Class: Flagpole

Inherits:
Object
  • Object
show all
Defined in:
lib/flagpole.rb,
lib/flagpole/version.rb

Constant Summary collapse

VERSION = 
"0.1.0".freeze

Instance Method Summary collapse

Constructor Details

#initialize(value = 0, flags) ⇒ Flagpole

Public: Initialize the set of flags.

value - An Integer with the initial value of the set. flags - The name of the flags you’re using.



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# File 'lib/flagpole.rb', line 6

def initialize(value = 0, flags)
  @flags = flags.zip(bitmap(value, flags.size)).to_h
end

Instance Method Details

#[](key) ⇒ Object

Public: Get a specific flag by name.

key - One of the flag names passed to the initializer.

Returns Boolean.



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# File 'lib/flagpole.rb', line 15

def [](key)
  @flags.fetch(key)
end

#[]=(flag, val) ⇒ Object

Public: Set a specific flag by name.

flag - One of the flag names passed to the initializer. value - A Boolean.

Returns nothing. Raises ArgumentError if passed a flag that isn’t in the set.



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# File 'lib/flagpole.rb', line 26

def []=(flag, val)
  fail ArgumentError, "#{flag} isn't a valid flag" unless @flags.key?(flag)
  @flags[flag] = val
end

#to_h ⇒ Object

Public: Returns a Hash with all the flags and their current values.



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# File 'lib/flagpole.rb', line 39

def to_h
  @flags
end

#to_i ⇒ Object

Public: Returns the current value of the flag set as an Integer.



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# File 'lib/flagpole.rb', line 32

def to_i
  @flags.each_value.with_index.inject(0) do |flag, (bit, power)|
    flag | (bit ? 1 : 0) * 2**power
  end
end

#value_of(flag) ⇒ Object

Public: Find the integer value of a single flag, regardless of whether it is set or not. This value can then be added/substracted from the integer value of this set for low-level manipulation of the flag set.

flag - The name of a flag.

Returns an Integer. Raises ArgumentError if passed a flag that isn’t in the set.



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# File 'lib/flagpole.rb', line 51

def value_of(flag)
  fail ArgumentError, "#{flag} isn't a valid flag" unless @flags.key?(flag)
  2 ** @flags.keys.index(flag)
end