[racket] Changing at-expressions to other-glyph-expressions

20 minutes ago, Matthew Flatt wrote:
> At Fri, 19 Apr 2013 16:42:40 -0700, Matthew Butterick wrote:
> > Thanks. Yes, I did see that in the docs. The problem with this technique is
> > that once I wrap the input text in @list| (or @list|^, or ... etc.) to get
> > the benefit of @-escaping, then I lose the ability to do defines within the
> > body of that text. (Throws error "define not allowed in expression
> > context.")
> 
> You could use `begin' instead of list:
> 
>  #lang scribble/base
>  
>  @; Everything within the following will be escaped.  Use |^ to unescape.
>  @begin|^{
>   
>  this is an example with @ signs in it.
> 
>  |^@(define x "at")
> 
>  @ is |^@x
> 
>  }^|

In the `scribble/text' language (which I think is what Butterick
uses), the right thing to use is `begin/text', which is kind of like
`list' but it allows definitions:

    #lang at-exp racket
    
    (require scribble/text)
    
    (output @begin/text{foo
                        @(define bar "blah")
                        @bar})

Alternatively, when `scribble/text' is used as a language, the binding
is `text':

    #lang scribble/text
    
    @(define x @text{foo
                     @(define bar "blah")
                     @bar})
    
    @x

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