Annotate YAML tags as metadata.

Author: SimY4

build.gradle.kts

@@ -34,7 +34,7 @@ repositories {
 dependencies {
   intellijPlatform {
     intellijIdea(providers.gradleProperty("platformVersion"))
-    bundledPlugins("org.jetbrains.kotlin", "com.intellij.java")
+    bundledPlugins("com.intellij.java", "org.jetbrains.kotlin", "org.jetbrains.plugins.yaml")
     plugins(
       "com.cursiveclojure.cursive:2025.2-252",
       "com.jetbrains.rust:252.27397.133",

src/main/kotlin/com/github/simy4/alabaster/YAMLAnnotator.kt

@@ -0,0 +1,21 @@
+package com.github.simy4.alabaster
+
+import com.intellij.lang.annotation.AnnotationHolder
+import com.intellij.lang.annotation.Annotator
+import com.intellij.lang.annotation.HighlightSeverity
+import com.intellij.openapi.editor.DefaultLanguageHighlighterColors
+import com.intellij.psi.PsiElement
+import com.intellij.psi.util.elementType
+import org.jetbrains.yaml.YAMLTokenTypes
+
+class YAMLAnnotator : Annotator {
+  override fun annotate(element: PsiElement, holder: AnnotationHolder) {
+    val elementType = element.elementType
+    when (elementType) {
+      YAMLTokenTypes.TAG ->
+        holder.newSilentAnnotation(HighlightSeverity.TEXT_ATTRIBUTES)
+          .textAttributes(DefaultLanguageHighlighterColors.METADATA)
+          .create()
+    }
+  }
+}

src/main/resources/META-INF/plugin.xml

@@ -40,6 +40,7 @@ Other languages work perfectly fine as well, but may do some extra unnecessary h
     <depends optional="true" config-file="with-python.xml">PythonCore</depends>
     <depends optional="true" config-file="with-rust.xml">com.jetbrains.rust</depends>
     <depends optional="true" config-file="with-scala.xml">org.intellij.scala</depends>
+    <depends optional="true" config-file="with-yaml.xml">org.jetbrains.plugins.yaml</depends>
 
     <extensions defaultExtensionNs="com.intellij">
         <themeProvider id="com.github.simy4.alabaster.light" path="/themes/alabaster.theme.json"/>

src/main/resources/META-INF/with-yaml.xml

@@ -0,0 +1,5 @@
+<idea-plugin>
+    <extensions defaultExtensionNs="com.intellij">
+        <annotator language="yaml" implementationClass="com.github.simy4.alabaster.YAMLAnnotator"/>
+    </extensions>
+</idea-plugin>