[operators] add "is assoc" trait for operators that are not left-asso…

…ciative

lib/operators.pod

@@ -72,6 +72,8 @@ For unaries this is interpreted as:
 
 =end table
 
+In the operator descriptions below, a default associativity of I<left>
+is assumed.
 
 =head1 Operator classification
 
@@ -131,7 +133,7 @@ Technically this is not an operator, but syntax special-cased in the compiler.
 
 =head2 prefix ++
 
-    multi sub prefix:<++>($x is rw)
+    multi sub prefix:<++>($x is rw) is assoc<none>
 
 Increments its argument by one, and returns the incremented value.
 
@@ -145,7 +147,7 @@ semantics.
 
 =head2 prefix --
 
-    multi sub prefix:<-->($x is rw)
+    multi sub prefix:<-->($x is rw) is assoc<none>
 
 Decrements its argument by one, and returns the decremented value.
 
@@ -160,7 +162,7 @@ semantics.
 
 =head2 postfix ++
 
-    multi sub postfix:<++>($x is rw)
+    multi sub postfix:<++>($x is rw) is assoc<none>
 
 Increments its argument by one, and returns the unincremented value.
 
@@ -181,7 +183,7 @@ undefined values, it returns 0:
 
 =head2 postfix --
 
-    multi sub postfix:<-->($x is rw)
+    multi sub postfix:<-->($x is rw) is assoc<none>
 
 Decrements its argument by one, and returns the undecremented value.
 
@@ -204,7 +206,7 @@ undefined values, it returns 0:
 
 =head2 infix **
 
-    multi sub infix:<**>(Any, Any) returns Numeric:D
+    multi sub infix:<**>(Any, Any) returns Numeric:D is assoc<right>
 
 The exponentiation operator coerces both arguments to L<Numeric>
 and calculates the left-hand-side raised to the power of the right-hand side.
@@ -458,7 +460,7 @@ Coerces both arguments to L<Str> and concatenates them.
 
 =head2 infix &
 
-    multi sub infix:<&>($a, $b) returns Junction:D
+    multi sub infix:<&>($a, $b) returns Junction:D is assoc<list>
 
 Creates an I<all> L<Junction> from its arguments. See L<Junction> for more
 details.
@@ -467,14 +469,14 @@ details.
 
 =head2 infix |
 
-    multi sub infix:<|>($a, $b) returns Junction:D
+    multi sub infix:<|>($a, $b) returns Junction:D is assoc<list>
 
 Creates an I<any> L<Junction> from its arguments. See L<Junction> for more
 details.
 
 =head2 infix ^
 
-    multi sub infix:<^>($a, $b) returns Junction:D
+    multi sub infix:<^>($a, $b) returns Junction:D is assoc<list>
 
 Creates a I<one> L<Junction> from its arguments. See L<Junction> for more
 details.