Author: lwall
Date: 2010-03-26 08:38:16 +0100 (Fri, 26 Mar 2010)
New Revision: 30205
Modified:
docs/Perl6/Spec/S02-bits.pod
docs/Perl6/Spec/S03-operators.pod
docs/Perl6/Spec/S05-regex.pod
docs/Perl6/Spec/S06-routines.pod
docs/Perl6/Spec/S12-objects.pod
Log:
[specs] Make it clear that pairs are *not* related to subscripts, but the
corresponding fatarrow semantics in particular, name extenders are just
strings or list of strings, properly indicated by :<> or :() in most cases
(this includes all operator names). Forbid name extension using :{}, and
since names may no longer be extended with :{}, we can free up that notation
for supplying a closure as a first argument to a method without an intervening
space. (We can't also get rid of the colon, or it's a hash subscript.)
Modified: docs/Perl6/Spec/S02-bits.pod
===
--- docs/Perl6/Spec/S02-bits.pod2010-03-26 04:10:22 UTC (rev 30204)
+++ docs/Perl6/Spec/S02-bits.pod2010-03-26 07:38:16 UTC (rev 30205)
@@ -13,8 +13,8 @@
Created: 10 Aug 2004
-Last Modified: 12 Mar 2010
-Version: 208
+Last Modified: 26 Mar 2010
+Version: 209
This document summarizes Apocalypse 2, which covers small-scale
lexical items and typological issues. (These Synopses also contain
@@ -2919,14 +2919,14 @@
infix:<+>
infix:<<+>>
infix:«+»
-infix:['+']
+infix:('+')
Despite the appearance as a subscripting form, these names are resolved
not at run time but at compile time. The pseudo-subscripts need not
be simple scalars. These are extended with the same two-element list:
infix:
-infix:['??','!!']
+infix:('??','!!')
An identifier may be extended with multiple named identifier
extensions, in which case the names matter but their order does not.
@@ -3280,10 +3280,10 @@
16 => $somevalue:16($somevalue) radix conversion function
'' => $x:($x) arglist or signature literal
'' => ($x,$y) :($x,$y)arglist or signature literal
-'' =>:identifier extension
-'' => «x» :«x»identifier extension
-'' => [$x,$y] :[$x,$y]identifier extension
-'' => { .say } :{ .say } adverbial block
+'' =>:name extension
+'' => «x» :«x»name extension
+'' => ($x,$y) :($x,$y)name extension
+'' => { .say } :{ .say } adverbial block (not allowed on names)
All of the adverbial forms (including the normal ones with
identifier keys) are considered special tokens and are recognized
@@ -3314,6 +3314,22 @@
standard Perl 6 grammar knows the current set of infix operators,
for instance.)
+Only identifiers that produce a list of one or more values (preferably
+strings) are allowed as name extensions; in particular, closures
+do not qualify as values, so the C<:{...}> form is not allowed as a
+name extender. In particular, this frees up the block form after a method
+name, so it allows us to parse a block as a method argument:
+
+@stuff.sort:{ +$_ }.map:{ $_ * 2 }
+
+These might look like it is using pairs, but it is really equivalent to
+
+@stuff.sort: { +$_ }.map: { $_ * 2 }
+
+and the colons are not introducing pairs, but rather introducing
+the argument list of the method. (In any other location, C<:{...}>
+would be taken as a pair mapping the null key to a closure.)
+
Either fatarrow or adverbial pair notation may be used to pass
named arguments as terms to a function or method. After a call with
parenthesized arguments, only the adverbial syntax may be used to pass
@@ -3327,8 +3343,9 @@
Note that (as usual) the C<{...}> form (either identifier-based
or special) can indicate either a closure or a hash depending on
-the contents. It does I always indicate a subscript despite
-being parsed as one. (The function to which it is passed can I
+the contents. It does I indicate a subscript, since C<:key{}> is
+really equivalent to C {}>, and the braces are not behaving
+as a postfix at all. (The function to which it is passed can I
the value as a subscript if it chooses, however.)
Note also that the C<< >> form is not a subscript and is
@@ -4414,16 +4431,16 @@
category: prefix:<+>
circumfix:<[ ]> [ @x ]
dotty:<.=> $obj.=method
-infix_circumfix_meta_operator:{'»','«'} @a »+« @b
+infix_circumfix_meta_operator:('»','«') @a »+« @b
infix_postfix_meta_operator:<=> $x += 2;
infix_prefix_meta_operator: $x !~~ 2;
infix:<+> $x + $y
package_declarator: role Foo;
postcircumfix:<[ ]> $x[$y] or $x.[$y]
-postfix_prefix_meta_operator:{'»'} @array »++
+postfix_prefix_meta_operat
