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    copied!<p>Sounds like a case for <a href="http://search.cpan.org/perldoc?Parse::RecDescent" rel="noreferrer">Parse::RecDescent</a>:</p> <pre><code>use strict; use warnings; use Parse::RecDescent; my $text = '((((!((cond1) || (cond2) || (cond3)) &amp;&amp; (cond4))) &amp;&amp; (cond5)) &lt;= (((cond6) || (cond7) || (cond8)) || (cond9)))'; #$::RD_TRACE=1; my $grammar = q{ startrule: expr expr: operand operation(s?) { $return = @{$item[2]} ? { 'operations' =&gt; $item[2], 'lvalue' =&gt; $item[1] } : $item[1] } operation: /\|\||&amp;&amp;|&lt;=/ operand { $return = { 'op' =&gt; $item[1], 'rvalue' =&gt; $item[2] } } operand: '(' expr ')' { $return = $item[2] } operand: '!' operand { $return = { 'op' =&gt; '!', 'value' =&gt; $item[2] } } operand: /\w+/ }; my $parser = Parse::RecDescent-&gt;new($grammar); my $result = $parser-&gt;startrule($text) or die "Couldn't parse!\n"; use Data::Dumper; $Data::Dumper::Indent = 1; $Data::Dumper::Sortkeys = 1; print Dumper $result; </code></pre> <p>The grammar, in English:</p> <p>The whole thing is an expression. An expression is an operand followed by zero or more binary operators and their operands. Each operand is either a parenthesized expression, '!' followed by an operand, or a word (e.g. <code>cond1</code>).</p> <p>Every node in the produced tree is in one of the following forms:</p> <ul> <li><code>cond1</code> - a condition</li> <li><code>{ 'op' =&gt; '!', 'value' =&gt; 'node' }</code> - ! applied to another node</li> <li><code>{ 'lvalue' =&gt; 'node', 'operations' =&gt; [ one or more of: { 'op' =&gt; 'binop', 'rvalue' =&gt; 'node' } ] }</code> - series of one or more operations representing node binop node binop node ...</li> </ul> <p>I didn't break series of binary operations (e.g. <code>((cond1) || (cond2) || (cond3))</code>) into a binary tree because you provided no information about precedence or associativity.</p> <p>Output for your example is:</p> <pre><code>$VAR1 = { 'lvalue' =&gt; { 'lvalue' =&gt; { 'lvalue' =&gt; { 'op' =&gt; '!', 'value' =&gt; { 'lvalue' =&gt; 'cond1', 'operations' =&gt; [ { 'op' =&gt; '||', 'rvalue' =&gt; 'cond2' }, { 'op' =&gt; '||', 'rvalue' =&gt; 'cond3' } ] } }, 'operations' =&gt; [ { 'op' =&gt; '&amp;&amp;', 'rvalue' =&gt; 'cond4' } ] }, 'operations' =&gt; [ { 'op' =&gt; '&amp;&amp;', 'rvalue' =&gt; 'cond5' } ] }, 'operations' =&gt; [ { 'op' =&gt; '&lt;=', 'rvalue' =&gt; { 'lvalue' =&gt; { 'lvalue' =&gt; 'cond6', 'operations' =&gt; [ { 'op' =&gt; '||', 'rvalue' =&gt; 'cond7' }, { 'op' =&gt; '||', 'rvalue' =&gt; 'cond8' } ] }, 'operations' =&gt; [ { 'op' =&gt; '||', 'rvalue' =&gt; 'cond9' } ] } } ] }; </code></pre>
 

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