From 86c259df7bfde0f25f48498e4e8c9048e8fc43cf Mon Sep 17 00:00:00 2001
From: Paul Jolly <paul@myitcv.io>
Date: Wed, 17 Apr 2024 16:39:25 +0100
Subject: [PATCH] lexers/cue: support CUE attributes

Currently the following CUE results in the chroma lexer producing an
error token for the '@':

    value: string @go(Value)

This code is, however, valid CUE. '@go' is an attributes.

This change adds lexer support for attributes in CUE.
---
 lexers/embedded/cue.xml      |  2 +-
 lexers/testdata/cue.actual   | 20 ++++++++
 lexers/testdata/cue.expected | 96 ++++++++++++++++++++++++++++++++++++
 3 files changed, 117 insertions(+), 1 deletion(-)

diff --git a/lexers/embedded/cue.xml b/lexers/embedded/cue.xml
index d6c3ea71b..2a12f3953 100644
--- a/lexers/embedded/cue.xml
+++ b/lexers/embedded/cue.xml
@@ -49,7 +49,7 @@
       <rule pattern="(true|false|null|_)\b">
         <token type="KeywordConstant"/>
       </rule>
-      <rule pattern="#?[_a-zA-Z$]\w*">
+      <rule pattern="[@#]?[_a-zA-Z$]\w*">
         <token type="Name"/>
       </rule>
     </state>
diff --git a/lexers/testdata/cue.actual b/lexers/testdata/cue.actual
index 830682b2b..1ac848839 100644
--- a/lexers/testdata/cue.actual
+++ b/lexers/testdata/cue.actual
@@ -34,3 +34,23 @@ _hidden: int
 regular: int
 $id: int
 #definition: int
+
+@protobuf(proto3)
+
+myStruct1: {
+    // Struct attribute:
+    @jsonschema(id="https://example.org/mystruct1.json")
+
+    // Field attributes
+    field: string @go(Field)
+    attr:  int    @xml(,attr) @go(Attr)
+}
+
+myStruct2: {
+    field: string @go(Field)
+    attr:  int    @xml(a1,attr) @go(Attr)
+}
+
+Combined: myStruct1 & myStruct2
+// field: string @go(Field)
+// attr:  int    @xml(,attr) @xml(a1,attr) @go(Attr)
diff --git a/lexers/testdata/cue.expected b/lexers/testdata/cue.expected
index c7c0dce4c..4dd52dd25 100644
--- a/lexers/testdata/cue.expected
+++ b/lexers/testdata/cue.expected
@@ -126,5 +126,101 @@
   {"type":"Operator","value":":"},
   {"type":"Text","value":" "},
   {"type":"KeywordType","value":"int"},
+  {"type":"Text","value":"\n\n"},
+  {"type":"Name","value":"@protobuf"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Name","value":"proto3"},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":"\n\n"},
+  {"type":"Name","value":"myStruct1"},
+  {"type":"Operator","value":":"},
+  {"type":"Text","value":" "},
+  {"type":"Punctuation","value":"{"},
+  {"type":"Text","value":"\n    "},
+  {"type":"CommentSingle","value":"// Struct attribute:"},
+  {"type":"Text","value":"\n    "},
+  {"type":"Name","value":"@jsonschema"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Name","value":"id"},
+  {"type":"Operator","value":"="},
+  {"type":"LiteralString","value":"\"https://example.org/mystruct1.json\""},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":"\n\n    "},
+  {"type":"CommentSingle","value":"// Field attributes"},
+  {"type":"Text","value":"\n    "},
+  {"type":"Name","value":"field"},
+  {"type":"Operator","value":":"},
+  {"type":"Text","value":" "},
+  {"type":"KeywordType","value":"string"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"@go"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Name","value":"Field"},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":"\n    "},
+  {"type":"Name","value":"attr"},
+  {"type":"Operator","value":":"},
+  {"type":"Text","value":"  "},
+  {"type":"KeywordType","value":"int"},
+  {"type":"Text","value":"    "},
+  {"type":"Name","value":"@xml"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Operator","value":","},
+  {"type":"Name","value":"attr"},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"@go"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Name","value":"Attr"},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":"\n"},
+  {"type":"Punctuation","value":"}"},
+  {"type":"Text","value":"\n\n"},
+  {"type":"Name","value":"myStruct2"},
+  {"type":"Operator","value":":"},
+  {"type":"Text","value":" "},
+  {"type":"Punctuation","value":"{"},
+  {"type":"Text","value":"\n    "},
+  {"type":"Name","value":"field"},
+  {"type":"Operator","value":":"},
+  {"type":"Text","value":" "},
+  {"type":"KeywordType","value":"string"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"@go"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Name","value":"Field"},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":"\n    "},
+  {"type":"Name","value":"attr"},
+  {"type":"Operator","value":":"},
+  {"type":"Text","value":"  "},
+  {"type":"KeywordType","value":"int"},
+  {"type":"Text","value":"    "},
+  {"type":"Name","value":"@xml"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Name","value":"a1"},
+  {"type":"Operator","value":","},
+  {"type":"Name","value":"attr"},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"@go"},
+  {"type":"Punctuation","value":"("},
+  {"type":"Name","value":"Attr"},
+  {"type":"Punctuation","value":")"},
+  {"type":"Text","value":"\n"},
+  {"type":"Punctuation","value":"}"},
+  {"type":"Text","value":"\n\n"},
+  {"type":"Name","value":"Combined"},
+  {"type":"Operator","value":":"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"myStruct1"},
+  {"type":"Text","value":" "},
+  {"type":"Operator","value":"\u0026"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"myStruct2"},
+  {"type":"Text","value":"\n"},
+  {"type":"CommentSingle","value":"// field: string @go(Field)"},
+  {"type":"Text","value":"\n"},
+  {"type":"CommentSingle","value":"// attr:  int    @xml(,attr) @xml(a1,attr) @go(Attr)"},
   {"type":"Text","value":"\n"}
 ]