My function would always get hung up on the unknown identifiers like
'title' or 'math' when it tried to evaluate the expressions passed as
arguments -
but you are right, the macro is not really necessary. I can quote the
expressions and use the html-writing module instead, which handles
quoted lists.
I was just looking for ways to achieve a cleaner syntax.
On 07.01.13 23:20, Matthias Felleisen wrote:
I don't see any need for a macro here. Why not use a function that iterates
over these 'forms':
(define (expr-iter . form)
(for ((f form))
(case (first f)
...
[(math) (eval (second f) some-useful-namespace)]
...)))
On Jan 7, 2013, at 3:57 PM, Philipp Dikmann wrote:
Hello Racket-Users,
in trying to iterate a series of expressions and evaluating them differently on
a case-by-case basis - specifically in the body of a (html-template) - Racket
is throwing errors indicating that my expressions end up in the wrong places.
In the code below, it appears that + is being interpreted as an HTML element
name; am I messing up expansion time and run time?
#lang racket
(require (planet neil/html-template:2:2))
(define-syntax-rule (expr-iter form ...)
(begin
(case (car 'form)
[(title) (display (cadr 'form))]
[(math) (eval (cadr 'form))]
[(html) (html-template
(eval (cadr 'form)))]) ...))
(expr-iter (title "sometitle")
(math (+ 1 2))
(html (p "hello")))
Best regards,
Philipp
____________________
Racket Users list:
http://lists.racket-lang.org/users
____________________
Racket Users list:
http://lists.racket-lang.org/users
