Downloaded 20 times
Uploaded byAndres Almiray
Jfokus functional groovy
The document discusses functional programming concepts in Groovy including closures, partial evaluation, composition, memoization, and tail calls. It explains that closures in Groovy are functions with an environment that binds free variables, and are not necessarily side effect free. Closures can have parameters with default values defined from right to left. Partial evaluation is achieved through currying closures from left to right or arbitrary indexes. Composition uses the >> and << operators to combine closures from left to right or vice versa. Memoization caches computed values. Tail calls use trampoline() and the @TailRecursive annotation. Iterators, streams using the groovy-stream library, and immutability with the @Immutable
More Related Content
Similar to Jfokus functional groovy
Jfokus functional groovy
- 1. FUNCTIONAL GROOVY ANDRES ALMIRAY CANOO ENGINEERINGA.G. @AALMIRAY
- 2. ABOUT THE SPEAKER Javadeveloper since the beginning True believer in open source Groovy committer since 2007 Project lead of the Griffon framework Currently working for
- 4.
- 5. GROOVY IS NOT HASKELL RUSSEL WINDER
- 6. CLOSURES == FUNCTIONS Closuresare functions (i.e, blocks of code) with an environment containing a binding for all free variables of the function
- 7. CLOSURES == FUNCTIONS Closuresare NOT side effect free by design
- 8. CLOSURES: PARAMETERS (1) Parametertypes may be omitted if type information is not needed
- 9. CLOSURES: PARAMETERS (2) Parametersmay have default values NOTE: Default values must be defined from right to left
- 10. CLOSURES: DEFAULT PARAMETER Closures mayhave a default parameter named it
- 11. CLOSURES LEAD TO… Partial Evaluation Composition Memoization Tail calls Iterators Streams
- 12. PARTIAL EVALUATION (1) Curryingcreates a new closure with fixed parameters, left to right
- 13. PARTIAL EVALUATION (2) Curryingmay be applied right to left too, even on an arbitrary index
- 14. COMPOSITION (1) Closures maybe composed (left to right) using the >> operator
- 15. COMPOSITION (2) Closures maybe composed (right to left) using the << operator
- 16. MEMOIZATION Cache computed valuesfor increased performance
- 17. TAIL CALLS (1) Recursiveclosures may use Tail Calls thanks to trampoline()
- 18. TAIL CALLS (2) Apply@TailRecursive on methods https://github.com/jlink/tailrec/
- 19.
- 20.
- 21.
- 22. OBJECTS AS PARTIALEVALS Any class may implement the call() method, enabling implicit evaluation
- 23. METHODS AS CLOSURES Anymethod may be transformed to a Closure using the .& operator
- 24. STREAMS (1) Lazy generators.Extension module created by @tim_yates http://timyates.github.com/groovy-stream/
- 25. STREAMS (2) Groovy isJava friendly. Usa any Java library such as functional-java
- 26. IMMUTABILITY The @Immutable ASTtransformation makes writing immutable classes trivial
- 27. GPARS http://gpars.codehaus.org/ Concurrent collectionprocessing Composable asynchronous functions Fork/Join abstraction Actor programming model Dataflow concurrency constructs CSP Agent - an thread-safe reference to mutable state
- 28. PARALLEL COLLECTIONS Gpars enhancesJDK/GDK collections with parallel execution enabled versions
- 29. RESOURCES • http://pragprog.com/magazines/2013-01/using- memoization-in-groovy • http://www.ibm.com/developerworks/views/java/ libraryview.jsp?search_by=functional+thinking: • https://github.com/jlink/tailrec/ • http://timyates.github.com/groovy-stream/ • http://www.jroller.com/vaclav/ • http://gpars.codehaus.org/ • http://www.slideshare.net/arturoherrero/functional- programming-with-groovy
- 30.
- 31.