[plt-dev] Re: [plt-bug] all/10895: quasiquote printing is buggy, confusing

From: Sam Tobin-Hochstadt (samth at ccs.neu.edu)
Date: Mon May 10 12:22:24 EDT 2010

On Thu, May 6, 2010 at 12:35 PM, Matthew Flatt <mflatt at cs.utah.edu> wrote:
> I've pushed a partial implementation; the documentation is not yet
> updated, and the Scribble value printer isn't yet converted.

This is mostly very nice, but I think the printing for structs with
custom printers isn't right. It seems that they always print with
leading quotes, which isn't right for Typed Scheme types, for example.
 It's especially not right if a custom printer prints nothing:

> (struct x () #:property prop:custom-write void)
> (x)

Note the dangling quote.  It seems there should be a way to make
custom structs print as if they should be quoted, but that shouldn't
be the default.

Finally, one more things I noticed when looking at the custom-write
docs: The following expression at the DrRacket repl errors with a
strange error message:

> #0='#(#0#)
. read: #..= expressions not allowed in read-syntax mode

This used to be allowed, right?
sam th
samth at ccs.neu.edu

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