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. For a version of this page that may be more recent, see ShortEquality in WG2's repo for R7RS-large.

Short­Equality

cowan
2015-05-31 23:51:54
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R5RS and R7RS define = as accepting at least two arguments; it is an error to supply fewer. However, that doesn't forbid Schemes from providing extension behavior. This is an investigation of what Schemes in the suite do with (=) and (= 1):

Returns #t for both (=) and (= 1): MIT, Gambit, Chicken, Guile, SCM, KSi, Sizzle

Signals an error for (=), but returns #t for (= 1): Chez, Vicare, Ypsilon, IronScheme, JScheme, STklos, XLisp, Elk, Llava, SXM

Signals an error for (=), but returns #f for (= 1): FemtoLisp

Signals an error in both cases: Racket, Gauche, Bigloo, Scheme48/scsh, Kawa, SISC, Larceny, Mosh, NexJ, SigScheme, Shoe, TinyScheme, Scheme 9, RScheme, S7, BDC, Rep, Schemik, UMB, Dfsch, Inlab, Oaklisp, Sagittarius, Foment, Picrin, Owl Lisp, Chibi