Author: larry
Date: Mon Jan 8 12:56:14 2007
New Revision: 13522
Modified:
doc/trunk/design/syn/S03.pod
Log:
eliminated Subset and Superset types.
eliminated .exists in favor of .contains
renamed LazyCat to just Cat for consistency with method and function variants
Modified: doc/trunk/design/syn/S03.pod
==============================================================================
--- doc/trunk/design/syn/S03.pod (original)
+++ doc/trunk/design/syn/S03.pod Mon Jan 8 12:56:14 2007
@@ -14,7 +14,7 @@
Date: 8 Mar 2004
Last Modified: 8 Jan 2007
Number: 3
- Version: 87
+ Version: 88
=head1 Changes to Perl 5 operators
@@ -645,12 +645,6 @@
Set Set identical sets $_ === X
Hash Set hash keys same set $_.keys === X
Any Set force set comparison Set($_) === X
- Set Subset subset .any === X.all
- Hash Subset subset of hash keys .any === X.all
- Any Subset force set comparison .Set.any === X.all
- Set Superset superset .all === X.any
- Hash Superset superset of hash keys .all === X.any
- Any Superset force set comparison .Set.all === X.any
Array Array arrays are comparable $_ «===» X (dwims * wildcards!)
Set Array array equiv to set $_ === Set(X)
@@ -658,10 +652,10 @@
Hash Hash hash keys same set $_.keys === X.keys
Set Hash hash keys same set $_ === X.keys
- Array Hash hash slice existence X.exists(any @$_)
+ Array Hash hash slice existence X.contains(any @$_)
Regex Hash hash key grep any($_.keys) === /X/
- Scalar Hash hash entry existence X.exists($_)
- Any Hash hash slice existence X.exists(any @$_)
+ Scalar Hash hash entry existence X.contains($_)
+ Any Hash hash slice existence X.contains(any @$_)
Str Regex string pattern match .match(X)
Hash Regex hash key "boolean grep" .any.match(/X/)
@@ -720,9 +714,9 @@
=========== ===============
List Seq Array
KeySet KeyBag KeyHash Hash
- Class Subset Enum Role Type
+ Class Enum Role Type
Subst Grammar Regex
- Char LazyCat Str
+ Char Cat Str
Int UInt etc. Num
Match Capture
Byte Str or Int
@@ -819,9 +813,9 @@
Array Seq array contains seq *,X,*
Array Seq array ends with seq *,X
Hash Str hash element truth .{X}
- Hash Str hash key existence .exists(X)
+ Hash Str hash key existence .contains(X)
Hash Num hash element truth .{X}
- Hash Num hash key existence .exists(X)
+ Hash Num hash key existence .contains(X)
Buf Int buffer contains int .match(X)
Str Char string contains char .match(X)
Str Str string contains string .match(X)
@@ -829,14 +823,21 @@
Str Array array contains string X.any
Num Array array contains number X.any
Scalar Array array contains object X.any
- Hash Array hash slice exists .exists(X.all) .exists(X.any)
- Any Set Subset relation Subset(X)
- Any Hash Subset relation Subset(X)
- Any Set Superset relation Superset(X)
- Any Hash Superset relation Superset(X)
- Any Set Sets intersect .exists(X.any)
- Set Array Subset relation X,* # (conjectured)
- Array Regex match array as string .cat.match(X)
+ Hash Array hash slice exists .contains(X.all) .contains(X.any)
+ Set Set subset relation .contains(X)
+ Set Hash subset relation .contains(X)
+ Any Set subset relation .Set.contains(X)
+ Any Hash subset relation .Set.contains(X)
+ Any Set superset relation X.contains($_)
+ Any Hash superset relation X.contains($_)
+ Any Set sets intersect .contains(X.any)
+ Set Array subset relation X,* # (conjectured)
+ Array Regex match array as string .Cat.match(X) cat(@$_).match(X)
+
+(Note that the C<.cat> method and the C<Cat> type coercion both take a
+single object, unlike the C<cat> function which, as a list operator,
+takes a syntactic list (or multilist) and flattens it. All of these
+return a Cat object, however.)
Boolean expressions are those known to return a boolean value, such
as comparisons, or the unary C<?> operator. They may reference C<$_>
@@ -878,8 +879,8 @@
the replication count of those unique keys. (Obviously, a C<Set> can
have only 0 or 1 replication because of the guarantee of uniqueness).
-The C<LazyCat> type allows you to have an infinitely extensible string.
-You can match an array or iterator by feeding it to a C<LazyCat>,
+The C<Cat> type allows you to have an infinitely extensible string.
+You can match an array or iterator by feeding it to a C<Cat>,
which is essentially a C<Str> interface over an iterator of some sort.
Then a C<Regex> can be used against it as if it were an ordinary
string. The C<Regex> engine can ask the string if it has more
@@ -891,7 +892,7 @@
the string, which may or may not be expeditious.)
The C<cat> operator takes a (potentially lazy) list and returns a
-C<LazyCat> object. In string context this coerces each of its elements
+C<Cat> object. In string context this coerces each of its elements
to strings lazily, and behaves as a string of indeterminate length.
You can search a gather like this:
@@ -899,16 +900,16 @@
$lazystr ~~ /pattern/;
-The C<LazyCat> interface allows the regex to match element boundaries
+The C<Cat> interface allows the regex to match element boundaries
with the C<< <,> >> assertion, and the C<StrPos> objects returned by
the match can be broken down into elements index and position within
that list element. If the underlying data structure is a mutable
array, changes to the array (such as by C<shift> or C<pop>) are tracked
-by the C<LazyCat> so that the element numbers remain correct. Strings,
+by the C<Cat> so that the element numbers remain correct. Strings,
arrays, lists, sequences, captures, and tree nodes can all be pattern
matched by regexes or by signatures more or less interchangably.
However, the structure searched is not guaranteed to maintain a C<.pos>
-unless you are searching a C<Str> or C<LazyCat>.
+unless you are searching a C<Str> or C<Cat>.
=head1 Meta operators
