cleanup

src/test/kotlin/org/kotlin99/binarytrees/P56.kt

@@ -8,12 +8,12 @@ import org.kotlin99.binarytrees.Tree.Node
 
 fun Tree<*>.isSymmetric(): Boolean = this == End || (this is Node<*> && left.isMirrorOf(right))
 
-fun Tree<*>.isMirrorOf(that: Tree<*>): Boolean = when {
-    this is Node<*> && that is Node<*> ->
-        left.isMirrorOf(that.right) && right.isMirrorOf(that.left)
-    this == End -> that == End
-    else -> false
-}
+fun Tree<*>.isMirrorOf(that: Tree<*>): Boolean =
+    when {
+        this is Node<*> && that is Node<*> -> left.isMirrorOf(that.right) && right.isMirrorOf(that.left)
+        this == End                        -> that == End
+        else                               -> false
+    }
 
 class P56Test {
     @Test fun `tree is mirror of another tree`() {

src/test/kotlin/org/kotlin99/binarytrees/P60.kt

@@ -11,11 +11,12 @@ import org.kotlin99.common.containsAll
 fun maxNodeAmountInHBTree(height: Int): Int =
     Math.pow(2.0, height.toDouble()).toInt() - 1
 
-fun minNodeAmountInHBTree(height: Int): Int = when {
-    height <= 0 -> 0
-    height == 1 -> 1
-    else        -> 1 + minNodeAmountInHBTree(height - 1) + minNodeAmountInHBTree(height - 2)
-}
+fun minNodeAmountInHBTree(height: Int): Int =
+    when {
+        height <= 0 -> 0
+        height == 1 -> 1
+        else        -> 1 + minNodeAmountInHBTree(height - 1) + minNodeAmountInHBTree(height - 2)
+    }
 
 fun maxHeightOfHBTree(nodeAmount: Int): Int =
     (1..Int.MAX_VALUE).first { minNodeAmountInHBTree(it) > nodeAmount } - 1

src/test/kotlin/org/kotlin99/multiwaytrees/P73.kt

@@ -25,16 +25,17 @@ private object SExprParser: TokenParser {
 }
 
 private fun Token.toMTree(): MTree<String> {
-    fun Token.toList(): List<Token> = when {
-        this is Atom -> listOf(this)
-        this is Seq -> this.tokens
-        else -> throw IllegalStateException(this.toString())
-    }
+    fun Token.toList(): List<Token> =
+        when (this) {
+            is Atom -> listOf(this)
+            is Seq  -> this.tokens
+            else    -> throw IllegalStateException(this.toString())
+        }
 
-    return when {
-        this is Seq -> MTree((tokens[0] as Atom).value, tokens[1].toList().map { it.toMTree() })
-        this is Atom -> MTree(value)
-        else -> throw IllegalStateException(this.toString())
+    return when (this) {
+        is Seq  -> MTree((tokens[0] as Atom).value, tokens[1].toList().map { it.toMTree() })
+        is Atom -> MTree(value)
+        else    -> throw IllegalStateException(this.toString())
     }
 }
 
@@ -45,7 +46,7 @@ private interface Token {
 }
 
 private data class Text(val value: String): Token {
-    override fun trim() = null
+    override fun trim(): Token? = null
     override fun length() = value.length
     override fun toString() = value
 }