njbartlett

package org.example.impl;

import org.example.api.Greeting;
import aQute.bnd.annotation.component.Component;

@Component
public class BasicGreeting implements Greeting {
    public String sayHello(String name) {
        return "Hello " + name;
    }

njbartlett

package org.example.api;

public interface Greeting {
    String sayHello(String name);
}

njbartlett

-- Find the longest shared prefix of two lists
-- e.g. findPrefix [1,2,3,4] [1,2,3,5] returns [1,2,3]
findPrefix :: (Eq a) => [a] -> [a] -> [a]
findPrefix xs = map fst . takeWhile (uncurry (==)) . zip xs

njbartlett

countCrossings :: TestCase -> Int
countCrossings = length . guardedPairs crosses

-- This is the "pairs" function from the first meeting, with the addition of a
-- predicate function to filter out unwanted pairs
guardedPairs :: (a -> a -> Bool) -> [a] -> [(a,a)]
guardedPairs p xs = [(x,y) | (x:ys) <- tails xs, y <- ys, p x y]

crosses :: Wire -> Wire -> Bool
crosses (Wire s1 e1) (Wire s2 e2) = if s1 < s2 then e1 > e2 else e1 < e2

njbartlett

module Main where

import Control.Monad
import Data.List

type Line = [Int]

data Wire = Wire { start :: Int
                 , end   :: Int } deriving Show