From: Kevin <kevin@kevin-brown.com>
Date: Sun, 10 May 2020 21:34:50 +0000 (-0400)
Subject: Fix AST for conditional expressions
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9e94e24afd92b2317768f11d991bf51eed2c7adf;p=thirdparty%2Fjinja.git

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.
---

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 )
     )
     ;