Class: Array

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Instance Method Summary collapse

Instance Method Details

#mask(*args) ⇒ Object 



1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
 
# File 'ext/string_bits/string_bits.c', line 1672

static VALUE
rb_ary_mask(int argc, VALUE *argv, VALUE self)
{
    VALUE bitmap;
    int lsb_first, invert, is_integer;
    parse_mask_kwargs(argc, argv, &bitmap, &lsb_first, &invert, &is_integer);

    ssize_t ary_len = RARRAY_LEN(self);
    const VALUE *src = RARRAY_CONST_PTR(self);
    VALUE result = rb_ary_new_capa(ary_len);

    if (is_integer) {
        for (ssize_t i = 0; i < ary_len; i++) {
            int bit = integer_get_bit(bitmap, i);
            if (invert) bit = !bit;
            rb_ary_push(result, bit ? src[i] : Qnil);
        }
    }
    else {
        const unsigned char *bmp = (const unsigned char *)RSTRING_PTR(bitmap);
        ssize_t bmp_len    = RSTRING_LEN(bitmap);
        ssize_t needed     = (ary_len + 7) >> 3;
        if (needed > bmp_len)
            rb_raise(rb_eArgError,
                     "bitmap too short: need %ld bytes for %ld elements, got %ld",
                     needed, ary_len, bmp_len);

        if (!lsb_first) {
            for (ssize_t i = 0; i < ary_len; i++) {
                int bit = (bmp[i >> 3] >> (7 - (i & 7))) & 1;
                if (invert) bit = !bit;
                rb_ary_push(result, bit ? src[i] : Qnil);
            }
        }
        else {
            for (ssize_t i = 0; i < ary_len; i++) {
                int bit = (bmp[i >> 3] >> (i & 7)) & 1;
                if (invert) bit = !bit;
                rb_ary_push(result, bit ? src[i] : Qnil);
            }
        }
    }

    return result;
}

#mask!(*args) ⇒ Object 



1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
 
# File 'ext/string_bits/string_bits.c', line 1718

static VALUE
rb_ary_mask_bang(int argc, VALUE *argv, VALUE self)
{
    VALUE bitmap;
    int lsb_first, invert, is_integer;
    parse_mask_kwargs(argc, argv, &bitmap, &lsb_first, &invert, &is_integer);

    ssize_t ary_len = RARRAY_LEN(self);
    rb_ary_modify(self);

    if (is_integer) {
        for (ssize_t i = 0; i < ary_len; i++) {
            int bit = integer_get_bit(bitmap, i);
            if (invert) bit = !bit;
            if (!bit) rb_ary_store(self, i, Qnil);
        }
    }
    else {
        const unsigned char *bmp = (const unsigned char *)RSTRING_PTR(bitmap);
        ssize_t bmp_len    = RSTRING_LEN(bitmap);
        ssize_t needed     = (ary_len + 7) >> 3;
        if (needed > bmp_len)
            rb_raise(rb_eArgError,
                     "bitmap too short: need %ld bytes for %ld elements, got %ld",
                     needed, ary_len, bmp_len);

        if (!lsb_first) {
            for (ssize_t i = 0; i < ary_len; i++) {
                int bit = (bmp[i >> 3] >> (7 - (i & 7))) & 1;
                if (invert) bit = !bit;
                if (!bit) rb_ary_store(self, i, Qnil);
            }
        }
        else {
            for (ssize_t i = 0; i < ary_len; i++) {
                int bit = (bmp[i >> 3] >> (i & 7)) & 1;
                if (invert) bit = !bit;
                if (!bit) rb_ary_store(self, i, Qnil);
            }
        }
    }

    return self;
}