On Mon, Jan 03 2011, Juan Jose Garcia-Ripoll wrote: > The specification of #= seems to be ill defined with respect to its > interaction > with reader macros. Take this: > > #1=(1 2 3 #.(print '#1#)) > > it crashes SBCL and produces garbage in ECL. Similar problems about the
It doesn't seem to crash if *print-circle* it set to 't'. It seems to print various internal symbols, though. SBCL prints an uninterned symbol. Clisp prints a #<READ-LABEL 1>. CCL prints what appears to be an intermediate construction of the list. All seem to return the correct list, however. But, the value printed seems to be not-well-defined. > interaction between #+ and #= > > (1 2 #+#1=(:ecl) 3 #+#1# 4) I can make this work in all non-ECL lisps, by doing something like: (1 2 #+#1=:ecl 3 #+#1# 4) or (1 2 #+#1=(or :ecl) 3 #+#1# 4) But that is a problem with the (:ecl) being an illegal #+ expression. > or the interaction with #. > > (1 #1=2 #.(print #1#)) This also seems to work fine on non-ECL lisp. > Is the reader for #+,#. expected to do some sharp-eq replacement in the > resulting forms? What about user code implementing reader macros? How shound > ECL recognize that an eager replacement is needed when reading inside some > user > reader macro, specially if he/she uses :recursive t??? I don't find anything in the spec that says how these should behave. The closest is that #+ should read the feature expression, and then read the following expression. But, I'm not sure the object is required to be well defined until the entire top-level form is defined. Hopefully others have more insight. David ------------------------------------------------------------------------------ Learn how Oracle Real Application Clusters (RAC) One Node allows customers to consolidate database storage, standardize their database environment, and, should the need arise, upgrade to a full multi-node Oracle RAC database without downtime or disruption http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ Ecls-list mailing list Ecls-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ecls-list
