Method: BitArray#initialize

Defined in:

ext/bitarray.c

#new(size) ⇒ Object #new(string) ⇒ Object #new(array) ⇒ Object

When called with a size, creates a new BitArray of the specified size, with all bits cleared. When called with a string or an array, creates a new BitArray from the argument.

If a string is given, it should consist of ones and zeroes. If there are any other characters in the string, the first invalid character and all following characters will be ignored.

b = BitArray.new("10101010")       => 10101010
b = BitArray.new("1010abcd")       => 1010
b = BitArray.new("abcd")           =>

If an array is given, the BitArray is initialized from its elements using the following rules:

1. 0, false, or nil => 0

2. anything else => 1

Note that the 0 is a number, not a string. “Anything else” means strings, symbols, non-zero numbers, subarrays, etc.

b = BitArray.new([0,0,0,1,1,0])            => 000110
b = BitArray.new([false, true, false])     => 010
b = BitArray.new([:a, :b, :c, [:d, :e]])   => 1111

# File 'ext/bitarray.c', line 289

static VALUE
rb_bitarray_initialize(VALUE self, VALUE arg)
{
    if (TYPE(arg) == T_FIXNUM || TYPE(arg) == T_BIGNUM) {
        struct bit_array *ba;
        Data_Get_Struct(self, struct bit_array, ba);

        long bits = NUM2LONG(arg);
        if (bits <= 0) {
            ba->bits = 0;
            ba->array_size = 0;
            return self;
        }
        
        ba->bits = bits;
        ba->array_size = ((bits - 1) / UINT_BITS) + 1;
        ba->array = ruby_xcalloc(ba->array_size, UINT_BYTES);

        return self;

    } else if (TYPE(arg) == T_STRING) {
        return rb_bitarray_from_string(self, arg);
    } else if (TYPE(arg) == T_ARRAY) { 
        return rb_bitarray_from_array(self, arg);
    } else {
        rb_raise(rb_eArgError, "must be size, string, or array");
    }
}