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Contents
# -*- coding: utf-8 -*-
require 'xot/bit_util'
module Xot
class BitFlag
include BitUtil
alias make_bit bit
def initialize(auto: false, none: 0, **flags, &block)
@bit2sym, @sym2bit, @auto, @next = {}, {none: none, no: none}, auto, 1
flags.each {|sym, value| flag sym, value}
BlockUtil.instance_eval_or_block_call self, &block if block
end
def flag(symbol, value = nil, bit: nil)
bit = value || make_bit(bit) || (@auto ? @next : nil)
raise ArgumentError if !bit
raise "flag: symbol #{symbol.inspect} or bit #{bit} is already registered." if
@sym2bit.key?(symbol) || @bit2sym.key?(bit)
single_bit = bit.to_s(2).count('1') == 1
@sym2bit[symbol] = bit
@bit2sym[bit] = symbol if single_bit
@next = bit << 1 if single_bit && bit >= @next
bit
end
def bits2symbols(bits)
array = []
bits.to_s(2).reverse.each_char.with_index do |char, index|
next unless char == '1'
symbol = @bit2sym[bit index]
raise "unknown bit #{index} for flag." unless symbol
array << symbol
end
array
end
def symbols2bits(*symbols)
symbols.flatten.reduce(0) {|value, symbol| value | sym2bit(symbol)}
end
private
def sym2bit(symbol)
bit = @sym2bit[symbol]
bit = flag symbol if !bit && @auto
raise "unknown symbol #{symbol.inspect} for flag." unless bit
bit
end
end# BitFlag
end# Xot
Version data entries
13 entries across 13 versions & 1 rubygems