From: Oleg Broytman <phd@phdru.name>
Date: Sat, 21 Jun 2014 19:23:14 +0000 (+0400)
Subject: Allow '&&'
X-Git-Tag: v0.3~10
X-Git-Url: https://git.phdru.name/?p=phdru.name%2Fcgi-bin%2Fblog-ru%2Fsearch-tags.git;a=commitdiff_plain;h=2167fc0e09f4343c0fe67c8c754e29a41769e684

Allow '&&'
---

diff --git a/ChangeLog b/ChangeLog
index a1748bd..e6ffcb8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Version 0.3 (2014-06-??)
+
+   Allow '&&'.
+
 Version 0.2 (2014-06-06)
 
    Ignore spaces.
diff --git a/TODO b/TODO
index cfeb865..312cfd3 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1,4 @@
-Allow '&&', ' and ' and ' AND '.
+Allow ' and ' and ' AND '.
 
 Allow '||', ' or ' and ' OR '.
 
diff --git a/parser/grammar b/parser/grammar
index ade8b12..17d3098 100644
--- a/parser/grammar
+++ b/parser/grammar
@@ -3,14 +3,14 @@
 # The grammar defines expressions in the following forms:
 #  TAG - search blog posts that contain the tag;
 #  !TAG - search blog posts that don't contain the tag;
-#  TAG & TAG - search blog posts that contain both tags;
-#  TAG | TAG - search blog posts that contain one of the tags or both;
+#  TAG && TAG, TAG & TAG - search blog posts that contain both tags;
+#  TAG | TAG - search blog posts that contain any of the tags;
 # Parentheses are allowed to group expressions:
 #  TAG & (TAG | TAG)
 #  !(TAG | TAG)
-# and so on. This  is the first version of the grammar and it allows
+# and so on. 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 stricter and more complex.
+# it will be fixed by making the grammar more complex and stricter.
 
 NAME : '[a-z][a-z0-9_]+'
 
@@ -20,13 +20,11 @@ OR_OP : '|'
 
 NOT_OP : '!'
 
-SP0 : '[ \t]*'
-
 SP1 : '[ \t]+'
 
 expression : NAME
+           | expression AND_OP AND_OP expression
            | expression AND_OP expression
            | expression OR_OP expression
            | NOT_OP expression
            | '(' expression ')'
-           | SP0 expression SP0
diff --git a/parser/parser.py b/parser/parser.py
index 2fcf716..38c4cd2 100644
--- a/parser/parser.py
+++ b/parser/parser.py
@@ -25,6 +25,10 @@ def p_expression_name(p):
     """expression : NAME"""
     p[0] = ('NAME', p[1])
 
+def p_expression_and_and(p):
+    """expression : expression AND_OP AND_OP expression"""
+    p[0] = ('AND', p[1], p[4])
+
 def p_expression_and(p):
     """expression : expression AND_OP expression"""
     p[0] = ('AND', p[1], p[3])
diff --git a/parser/test_parser.py b/parser/test_parser.py
index 804505f..a8d5227 100755
--- a/parser/test_parser.py
+++ b/parser/test_parser.py
@@ -21,6 +21,9 @@ class TestParser(unittest.TestCase):
         self.assertEqual(parser.parse('!(xxx & yyy)'),
             ('NOT', ('PARENS', ('AND', ('NAME', 'xxx'), ('NAME', 'yyy'))))
         )
+        self.assertEqual(parser.parse('!(xxx && yyy)'),
+            ('NOT', ('PARENS', ('AND', ('NAME', 'xxx'), ('NAME', 'yyy'))))
+        )
         self.assertEqual(parser.parse('!xxx&yyy&zzz|ooo'),
             ('OR', ('AND', ('AND', ('NOT', ('NAME', 'xxx')), ('NAME', 'yyy')), ('NAME', 'zzz')), ('NAME', 'ooo'))
         )