Hi all,
while working on the BACNet mspec I did notice, that it would be quite
beneficial, if we had support for some sort of enum concept.
While thinking even more about it, perhaps it would also be good NOT to use
enum types in Java as quite often only a part of the enum value range is
specified and the rest can be freely defined by the vendors or users.
Using enums in Java would sort of eliminate this ability.
So I would suggest to generally use some singleton classes pattern as it is
mostly used in languages without enum support.
Here a suggested syntax:
For classical “single-value” enums:
[enum 'ApplicationTags' uint 4
['0x0' 'NULL']
['0x1' 'BOOLEAN']
['0x2' 'UNSIGNED_INTEGER']
['0x3' 'SIGNED_INTEGER']
['0x4' 'REAL']
['0x5' 'DOUBLE']
['0x6' 'OCTET_STRING']
['0x7' 'CHARACTER_STRING']
['0x8' 'BIT_STRING']
['0x9' 'ENUMERATED']
['0xA' 'DATE']
['0xB' 'TIME']
['0xC' 'BACNET_OBJECT_IDENTIFIER']
]
In the S7 protocol we sometimes have one code that defines the value, but there
are multiple other values tied to these constants.
Here I would use something like this:
[enum 'ApplicationTags' uint 4 [uint 8 'hurz', char 8 'lalala', bit 'dumdidum']
['0x0' 'NULL' ['0x1', 'A', '1']]
['0x1' 'BOOLEAN' ['0x1', 'A', '1']]
['0x2' 'UNSIGNED_INTEGER' ['0x1', 'A', '1']]
['0x3' 'SIGNED_INTEGER' ['0x1', 'A', '1']]
...
]
What do you think?
Chris
