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<table class="wysiwyg-macro" data-macro-name="warning" data-macro-parameters="title=Warning" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e3dhcm5pbmc6dGl0bGU9V2FybmluZ30&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="RICH_TEXT"><tr><td class="wysiwyg-macro-body">
<p>This page was created to report about the changes in syntax when we switched to a new parser back in 2004. So some of the points below are not necessarily representative of what Groovy supports nowadays. Please take the notes below with a grain of salt!</p></td></tr></table>

<p>Here is a checklist of changes you'll need to make to a Groovy classic codebase to ensure compatibility with the new Groovy JSR syntax.</p>

<h2>Safe navigation</h2>

<p>In Classic Groovy we used to use this syntax</p>

<p>Instead of using the arrow operator for safe navigation to avoid NullPointerException, we're now using the ?. operator</p>

<p>Now in the JSR we use this syntax</p>

<h2>Parameter separator in the closure syntax</h2>

<p>This allows us to use one single token for the separator between the closure in Classic Groovy we used to use this syntax</p>

<p>Now in the JSR we use this syntax</p>

<p>This allows us to use one single token for the separator between the closure parameters and the code in in the closure which works with arbitrarily complex parameter list expressions and default values. e.g.</p>

<h2>Property keyword</h2>

<ul>
	<li>property keyword has been replaced with an annotation
<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>
class Foo {
    property foo
}
</pre></td></tr></table>
<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>
class Foo {
    @Property foo
}
</pre></td></tr></table></li>
</ul>

<h2>Introduction of the 'def' keyword</h2>

<ul>
	<li>local variable declarations and fields currently need to be specified with 'def', a modifier, and/or a type. e.g.
<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>
def foo() {
  int x = 123
  y = 456 // classic
}

def foo() {
  int x = 123
  def y = 456 // JSR
}

class Foo {
    telson  // classic
    int sharna
}
class Foo {
    def telson  // JSR
    int sharna
}
</pre></td></tr></table>
(Syntactically, the new keyword 'def' acts for methods as a modifier like 'public'.)</li>
</ul>

<p>For Scripts (as opposed to explicitely declared classes) the syntax is not changed, i.e. variable declarations without 'def' are still allowed, because those variables are automatically created in the script binding if they don't already exist.</p>

<h2>Introduction of the 'as' keyword</h2>

<ul>
	<li>We can change types of objects with using the 'as' keyword,<br />
e.g.
<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>
def d0 = new Date(2005-1900, 5-1, 7)   // in classic Groovy or Java
println d0

def d1 = [2005-1900, 5-1, 8] as Date    // since jsr-01
println d1

Date d2 = [2005-1900, 5-1, 9] as Date   // since jsr-01
println d2

Date d3 = [2005-1900, 5-1, 10]          // since jsr-01
println d3

// def n0 = new int[] { 1, 3, 5, 6 }   // Not work. This style is not supported since groovy-1.0-jsr-01.

def n1 = [ 1, 3, 5, 7 ] as int[]
println n1.class
println n1.size()
println n1.length
println n1[0]
println n1[-1]

// int[] n2 = [ 2, 4, 6, 8,10 ] as int[]    // work
int[] n2 = [ 2, 4, 6, 8, 10 ]               // work
println n2.class
println n2.size()
println n2.length
println n2[0]
println n2[-1]

// String[] n3 = [ "a", "ab", "abc", "abcd", "abcde", "abcdef" ] as String[]    // work
String[] n3 = [ "a", "ab", "abc", "abcd", "abcde", "abcdef" ]                   // work
println n3.class
println n3.size()
println n3.length
println n3[0]
println n3[-1]
</pre></td></tr></table></li>
</ul>

<h2>Default access level of class members</h2>

<p>The default access level for members of Groovy classes has changed from &quot;public&quot; to &quot;protected&quot;</p>

<p>Classic Groovy</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>
class Foo {
    readMe_a;
    readMe_b
}
xyz = new Foo(readMe_a:"Hello",readMe_b:"World")
println xyz.readMe_a
println xyz.readMe_b
</pre></td></tr></table>

<p>Now in JSR Groovy</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>
class Foo {
    public readMe_a;
    def readMe_b //def is now required because of the "def keyword" change mentioned earlier
}
xyz = new Foo(readMe_a:"Hello",readMe_b:"World")
println xyz.readMe_a
println xyz.readMe_b //errors in JSR Groovy
</pre></td></tr></table>

<h2>Array creation</h2>

<ul>
	<li>no special array syntax. To make the language much cleaner, we now have a single syntax to work with lists and arrays in the JSR. Also note that we can now easily coerce from any collection or array to any array type</li>
</ul>

// JSR
String[] args = [ "a", "b" ]
def x = [1, 2, 3] as int[]
long[] y = x
</pre></td></tr></table>

<ul>
	<li><strong>Be careful:</strong> we don't support native multi-dimensional array creation right now.</li>
</ul>

<h2>float and double notation</h2>

<ul>
	<li>float and double literals cannot start with dot. So</li>
</ul>

<p>This is to avoid ambiguity with things like ranges (1..2) and so forth</p>

<h2>Explicit method pointer syntax</h2>

<p>In classic Groovy you could access method pointers automatically if there was no java bean property of the given method name.</p>

<p>This often caused confusion; as folks would use a property access to find something and get a method by accident (e.g. typo) and get confused. So now we make getting a method pointer explicit as follows</p>

def foo = ...
def p = foo.&amp;bar

// lets call the bar method on the foo object
p(1, 2, 3)
</pre></td></tr></table>

<h2>No 'do ... while()' syntax as yet.</h2>

<p>Due to ambiguity, we've not yet added support for do .. while to Groovy</p>

<h2>'No Dumb Expression' rule</h2>

<ul>
	<li>no dumb expression rule, so we will catch dumb expressions (where a carriage return has broken the script). e.g.
<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>
def foo() {
  def x = 1
  +5  // dumb expression!
  return 8
}
</pre></td></tr></table></li>
</ul>

<h2>Markup and builders</h2>

<ul>
	<li>markup / builders will change a little, but the classic syntax still applies. Not sure of the new syntax, but we'll have some kinda start/stop syntax to denote a markup block. Maybe a keyword, like</li>
</ul>

// or something like this
builder.{
  // same stuff as before goes here
}
</pre></td></tr></table>

<h2>Strings and GStrings</h2>

<ul>
	<li>single and double quote strings can only span one line; for multiple lines use triple quotes</li>
</ul>

<ul>
	<li>heredocs removal - they are kinda ugly anyway <img class="emoticon emoticon-smile" data-emoticon-name="smile" border="0" src="/s/en_GB/3278/15/_/images/icons/emoticons/smile.png" alt="(smile)" title="(smile)" />. If you want to use them, just use treble quote instead</li>
</ul>

<ul>
	<li>escaping of $ inside GStrings must use \$</li>
</ul>

<ul>
	<li>A new string definition is also supported which is escaping friendly, and thus particularly friendly for regex notation:</li>
</ul>

switch('abc'){
       case ~/.../ : whatever
}

assert 'EUOUAE'.matches(/^[aeiou]*$/)
assert 'EUOUAE' ==~ /^[aeiou]*$/
assert 'football'.replaceAll(/foo/, "Bar") == 'Bartball'
</pre></td></tr></table>

<h2>Assertions</h2>

<ul>
	<li>assert uses comma instead of colon to delimit the two parameter form of assertion statement</li>
</ul>

<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>
assert 0 &lt;= value : "Must be non-negative"  // classic
</pre></td></tr></table>
<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>
assert 0 &lt;= value , "Must be non-negative"  // JSR
</pre></td></tr></table>

<h2>return/break/continue semantics in closures</h2>

<p><strong>NOT YET IMPLEMENTED</strong></p>

<ul>
	<li>return/break/continue to behave inside closures like these statements work in other blocks (such as the block on a for() or while() loop. More details here</li>
</ul>

<h2>Integer division</h2>

<p>Previously, in Groovy Classic, we used the backward slash as the integer division operator. This operator being confusing with escaping sequences was removed. So instead of \ please use the intdiv() method.</p>

<p>Becomes</p>

<h2>Exclusive range</h2>

<p>The operator for creating ranges with the upper bound excluded from the range has changed.</p>

<p>Instead of:</p>

<p>The syntax is now:</p>