commit d945843738bf9dab0abbdbf2caeeb25ae24ab56a
parent df70f9207245626c10b9eb04854bb3db37597141
Author: Greg Hendershott <greghendershott@gmail.com>
Date: Mon, 29 Oct 2012 11:37:10 -0400
Misc edits.
Diffstat:
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/main.rkt b/main.rkt
@@ -237,10 +237,10 @@ The @racket[(print stx)] shows what our transformer is given: a syntax
object.
A syntax object consists of several things. The first part is the
-s-expression representing the code, such as @racket['(i am a
-list)]. Racket (and Scheme and Lisp) expressions are s-expressions---
-code and data have the same structure, and this makes it vastly easier
-to rewrite syntax, i.e. write macros.
+s-expression representing the code, such as @racket['(+ 1
+2)]. Racket (and Scheme and Lisp) expressions are s-expressions---code
+and data have the same structure, and this makes it vastly easier to
+rewrite syntax, i.e. write macros.
Racket syntax is also decorated with some interesting information such
as the source file, line number, and column. Finally, it has
@@ -690,17 +690,21 @@ size" template. Let's try that:
(let ([name (string->symbol (format "~a-~a" #'a #'b))])
#'(define (name args ...)
body0 body ...))]))
+]
+
+No more error---good! Let's try to use it:
+
+@i[
(hyphen-define/wrong1.1 foo bar () #t)
(foo-bar)
]
-Our macro definition didn't give an error, so that's good progress!
-But when we tried to use it, no luck. It seems that a function named
-@racket[foo-bar] wasn't defined.
+It seems we're defining a function with a name other than
+@racket[foo-bar]?
This is where the Macro Stepper in DrRacket is invaluable. Even if you
-prefer to work mostly in Emacs (like I do), this is a situation where
-it's worth using DrRacket temporarily for its Macro Stepper.
+prefer mostly to use Emacs, this is a situation where it's worth using
+DrRacket at least temporarily for its Macro Stepper.
@image[#:scale 0.5 "macro-stepper.png"]
