Author: lwall Date: 2010-07-13 01:59:37 +0200 (Tue, 13 Jul 2010) New Revision: 31651
Modified: docs/Perl6/Spec/S13-overloading.pod Log: [S13] try to make multisig semantics slightly more generic so sigs can do better pattern matching Modified: docs/Perl6/Spec/S13-overloading.pod =================================================================== --- docs/Perl6/Spec/S13-overloading.pod 2010-07-12 23:51:27 UTC (rev 31650) +++ docs/Perl6/Spec/S13-overloading.pod 2010-07-12 23:59:37 UTC (rev 31651) @@ -99,12 +99,14 @@ that will be imported wherever they are needed. When you use the multiple signature syntax, the alternate signatures -must all bind the same set of formal variable names, though they -are allowed to vary in any other way, such as by type, or by which -parameters are considered optional or named-only or slurpy. In other -words, the compiler is allowed to complain if any of the alternatives -omits any of the variable names. This is intended primarily to catch -editing errors. +are not required to all bind the same set of formal variable names, +nor are all parameters of a given name required to bind with the +same type. Unbound parameters will be born with an undefined value +(even if they have a default). For any parameter that occurs in +multiple signatures with non-identical nominal types, the actual +lexical variable will declared with a nominal type of C<Mu>, and +if unbound, will contain C<Mu>. To catch parameter name typos, +the compiler may warn about unused parameters. Conjectural: If the first parameter to a C<multi> signature is followed by an invocant colon, that signature represents two signatures, one
