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 DatumLabels in WG2's repo for R7RS-large.


2015-06-01 04:56:44

I tested datum-label support with the following expression:

(let ((x '(#1=(a b) #1#))) (eq? (car x) (cadr x)))

Gauche, MIT, Bigloo, Kawa, Chez, Ikarus/Vikare, Larceny*, Mosh, STklos, FemtoLisp, Sagittarius, Foment, Picrin support the syntax and return #t;

Racket, Chicken, Scheme48/scsh, Guile, SISC, SCM, Larceny*, Ypsilon, IronScheme, NexJ, JScheme, KSi, SigScheme, TinyScheme, Scheme 9, RScheme, S7, XLisp, Rep, Schemik, Elk, SXM, Sizzle, Dfsch, Inlab, Oaklisp, Owl Lisp, Chibi (native mode) report lexical syntax errors;

Gambit, Shoe, BDC, UMB, Llava, Chibi (R7RS mode) return #f for whatever reason.

*Larceny v0.98 normally recognizes the syntax, but reports a lexical error in R6RS mode (as is required by the R6RS).