Annotation Type Newify
-
@Documented @Retention(SOURCE) @Target({CONSTRUCTOR,METHOD,TYPE,FIELD,LOCAL_VARIABLE}) public @interface Newify
Annotation that supports writing constructor call expressions without the 'new' keyword. Instead they can be written "Ruby-style" as a method call to a 'new' method or "Python-style" by just omitting the 'new' keyword.WARNING: For the Python style with class-name-matching pattern, the pattern should be chosen as to avoid matching method names if possible. If following Java/Groovy naming conventions, class names (contrary to method names) start with an uppercase letter. In this case
pattern="[A-Z].*"
(seePattern
for supported Java pattern syntax) is the recommended pattern to allow all classes to be created without requiring a new keyword. Using a pattern that also matches method names (e.g. ".+", ".*" or "[a-zA-Z].*") might negatively impact build performance, since the Groovy compiler will have to match every class in context against any potential constructor call.@Newify allows you to write code snippets like this ("Python-style"):
@Newify([Tree,Leaf])
class MyTreeProcessor { def myTree = Tree(Tree(Leaf("A"), Leaf("B")), Leaf("C")) def process() { ... } }// Any class whose name matches pattern can be created without new
@Newify(pattern="[A-Z].*")
class MyTreeProcessor { final myTree = Tree(Tree(Leaf("A"), Leaf("B")), Leaf("C")) final sb = StringBuilder("...") def dir = File('.') def root = XmlSlurper().parseText(File(dir, sb.toString()).text) }@Newify
class MyTreeProcessor { def myTree = Tree.new(Tree.new(Leaf.new("A"), Leaf.new("B")), Leaf.new("C")) def process() { ... } }class MyTreeProcessor { def myTree = new Tree(new Tree(new Leaf("A"), new Leaf("B")), new Leaf("C")) def process() { ... } }
The annotation can be used on a whole class as shown above or selectively on a particular method, constructor or field.The "Ruby-style" new conversions occur automatically unless the 'auto=false' flag is given when using the annotation. You might do this if you create a new method using meta programming.
For the "Python-style" conversions you can either specify each class name on which you want them to apply, or supply a pattern to match class names against. The transformation then works by matching the basename of the provided classes to any similarly named instance method calls not specifically bound to an object, i.e. associated with the 'this' object. In other words
Leaf("A")
would be transformed tonew Leaf("A")
butx.Leaf("A")
would not be touched.An example showing how to use the annotation at different levels:
@Newify(auto=false, value=Foo)
class Main {@Newify
// turn auto on for field def field1 = java.math.BigInteger.new(42) def field2, field3, field4@Newify(pattern="[A-z][A-Za-z0-9_]*")
// Any class name that starts with an uppercase letter def process() { field2 = A(Bb(Ccc("my bar"))) }@Newify(Baz)
Main() { field3 = Foo("my foo") field4 = Baz("my baz") } }