1.3 KiB
1.3 KiB
| title |
|---|
| Enums |
Enums
Enums in Nimrod are like enums in C, but are type-checked. There are no anonymous enums in Nimrod.
type
# Note the Hungarian notation, used to avoid conflicts
CompassDirections = enum
cdNorth, cdEast, cdSouth, cdWest
# {.pure.} means it values must be prefixed with the enum's name
Colors {.pure.} = enum
Red = "FF0000", Green = (1, "00FF00"), Blue = "0000FF"
# Enums can have holes in them
# Not recommended, exists only for interoperability with C
Signals = enum
sigQuit = 3, sigAbort = 6, sigKill = 9
# Iterates through the values
for direction in cdNorth..cdWest:
# `ord()` returns the integer value of the enum
# `CompassDirections()` is the inverse of `ord()`
echo CompassDirections(ord(direction)), " ord: ", ord(direction)
# `ord` gives the integer value, even if there are holes
echo ord(sigQuit)
# Enums are ordinal and have `inc` and `dec`
var ordinal = low(int)
inc ordinal
dec ordinal
echo high(char)
when false:
var nonOrdinal = sigQuit
# `Signals` has holes and so isn't ordinal,
# so `inc` and `dec` don't work
inc nonOrdinal
dec nonOrdinal
# The custom `$` makes it echo the hex value
for color in Colors.Red..Colors.Blue:
echo color
$ nimrod c -r enums.nim
cdNorth ord: 0
cdEast ord: 1
cdSouth ord: 2
cdWest ord: 3
3
FF0000
00FF00
0000FF