Ken Tilton <email@example.com> wrote:
| Rob Warnock wrote:
| > Dustin Withers <firstname.lastname@example.org> wrote:
| > It appears that you are confusing macroexpansion time [which is
| > either part of compile-time or evaluation-time (for interpreted
| > code)] with run-time -- when the Common Lisp code actually executes.
| Nah, it just so happens that cl-who does not evaluate that particular
| argument. They could have written in differently and then the OP would
| be all set.
But... but... it's the &BODY argument of a *macro*. Macro arguments
[Aside: HTOUT (and presumably, HTMLGEN as well) does it exactly the
same way as CL-WHO. (Sub)Forms starting with keywords are rewritten
into executable CL code; other (sub)forms are left as is. The final
result is returned from the macro and compiled/evaluated as usual.]
| I do not use cl-who, but if I were in the OP's situation, I would cross
| my fingers and examine the source to with-html-output. It might expand
| into CALL-WITH-HTML-OUTPUT, which /would/ handle the runtime value of
| the argument.
Not really. Here's the entire definition of WITH-HTML-OUTPUT:
(defmacro with-html-output ((var &optional stream
((:indent *indent*) *indent*))
"Transform the enclosed BODY consisting of HTML as s-expressions
into Lisp code to write the corresponding HTML as strings to VAR -
which should either hold a stream or which'll be bound to STREAM if
(when (and *indent*
(not (integerp *indent*)))
(setq *indent* 0))
(when (eq prologue t)
(setq prologue *prologue*))
`(let ((,var ,(or stream var)))
,(tree-to-commands body var prologue)))
The only important bit is the last two lines. Note that whatever
TREE-TO-COMMANDS returns is spliced into the code. No evaluation
whatsoever is done to BODY before being handed to TREE-TO-COMMANDS,
so what the OP wanted to do simply isn't possible. [At least, not
using the WITH-HTML-OUTPUT macro.]
| If not, I would uncross my fingers so I can use the keyboard
| to hack a CALL-WITH-HTML-OUTPUT out of WITH-HTML-OUTPUT.
Go back and look at my suggestion *not* to call TREE-TO-COMMANDS
+--- The really ugly bit.
(eval (cl-who::tree-to-commands (replace-tags-with-keywords my-tree)
Given that MY-TREE is generated at *run-time* from reading an XML
document [he mentioned a purchase order -- presumably all possible
purchase orders are not known at compile time], do you really want
him to be calling EVAL there, at run-time? ...when a simple tree-walk
of MY-TREE could output the desired text *without* any use of EVAL?
Rob Warnock <email@example.com>
627 26th Avenue <URL:http://rpw3.org/>
San Mateo, CA 94403 (650)572-2607