Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation

comment on

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

I did some studying on non-determinism.

An example of a non-deterministic algorithm is mergesort.

use sort '_mergesort'; my @sorted = sort { substr($a, 0, 1) cmp substr($b, 0, 1) } qw( foo bar baz );

It is guarantees that the results will the sorted, but the relative ordering of baz and bar is not specified. Therefore, mergesort is non-deterministic.

Let's see if we can replicate the same situation with the parser.

The goals of Perl's parser include the production of functions.

package Mod; BEGIN { my ($sub) = map "sub { $_ }", join ' ', map "$_();", sort { substr($a, 0, 1) cmp substr($b, 0, 1) } qw( foo bar baz ); } sub foo { print "$foo\n" }; sub bar { print "$bar\n" }; sub baz { print "$baz\n" }; 1;

The parser produces a function that calls foo(), bar() and baz(), but the order in which the calls are organized is not specified. Therefore, the parser is non-deterministic.

I don't know what that means wrt Perl's parsability, since I don't know I don't know how that's defined.

In reply to Re^4: Unparseability is A Good Thing by ikegami
in thread Unparseability is A Good Thing by Jeffrey Kegler

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

  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?

What's my password?
Create A New User
Domain Nodelet?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others musing on the Monastery: (1)
As of 2022-01-29 04:33 GMT
Find Nodes?
    Voting Booth?
    In 2022, my preferred method to securely store passwords is:

    Results (74 votes). Check out past polls.