annotation highlighting

lynglib/src/commonMain/kotlin/net/sergeych/lyng/highlight/SimpleLyngHighlighter.kt

@@ -140,16 +140,22 @@ class SimpleLyngHighlighter : LyngHighlighter {
 
         for (t in tokens) {
             val k = kindOf(t.type, t.value) ?: continue
-            val start = src.offsetOf(t.pos)
+            val start0 = src.offsetOf(t.pos)
             val range = when (t.type) {
-                Type.STRING, Type.STRING2 -> adjustQuoteSpan(start, '"')
-                Type.CHAR -> adjustQuoteSpan(start, '\'')
+                Type.STRING, Type.STRING2 -> adjustQuoteSpan(start0, '"')
+                Type.CHAR -> adjustQuoteSpan(start0, '\'')
                 Type.HEX -> {
                     // Parser returns HEX token value without the leading "0x"; include it in highlight span
-                    val end = (start + 2 + t.value.length).coerceAtMost(text.length)
-                    TextRange(start, end)
+                    val end = (start0 + 2 + t.value.length).coerceAtMost(text.length)
+                    TextRange(start0, end)
                 }
-                else -> TextRange(start, (start + t.value.length).coerceAtMost(text.length))
+                Type.ATLABEL -> {
+                    // Parser returns value without leading '@'; token pos points at '@'.
+                    // So we need to include '@' (1 char) + the identifier length.
+                    val end = (start0 + 1 + t.value.length).coerceAtMost(text.length)
+                    TextRange(start0, end)
+                }
+                else -> TextRange(start0, (start0 + t.value.length).coerceAtMost(text.length))
             }
             if (range.endExclusive > range.start) raw += HighlightSpan(range, k)
         }

lynglib/src/commonTest/kotlin/net/sergeych/lyng/highlight/HighlightMappingTest.kt

@@ -81,4 +81,44 @@ class HighlightMappingTest {
         assertTrue(labeled.any { it.first == "(" && it.second == HighlightKind.Punctuation })
         assertTrue(labeled.any { it.first == ")" && it.second == HighlightKind.Punctuation })
     }
+
+    @Test
+    fun annotationsIncludeAtAndFullName() {
+        // Simple standalone annotation must include full token including '@'
+        run {
+            val text = "@Ann"
+            val spans = SimpleLyngHighlighter().highlight(text)
+            val annSpans = spans.filter { it.kind == HighlightKind.Label }
+            assertTrue(annSpans.size == 1)
+            val frag = text.substring(annSpans[0].range.start, annSpans[0].range.endExclusive)
+            assertTrue(frag == "@Ann")
+        }
+        // Qualified name: we at least must not drop the last character of the @segment
+        run {
+            val text = "@Qualified.Name"
+            val spans = SimpleLyngHighlighter().highlight(text)
+            val annSpans = spans.filter { it.kind == HighlightKind.Label }
+            assertTrue(annSpans.size == 1)
+            val s = annSpans[0]
+            val frag = text.substring(s.range.start, s.range.endExclusive)
+            assertTrue(frag.startsWith("@Qualified"))
+            // Ensure we did not miss the last char of this segment
+            assertTrue(frag.last() == 'd')
+            // Next token after the span should be '.'
+            assertTrue(text.getOrNull(s.range.endExclusive) == '.')
+        }
+        // Multiple annotations: every Label span must include '@' and end on an identifier boundary
+        run {
+            val text = "@Ann @Another(1) fun x() {}"
+            val spans = SimpleLyngHighlighter().highlight(text)
+            val annSpans = spans.filter { it.kind == HighlightKind.Label }
+            assertTrue(annSpans.size >= 2)
+            for (s in annSpans) {
+                val frag = text.substring(s.range.start, s.range.endExclusive)
+                assertTrue(frag.startsWith("@"))
+                // last char must be letter/digit/underscore/tilde/dollar per idNextChars
+                assertTrue(frag.last().isLetterOrDigit() || frag.last() == '_' || frag.last() == '$' || frag.last() == '~')
+            }
+        }
+    }
 }