OpenEuphoria

Enum?

• Posted by Jeremy Cowgar <jeremy at ?o?gar.com> May 14, 2008
• 775 views

I do this all the time and I know others do because I see in it code everywhere.
Here are some examples, some of which you will recognize:

constant FILE_NO = 1,           -- file number
	 LINE_NO = 2,           -- local line number
	 FILE_PTR = 3,          -- open file number 
	 FILE_START_SYM = 4,    -- symbol before start of file
	 OP_WARNING = 5,        -- save/restore with/without options
	 OP_TRACE = 6,          
	 OP_TYPE_CHECK = 7,
	 OP_PROFILE_TIME = 8,
	 OP_PROFILE_STATEMENT = 9,
         OP_DEFINES = 10        -- ifdef defines

global constant GET_SUCCESS = 0,
		GET_EOF = -1,
		GET_FAIL = 1,
		GET_NOTHING = -2

global constant 
	D_NAME = 1,
	D_ATTRIBUTES = 2,
	D_SIZE = 3,
	D_YEAR = 4,
	D_MONTH = 5,
	D_DAY = 6,
	D_HOUR = 7,
	D_MINUTE = 8,
	D_SECOND = 9

Etc... This is fine, but what if you want to add a new element and not at the
end? I am sure we've all done it. Well, I borrowed a good thing from other
languages called an enum (enumeration)... I've done the code already but have not
committed. What do you think?

global enum D_NAME, D_ATTRIBUTES, D_SIZE, ...
global enum PERSON_NAME, PERSON_AGE=5, PERSON_DOB, PERSON_EMAIL

printf(1, "name=%d, attributes=%d, size=%d\n", {
    D_NAME, D_ATTRIBUTES, D_SIZE})
printf(1, "person_name=%d, age=%d, dob=%d, email=%d\n", {
    PERSON_NAME, PERSON_AGE, PERSON_DOB, PERSON_EMAIL})

-- name=1, attributes=2, size=3
-- person_name=1, age=5, dob=6, email=7

An enum is not a new type, it emits a constant. They can be local or global. I
think it has a lot of benefit but wanted to get community input.

--
Jeremy Cowgar
http://jeremy.cowgar.com