[r6rs-discuss] [Formal] Exactness is orthogonal to type
agj at alum.mit.edu
Sun Oct 1 14:53:22 EDT 2006
submitter's name: Aubrey Jaffer
submitter's email address: agj at alum.mit.edu
type of issue: Defect
R6RS component: Arithmetic
version of the report: 5.91
one-sentence summary of the issue:
Exactness is orthogonal to type
full description of the issue:
Page 2: 2.1. Numerical Types
In order to catch uses of inexact numbers where exact numbers are
required, Scheme explicitly distinguishes exact from inexact
numbers. This distinction is orthogonal to the dimension of type.
To my ear this says that each numerical type must be present in both
exact and inexact varieties. If that is the case, then the functions
of sections "16.5. Exact arithmetic" and "16.6. Inexact arithmetic"
are largely pointless; numeric code must dispatch to any of the
numeric types whether restricted to exacts or inexacts.
I propose that either
* "This distinction is orthogonal to the dimension of type." be
removed or modified; or
* Sections "16.5. Exact arithmetic" and "16.6. Inexact arithmetic"
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