[plt-scheme] Difficulty with struct contracts in v299

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Mon Jan 24 23:31:23 EST 2005

At Mon, 24 Jan 2005 20:56:23 -0500, Richard Cobbe wrote:
> I'm having a slight problem with structure contracts in DrScheme
> 299.26-cvs9jan2005.

MzScheme bug now fixed in CVS.

The problem had to do with expansion-time information associated with
the `exn' structure types, which in v299 do not have mutators. The
expansion-time information incorrectly included some accessors in the
mutator list.

To correct the problem, I had to expand the definition of
expansion-time information for structure types. The mutator list is now
allowed to contain #f in place of a mutator identifier. I've updated
`struct-declaration-info?' in `(lib "struct.ss" "syntax")' to reflect
this change.


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