[plt-scheme] Re: How to use a custom procedure as read?
On Tue, Sep 30, 2008 at 3:45 AM, Ali <emailaliclark at gmail.com> wrote:
>> > (swap-the-reader-in)
>> > ... code using custom reader ...
>> > (swap-the-reader-out)
>> > ... normal reader again ...
...
> Thanks. Do I have to write the code in a module? I'd much rather be
> able to swap in and out of the custom reader mode as with above.
You have to write your code in a separate module. If you did not,
Scheme would have to evaluate your code as the module was loaded to
work out that you were swapping in a new reader. This would break a
lot of things, the module system being the prime one.
Note the documentation you are reading is for v4, while you're using
v3. I suggest you upgrade your installation.
Finally, writing a custom reader is a fairly advanced task. What is
the problem you're trying to solve? Perhaps list members can suggest
a simpler way of solving it.
HTH,
N.