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 ExactSqrt version 1

## author

cowan

## comment

## ipnr

127.11.51.1

## name

ExactSqrt

## readonly

0

## text

This is an investigation of whether implementations return `#t` or `#f` to `(exact? (sqrt 25/4))`. RnRS recommends, but does not require, that the value is `#t`, but implementations are free to convert 25/4 to an inexact value and return the inexact square root of that. On implementations where exact rationals are not supported, `(exact? (sqrt 4))` was substituted.
Supports exact `sqrt`: Racket, Gauche, MIT, Gambit, Chicken with the `numbers` egg, Guile, Chez, Vicare, Larceny, Ypsilon, Mosh, !IronScheme, STklos, Unlikely, Rep, Sizzle, LMU, Sagittarius, Owl Lisp
Supports only inexact `sqrt`: plain Chicken, Bigloo, Scheme48/scsh, Kawa, SISC, SCM, NexJ, JScheme, KSi, BDC, Schemik, UMB, Elk, SXM, Dfsch, Inlab, Foment, Picrin, Chibi
Does not support `sqrt`: !SigScheme, Shoe, Llava, !FemtoLisp, Oaklisp
Indeterminate results (`exact?` does not exist and neither `eq?` nor the printer can be relied on to distinguish): SIOD, XLisp

## time

2015-09-15 19:44:34

## version

1