Class: FFI::Enum

Inherits:

Object

• Object
• FFI::Enum

show all

Includes:

DataConverter

Defined in:

lib/ffi/enum.rb

Overview

enum fruits {
  apple,
  banana,
  orange,
  pineapple
};

Instance Attribute Summary (collapse)

• - (Object) tag readonly

  Returns the value of attribute tag.

Instance Method Summary (collapse)

• - (Object) [](query) (also: #find)

  Get a symbol or a value from the enum.

• - (Object) from_native(val, ctx)

  Symbol name if it exists for val.

• - (Enum) initialize(info, tag = nil) constructor

  A new instance of Enum.

• - (Type::INT) native_type

  Get native type of Enum.

• - (Hash) symbol_map (also: #to_h, #to_hash)

  Get the symbol map.

• - (Array) symbols

  Enum symbol names.

• - (Integer) to_native(val, ctx)

  Value of a enum symbol.

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# File 'lib/ffi/enum.rb', line 80

def initialize(info, tag=nil)
  @tag = tag
  @kv_map = Hash.new
  unless info.nil?
    last_cst = nil
    value = 0
    info.each do |i|
      case i
      when Symbol
        @kv_map[i] = value
        last_cst = i
        value += 1
      when Integer
        @kv_map[last_cst] = i
        value = i+1
      end
    end
  end
  @vk_map = Hash[@kv_map.map{|k,v| [v,k]}]
end

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# File 'lib/ffi/enum.rb', line 76

def tag
  @tag
end

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# File 'lib/ffi/enum.rb', line 115

def [](query)
  case query
  when Symbol
    @kv_map[query]
  when Integer
    @vk_map[query]
  end
end

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# File 'lib/ffi/enum.rb', line 155

def from_native(val, ctx)
  @vk_map[val] || val
end

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# File 'lib/ffi/enum.rb', line 136

def native_type
  Type::INT
end

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# File 'lib/ffi/enum.rb', line 127

def symbol_map
  @kv_map
end

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# File 'lib/ffi/enum.rb', line 102

def symbols
  @kv_map.keys
end

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# File 'lib/ffi/enum.rb', line 143

def to_native(val, ctx)
  @kv_map[val] || if val.is_a?(Integer)
    val
  elsif val.respond_to?(:to_int)
    val.to_int
  else
    raise ArgumentError, "invalid enum value, #{val.inspect}"
  end
end