anophoric if example

[sbloch]

Working my way through this tutorial; thanks!

Section 5 ends with "But we can still define it as a normal variable" and an example of doing so. It doesn't mention that after one has defined it as a normal variable, "aif" no longer works:
syntax-parameterize: not bound as a syntax parameter in: it

I tried to fix this by putting the define-syntax-parameter in a local scope around the body of the macro definition:

(define-syntax aif
(local ((define-syntax-parameter it ; etc.))
(lambda (stx)
(syntax-case ; etc.))))

but apparently define-syntax-parameter doesn't count as a "definition" for local's purposes. And I suspect that if it were defined only locally, it wouldn't serve the intended purpose anyway.

[greghendershott]

Thanks for catching this. What I should have written is that it can still be defined locally. At the top level top level that you can't redefine it.

;; Although we can't redefine `it` at the top level -- that would conflict
;; with the syntax parameter -- we can still define `it` in a local context.

;; For example:

(let ([it "hi"])
  it)

(define (foo)
  (define it "hi")
  it)

I'll update Scribble and push to the web site, when I have a bit more time, then mark this as closed. Thanks again!