Allow 'NOT ' and 'not '

[phdru.name/cgi-bin/blog-ru/search-tags.git] / parser / grammar

diff --git a/parser/grammar b/parser/grammar
index 7c34096e3bdb10aaee6557185dcca6c60fb6d893..14753c88e28544d5252a74dc38a142fc11e20d83 100644 (file)
--- a/parser/grammar
+++ b/parser/grammar
@@ -8,9 +8,9 @@
 # Parentheses are allowed to group expressions; for example:
 #  TAG & (TAG | TAG)
 #  !(TAG | TAG)
-# Allowed operators: conjunction - & &&
-#                    disjunction - | ||
-#                    negation    - !
+# Allowed operators: conjunction - & && AND and
+#                    disjunction - | || OR or
+#                    negation    - ! NOT not
 # This  is a simple version of the grammar and it allows
 # rather stupid expressions, like !!TAG or ((TAG)); in the future
 # it will be fixed by making the grammar more complex and stricter.
@@ -28,10 +28,34 @@ SP1 : '[ \t]+'
 expression : NAME
            | expression SP0 AND_OP AND_OP SP0 expression
            | expression SP0 AND_OP SP0 expression
-           | NOT_OP SP0 expression
+           | l_expression and_word r_expression
            | expression SP0 OR_OP OR_OP SP0 expression
            | expression SP0 OR_OP SP0 expression
-           | '(' SP0 expression SP0 ')'
+           | l_expression or_word r_expression
+           | NOT_OP SP0 expression
+           | not_word r_expression
+           | expression_parens
+
+l_expression : expression_parens
+             | expression_sp
+
+r_expression : expression_parens
+             | sp_expression
+
+expression_parens : '(' SP0 expression SP0 ')'
+
+sp_expression : SP1 expression
+
+expression_sp : expression SP1
+
+and_word : 'A' 'N' 'D'
+         | 'a' 'n' 'd'
+
+or_word : 'O' 'R'
+        | 'o' 'r'
+
+not_word : 'N' 'O' 'T'
+         | 'n' 'o' 't'
 
 SP0 : SP1 | empty