Author: larry
Date: Fri Feb 8 16:36:58 2008
New Revision: 14505
Modified:
doc/trunk/design/syn/S03.pod
Log:
Missing associativity specs noted by moritz++ and [particle]++
Modified: doc/trunk/design/syn/S03.pod
==============================================================================
--- doc/trunk/design/syn/S03.pod (original)
+++ doc/trunk/design/syn/S03.pod Fri Feb 8 16:36:58 2008
@@ -12,9 +12,9 @@
Maintainer: Larry Wall <[EMAIL PROTECTED]>
Date: 8 Mar 2004
- Last Modified: 5 Feb 2008
+ Last Modified: 8 Feb 2008
Number: 3
- Version: 130
+ Version: 131
=head1 Overview
@@ -27,35 +27,57 @@
levels from "tightest" to "loosest", along with a few examples of
each level:
- Level Examples
- ===== ========
- Terms 42 3.14 "eek" qq["foo"] $x :!verbose @$array
- Method postfix .meth .+ .? .* .() .[] .{} .<> .«» .:: .= .^ .:
- Autoincrement ++ --
- Exponentiation **
- Symbolic unary ! + - ~ ? | +^ ~^ ?^ \ ^ =
- Multiplicative * / % +& +< +> ~& ~< ~> ?& div mod
- Additive + - +| +^ ~| ~^ ?| ?^
- Replication x xx
- Concatenation ~
- Junctive and (all) &
- Junctive or (any) | ^
- Named unary rand sleep abs
- Nonchaining infix but does <=> leg cmp .. ..^ ^.. ^..^
- Chaining infix != == < <= > >= eq ne lt le gt ge ~~ === eqv !eqv
- Tight and &&
- Tight or || ^^ // min max
- Conditional ?? !! ff fff
- Item assignment = := ::= => += -= **= xx= .=
- Loose unary true not
- Comma operator , p5=>
- List infix Z minmax X X~X X*X XeqvX
- List prefix = : print push say die map substr ... [+] [*] any $ @
- Loose and and andthen
- Loose or or xor orelse
- Terminator ; <==, ==>, <<==, ==>>, {...}, modifiers, extra ), ], }
+ A Level Examples
+ = ===== ========
+ N Terms 42 3.14 "eek" qq["foo"] $x :!verbose @$array
+ L Method postfix .meth .+ .? .* .() .[] .{} .<> .«» .:: .= .^ .:
+ L Autoincrement ++ --
+ R Exponentiation **
+ L Symbolic unary ! + - ~ ? | +^ ~^ ?^ \ ^ =
+ L Multiplicative * / % +& +< +> ~& ~< ~> ?& div mod
+ L Additive + - +| +^ ~| ~^ ?| ?^
+ N Replication x xx
+ L Concatenation ~
+ X Junctive and &
+ X Junctive or | ^
+ L Named unary rand sleep abs
+ N Nonchaining infix but does <=> leg cmp .. ..^ ^.. ^..^
+ C Chaining infix != == < <= > >= eq ne lt le gt ge ~~ === eqv !eqv
+ L Tight and &&
+ L Tight or || ^^ // min max
+ L Conditional ?? !! ff fff
+ R Item assignment = := ::= => += -= **= xx= .=
+ L Loose unary true not
+ X Comma operator , p5=>
+ X List infix Z minmax X X~X X*X XeqvX
+ R List prefix : print push say die map substr ... [+] [*] any $ @
+ L Loose and and andthen
+ L Loose or or xor orelse
+ N Terminator ; <==, ==>, <<==, ==>>, {...}, unless, extra ), ], }
+
+The associativities specified above are:
+
+ Assoc Meaning of $a op $b op $c
+ ===== =========================
+ L left ($a op $b) op $c
+ R right $a op ($b op $c)
+ N non ILLEGAL
+ C chain ($a op $b) and ($b op $c)
+ X list op($a, $b, $c) or op($a; $b; $c)
+
+Note that list associativity only works between identical operators.
+If two different list-associative operators have the same precedence,
+they are assumed to be left-associative with respect to each other.
+For example, the C<X> cross operator and the C<Z> zip operator both
+have a precedence of "list infix", but:
-If you don't see your favorite operator there, the following
+ @a X @b Z @c
+
+is parsed as:
+
+ (@a X @b) Z @c
+
+If you don't see your favorite operator above, the following
sections cover all the operators in precedence order. Basic operator
descriptions are here; special topics are covered afterwards.
@@ -239,7 +261,7 @@
As in Perl 5, a list operator looks like a term to the expression on
its left, so it binds tighter than comma on the left but looser than
-comma on the right--see List operator precedence below.
+comma on the right--see List prefix precedence below.
=back
