[racket-dev] . . for-each: arity mismatch for procedure

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Fri Apr 8 11:23:19 EDT 2011

On Apr 8, 2011, at 9:57 AM, Matthew Flatt wrote:

> At Thu, 7 Apr 2011 12:05:01 -0600, Matthew Flatt wrote:
>> At Thu, 7 Apr 2011 13:29:10 -0400, Matthias Felleisen wrote:
>>> I suspect that this is a bug 
>>> in arity checking/reporting (at Matthew's level). 
>> Me too, since I changed something related, but I haven't been able to
>> replicate the problem so far. Let me know if you can.
> Fixed. It was an arity-reporting bug, but not as new as I thought. The
> key ingredients were `for-each' and a chaperoned (via a contract)
> procedure.

I am glad I noticed and sent the message before writing it off as some random C event I couldn't possibly recreate. It is a wonderful illustration of the principle of unsafety. An unsafe language picks random bits and (semi)interprets them for you. -- Matthias

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