Lambda calculus! But it doesn't have integers (or any data types for that matter), you say? Sure it does, it has Church numerals!
my $two = sub { my($f,$x) = @_; $f->($f->($x)); };
sub add {
my($m,$n) = @_;
sub { my($f,$x) = @_; $m->($f, $n->($f, $x)) };
}
sub decode { my($n) = @_; $n->( sub{$_[0]+1}, 0 ); }
print decode( add($two, $two) ), $/;
Yeah, at some point we have to convert the Church numeral to something that Perl can print.. but you get the idea.
-
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 How to display code and escape characters
are good places to start.
|
