[r6rs-discuss] [Formal] Requirement to detect circular lists

[AndrevanTonder]

Name        : Andre van Tonder
Email       : andre at het.brown.edu
Type        : defect
Priority    : minor
Component   : Mutable list arguments
Version     : 5.91
Pages       : 123-125
Dependencies: None

Summary:
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Requirement of cycle detection in list procedures
may be too onerous, potential performance problem.

Description:
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The draft requires procedures such as length, and
various others, to detect and raise an exception
if passed a circular list.

This may adversely affect performance globally
to accommodate an uncommon bug, in addition
to complicating the implementation of these
procedures rather significantly.

Suggestion:
-----------

Allow these procedures to not return when passed
a circular list.