@Documented @Retention(RetentionPolicy.SOURCE) @Target({ElementType.TYPE}) public @interface RecordOptions
Class annotation used to assist in the creation of record-like classes.
Type | Name and Description |
---|---|
boolean |
components If true , this adds a method components() to the record
which returns its components as a typed tuple Tuple0 , Tuple1 ... |
boolean |
copyWith If true , this adds a method copyWith which takes a Map of
new property values and returns a new instance of the record class with
these values set.
|
boolean |
getAt If true , this adds a method getAt(int) which given
an integer n, returns the n'th component in the record.
|
RecordTypeMode |
mode Mode to use when creating record type classes. |
boolean |
size If true , this adds a method size() to the record which returns the number of components. |
boolean |
toList If true , this adds a method toList() to the record
which returns the record's components as a list. |
boolean |
toMap If true , this adds a method toMap() to the record. |
If true
, this adds a method components()
to the record
which returns its components as a typed tuple Tuple0
, Tuple1
...
Example:
import groovy.transform.*
@RecordOptions(components=true)
record Point(int x, int y, String color) {}
def (x, y, c) = new Point(100, 200, 'green').components()
assert x == 100
assert y.intdiv(2) == 100
assert c.toUpperCase() == 'GREEN'
The signature of the components method for this example is:
Tuple3<Integer, Integer, String> components()This is suitable for destructuring in
TypeChecked
scenarios.
If a method components()
already exists in the class,
then this setting is ignored, and no additional method is generated.
It is a compile-time error if there are more components in the record
than the largest TupleN class in the Groovy codebase. If true
, this adds a method copyWith
which takes a Map of
new property values and returns a new instance of the record class with
these values set.
Example:
@groovy.transform.RecordType
(copyWith = true)
class Person {
String first, last
}
def tim = new Person('tim', 'yates')
def alice = tim.copyWith(first:'alice')
assert tim.toString() == 'Person[first=tim, last=yates]'
assert alice.toString() == 'Person[first=alice, last=yates]'
Unknown keys in the map are ignored, and if the values would not change
the object, then the original object is returned.
If a method called copyWith
that takes a single parameter already
exists in the class, then this setting is ignored, and no method is generated. If true
, this adds a method getAt(int)
which given
an integer n, returns the n'th component in the record.
Example:
import static groovy.test.GroovyAssert.shouldFail record Point(int x, int y, String color) {} def p = new Point(100, 200, 'green') assert p[0] == 100 assert p[1] == 200 assert p[2] == 'green' shouldFail(IllegalArgumentException) { p[-1] } // getAt also enables destructuring def (x, y, c) = p assert x == 100 assert y == 200 assert c == 'green'If a method
getAt(int)
already exists in the class,
then this setting is ignored, and no additional method is generated. Mode to use when creating record type classes.
If true
, this adds a method size()
to the record which returns the number of components.
Example:
record Point(int x, int y, String color) {} def p = new Point(100, 200, 'green') assert p.size() == 3If a method
size()
already exists in the class,
then this setting is ignored, and no additional method is generated. If true
, this adds a method toList()
to the record
which returns the record's components as a list.
Example:
record Point(int x, int y, String color) {} def p = new Point(100, 200, 'green') assert p.toList() == [100, 200, 'green']If a method
toList()
already exists in the class,
then this setting is ignored, and no additional method is generated. If true
, this adds a method toMap()
to the record.
Example:
record Point(int x, int y, String color) {} def p = new Point(100, 200, 'green') assert p.toMap() == [x:100, y:200, color:'green']If a method
toMap()
already exists in the class,
then this setting is ignored, and no additional method is generated.