| Functional Eye for the Java Guy
|
| Convenor: Ben, Michael
|
| Participants:
Mike, Dimitry, Alexandro, giannis, Alexander, Elisabeth, Sven, Stefan, Aarne, Kirk, Rickard, Tasos, Michaelis, Andreas, John, Heinz and more
|
| Summary:
show of hands 10 people know
ugly code example
- for "functional java"
- 4 levels of nested classes
- unreadable
issues with java
- no native function types
- all based around classes , class is smallest unit
- SAM - Single Abstract Method (interface) (no state, one method)
- inner classes (Class$Inner), hold on to outer class references
- closing about context, final outer variables
when do you use FP
- list comprehensions
- composable functions
- reusable code
OO vs. FP
- OO -> box with state which contains method that change that state all the time
- FP -> functions are transformations, side-effect free
- higher order functions
what is the difference to methods in a object that just use ? -> still access to mutable object state/context
some examples in clojure
- schwarz function (a bit too complex)
- sorts a list by a user defined function
- introduced defn, map, sort-by, lambdas, list, let, nth
- simplified (sort-by f x)
Rickard :
- Specification -> composable predicates that return boolean values -> usable for filtering
- filter, map -> function applications to sequences/lists
smalltalk example by Kirk
- if, while statement implemented using language constructs (blocks)
Partial audio recording
Audio recording
|
| Recommendations:
(as above)
|
|
|
