This site is a static rendering of the Trac instance that was used by R7RS-WG1 for its work on R7RS-small (PDF), which was ratified in 2013. For more information, see Home.

Source for wiki Zero version 1

author

cowan

comment

ipnr

98.14.172.204

name

Zero

readonly

text

This page talks about various aspects of zero.  Thanks to Alexey Radul for some of the ideas here.

=== Exact division by zero ===

PLT, MIT, Gambit, Chicken, Bigloo, Scheme48/scsh, Guile, SISC, Chez, Ikarus, Larceny, Mosh, Scheme 7, sscm, SXM, VSCM, and Chibi report an error.

Gauche, Kawa, SCM, Scheme 9 return inexact infinity.

=== Inexact division by exact zero ===

PLT, MIT, Gambit, Chicken, Scheme48/scsh, Guile, Scheme 7, SXM, VSCM report an error.

Gauche, Bigloo, Kawa, SISC, Chez, Ikarus, Larceny, Mosh, Scheme 9 return inexact infinity.

SSCM does not handle inexact numbers.

=== Division by inexact zero ===

Chicken, Scheme 7, SXM, VSCM report an error.

PLT, Gauche, Gambit, Bigloo, Scheme48/scsh, Guile, Kawa, SISC, Chez, SCM, Ikarus, Larceny, Mosh, Scheme 9, Chibi return inexact infinity.

SSCM does not handle inexact numbers.

=== Inexact multiplication by exact zero ===

PLT, MIT, Gambit, Guile, Chez, SXM return exact 0.

Gauche, Chicken, Bigloo, Scheme48/scsh, Kawa, SISC, SCM, Ikarus, Larceny, Mosh, Scheme 9, Scheme 7, VSCM, Chibi return inexact 0.0.

SSCM does not handle inexact numbers.

=== Complex numbers with 0.0 imaginary part.

Gauche, MIT-Scheme, Chicken (with the numbers egg), Scheme48/scsh, Guile, Kawa, SISC, SCM, Scheme 7, VSCM consider 3.0+0.0i to be a real number.

PLT, Gambit, Chez, Ikarus, Larceny, Mosh do not.

Bigloo, Scheme 9, SSCM, SXM, Chibi do not implement general complex numbers.

time

2010-03-18 13:28:53