Dierk

trait HasId {
    long id
}
trait HasVersion {
    long version
}
trait Persistent {
    boolean save() { println "saving ${this.dump()}" }
}
trait Entity implements Persistent, HasId, HasVersion {

Dierk

// has all methods of List
trait ListLike {
    @Delegate List linkedList = new LinkedList()
}

// stores anything but exposes only Strings
class StringList implements ListLike {
    String get(int index) { linkedList.get(index).toString() }
}

Dierk

module realworld.experiments.ExampleTests where

test_that_is_expected_to_pass  = 1 == 1

test_that_is_expected_to_fail  = 1 == 2

Dierk

//@Grab('org.spockframework:spock-core:0.7-groovy-2.0')
import spock.lang.*

import java.lang.reflect.Field

class FregeSpec extends Specification {
    @Shared Class       testClass  = realworld.experiments.ExampleTests
    @Shared List<Field> testFields = testClass.fields.findAll { Field it -> it.modifiers == 25 && it.name.startsWith("test") }

    @Unroll

Dierk

import java.util.function.Function // requires Java 8

class NullSafe<T> {
    protected final T t
    protected NullSafe(T t) {this.t = t}
    
    static NullSafe<T> enter(T t) { new NullSafe<T>(t) } // enter or "return" is like a constructor
    
    // in the general case, applicative would have the type Function<T, NullSafe<T>> but we don't need that here
    NullSafe<T> rightShift (Function<T,T> applicative) {

Dierk

module Lab4 where

------------------------------------------------------------------------------------------------------------------------------
-- RECURSIVE FUNCTIONS, Frege version by Dierk Koenig
------------------------------------------------------------------------------------------------------------------------------

-- import frege.prelude.Math(pi)       -- uncomment this when trying to use pi

-- ===================================
-- Ex. 0

Dierk

-- Functional parsing library from chapter 8 of Programming in Haskell,
-- Graham Hutton, Cambridge University Press, 2007.
-- Template file for the homework in the FP101x EdX course.
-- Read also: http://www.cs.nott.ac.uk/~gmh/monparsing.pdf
-- adapted to Frege by Dierk Koenig
-- uncomment code as needed

module Parsing where

import Data.Char

Dierk

module Countdown where

-- Countdown example from chapter 11 of Programming in Haskell,
-- Graham Hutton, Cambridge University Press, 2007.
-- Template for homework 10 in the FP101x course
-- Frege adaptions by Dierk Koenig


-- How Java's Date looks like through the Frege glasses
data Date = native java.util.Date where

Dierk

------------------------------------------------------------------------------------------------------------------------------
-- ROSE TREES, FUNCTORS, MONOIDS, FOLDABLES, Frege version by Dierk Koenig
------------------------------------------------------------------------------------------------------------------------------

module Lab6 where

import frege.prelude.Math(round, sin)

data Rose a = Rose a [Rose a]
derive Show Rose a

Dierk

module FunctionRecord where

data FRecord    = FRecord {
    parent      :: FRecord,
    name        :: String,
    toString    :: (FRecord ->  String)
}

prototype = FRecord   { parent = prototype, name = undefined, toString = (\r -> r.name) }
dierk     = prototype.{ name = "Dierk" }