Author: lwall
Date: 2009-02-24 05:36:33 +0100 (Tue, 24 Feb 2009)
New Revision: 25513
Modified:
docs/Perl6/Spec/S02-bits.pod
docs/Perl6/Spec/S03-operators.pod
docs/Perl6/Spec/S12-objects.pod
docs/Perl6/Spec/S16-io.pod
docs/Perl6/Spec/S28-special-variables.pod
Log:
kill DEF* variants
Modified: docs/Perl6/Spec/S02-bits.pod
===================================================================
--- docs/Perl6/Spec/S02-bits.pod 2009-02-24 04:11:42 UTC (rev 25512)
+++ docs/Perl6/Spec/S02-bits.pod 2009-02-24 04:36:33 UTC (rev 25513)
@@ -1409,14 +1409,14 @@
is subject to:
$foo ordinary scoping
- $.foo object attribute accessor
+ $.foo object attribute public accessor
$^foo self-declared formal positional parameter
$:foo self-declared formal named parameter
$*foo contextualizable global variable
$?foo compiler hint variable
$=foo pod variable
$<foo> match variable, short for $/{'foo'}
- $!foo explicitly private attribute (mapped to $foo though)
+ $!foo object attribute private storage (mapped to $foo though)
Most variables with twigils are implicitly declared or assumed to
be declared in some other scope, and don't need a "my" or "our".
Modified: docs/Perl6/Spec/S03-operators.pod
===================================================================
--- docs/Perl6/Spec/S03-operators.pod 2009-02-24 04:11:42 UTC (rev 25512)
+++ docs/Perl6/Spec/S03-operators.pod 2009-02-24 04:36:33 UTC (rev 25513)
@@ -2840,6 +2840,13 @@
By default C<min> and C<max> use C<cmp> semantics. As with all C<cmp>-based
operators, this may be modified by an adverb specifying different semantics.
+=item *
+
+Note that, like most other operators, a comparison naturally throws
+an exception if either of its arguments is undefined. However,
+various parallelizable contexts such as sort and hyper suppress this,
+er, somehow.
+
=back
=head1 Range semantics
Modified: docs/Perl6/Spec/S12-objects.pod
===================================================================
--- docs/Perl6/Spec/S12-objects.pod 2009-02-24 04:11:42 UTC (rev 25512)
+++ docs/Perl6/Spec/S12-objects.pod 2009-02-24 04:36:33 UTC (rev 25513)
@@ -1298,6 +1298,11 @@
my enum Day ['Sun','Mon','Tue','Wed','Thu','Fri','Sat'];
my enum Day <Sun Mon Tue Wed Thu Fri Sat>;
+For any enum value the C<.perl> method will return its long name.
+A numeric enum value numifies to its numeric value and stringifies to its
short name.
+A string enum value has no special numeric value, and stringifies to its
string value
+rather than its name. [XXX inconsistent]
+
If the first value is unspecified, it defaults to 0. To specify the
first value, use pair notation (see below).
Modified: docs/Perl6/Spec/S16-io.pod
===================================================================
--- docs/Perl6/Spec/S16-io.pod 2009-02-24 04:11:42 UTC (rev 25512)
+++ docs/Perl6/Spec/S16-io.pod 2009-02-24 04:36:33 UTC (rev 25513)
@@ -13,8 +13,8 @@
Tim Nelson <[email protected]>
Daniel Ruoso <[email protected]>
Date: 12 Sep 2006
- Last Modified: 19 Feb 2009
- Version: 20
+ Last Modified: 23 Feb 2009
+ Version: 21
This is a draft document. Many of these functions will work as in Perl
5, except we're trying to rationalize everything into roles. For
@@ -24,23 +24,47 @@
corresponding global function, it's merely an exported version of
the method.
-=head1 Default IO handles
+=head1 Overridable IO handles
-In Perl 6, there are the I<standard> handles, and the I<default> handles.
+In Perl 6, there are the I<standard> IO handles, and any number of overriding
+inner filehandles for the same symbol.
-The I<standard> ones are our old familiar friends (with new names). Standard
input
-changed from STDIN to C<$*IN>, standard output changed from STDOUT to
C<$*OUT>, and
-standard error changed from STDERR to C<$*ERR>.
+The I<standard> handles are our old familiar friends (with new names).
+Standard input changed from STDIN to C<$*IN>, standard output changed
+from STDOUT to C<$*OUT>, and standard error changed from STDERR to
+C<$*ERR>. In Perl 6 these symbols represent more of a concept than
+a given filehandle, since the meaning is contextually determined.
+The process's version of these handles live in the C<PROCESS::>
+namespace, which is more global than the per-interpreter C<GLOBAL::>
+namespace.
-However, the I<default> ones replace the single handle set by the Perl 5
select() call
-with with three new variables.
-At the start of the program, the default handles (C<$*DEFIN>, C<$*DEFOUT>, and
-C<$*DEFERR>) are aliased to the standard handles, but may be temporarily or
permanently
-rebound to some other file handle.
+When no explicit filehandle is used, the standard IO operators are
+defined in terms of the contextual variables. So the C<print> function
+prints to C<$*OUT>, while C<warn> warns to C<$*ERR>. The C<< =<> >>
+term inputs from C<$*IN>. So any given dynamic scope (interpreter,
+thread, function or method call) may redefine the current meaning of
+any of those filehandles within the dynamic scope of itself and of
+its called routines.
-Many of the roles and functions below will operate on the default handles. To
set all 3
-at once, do C<($*DEFIN, $*DEFOUT, $*DEFERR) ::= ($*IN, $*OUT, $*ERR)>.
+So to put it another way, when you write something like
+ say "Howdy, world!"
+
+the C<say> function looks for the current meaning of C<$*OUT>, and
+takes the closest definition it can find in its callers. If none
+of the callers have overridden the definition, it looks in the
+interpreter's C<GLOBAL> namespace. If the interpreter hasn't overridden
+the meaning, it takes the meaning from C<PROCESS>. In essence, any
+dynamic scope in Perl 6 is allowed to do IO redirection much like
+a Unix shell does with its subprocesses, albeit with a different
+syntax:
+
+ {
+ temp $*OUT = open $newfile, :w;
+ foo() # all stdout goes to $newfile
+ }
+ # stdout reverts to outer scope's definition
+
=head1 Roles and Classes
The roles and classes that define most of the functionality for IO are defined
in
Modified: docs/Perl6/Spec/S28-special-variables.pod
===================================================================
--- docs/Perl6/Spec/S28-special-variables.pod 2009-02-24 04:11:42 UTC (rev
25512)
+++ docs/Perl6/Spec/S28-special-variables.pod 2009-02-24 04:36:33 UTC (rev
25513)
@@ -9,7 +9,7 @@
Contributions: Tim Nelson <[email protected]>
Date: 23 Feb 2009, created from miscellaneous documents lying around
Last Modified: 23 Feb 2009
- Version: 1
+ Version: 2
=head1 Introduction
@@ -23,53 +23,45 @@
Perl 5 variable(s). The list of main entries is also followed by
a table showing the 5 and 6 variables side-by-side.
-Most/All variables of the form $*SOMETHING should also work in the form
-$SOMETHING (without the '*') unless masked by "my $SOMETHING".
-
=head1 Overview
=head2 Secondary Sigils (also known as "twigils"):
- $+ # currently compiling scope (see S02)
- $? # lexically-scoped (compile time, see S02)
- $* # global (run time, see S02)
- $= # file-scoped (see S02)
- $^ # implicit block argument (see S06 placeholder variables)
+ $? # constants (variable only at compile time, see S02)
+ $* # context variables and globals (run time, see S02)
+ $= # pod documents, file-scoped (see S02)
+ $^ # self-declaring block positional parameter (see S06 placeholder
variables)
+ $: # self-declaring block named parameter (see S06 placeholder variables)
$< # current $/ scope (see S02)
- $. # public attribute (see S12 attributes)
- $! # private attribute (see S12 attributes)
+ $. # public attribute accessor (see S12 attributes)
+ $! # private attribute storage (see S12 attributes)
=head2 Named variables (see S02):
- $/ # match object from last rule (see S05)
- $0 # first captured value from match: $/.[0]
+ $/ # match object from last match (see S05)
+ $0 # first captured value from match: $/[0]
@*ARGS # command-line arguments
&?BLOCK # current block (itself, see S06)
@?BLOCK # current blocks (themselves, see S06)
- $?BLOCKLABEL # label of current block (see S06)
- # XXX redundant with $?LABEL?
::?CLASS # current class (as package name)
$?CLASS # current class (as variable)
@?CLASS # current classes
%?CONFIG # configuration hash
$=DATA # data block handle (=begin DATA ... =end)
- $*DEFIN # Default input file handle (see S16)
- $*DEFOUT # Default output file handle (see S16)
- $*DEFERR # Default error file handle (see S16)
$*EGID # effective group id
%*ENV # system environment
$*ERR # standard error handle (see S16)
$*EUID # effective user id
$*EXECUTABLE_NAME # executable name
- $?FILE # current file
+ $?FILE # current filename of source file
$?GRAMMAR # current grammar
@?GRAMMAR # current grammars
$*GID # group id
$*IN # standard input handle (see S16)
$?LABEL # label of current block
@?LABEL # labels of current blocks
- $?LINE # current line
+ $?LINE # current line number in source file
$?MODULE # current module
@?MODULE # current modules
$?OS # operating system compiled for
@@ -84,9 +76,6 @@
$*PERLVER # perl version running under
$*PROGRAM_NAME # name of the program being executed
$*PID # system process id
- $?PUGS_VERSION # Pugs version (not canonical)
- $*PUGS_HAS_HSPLUGINS # True if Pugs was compiled with support for hsplugins
- # (not canonical)
::?ROLE # current role (as package name)
$?ROLE # current role (as variable)
@?ROLE # current roles
@@ -94,12 +83,17 @@
@?ROUTINE # current subs or methods (themselves)
$*UID # system user id
-There were threads on p6l about unifying all variables which concern the OS or
-the VM ($*UID, $*PROGRAM_NAME, etc.) into two variables, $?ENV (compile-time
-environment) and $*ENV (runtime environment). Larry did like the idea, but
-"ENV" is probably to overloaded to mean the hash of environment variables
-(which would be found under $*ENV.environment or some-such).
+Note that contextual variables such as C<$*OUT> may have more than
+one current definition in the outer dynamic context, in which case
+the innermost dynamic scope determines the meaning. For instance,
+C<$PROCESS::OUT> is the stdout for the entire process, but each
+interpreter can set its own C<$GLOBAL::OUT> to make C<$*OUT> mean
+whatever it wants independently of other interpreters. Any dynamic
+scope may also declare a local meaning of C<$*OUT> that applies only
+to called code. Likewise each thread could log its own errors
+to its own C<$*ERR>, since a thread is a dynamic scope.
+
=head1 Special Variables
This section only lists variables that don't have a "See S16" or suchlike next
to them in
