Author: lwall
Date: 2009-12-03 20:00:40 +0100 (Thu, 03 Dec 2009)
New Revision: 29250
Modified:
docs/Perl6/Spec/S02-bits.pod
docs/Perl6/Spec/S12-objects.pod
docs/Perl6/Spec/S32-setting-library/Containers.pod
Log:
make pair values sequences both associative and positional
revise enum mixins to distinguish attribute vs method mixin
Modified: docs/Perl6/Spec/S02-bits.pod
===================================================================
--- docs/Perl6/Spec/S02-bits.pod 2009-12-03 15:33:14 UTC (rev 29249)
+++ docs/Perl6/Spec/S02-bits.pod 2009-12-03 19:00:40 UTC (rev 29250)
@@ -13,8 +13,8 @@
Created: 10 Aug 2004
- Last Modified: 23 Nov 2009
- Version: 192
+ Last Modified: 3 Dec 2009
+ Version: 193
This document summarizes Apocalypse 2, which covers small-scale
lexical items and typological issues. (These Synopses also contain
@@ -1151,7 +1151,7 @@
Set Unordered collection of values that allows no duplicates
Bag Unordered collection of values that allows duplicates
PairVal An immutable Pair
- PairValSet Set of PairVals with no duplicate keys
+ PairValSeq Seq of PairVals with no duplicate keys
Signature Function parameters (left-hand side of a binding)
Parcel List of syntactic objects
Capture Function call arguments (right-hand side of a binding)
@@ -1206,7 +1206,7 @@
Set Associative[Bool]
Bag Associative[UInt]
PairVal Associative
- PairValSet Associative
+ PairValSeq Associative Postional Iterable
Signature
Parcel Positional
Capture Positional Associative
@@ -1227,7 +1227,7 @@
KeySet KeyHash of Bool (does Set in list/array context)
KeyBag KeyHash of UInt (does Bag in list/array context)
Pair A single key-to-value association
- PairSet A Set of Pairs
+ PairSeq A Seq of Pairs
Buf Perl buffer (a stringish array of memory locations)
IO Perl filehandle
Routine Base class for all wrappable executable objects
@@ -1275,7 +1275,7 @@
replicated the number of times specified by its corresponding value.
(Use C<.kv> or C<.pairs> to suppress this behavior in list context.)
-As with C<Hash> types, C<Pair> and C<PairSet> are mutable in their
+As with C<Hash> types, C<Pair> and C<PairSeq> are mutable in their
values but not in their keys. (A key can be a reference to a mutable
object, but cannot change its C<.WHICH> identity. In contrast,
the value may be rebound to a different object, just as a hash
@@ -1288,8 +1288,9 @@
Hash Associative
KeySet KeyHash[Bool]
KeyBag KeyHash[UInt]
+ KeyHash Associative
Pair Associative
- PairSet Associative
+ PairSeq Associative Postional Iterable
Buf Stringy
IO
Routine Callable
Modified: docs/Perl6/Spec/S12-objects.pod
===================================================================
--- docs/Perl6/Spec/S12-objects.pod 2009-12-03 15:33:14 UTC (rev 29249)
+++ docs/Perl6/Spec/S12-objects.pod 2009-12-03 19:00:40 UTC (rev 29250)
@@ -13,8 +13,8 @@
Created: 27 Oct 2004
- Last Modified: 28 Nov 2009
- Version: 93
+ Last Modified: 3 Dec 2009
+ Version: 94
=head1 Overview
@@ -1713,7 +1713,7 @@
3 ~~ Day # True, using Day as a subset of Int
Day.mapping # hash of key/value pairs
-The C<.mapping> method returns a C<PairValSet> that may be used like
+The C<.mapping> method returns a C<PairValSeq> that may be used like
a constant hash value:
my enum CoinFace <Heads Tails>;
@@ -1747,7 +1747,9 @@
%e<ook.> = 1;
%e<ook?> = 2;
-The enum installer inspects list values for pairs, where the value
+The return value of an anonymous enum is a c<PairValSeq>.
+
+The enum composer inspects list values for pairs, where the value
of the pair sets the next value explicitly. Non-pairs C<++> the
previous value. (Str and buf types increment like Perl 5 strings.)
Since the C<«...»> quoter automatically recognizes
@@ -1782,7 +1784,7 @@
or the old one.) Any explicit sub or type definition hides all imported
enum values of the same name but will produce a warning unless
C<is redefined> is included. Note that true() is a built-in function
-and requires an argument, while True is short for C<Bool::True> and
+and requires an argument, while C<True> is short for C<Bool::True> and
does not take an argument.
Since non-native enum values know their enum type, they may be used to
@@ -1801,16 +1803,31 @@
An enum type is not in itself a role type; however, the C<but>
and C<does> operators know that when a user supplies an enum type,
it implies the generation of an anonymous mixin role that creates an
-attribute of the enum type along with an accessor. If we assume
-there is a C<Has> role that creates an attribute, then
+an appropriate accessor, read-write if an attribute is being created, and
+read-only otherwise. It depends on whether you mix in the whole
+or a specific enum value or the whole enum type:
+ $x = "Today" but Tue; # $x.Day is read-only
+ $x = "Today" but Day; # $x.Day is read-write
+
+Mixing in a specific enum object implies only the readonly accessor.
+
$x = "Today" but Tue;
-really means something more like:
+really means something like:
- $x = "Today";
- $x does Has[Day, '$.Day', (:rw), { Tue }];
+ $x = "Today".clone;
+ $x does anon role { method Day { Day::Tue } };
+The fully qualified form does the same thing, and is useful
+in case of enum collision:
+
+ $x = "Today" but Day::Tue;
+
+Note that the method name is still C<.Day>, however. If
+you wish to mix in colliding method names, you'll have to
+mixin your own anonymous role with different method names.
+
Since enum supplies the type name as a coercion, you can
also say:
@@ -1839,6 +1856,21 @@
all return false.
+Mixing in the whole enum type produces a read-write attribute:
+
+ $x = "Today" but Day; # read-write .Day
+
+really means something like:
+
+ $x = "Today".clone;
+ $x does anon role { has Day $.Day is rw }
+
+Note that the attribute is not initialized. If that is desired
+you can supply a C<WHENCE> closure:
+
+ $x = "Today" but Day{ :Day(Tue) }
+ $x = "Today" but Day{ Tue } # conjecturally, for "simple" roles
+
To add traits to an enum declaration, place them after the declared
name but before the list:
@@ -1876,7 +1908,7 @@
$obj.Bool.Int != 0
Never compare a value to "C<true>", or even "C<True>". Just use it
-in a boolean context.
+in a boolean context. Well, almost never...
If you wish to be explicit about a boolean context, use the high-level
C<true> function or C<?> prefix operator, which are underlying based
Modified: docs/Perl6/Spec/S32-setting-library/Containers.pod
===================================================================
--- docs/Perl6/Spec/S32-setting-library/Containers.pod 2009-12-03 15:33:14 UTC
(rev 29249)
+++ docs/Perl6/Spec/S32-setting-library/Containers.pod 2009-12-03 19:00:40 UTC
(rev 29250)
@@ -19,8 +19,8 @@
Created: 19 Feb 2009 extracted from S29-functions.pod
- Last Modified: 29 Sep 2009
- Version: 9
+ Last Modified: 3 Dec 2009
+ Version: 10
The document is a draft.
@@ -810,19 +810,22 @@
=back
-=head2 PairValSet
+=head2 PairValSeq
- class PairValSet does Associative {...}
+ class PairValSeq does Associative does Positional {...}
-An immutable hash value, essentially. The keys may
-not contain duplicates, while the values may.
+An immutable hash value, viewable either as a (readonly) hash or
+as a sequence of C<PairVal>s. The keys may not contain duplicates,
+while the values may.
-=head2 PairSet
+=head2 PairSeq
- class PairSet does Associative {...}
+ class PairSeq does Associative does Positional {...}
-A hash value that is mutable only in values. The keys may
-not contain duplicates, while the values may.
+A hash value that is mutable only in values, differing from a normal
+hash insofar as the key set is frozen. It may be accessed either as
+a frozen hash or as a sequence of C<Pair>s. The keys may not contain
+duplicates, while the values may.
=head2 Set
