+
+
+PROBLEM??
+
+ a if c else b
+could have a natural precedence:
+
+ A if C else B if q else a if c else b
+would be
+ A if C else (B if q else (a if c else b))
+Hmm.. not what I imagined. But what I imaging suggested that left-association what
+ a op b op c -> (a op b) op c
+requires that we reduce even when we could shift, ... maybe .... I should leave this
+until I do precedence.
+
+--------------------------
+
+Thinking about bit operators.
+
+#foo is 2^foo
+So #12-#4 is
+ 1000000000000 -
+ 10000
+= 111111110000
+which is bits 4 thru 11
+
+I'm wondering if it is useful to have a field-select operator,
+which could be '#' as infix (rather than prefix) so
+
+ var # field
+
+would be an lval which can only modify the selected bits
+
+ var # #12-#4 = #6-#4
+would clear bits 6-11. Doesn't actually read very well, does it?
+Probably better to use field syntax, with a way to declare fields for an int.
+This would be a record.
+
+Still.
+ var &~= #4
+ var |= #4
+to clear and set bits looks OK.
+But ... what syntax do I want for test-and-set? More genericly cmpxchg.
+An operator that modifies a variable is something I wanted to avoid.
+ var ? oldval = newval
+could 'use false' if it fails.