+- exactly where does auto enref/deref happen?
+ .foo modifier does auto-deref
+ (args) modifier does auto-deref (if that makes sense)
+ assignments does auto-enref
+ function parameter passing does auto enref and auto deref
+
+ general operators? Not comparison. Not test. Probably not anything.
+
+- can "A if B else C" have "A" and "C" be different - one a ref and one not?
+ This might make sense if a ref was wanted - an lvalue is then accepted.
+
+- ? modifier for type makes "no such value" an option, detected by '?' operator
+- $ operator to convert to ?number from ... ref? enum?
+ ?$"hello" can test if the conversion would work. '$foo ?? default'
+ provides a default value
+- a suffix on a number/string can provide soft typing which is interpreted
+ in type context. Must like .enumvalue is interpreted only the context of
+ expected type, '43i' would only be meaningful in the same context.
+- const arrays that are initialized incrementally throughout the code,
+ and post-processed at compile-time, e.g. to sort or derive LR tables.
+ Maybe even across modules.
+ Need a syntax
+ Maybe 'const' can be followed by name of a const which forms the namespace.
+ So a struct bar containing x and y could be initialized
+ const foo::bar
+ x ::= 1; y::=2
+ Then an array could be extended with [+]
+ const ra[+]
+ x::=2 ...
+
+ The syntax needs to be clearly different from
+ const a::num=1; b::=2
+ if that is still allowed
+ Maybe the '=' is enough to differentiate
+
+- IN and OUT should not be completely ignored when not expected.
+ As well as causing NEWLINE to be ignored, there should be some
+ balance requirement. Some productions should be required to be
+ balanced. Lists should not have gratuitous indents.
+ Revisit everything I considered before, but now consider it only
+ for ignore IN/OUT.
+
+- "debug" code that can be compiled out. For code, "if debug" is enough
+ if the const can be set easily. For structure members a 'debugonly'
+ attribute needs to be handled. Of course 'debug' is multifaceted.
+ We might want tracing, consistency, profiling, etc.
+