Class: Array

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

Instance Method Summary collapse

Instance Method Details

#mask(*args) ⇒ Object 



1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
 
# File 'ext/string_bits/string_bits.c', line 1852

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 %" PRIdPTR " bytes for %" PRIdPTR
                     " elements, got %" PRIdPTR,
                     (intptr_t)needed, (intptr_t)ary_len, (intptr_t)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 



1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
 
# File 'ext/string_bits/string_bits.c', line 1899

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 %" PRIdPTR " bytes for %" PRIdPTR
                     " elements, got %" PRIdPTR,
                     (intptr_t)needed, (intptr_t)ary_len, (intptr_t)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;
}