arg) @Id) > (con @Arg (apply '@Fun @Arg)) > (set @Arg @Id) ) > (eval (cdr @Arg)) ) ) ) ) > (====)
Nice! Very clever! :) Minor: I would suggest to use 'name' instead of 'pack' to produce the unique transient symbol, as it is cheaper and probably more clear. Cheers, - Alex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
