Enumeration_IO

[mfeldman@seas.gwu.edu (Mike Feldman)]

In preparing some programs for a book I am working on, I have gotten
interested in the idiosyncracies of Enumeration_IO. Specifically, the
PUT operations in this generic package are supposed to have a parameter
SET of type TYPE_SET, where TYPE_SET is (LOWER_CASE, UPPER_CASE).

Well, consider an enumeration type
  type COLORS is (red, blue, green);
and an instance 
  package COLOR_IO is new TEXT_IO.ENUMERATION_IO(ENUM => COLORS);
and a variable
  C : COLORS := blue;
and an output operation
  COLOR_IO.PUT(ITEM => C);

All is well so far, everything compiles and runs except that the output
value is BLUE, because the default is Upper_Case. Now change the output
operation to
  COLOR_IO.PUT(ITEM => C, SET => LOWER_CASE);

Irvine Ada (HP835), IntegrAda (IBM-PC), VADS (Sun3) and AdaVantage (Sun3)
ALL bail out on a "LOWER_CASE is an undefined identifier" diagnostic.
Clearly something is going on here. According to LRM 14.3.9 this should be
allowed. Can anyone provide some enlightenment here?

I will post a program if anyone wants to try this out.
---------------------------------------------------------------------------
Prof. Michael Feldman
Department of Electrical Engineering and Computer Science
The George Washington University
Washington, DC 20052
+1-202-994-5253
mfeldman@seas.gwu.edu
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