--- This message is a formal comment which was submitted to [EMAIL PROTECTED], following the requirements described at: http://www.r6rs.org/process.html --- name: Kent Dybvig email: [EMAIL PROTECTED] type: defect priority: minor component: libraries version: 5.92
Summary: eliminate library export immutability loophole Description: The present description of libraries leaves open the possibility that a continuation grabbed within a variable definition's right-hand-side expression and subsequently invoked might cause the reinitialization, with different values, of some or all of the local counterparts of the exported variables, effecting implicit assignments to variables that are supposed to immutable. Since the effect of returning twice to the continuation of the last body expression is unspecified, this may also result in implicit assignments to the exported variables. If not, the values of the exported variables and their local counterparts may differ. While explicit assignments to immutable variables are syntax violations, no exception is presently associated with this implicit form of assignment. Proposal: Add new wording to the effect that the continuation of the right-hand-side expression of a library variable definition should not be returned to more than once and that implementations either "should" or "must" raise an exception if this occurs. _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
