Add Kotlin support

Closes #220

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## 0.27 (unreleased)
 
+### Parsing
+
+Added support for Kotlin.
+
 ### Command Line Interface
 
 Difftastic now validates environment variables the same way as

build.rs

@@ -144,6 +144,11 @@ fn main() {
             src_dir: "vendor/tree-sitter-json-src",
             extra_files: vec![],
         },
+        TreeSitterParser {
+            name: "tree-sitter-kotlin",
+            src_dir: "vendor/tree-sitter-kotlin-src",
+            extra_files: vec!["scanner.c"],
+        },
         TreeSitterParser {
             name: "tree-sitter-lua",
             src_dir: "vendor/tree-sitter-lua-src",

manual/src/introduction.md

@@ -20,6 +20,7 @@ tool that understands syntax. It supports the following languages:
 * Java
 * JavaScript (and JSX)
 * JSON
+* Kotlin
 * Lua
 * Nix
 * OCaml

manual/src/upstream_parsers.md

@@ -21,6 +21,7 @@ Difftastic uses the following tree-sitter parsers:
 | Java            | [tree-sitter/tree-sitter-java](https://github.com/tree-sitter/tree-sitter-java)                                                                       |
 | JavaScript, JSX | [tree-sitter/tree-sitter-javascript](https://github.com/tree-sitter/tree-sitter-javascript)                                                           |
 | JSON            | [tree-sitter/tree-sitter-json](https://github.com/tree-sitter/tree-sitter-json)                                                                       |
+| Kotlin          | [fwcd/tree-sitter-kotlin](https://github.com/fwcd/tree-sitter-kotlin)                                                                                 |
 | Lua             | [nvim-treesitter/tree-sitter-lua](https://github.com/nvim-treesitter/tree-sitter-lua)                                                                 |
 | Nix             | [cstrahan/tree-sitter-nix](https://github.com/cstrahan/tree-sitter-nix)                                                                               |
 | OCaml           | [tree-sitter/tree-sitter-ocaml](https://github.com/tree-sitter/tree-sitter-ocaml)                                                                     |

sample_files/Session_after.kt

@@ -0,0 +1,216 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.iosched.model
+
+import com.google.samples.apps.iosched.model.SessionType.Companion.reservableTypes
+import org.threeten.bp.ZonedDateTime
+
+typealias SessionId = String
+
+/**
+ * Describes a conference session. Sessions have specific start and end times, and they represent a
+ * variety of conference events: talks, sandbox demos, office hours, etc. A session is usually
+ * associated with one or more [Tag]s.
+ */
+data class Session(
+    /**
+     * Unique string identifying this session.
+     */
+    val id: SessionId,
+
+    /**
+     * Start time of the session
+     */
+    val startTime: ZonedDateTime,
+
+    /**
+     * End time of the session
+     */
+    val endTime: ZonedDateTime,
+
+    /**
+     * Session title.
+     */
+    val title: String,
+
+    /**
+     * Body of text explaining this session in detail.
+     */
+    val description: String,
+
+    /**
+     * The session room.
+     */
+    val room: Room?,
+
+    /**
+     * Full URL for the session online.
+     */
+    val sessionUrl: String,
+
+    /**
+     * Indicates if the Session has a live stream.
+     */
+    val isLivestream: Boolean,
+
+    /**
+     * Full URL to YouTube.
+     */
+    val youTubeUrl: String,
+
+    /**
+     * URL to the Dory page.
+     */
+    val doryLink: String,
+
+    /**
+     * The [Tag]s associated with the session. Ordered, with the most important tags appearing
+     * first.
+     */
+    val tags: List<Tag>,
+
+    /**
+     * Subset of [Tag]s that are for visual consumption.
+     */
+    val displayTags: List<Tag>,
+
+    /**
+     * The session speakers.
+     */
+    val speakers: Set<Speaker>,
+
+    /**
+     * The session's photo URL.
+     */
+    val photoUrl: String,
+
+    /**
+     * IDs of the sessions related to this session.
+     */
+    val relatedSessions: Set<SessionId>
+) {
+
+    /**
+     * Returns whether the session is currently being live streamed or not.
+     */
+    fun isLive(): Boolean {
+        val now = ZonedDateTime.now()
+        // TODO: Determine when a session is live based on the time AND the liveStream being
+        // available.
+        return startTime <= now && endTime >= now
+    }
+
+    val hasPhoto inline get() = photoUrl.isNotEmpty()
+
+    /**
+     * Returns whether the session has a video or not. A session could be live streaming or have a
+     * recorded session. Both live stream and recorded videos are stored in [Session.youTubeUrl].
+     */
+    val hasVideo inline get() = youTubeUrl.isNotEmpty()
+
+    val hasPhotoOrVideo inline get() = hasPhoto || hasVideo
+
+    /**
+     * The year the session was held.
+     */
+    val year = startTime.year
+
+    /**
+     * The duration of the session.
+     */
+    // TODO: Get duration from the YouTube video. Not every talk fills the full session time.
+    val duration = endTime.toInstant().toEpochMilli() - startTime.toInstant().toEpochMilli()
+
+    /**
+     * The type of the event e.g. Session, Codelab etc.
+     */
+    val type: SessionType by lazy(LazyThreadSafetyMode.PUBLICATION) {
+        SessionType.fromTags(tags)
+    }
+
+    fun levelTag(): Tag? {
+        return tags.firstOrNull { it.category == Tag.CATEGORY_LEVEL }
+    }
+
+    /**
+     * Whether this event is reservable, based upon [type].
+     */
+    val isReservable: Boolean by lazy(LazyThreadSafetyMode.PUBLICATION) {
+        type in reservableTypes
+    }
+
+    fun isOverlapping(session: Session): Boolean {
+        return this.startTime < session.endTime && this.endTime > session.startTime
+    }
+
+    /**
+     * Detailed description of this event. Includes description, speakers, and live-streaming URL.
+     */
+    fun getCalendarDescription(
+        paragraphDelimiter: String,
+        speakerDelimiter: String
+    ): String = buildString {
+        append(description)
+        append(paragraphDelimiter)
+        append(speakers.joinToString(speakerDelimiter) { speaker -> speaker.name })
+        if (!isLivestream && !youTubeUrl.isEmpty()) {
+            append(paragraphDelimiter)
+            append(youTubeUrl)
+        }
+    }
+}
+
+/**
+ * Represents the type of the event e.g. Session, Codelab etc.
+ */
+enum class SessionType(val displayName: String) {
+
+    KEYNOTE("Keynote"),
+    SESSION("Session"),
+    APP_REVIEW("App Reviews"),
+    GAME_REVIEW("Game Reviews"),
+    OFFICE_HOURS("Office Hours"),
+    CODELAB("Codelab"),
+    MEETUP("Meetup"),
+    AFTER_DARK("After Dark"),
+    UNKNOWN("Unknown");
+
+    companion object {
+
+        /**
+         * Examine the given [tags] to determine the [SessionType]. Defaults to [SESSION] if no
+         * category tag is found.
+         */
+        fun fromTags(tags: List<Tag>): SessionType {
+            val typeTag = tags.firstOrNull { it.category == Tag.CATEGORY_TYPE }
+
+            return when (typeTag?.tagName) {
+                Tag.TYPE_KEYNOTE -> KEYNOTE
+                Tag.TYPE_SESSIONS -> SESSION
+                Tag.TYPE_APP_REVIEWS -> APP_REVIEW
+                Tag.TYPE_GAME_REVIEWS -> GAME_REVIEW
+                Tag.TYPE_OFFICEHOURS -> OFFICE_HOURS
+                Tag.TYPE_CODELABS -> CODELAB
+                Tag.TYPE_MEETUPS -> MEETUP
+                Tag.TYPE_AFTERDARK -> AFTER_DARK
+                else -> UNKNOWN
+            }
+        }
+
+        internal val reservableTypes = listOf(SESSION, OFFICE_HOURS, APP_REVIEW, GAME_REVIEW)
+    }
+}

sample_files/Session_before.kt

@@ -0,0 +1,212 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.iosched.model
+
+import com.google.samples.apps.iosched.model.SessionType.Companion.reservableTypes
+import org.threeten.bp.ZonedDateTime
+
+typealias SessionId = String
+
+/**
+ * Describes a conference session. Sessions have specific start and end times, and they represent a
+ * variety of conference events: talks, sandbox demos, office hours, etc. A session is usually
+ * associated with one or more [Tag]s.
+ */
+data class Session(
+    /**
+     * Unique string identifying this session.
+     */
+    val id: SessionId,
+
+    /**
+     * Start time of the session
+     */
+    val startTime: ZonedDateTime,
+
+    /**
+     * End time of the session
+     */
+    val endTime: ZonedDateTime,
+
+    /**
+     * Session title.
+     */
+    val title: String,
+
+    /**
+     * Body of text explaining this session in detail.
+     */
+    val description: String,
+
+    /**
+     * The session room.
+     */
+    val room: Room?,
+
+    /**
+     * Full URL for the session online.
+     */
+    val sessionUrl: String,
+
+    /**
+     * Indicates if the Session has a live stream.
+     */
+    val isLivestream: Boolean,
+
+    /**
+     * Full URL to YouTube.
+     */
+    val youTubeUrl: String,
+
+    /**
+     * URL to the Dory page.
+     */
+    val doryLink: String,
+
+    /**
+     * The [Tag]s associated with the session. Ordered, with the most important tags appearing
+     * first.
+     */
+    val tags: List<Tag>,
+
+    /**
+     * Subset of [Tag]s that are for visual consumption.
+     */
+    val displayTags: List<Tag>,
+
+    /**
+     * The session speakers.
+     */
+    val speakers: Set<Speaker>,
+
+    /**
+     * The session's photo URL.
+     */
+    val photoUrl: String?,
+
+    /**
+     * IDs of the sessions related to this session.
+     */
+    val relatedSessions: Set<SessionId>
+) {
+
+    /**
+     * Returns whether the session is currently being live streamed or not.
+     */
+    fun isLive(): Boolean {
+        val now = ZonedDateTime.now()
+        // TODO: Determine when a session is live based on the time AND the liveStream being
+        // available.
+        return startTime <= now && endTime >= now
+    }
+
+    /**
+     * Returns whether the session has a video or not. A session could be live streaming or have a
+     * recorded session. Both live stream and recorded videos are stored in [Session.youTubeUrl].
+     */
+    fun hasVideo() = youTubeUrl.isNotEmpty()
+
+    /**
+     * The year the session was held.
+     */
+    val year = startTime.year
+
+    /**
+     * The duration of the session.
+     */
+    // TODO: Get duration from the YouTube video. Not every talk fills the full session time.
+    val duration = endTime.toInstant().toEpochMilli() - startTime.toInstant().toEpochMilli()
+
+    /**
+     * The type of the event e.g. Session, Codelab etc.
+     */
+    val type: SessionType by lazy(LazyThreadSafetyMode.PUBLICATION) {
+        SessionType.fromTags(tags)
+    }
+
+    fun levelTag(): Tag? {
+        return tags.firstOrNull { it.category == Tag.CATEGORY_LEVEL }
+    }
+
+    /**
+     * Whether this event is reservable, based upon [type].
+     */
+    val isReservable: Boolean by lazy(LazyThreadSafetyMode.PUBLICATION) {
+        type in reservableTypes
+    }
+
+    fun isOverlapping(session: Session): Boolean {
+        return this.startTime < session.endTime && this.endTime > session.startTime
+    }
+
+    /**
+     * Detailed description of this event. Includes description, speakers, and live-streaming URL.
+     */
+    fun getCalendarDescription(
+        paragraphDelimiter: String,
+        speakerDelimiter: String
+    ): String = buildString {
+        append(description)
+        append(paragraphDelimiter)
+        append(speakers.joinToString(speakerDelimiter) { speaker -> speaker.name })
+        if (!isLivestream && !youTubeUrl.isEmpty()) {
+            append(paragraphDelimiter)
+            append(youTubeUrl)
+        }
+    }
+}
+
+/**
+ * Represents the type of the event e.g. Session, Codelab etc.
+ */
+enum class SessionType(val displayName: String) {
+
+    KEYNOTE("Keynote"),
+    SESSION("Session"),
+    APP_REVIEW("App Reviews"),
+    GAME_REVIEW("Game Reviews"),
+    OFFICE_HOURS("Office Hours"),
+    CODELAB("Codelab"),
+    MEETUP("Meetup"),
+    AFTER_DARK("After Dark"),
+    UNKNOWN("Unknown");
+
+    companion object {
+
+        /**
+         * Examine the given [tags] to determine the [SessionType]. Defaults to [SESSION] if no
+         * category tag is found.
+         */
+        fun fromTags(tags: List<Tag>): SessionType {
+            val typeTag = tags.firstOrNull { it.category == Tag.CATEGORY_TYPE }
+
+            return when (typeTag?.tagName) {
+                Tag.TYPE_KEYNOTE -> KEYNOTE
+                Tag.TYPE_SESSIONS -> SESSION
+                Tag.TYPE_APP_REVIEWS -> APP_REVIEW
+                Tag.TYPE_GAME_REVIEWS -> GAME_REVIEW
+                Tag.TYPE_OFFICEHOURS -> OFFICE_HOURS
+                Tag.TYPE_CODELABS -> CODELAB
+                Tag.TYPE_MEETUPS -> MEETUP
+                Tag.TYPE_AFTERDARK -> AFTER_DARK
+                else -> UNKNOWN
+            }
+        }
+
+        internal val reservableTypes = listOf(SESSION, OFFICE_HOURS, APP_REVIEW, GAME_REVIEW)
+    }
+}

src/guess_language.rs

@@ -37,6 +37,7 @@ pub enum Language {
     JavaScript,
     Json,
     Jsx,
+    Kotlin,
     Lua,
     Nix,
     OCaml,
@@ -210,6 +211,7 @@ pub fn from_extension(extension: &OsStr) -> Option<Language> {
         "cjs" | "js" | "mjs" => Some(JavaScript),
         "jsx" => Some(Jsx),
         "json" => Some(Json),
+        "kt" | "ktm" | "kts" => Some(Kotlin),
         "lua" => Some(Lua),
         "nix" => Some(Nix),
         "ml" => Some(OCaml),

src/sliders.rs

@@ -61,8 +61,8 @@ fn prefer_outer_delimiter(language: guess_language::Language) -> bool {
         // languages have syntax like `foo(bar)` or `foo[bar]` where
         // the inner delimiter is more relevant.
         Bash | C | CPlusPlus | CSharp | Css | Dart | Elixir | Elm | Gleam | Go | Haskell | Java
-        | JavaScript | Jsx | Lua | Nix | OCaml | OCamlInterface | Php | Python | Ruby | Rust
-        | Scala | Tsx | TypeScript | Yaml | Zig => false,
+        | JavaScript | Jsx | Kotlin | Lua | Nix | OCaml | OCamlInterface | Php | Python | Ruby
+        | Rust | Scala | Tsx | TypeScript | Yaml | Zig => false,
     }
 }
 

src/tree_sitter_parser.rs

@@ -61,6 +61,7 @@ extern "C" {
     fn tree_sitter_java() -> ts::Language;
     fn tree_sitter_javascript() -> ts::Language;
     fn tree_sitter_json() -> ts::Language;
+    fn tree_sitter_kotlin() -> ts::Language;
     fn tree_sitter_lua() -> ts::Language;
     fn tree_sitter_nix() -> ts::Language;
     fn tree_sitter_ocaml() -> ts::Language;
@@ -379,6 +380,20 @@ pub fn from_language(language: guess::Language) -> TreeSitterConfig {
                 .unwrap(),
             }
         }
+        Kotlin => {
+            let language = unsafe { tree_sitter_kotlin() };
+            TreeSitterConfig {
+                name: "Kotlin",
+                language,
+                atom_nodes: vec!["line_string_literal", "character_literal"]
+                    .into_iter()
+                    .collect(),
+                delimiter_tokens: vec![("(", ")"), ("{", "}"), ("[", "]"), ("<", ">")]
+                    .into_iter()
+                    .collect(),
+                highlight_query: ts::Query::new(language, "").unwrap(),
+            }
+        }
         Lua => {
             let language = unsafe { tree_sitter_lua() };
             TreeSitterConfig {

vendor/tree-sitter-kotlin-src

@@ -0,0 +1 @@
+tree-sitter-kotlin/src