rb_u_string_chop.c

#include "rb_includes.h"

/* Returns the receiver, minus its last character, inheriting any taint and
 * untrust, unless the receiver is {#empty?} or if the last character is
 * invalidly encoded, in which case the receiver is returned.
 *
 * If the last character is U+000A LINE FEED and the second-to-last character
 * is U+000D CARRIAGE RETURN, both characters are removed.
 *
 * @return [U::String]
 * @see #chomp
 * @see #lstrip
 * @see #rstrip
 * @see #strip */
VALUE
rb_u_string_chop(VALUE self)
{
        const struct rb_u_string *string = RVAL2USTRING(self);

        if (USTRING_LENGTH(string) == 0)
                return self;

        const char *begin = USTRING_STR(string);
        const char *end = USTRING_END(string);

        const char *last;
        uint32_t c = u_decode_r(&last, begin, end);
        if (c == '\n')
                if (*(last - 1) == '\r')
                        last--;

        return rb_u_string_new_c(self, begin, last - begin);
}