Refactor 2015/Day01

src/main/kotlin/be/amedee/adventofcode/aoc2015/day01/Day01.kt

@@ -46,27 +46,33 @@ fun findBasementPosition(instructions: String): Int {
 }
 
 class Day01 {
-    fun readElevatorInstructionsFromFile(fileName: String): String {
-        val packageName = javaClass.`package`.name.replace(".", "/")
-        val filePath = "/$packageName/$fileName"
-        val inputStream = javaClass.getResourceAsStream(filePath)
-        return BufferedReader(InputStreamReader(inputStream!!)).use { it.readText().trim() }
-    }
+    fun readElevatorInstructionsFromFile(fileName: String): String =
+        BufferedReader(
+            InputStreamReader(
+                this.javaClass.getResourceAsStream(
+                    "/${
+                        this.javaClass.`package`.name.replace(
+                            ".",
+                            "/",
+                        )
+                    }/$fileName",
+                )!!,
+            ),
+        ).use { it.readText().trim() }
 }
 
+private const val INPUT = "input"
+
 /**
  * Santa is trying to deliver presents in a large apartment building,
  * but he can't find the right floor - the directions he got are a little confusing.
  */
 fun main() {
-    val inputFile = "input"
-    val puzzleInput = Day01().readElevatorInstructionsFromFile(inputFile)
+    val puzzleInput = Day01().readElevatorInstructionsFromFile(INPUT)
 
-    val endFloor = followInstructions()(puzzleInput)
-    println("Santa ends up on floor $endFloor.")
+    println("Santa ends up on floor ${followInstructions()(puzzleInput)}.")
 
-    val basementPosition = findBasementPosition(puzzleInput)
-    when (basementPosition) {
+    when (val basementPosition = findBasementPosition(puzzleInput)) {
         0 -> println("Santa never enters the basement.")
         else -> println("Santa enters the basement at character position ${"%,d".format(basementPosition)}.")
     }