Browse Source

review feedback

master
kageru 1 year ago
parent
commit
10d70c6f84
Signed by: kageru
GPG Key ID: 8282A2BEA4ADA3D2
  1. 29
      src/main/kotlin/rps/Game.kt
  2. 3
      src/test/kotlin/rps/GameTest.kt

29
src/main/kotlin/rps/Game.kt

@ -1,18 +1,15 @@
package rps
import kotlin.random.Random
const val TURNS = 100
val PLAYER_TWO_CHOICE = Move.ROCK
fun main() {
println("Outcome from Player 1’s perspective: ${playGame(TURNS)}")
}
/** Determine the [Outcome] of [first] vs [second] from the perspective of [first]. */
fun determineOutcome(first: Move, second: Move): Outcome = when {
first.strongAgainst() == second -> Outcome.WIN
first == second -> Outcome.DRAW
fun determineOutcome(first: Move, second: Move): Outcome = when(second) {
in first.strongAgainst() -> Outcome.WIN
first -> Outcome.DRAW
else -> Outcome.LOSS
}
@ -24,15 +21,13 @@ fun List<Outcome>.calculateGameSummary() = GameSummary(
losses = count { it == Outcome.LOSS },
)
fun playGame(turns: Int): GameSummary = generateSequence { randomMove() }
fun playGame(turns: Int): GameSummary = generateSequence { randomMove() to randomMove() }
.take(turns)
.map { determineOutcome(it, PLAYER_TWO_CHOICE) }
.map { (p1, p2) -> determineOutcome(p1, p2) }
.toList()
.calculateGameSummary()
fun randomMove(): Move = Move.values().let { allMoves ->
allMoves[Random.nextInt(allMoves.size)]
}
fun randomMove(): Move = Move.values().random()
/*
* Classes and named tuples below this point.
@ -43,13 +38,13 @@ fun randomMove(): Move = Move.values().let { allMoves ->
* A possible move in a game of rock-paper-scissors.
*
* [strongAgainst] is a function for lazy evaluation because otherwise we cant access SCISSORS before its been defined.
* If the game needs to be expanded (e.g. the somewhat common rock, paper, scissors, salamander, spock),
* this argument could be a List<Move> instead.
*/
enum class Move(val strongAgainst: () -> Move) {
ROCK({ SCISSORS }),
PAPER({ ROCK }),
SCISSORS({ PAPER })
enum class Move(val strongAgainst: () -> Set<Move>) {
ROCK({ setOf(SCISSORS, LIZARD) }),
PAPER({ setOf(ROCK, SPOCK) }),
SCISSORS({ setOf(PAPER, LIZARD) }),
LIZARD({ setOf(SPOCK, PAPER) }),
SPOCK({ setOf(SCISSORS, ROCK) }),
}
// purposely not calling this Result to avoid confusion with kotlin.Result and similar

3
src/test/kotlin/rps/GameTest.kt

@ -13,6 +13,9 @@ class GameTest {
Triple(ROCK, PAPER, LOSS),
Triple(PAPER, SCISSORS, LOSS),
Triple(ROCK, ROCK, DRAW),
Triple(ROCK, LIZARD, WIN),
Triple(LIZARD, SPOCK, WIN),
Triple(SPOCK, PAPER, LOSS),
)
for ((first, second, expected) in games) {
assertEquals(determineOutcome(first, second), expected)

Loading…
Cancel
Save