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[svn:perl6-synopsis] r14601 - doc/trunk/design/syn

November 7, 2008 09:54
[svn:perl6-synopsis] r14601 - doc/trunk/design/syn
Message ID:
Author: larry
Date: Fri Nov  7 09:54:43 2008
New Revision: 14601


get rid of pair methods; $obj ~~ :foo($bar) now simply does $ ~~ $bar
with all other adverbial pair notations having corresponding meanings, so
you can do things like $obj ~~ :$attr and $filehandle ~~ :!s.
Note that these now call ordinary methods, so for good or ill Str now has
a bunch of single-character methods like "foo".r.

Modified: doc/trunk/design/syn/S03.pod
--- doc/trunk/design/syn/S03.pod	(original)
+++ doc/trunk/design/syn/S03.pod	Fri Nov  7 09:54:43 2008
@@ -12,9 +12,9 @@
   Maintainer: Larry Wall <>
   Date: 8 Mar 2004
-  Last Modified: 17 Oct 2008
+  Last Modified: 7 Nov 2008
   Number: 3
-  Version: 145
+  Version: 146
 =head1 Overview
@@ -2169,16 +2169,19 @@
 =item *
-The filetest operators are gone.  We now use a C<Pair> as either a
-pattern or a method name to get the same effect:
+The filetest operators are gone.  We now use a C<Pair> as a
+pattern that calls an object's method:
     if $filename ~~ :e { say "exists" }
-    if $filename.:e { say "exists" }
+is the same as
+    if $filename.e { say "exists" }
 The 1st form actually translates to the latter form, so the object's
-class decides how to dispatch pair methods.  It just happens that
+class decides how to dispatch methods.  It just happens that
 C<Str> (filenames), C<IO> (filehandles), and C<Statbuf> (stat buffers)
-default to the expected filetest semantics, but C<$regex.:i> might
+default to the expected filetest semantics, but C<$regex.i> might
 tell you whether the regex is case insensitive, for instance.
 Using the pattern form, multiple tests may be combined via junctions:
@@ -2202,11 +2205,11 @@
 The advantage of the method form is that it can be used in places that
 require tighter precedence than C<~~> provides:
-    sort { $^a.:M <=> $^b.:M }, @files
+    sort { $^a.M <=> $^b.M }, @files
 though that's a silly example since you could just write:
-    sort { .:M }, @files
+    sort { .M }, @files
 But that demonstrates the other advantage of the method form, which is
 that it allows the "unary dot" syntax to test the current topic.
@@ -2227,7 +2230,9 @@
 C<.file> attempts to return C<.io.file>.
 Note that C<:s> still returns the filesize, but C<:!s> is true
-only if the file is of size 0.
+only if the file is of size 0, since it is smartmatched
+against the implicit False argument.  By the same token,
+C<:s(0..1024)> will be true only for files of size 1K or less.
 (Inadvertent use of the PerlĀ 5 forms will normally result in treatment
 as a negated postdeclared subroutine, which is likely to produce an
@@ -2996,7 +3001,7 @@
     Any       Num       numeric equality        +$_ == X
     Any       Str       string equality         ~$_ eq X
-    Any       Pair      test object             .:Xkey(Xval) (e.g. filetests)
+    Any       Pair      test object attribute   .Xkey ~~ Xval (e.g. filetests)
     Set       Set       identical sets          $_ === X
     Hash      Set       hash keys same set      $_.keys === X

Modified: doc/trunk/design/syn/S12.pod
--- doc/trunk/design/syn/S12.pod	(original)
+++ doc/trunk/design/syn/S12.pod	Fri Nov  7 09:54:43 2008
@@ -12,9 +12,9 @@
   Maintainer: Larry Wall <>
   Date: 27 Oct 2004
-  Last Modified: 14 Oct 2008
+  Last Modified: 7 Nov 2008
   Number: 12
-  Version: 64
+  Version: 65
 =head1 Overview
@@ -731,20 +731,6 @@
     my Dog $spot .= new(:tail<LONG> :legs<SHORT>);
-=head1 Pair query methods
-Certain classes such as filehandles allow colon pairs to be used as if they
-were methods.  Method names beginning with a colon:
-    $filehandle.:e
-    $filehandle.:!x
-are expected to return a value that can be used as a boolean.
-While this is primarily intended for use by file tests, other classes
-may define such methods to provide a similar mechanism for interrogating
-properties.  (Also note that syntactic category names are reserved for
-calling operators as if they were methods.)
 =head1 Calling sets of methods
 For any method name, there may be some number of candidate methods Perl Programming lists via nntp and http.
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