Added FormatLanguage annotation to JSON (#2234)

Resolves #2166

Co-authored-by: Leonid Startsev <sandwwraith@gmail.com>

Author: shanshin

formats/json/commonMain/src/kotlinx/serialization/json/Json.kt

@@ -85,13 +85,23 @@ public sealed class Json(
         }
     }
 
+    /**
+     * Decodes and deserializes the given JSON [string] to the value of type [T] using deserializer
+     * retrieved from the reified type parameter.
+     *
+     * @throws SerializationException in case of any decoding-specific error
+     * @throws IllegalArgumentException if the decoded input is not a valid instance of [T]
+     */
+    public inline fun <reified T> decodeFromString(@FormatLanguage("json", "", "") string: String): T =
+            decodeFromString(serializersModule.serializer(), string)
+
     /**
      * Deserializes the given JSON [string] into a value of type [T] using the given [deserializer].
      *
      * @throws [SerializationException] if the given JSON string is not a valid JSON input for the type [T]
      * @throws [IllegalArgumentException] if the decoded input cannot be represented as a valid instance of type [T]
      */
-    public final override fun <T> decodeFromString(deserializer: DeserializationStrategy<T>, string: String): T {
+    public final override fun <T> decodeFromString(deserializer: DeserializationStrategy<T>, @FormatLanguage("json", "", "") string: String): T {
         val lexer = StringJsonLexer(string)
         val input = StreamingJsonDecoder(this, WriteMode.OBJ, lexer, deserializer.descriptor, null)
         val result = input.decodeSerializableValue(deserializer)
@@ -122,7 +132,7 @@ public sealed class Json(
      *
      * @throws [SerializationException] if the given string is not a valid JSON
      */
-    public fun parseToJsonElement(string: String): JsonElement {
+    public fun parseToJsonElement(@FormatLanguage("json", "", "") string: String): JsonElement {
         return decodeFromString(JsonElementSerializer, string)
     }
 }

formats/json/commonMain/src/kotlinx/serialization/json/internal/FormatLanguage.kt

@@ -0,0 +1,45 @@
+package kotlinx.serialization.json.internal;
+
+import kotlinx.serialization.InternalSerializationApi
+
+/**
+ * Multiplatform analogue of `org.intellij.lang.annotations.Language` annotation.
+ *
+ * An alias is used instead of class, because the actual class in the JVM will conflict with the class from the stdlib -
+ * we want to avoid the situation with different classes having the same fully-qualified name.
+ * [see](https://github.com/JetBrains/java-annotations/issues/34)
+ *
+ * Specifies that an element of the program represents a string that is a source code on a specified language.
+ * Code editors may use this annotation to enable syntax highlighting, code completion and other features
+ * inside the literals that assigned to the annotated variables, passed as arguments to the annotated parameters,
+ * or returned from the annotated methods.
+ * <p>
+ * This annotation also could be used as a meta-annotation, to define derived annotations for convenience.
+ * E.g. the following annotation could be defined to annotate the strings that represent Java methods:
+ *
+ * <pre>
+ *   &#64;Language(value = "JAVA", prefix = "class X{", suffix = "}")
+ *   &#64;interface JavaMethod {}
+ * </pre>
+ * <p>
+ * Note that using the derived annotation as meta-annotation is not supported.
+ * Meta-annotation works only one level deep.
+ */
+
+@InternalSerializationApi
+@Retention(AnnotationRetention.BINARY)
+@Target(
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY_GETTER,
+    AnnotationTarget.PROPERTY_SETTER,
+    AnnotationTarget.FIELD,
+    AnnotationTarget.VALUE_PARAMETER,
+    AnnotationTarget.LOCAL_VARIABLE,
+    AnnotationTarget.ANNOTATION_CLASS
+)
+public expect annotation class FormatLanguage(
+    public val value: String,
+    // default parameters are not used due to https://youtrack.jetbrains.com/issue/KT-25946/
+    public val prefix: String,
+    public val suffix: String,
+)

formats/json/jsMain/src/kotlinx/serialization/json/internal/FormatLanguage.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2017-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.json.internal;
+
+import kotlinx.serialization.InternalSerializationApi
+
+@InternalSerializationApi
+public actual typealias FormatLanguage = org.intellij.lang.annotations.Language

formats/json/jsMain/src/kotlinx/serialization/json/internal/IntelliJAnnotation.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+@file:Suppress("PackageDirectoryMismatch")
+
+package org.intellij.lang.annotations
+
+import kotlinx.serialization.InternalSerializationApi
+
+/**
+ * JS implementation of JVM-only `org.intellij.lang.annotations.Language` class, adds syntax support by IDE.
+ *
+ * This class is missing from the Kotlin/JS targets, so it needs to be distributed along with the serialization runtime.
+ *
+ * Copy-paste from [https://github.com/JetBrains/java-annotations](https://github.com/JetBrains/java-annotations).
+ *
+ * @see [kotlinx.serialization.json.internal.FormatLanguage]
+ */
+@InternalSerializationApi
+@Retention(AnnotationRetention.BINARY)
+@Target(
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY_GETTER,
+    AnnotationTarget.PROPERTY_SETTER,
+    AnnotationTarget.FIELD,
+    AnnotationTarget.VALUE_PARAMETER,
+    AnnotationTarget.LOCAL_VARIABLE,
+    AnnotationTarget.ANNOTATION_CLASS,
+)
+public annotation class Language(
+    val value: String,
+    val prefix: String = "",
+    val suffix: String = "",
+)

formats/json/jvmMain/src/kotlinx/serialization/json/internal/FormatLanguage.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2017-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.json.internal;
+
+import kotlinx.serialization.InternalSerializationApi
+
+@InternalSerializationApi
+public actual typealias FormatLanguage = org.intellij.lang.annotations.Language

formats/json/nativeMain/src/kotlinx/serialization/json/internal/FormatLanguage.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2017-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.json.internal;
+
+import kotlinx.serialization.InternalSerializationApi
+
+@InternalSerializationApi
+public actual typealias FormatLanguage = org.intellij.lang.annotations.Language

formats/json/nativeMain/src/kotlinx/serialization/json/internal/IntelliJAnnotation.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+@file:Suppress("PackageDirectoryMismatch")
+
+package org.intellij.lang.annotations
+
+import kotlinx.serialization.InternalSerializationApi
+
+/**
+ * Native implementation of JVM-only `org.intellij.lang.annotations.Language` class, adds syntax support by IDE.
+ *
+ * This class is missing from the Kotlin/Native targets, so it needs to be distributed along with the serialization runtime.
+ *
+ * Copy-paste from [https://github.com/JetBrains/java-annotations](https://github.com/JetBrains/java-annotations).
+ *
+ * @see [kotlinx.serialization.json.internal.FormatLanguage]
+ */
+@InternalSerializationApi
+@Retention(AnnotationRetention.BINARY)
+@Target(
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY_GETTER,
+    AnnotationTarget.PROPERTY_SETTER,
+    AnnotationTarget.FIELD,
+    AnnotationTarget.VALUE_PARAMETER,
+    AnnotationTarget.LOCAL_VARIABLE,
+    AnnotationTarget.ANNOTATION_CLASS,
+)
+public annotation class Language(
+    val value: String,
+    val prefix: String = "",
+    val suffix: String = "",
+)