Use more Sequences to reduce collection processing

https://kotlinlang.org/docs/sequences.html

app/src/main/java/com/keylesspalace/tusky/adapter/EmojiAdapter.kt

@@ -31,8 +31,10 @@ class EmojiAdapter(
     private val animate: Boolean
 ) : RecyclerView.Adapter<BindingHolder<ItemEmojiButtonBinding>>() {
 
-    private val emojiList: List<Emoji> = emojiList.filter { emoji -> emoji.visibleInPicker == null || emoji.visibleInPicker }
+    private val emojiList: List<Emoji> = emojiList.asSequence()
+        .filter { emoji -> emoji.visibleInPicker == null || emoji.visibleInPicker }
         .sortedBy { it.shortcode.lowercase(Locale.ROOT) }
+        .toList()
 
     override fun getItemCount() = emojiList.size
 

app/src/main/java/com/keylesspalace/tusky/adapter/PollAdapter.kt

@@ -63,8 +63,10 @@ class PollAdapter : RecyclerView.Adapter<BindingHolder<ItemPollBinding>>() {
     }
 
     fun getSelected(): List<Int> {
-        return pollOptions.filter { it.selected }
+        return pollOptions.asSequence()
+            .filter { it.selected }
             .map { pollOptions.indexOf(it) }
+            .toList()
     }
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BindingHolder<ItemPollBinding> {

app/src/main/java/com/keylesspalace/tusky/components/announcements/AnnouncementsViewModel.kt

@@ -59,7 +59,8 @@ class AnnouncementsViewModel @Inject constructor(
                 .fold(
                     {
                         announcementsMutable.postValue(Success(it))
-                        it.filter { announcement -> !announcement.read }
+                        it.asSequence()
+                            .filter { announcement -> !announcement.read }
                             .forEach { announcement ->
                                 mastodonApi.dismissAnnouncement(announcement.id)
                                     .fold(

app/src/main/java/com/keylesspalace/tusky/components/compose/ComposeViewModel.kt

@@ -389,13 +389,14 @@ class ComposeViewModel @Inject constructor(
                 val emojiList = emoji.replayCache.firstOrNull() ?: return emptyList()
                 val incomplete = token.substring(1)
 
-                return emojiList.filter { emoji ->
-                    emoji.shortcode.contains(incomplete, ignoreCase = true)
-                }.sortedBy { emoji ->
-                    emoji.shortcode.indexOf(incomplete, ignoreCase = true)
-                }.map { emoji ->
-                    AutocompleteResult.EmojiResult(emoji)
-                }
+                return emojiList.asSequence()
+                    .filter { emoji ->
+                        emoji.shortcode.contains(incomplete, ignoreCase = true)
+                    }.sortedBy { emoji ->
+                        emoji.shortcode.indexOf(incomplete, ignoreCase = true)
+                    }.map { emoji ->
+                        AutocompleteResult.EmojiResult(emoji)
+                    }.toList()
             }
             else -> {
                 Log.w(TAG, "Unexpected autocompletion token: $token")

app/src/main/java/com/keylesspalace/tusky/components/timeline/viewmodel/NetworkTimelineViewModel.kt

@@ -175,7 +175,8 @@ class NetworkTimelineViewModel @Inject constructor(
                     val overlappedTo = statusData.indexOfFirst { it.asStatusOrNull()?.id?.isLessThan(lastId) ?: false }
 
                     if (overlappedFrom < overlappedTo) {
-                        data.mapIndexed { i, status -> i to statusData.firstOrNull { it.asStatusOrNull()?.id == status.id }?.asStatusOrNull() }
+                        data.asSequence()
+                            .mapIndexed { i, status -> i to statusData.firstOrNull { it.asStatusOrNull()?.id == status.id }?.asStatusOrNull() }
                             .filter { (_, oldStatus) -> oldStatus != null }
                             .forEach { (i, oldStatus) ->
                                 data[i] = data[i].asStatusOrNull()!!

app/src/main/java/com/keylesspalace/tusky/components/trending/viewmodel/TrendingViewModel.kt

@@ -84,9 +84,11 @@ class TrendingViewModel @Inject constructor(
             }
 
             val tags = response.body()!!
+                .asSequence()
                 .filter { homeFilters?.none { filter -> filter.phrase.equals(it.name, ignoreCase = true) } ?: false }
                 .sortedBy { tag -> tag.history.sumOf { it.uses.toLongOrNull() ?: 0 } }
                 .map { it.toViewData() }
+                .toList()
                 .asReversed()
 
             _uiState.value = TrendingUiState(tags, LoadingState.LOADED)

app/src/main/java/com/keylesspalace/tusky/network/FilterModel.kt

@@ -59,7 +59,7 @@ class FilterModel @Inject constructor() {
         val now = Date()
         val nonExpiredFilters = filters.filter { it.expiresAt?.before(now) != true }
         if (nonExpiredFilters.isEmpty()) return null
-        val tokens = nonExpiredFilters
+        val tokens = nonExpiredFilters.asSequence()
             .map { filterToRegexToken(it) }
 
         return Pattern.compile(TextUtils.join("|", tokens), Pattern.CASE_INSENSITIVE)

app/src/main/java/com/keylesspalace/tusky/util/LocaleUtils.kt

@@ -64,7 +64,8 @@ fun getInitialLanguages(language: String? = null, activeAccount: AccountEntity?
     val system = AppCompatDelegate.getApplicationLocales().toList() +
         LocaleListCompat.getDefault().toList()
 
-    return (selected + system.map { it.language }).distinct().filter { it.isNotEmpty() }
+    return (selected + system.map { it.language })
+        .asSequence().distinct().filter { it.isNotEmpty() }.toList()
 }
 
 fun getLocaleList(initialLanguages: List<String>): List<Locale> {

app/src/test/java/com/keylesspalace/tusky/SpanUtilsTest.kt

@@ -136,8 +136,11 @@ class SpanUtilsTest {
         }
 
         override fun <T : Any> getSpans(start: Int, end: Int, type: Class<T>): Array<T> {
-            return spans.filter { it.start >= start && it.end <= end && type.isInstance(it) }
+            @Suppress("UNCHECKED_CAST")
+            return spans.asSequence()
+                .filter { it.start >= start && it.end <= end && type.isInstance(it) }
                 .map { it.span }
+                .toList()
                 .toTypedArray() as Array<T>
         }