each_char

/*
 *  Document-method: each_char
 *  call-seq:
 *     str.each_char {|cstr| block }    => str
 *  
 *  Passes each character in <i>str</i> to the given block.
 *     
 *     "hello".each_char {|c| print c, ' ' }
 *     
 *  <em>produces:</em>
 *     
 *     h e l l o 
 */

static VALUE
rb_str_each_char(VALUE str)
{
    int i, len, n;
    const char *ptr;

    RETURN_ENUMERATOR(str, 0, 0);
    str = rb_str_new4(str);
    ptr = RSTRING(str)->ptr;
    len = RSTRING(str)->len;
    for (i = 0; i < len; i += n) {
        n = mbclen(ptr[i]);
        rb_yield(rb_str_substr(str, i, n));
    }
    return str;
}