Enums

Syntax

enum Name [attributes]
  ALPHA
  BETA
  GAMMA
endEnum

println Name.ALPHA         # ALPHA
println Name.ALPHA.name    # ALPHA
println Name.ALPHA.value   # 0
println Name.ALPHA->Int32  # 0
println Name.ALPHA->String # ALPHA
println Name.categories    # [ALPHA,BETA,GAMMA]
println Name.ALPHA == Name("ALPHA")  # true

enum Name( x:Real64, y=-1:Int32 )
  CATEGORIES
    ALPHA(1.1) = 1
    BETA(2.2)
    GAMMA(3.3,3)

  METHODS
    method z->Int32
      which (this)
        case BETA: return 1
        others:    return 0
      endWhich
endEnum

println Name.ALPHA->Int32  # 1
forEach (category in Name.categories)
  println "$ x:$ y:$ z:$"(category,category.x,category.y,category.z)
  # ALPHA x:1.1 y:-1 z:0
  # BETA x:2.2 y:-1 z:1
  # GAMMA x:3.3 y:3 z:0
endForEach

enum Flags [bitflags]
  ALPHA, BETA, GAMMA
endEnum

local flags = Flags[ALPHA,GAMMA] # equivalent to: Flags.ALPHA | Flags.GAMMA
trace flags.is_alpha  # true
trace flags.is_beta   # false
flags.is_alpha = false
trace flags           # GAMMA

Description

Enums are fast and efficient enumerated types. Underneath the hood they are implemented using pass-by-value compounds consisting of a single Int32 value. Any additional properties that are used to define enum categories are implemented as getter methods; they are not stored directly with each enum value.

Attributes

Attribute	Description
[bitflags]	Define category values as powers of two - 1, 2, 4, 8, ... instead of 0, 1, 2, 3, .... A bitflags enum also defines bitwise operators &, |, and ! as well as access methods is_x for each category X.

Properties

Property	Type	Description
value	Int32	The ordinal used to represent one of the enumerated categories.

Constructors

Constructor	Return Type	Description
EnumType(Int32)	EnumType	Creates an enumerated value from its ordinal.
EnumType(String)	EnumType	Creates an enumerated value from its String name.

Global Methods

Method	Return Type	Description
categories()	EnumType[]	Returns a list of every category defined in the enum.

Methods

Method	Return Type	Description
name()	String	Returns the name of the category.
operator?()	Logical	Returns true if the category's ordinal value is non-zero (if (enum_value?) ...).
operator==(other:EnumType)	Logical	Returns true if this enum's category matches the other (if (enum_value == Category.ALPHA).
to->Int32	Int32	Returns the category ordinal value.
to->String	String	Returns the category name.

[bitflags] Methods

Method	Return Type	Description
is_category()	Logical	Replicated for each bitflag category. E.g. an "Attributes" [bitflags] enum with categories BLOCKER and PUSHABLE will have methods is_blocker() and is_pushable().
set_is_category(Logical)	nil	Sets the desired category flag on an enum-type value. E.g. set_is_blocker(), set_is_pushable().
operator!()	EnumType	Returns an enum containing the bitwise complement of the original ordinal value.
operator&(other:EnumType)	EnumType	Returns the Bitwise-AND of two enums (if ((attributes & layer_mask)?) ...).
operator|(other:EnumType)	EnumType	Returns the Bitwise-OR of two enums.