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 EmptyList in WG2's repo for R7RS-large.


2014-12-28 08:28:57

The empty list is self-evaluating in Gauche, MIT, Kawa, SISC, Chibi, SCM, NexJ, STklos, SigScheme, TinyScheme, Scheme 9, Dream, S7, BDC, Xlisp, Rep, Jscheme, Schemik, VX, Oaklisp, Sizzle, Spark, Femtolisp, Dfsch, Inlab, Owl Lisp, Sagittarius.

Racket, Gambit, Chicken, Bigloo, Guile, Scheme48/scsh, Chez, Ikarus/Vicare, Larceny, Ypsilon, Mosh, IronScheme, KSi, Shoe, Elk, RScheme, UMB, Llava, SXM, signal a syntax error.

Larceny signals a syntax warning but then treats the empty list as self-evaluating.

In XLisp, Rep, VX, (car '()) and (cdr '()) evaluate to the empty list, as in Common Lisp.