Proposal: Enum types as valid With-statement parameters

[Chris Nicholson-Sauls]

I recently found myself writing the following code:

# struct Var {
#
#   // ... other stuff ...
#
#   bool truth () {
#     switch (type) {
#       case VarType.Clear  :
#       case VarType.Error  : return false              ;
#       case VarType.Object : return o !is null         ;
#       case VarType.Int    : return i != 0_L           ;
#       case VarType.Float  : return f != 0.0_L         ;
#       case VarType.String : return s.length != 0      ;
#       case VarType.Symbol : return validSymbol()      ;
#       case VarType.Bool   : return b                  ;
#       case VarType.List   : return l.length != 0      ;
#       case VarType.Map    : return m.keys.length != 0 ;
#       case VarType.Frob   : return true               ;
#     }
#   }
#
#   // ... other stuff ...
#
# }

It would have been nice to be able to write this as:

# struct Var {
#
#   // ... other stuff ...
#
#   bool truth () {
#     with (VarType) switch (type) {
#       case Clear  :
#       case Error  : return false              ;
#       case Object : return o !is null         ;
#       case Int    : return i != 0_L           ;
#       case Float  : return f != 0.0_L         ;
#       case String : return s.length != 0      ;
#       case Symbol : return validSymbol()      ;
#       case Bool   : return b                  ;
#       case List   : return l.length != 0      ;
#       case Map    : return m.keys.length != 0 ;
#       case Frob   : return true               ;
#     }
#   }
#
#   // ... other stuff ...
#
# }

Walter: how difficult would it be to allow named Enum types as valid With-statement 
parameters?  When named Enums are used in tandem with constructs such as Switch, this 
could save quite a lot of typing, and is still perfectly clear when reading code.

-- Chris Nicholson-Sauls