Class constant parsing of Ruby

A constant begins with a capital letter. It should be assigned up to one time. In the current version of Ruby, the re-assignment of constants produces only warnings rather than errors (the Non-ansi version of EVAL.RB does not report this warning)

ruby>fluid=30
ruby>fluid=31
ruby>solid=32
ruby>solid=33
(eval ): 1:warning:already initialized constant Solid
33

Constants can be defined in classes, but unlike real variables, they can be accessed outside the class.

Ruby> Class Constclass
| C1=101
| c2=102
| c3=103
| def show
| print C1, "", C2, "", C3, "\ n"
| end |-nil ruby>
: ( Eval): 1:uninitialized constant C1
ruby> constclass::c1-ruby>
ConstClass.new.show
101 102
Nil