Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

Nonsense. It's easy-peasy. Slurp the whole file into memory; convert to a character string, then then offer filehandle-like accessors to that string.

Obviously, you want to avoid slurping the whole file into memory, but that's "just" an optimization. Worry about that when you've got the easy-peasy implementation working right.

As it happens, with UTF-32 you do know whether you're in the middle of a character (as in: codepoint, rather than grapheme), because each character is exactly 32 bits. Just take the byte offset modulo 4. So UTF-32 is an easy case to optimize and avoid slurping the entire file.

UTF-8 is harder but not much. If the high bit is set on a byte, you're in a multibyte sequence. If the second highest bit is also set, you're at the start of a multibyte sequence, and then you can count how many bits there are until the first zero bit, and that tells you how many bytes are in the sequence.

So you optimize specific, common cases, and fall back to the slurping technique.

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

In reply to Re^2: How do I use the "File::ReadBackwards" and open in "Unicode text, UTF-32, little-endian" mode by tobyink
in thread How do I use the "File::ReadBackwards" and open in "Unicode text, UTF-32, little-endian" mode by hashperl

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others exploiting the Monastery: (4)
    As of 2018-05-26 08:31 GMT
    Find Nodes?
      Voting Booth?