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Source for wiki MaxInfNan version 2

author

cowan

comment

ipnr

98.14.173.81

name

MaxInfNan

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text

R6RS requires that `(max +inf.0 x)` for any real x return `+inf.0`; it is silent about `(max x +inf.0)`, but I'd think that was entailed.  I tested `(max +inf.0 +nan.0)` against the test suite.

Racket, Gauche, MIT, Chicken (with and without the numbers egg), Scheme48, Guile, Ypsilon, Mosh, !IronScheme, STklos, Elk, VX return `+inf.0`.

Gambit, Bigloo, Kawa, SISC, Chibi, Chez, Vicare, Larceny, NexJ, UMB, Spark, Femtolisp return `+nan.0`.  

My other Schemes throw errors, either because they don't like inexact numbers, they don't like division by 0.0, or they produce cockeyed values of `(/ 1.0 0.0)` and/or `(/ 0.0 0.0)`.

Note that the six R6RS implementations are split 3-3 (or 4-3 if Guile, which does not fully implement R6RS, is included), and that all the Java ones prefer `+nan.0`, as Java does.

time

2012-06-21 00:04:43