[fleet, util] drop grouping util methods

GitOrigin-RevId: bffaa59d0f91ca8681806090cd79d6c18ada6b7a

fleet/util/core/srcCommonMain/fleet/util/List.kt

@@ -1,36 +0,0 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
-package fleet.util
-
-fun <T> Iterable<Set<T>>.union(): Set<T> = flatMapTo(mutableSetOf()) { it }
-
-//@fleet.kernel.plugins.InternalInPluginModules(where = ["fleet.util.test"])
-fun <T> MutableList<T>.updateGrouping(
-  beforeGroup: MutableList<T>.(isOpening: Boolean) -> Unit = {},
-  afterGroup: MutableList<T>.(isClosing: Boolean) -> Unit = {},
-  body: MutableList<T>.(newGroup: () -> Unit) -> Unit,
-) {
-  beforeGroup(true)
-  var count = size
-  var lastGroupEnd = size
-  body {
-    if (count < size) {
-      afterGroup(false)
-      lastGroupEnd = size
-      beforeGroup(false)
-      count = size
-    }
-  }
-  if (count == size)
-    while (size > lastGroupEnd) { removeLast() }
-  afterGroup(true)
-}
-
-fun <T> MutableList<T>.updateSeparating(
-  separator: MutableList<T>.() -> Unit = {},
-  body: MutableList<T>.(newGroup: () -> Unit) -> Unit,
-) = updateGrouping(
-  beforeGroup = { isOpening -> if (!isOpening) separator() },
-) { newGroup ->
-  newGroup()
-  body(newGroup)
-}