method

slice!

v1_8_7_330 - Show latest stable - 0 notes - Class: Array

slice!(...) public

Deletes the element(s) given by an index (optionally with a length) or by a range. Returns the deleted object, subarray, or nil if the index is out of range. Equivalent to:

def slice!(*args)
  result = self[*args]
  self[*args] = nil
  result
end

a = [ "a", "b", "c" ]
a.slice!(1)     #=> "b"
a               #=> ["a", "c"]
a.slice!(-1)    #=> "c"
a               #=> ["a"]
a.slice!(100)   #=> nil
a               #=> ["a"]

Show source

/*
 *  call-seq:
 *     array.slice!(index)         -> obj or nil
 *     array.slice!(start, length) -> sub_array or nil
 *     array.slice!(range)         -> sub_array or nil 
 *  
 *  Deletes the element(s) given by an index (optionally with a length)
 *  or by a range. Returns the deleted object, subarray, or
 *  <code>nil</code> if the index is out of range. Equivalent to:
 *     
 *     def slice!(*args)
 *       result = self[*args]
 *       self[*args] = nil
 *       result
 *     end
 *     
 *     a = [ "a", "b", "c" ]
 *     a.slice!(1)     #=> "b"
 *     a               #=> ["a", "c"]
 *     a.slice!(-1)    #=> "c"
 *     a               #=> ["a"]
 *     a.slice!(100)   #=> nil
 *     a               #=> ["a"]
 */

static VALUE
rb_ary_slice_bang(argc, argv, ary)
    int argc;
    VALUE *argv;
    VALUE ary;
{
    VALUE arg1, arg2;
    long pos, len, orig_len;

    rb_ary_modify_check(ary);
    if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {
        pos = NUM2LONG(arg1);
        len = NUM2LONG(arg2);
      delete_pos_len:
        if (len < 0) return Qnil;
        orig_len = RARRAY_LEN(ary);
        if (pos < 0) {
            pos += orig_len;
            if (pos < 0) return Qnil;
        }
        else if (orig_len < pos) return Qnil;
        if (orig_len < pos + len) {
            len = orig_len - pos;
        }
        if (len == 0) return rb_ary_new2(0);
        arg2 = rb_ary_new4(len, RARRAY_PTR(ary)+pos);
        RBASIC(arg2)->klass = rb_obj_class(ary);
        rb_ary_splice(ary, pos, len, Qnil);    /* Qundef in 1.9 */
        return arg2;
    }

    if (!FIXNUM_P(arg1)) {
        switch (rb_range_beg_len(arg1, &pos, &len, RARRAY_LEN(ary), 0)) {
          case Qtrue:
            /* valid range */
            goto delete_pos_len;
          case Qnil:
            /* invalid range */
            return Qnil;
          default:
            /* not a range */
            break;
        }
    }

    return rb_ary_delete_at(ary, NUM2LONG(arg1));
}

slice!

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