From 72252bca20db43819fdab1de0c577449f63ff53e Mon Sep 17 00:00:00 2001
From: Christian <me@rndm.de>
Date: Wed, 21 Aug 2024 10:35:49 +0200
Subject: [PATCH] feat: add support for camunda variable escaping extension

fixes #36
---
 src/feel.grammar     |  6 +++++-
 test/expressions.txt | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/feel.grammar b/src/feel.grammar
index 3d7dd41..691524b 100644
--- a/src/feel.grammar
+++ b/src/feel.grammar
@@ -323,7 +323,7 @@ Identifier {
 }
 
 VariableName {
-  (!name Identifier ~ident)+
+  (!name Identifier ~ident)+ | backtickIdentifier
 }
 
 AdditionalIdentifier[@name=Identifier] {
@@ -453,6 +453,10 @@ commaSep<Expr> {
     (digits ("." digits)? | "." digits)
   }
 
+  backtickIdentifier {
+    "`" (![\\\n`] | "\\" _)* "`"
+  }
+
   @precedence { BlockComment, LineComment, divide }
 
   @precedence {
diff --git a/test/expressions.txt b/test/expressions.txt
index 1525c2b..bb7cb17 100644
--- a/test/expressions.txt
+++ b/test/expressions.txt
@@ -2619,4 +2619,19 @@ foo[[[[[[[(1..10).start included]]]]]]]
 
 Expression(
   FilterExpression(VariableName(...), List(...))
+)
+
+
+# Camunda escape character { "top": "Expressions" }
+
+`foo`;
+foo.`bar`;
+foo.`bar-baz`;
+
+==>
+
+Expressions(
+  VariableName(...),
+  PathExpression(VariableName(...), VariableName(...)),
+  PathExpression(VariableName(...), VariableName(...))
 )
\ No newline at end of file