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Complex­Representations

cowan
2012-07-16 01:07:48
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How a variety of Schemes represent complex numbers:

Exact, inexact, and mixed complex number representations, where inexact and mixed numbers that are = are nevertheless distinct in the sense of eqv?: Gambit, Chibi. (Also CLISP, Pure.)

Exact, inexact, and mixed complex number representations, where inexact and mixed numbers that are = are the same in the sense of eqv?: MIT, STklos.

Exact and inexact complex number representations only (mixed complex numbers become inexact): Racket, Chicken with the numbers egg, Scheme48/scsh, Kawa, Chez, Vicare, Larceny, Ypsilon, IronScheme, Wraith. (Also ABCL, Allegro CL, Clozure CL, CMUCL, ECL, GNU CL, LispWorks, SBCL, Scieneer CL.)

Inexact complex number representations only: Gauche, Guile, SISC, SCM, KSi, Scheme 7, UMB, Stalin. (Also Fortran, C/C++, Python, etc.)

Exact complex number representations only: Owl Lisp (which has no inexact numbers).

No complex numbers: plain Chicken, Bigloo, Ikarus, NexJ, SigScheme, Shoe, TinyScheme, Scheme 9, Dream, RScheme, BDC, XLisp, Rep, Schemik, Elk, VX, Oaklisp.

Mosh has a bug whereby numbers that are = are always eqv? even if they differ in exactness; it supports exact, inexact, and mixed complex number representations, but doesn't differentiate exact from inexact properly.

See also NumericTower.