From 9e94e24afd92b2317768f11d991bf51eed2c7adf Mon Sep 17 00:00:00 2001
From: Kevin <kevin@kevin-brown.com>
Date: Sun, 10 May 2020 17:34:50 -0400
Subject: [PATCH] Fix AST for conditional expressions

Previously all conditional expressions were left associative which
produced an AST that was nothing like the one in Jinja and one which
did not respect order of operations within conditions. The conditional
expression part of the grammar has been rewritten to be more explicit
about what can and cannot match which appears to have fixed those
issues with the AST.
---
 grammar.ebnf | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/grammar.ebnf b/grammar.ebnf
index f04cede1..0c47bba9 100644
--- a/grammar.ebnf
+++ b/grammar.ebnf
@@ -212,17 +212,45 @@ variable_accessor_call_parameter_key
 
 variable_accessor_call_parameter_value
     =
-    | variable_tests
+    | conditional_expression
     | variable_identifier
     ;
 
+conditional_expression
+    =
+    | conditional_expression_logical
+    | conditional_expression_comparator
+    | conditional_expression_test
+    ;
+
+conditional_expression_logical
+    =
+    left:conditional_expression
+    {SP}* logical_operator:variable_tests_logical_operator {SP}*
+    right:conditional_expression
+    ;
+
+conditional_expression_comparator
+    =
+    left:variable_identifier
+    {SP}* comparator:variable_tests_comparator {SP}*
+    right:variable_identifier
+    ;
+
+conditional_expression_test
+    =
+    test_variable:variable_identifier
+    {SP}* "is" {SP}*
+    test_function:variable_identifier
+    ;
+
 variable_tests
     =
-    left:variable_identifier {SP}*
+    left:variable_tests {SP}*
     (
+        | ( logical_operator:variable_tests_logical_operator {SP}* right:variable_tests )
+        | ( comparator:variable_tests_comparator {SP}* right:variable_tests )
         | ( "is" {SP}* test_function:variable_accessor_call_parameter_value )
-        | ( comparator:variable_tests_comparator {SP}* right:variable_accessor_call_parameter_value )
-        | ( logical_operator:variable_tests_logical_operator {SP}* right:variable_accessor_call_parameter_value )
     )
     ;
 
-- 
2.47.3