Copy Page

You are not logged in. Any changes you make will be marked as anonymous. You may want to Log In if you already have an account. You can also Sign Up for a new account.

<p>Use this page to list use cases for AST-level macros in Groovy.</p>

<p>How do you want to use such macros? Show examples of their usage (without showing how they're implemented). Add to the bottom of the page.</p>

<h2>Increase code readability</h2>

<h4>Rearrange code portions</h4>

<p>The end-weight principle for natural languages says the longer stuff should be at the end of a sentence.<br />
In Groovy/Java, while and if statements are usually heavy in the block/statement, and light in the condition.<br />
When the statement/block is short and the condition long, it can be more readable to put the block last.<br />
Eg:</p>

<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
do{ i++; return c }if(
  ( severance.taxAmount >= TaxYear2006.taxAmounts.severanceLimit[ 'dependent' ] ||
     ... ... ...
     ... ... ...
)
</pre></td></tr></table>
<p>is transformed to:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
if( ... ... ... ){ i++; return c }
</pre></td></tr></table>
<p>We could use 'unless' and 'until' if using 'if' and 'while' caused problems.</p>

<h4>Common modifier</h4>

<p>When a long list of methods and/or fields have the same modifier/s,<br />
it may be more readable to apply them to a whole block, eg:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
static{
  def a(){ ... }
  def b(){ ... }
}
 
</pre></td></tr></table>
<p>becomes</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
static a(){ ... }
static b(){ ... }
</pre></td></tr></table>

<h4>Transform statements</h4>

<h4>Names for operators</h4>

<p>Use names instead of symbols for operators, eg:</p>

<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
if(a &amp;&amp; b)
</pre></td></tr></table>
<p>or change their names to something shorter, eg:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
if( a of A )
</pre></td></tr></table>
<p>becomes</p>

<h4>Equivalence of block and statement </h4>

<p>Forgoing curlies for all statements, making a statement and block equivalent always:<br />
Eg:</p>

<h2>Use other natural languages with Groovy</h2>

<p>Enable fuller internationalization of Groovy, eg:</p>

<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
mientras( i &lt; 10 ){ ... ... ... }
</pre></td></tr></table>
<p>would convert to </p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
while( i &lt; 10 ){ ... ... ... }
</pre></td></tr></table>
<p>if a Spanish option for Groovy was loaded. </p>

<h2>More Seamless Integration with Java and Java-like languages</h2>

<p>Embed Java code within Groovy without quoting it,<br />
and without needing to bind variables to the same name, ie, no binding.setVariable('i', i).<br />
eg:</p>

<h2>Simplify the Antlr lexer/parser</h2>

<p>Many existing syntactic sugars could be re-implemented as macros in a standard macro library.<br />
This might simplify the Antlr lexer/parser, enabling better maintenance of and extensions to it.</p>

<p>Eg, properties where:</p>