lib/parse-sexp: support regular expressions

At least to the degree that the Xapian QueryParser based parser
also supports them. Support short alias 'rx' as it seems to make more
complex queries nicer to read.

1 files changed, 44 insertions, 10 deletions

diff --git a/lib/parse-sexp.cc b/lib/parse-sexp.cc
index 0192bda9..84914296 100644
--- a/lib/parse-sexp.cc
+++ b/lib/parse-sexp.cc
@@ -13,6 +13,8 @@ typedef enum {
     SEXP_FLAG_BOOLEAN	= 1 << 1,
     SEXP_FLAG_SINGLE	= 1 << 2,
     SEXP_FLAG_WILDCARD	= 1 << 3,
+    SEXP_FLAG_REGEX	= 1 << 4,
+    SEXP_FLAG_DO_REGEX	= 1 << 5,
 } _sexp_flag_t;
 
 /*
@@ -48,15 +50,15 @@ static _sexp_prefix_t prefixes[] =
     { "body",           Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
       SEXP_FLAG_FIELD },
     { "from",           Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
-      SEXP_FLAG_FIELD | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "folder",         Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "id",             Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "is",             Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "mid",            Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "mimetype",       Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
       SEXP_FLAG_FIELD | SEXP_FLAG_WILDCARD },
     { "not",            Xapian::Query::OP_AND_NOT,      Xapian::Query::MatchAll,
@@ -64,17 +66,21 @@ static _sexp_prefix_t prefixes[] =
     { "or",             Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
       SEXP_FLAG_NONE },
     { "path",           Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "property",       Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
+    { "regex",          Xapian::Query::OP_INVALID,      Xapian::Query::MatchAll,
+      SEXP_FLAG_SINGLE | SEXP_FLAG_DO_REGEX },
+    { "rx",             Xapian::Query::OP_INVALID,      Xapian::Query::MatchAll,
+      SEXP_FLAG_SINGLE | SEXP_FLAG_DO_REGEX },
     { "starts-with",    Xapian::Query::OP_WILDCARD,     Xapian::Query::MatchAll,
       SEXP_FLAG_SINGLE },
     { "subject",        Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
-      SEXP_FLAG_FIELD | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "tag",            Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "thread",         Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
-      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD },
+      SEXP_FLAG_FIELD | SEXP_FLAG_BOOLEAN | SEXP_FLAG_WILDCARD | SEXP_FLAG_REGEX },
     { "to",             Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
       SEXP_FLAG_FIELD | SEXP_FLAG_WILDCARD },
     { }
@@ -180,6 +186,30 @@ _sexp_parse_one_term (notmuch_database_t *notmuch, std::string term_prefix, cons
     }
 
 }
+
+notmuch_status_t
+_sexp_parse_regex (notmuch_database_t *notmuch,
+		   const _sexp_prefix_t *prefix, const _sexp_prefix_t *parent,
+		   std::string val, Xapian::Query &output)
+{
+    if (! parent) {
+	_notmuch_database_log (notmuch, "illegal '%s' outside field\n",
+			       prefix->name);
+	return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
+    }
+
+    if (! (parent->flags & SEXP_FLAG_REGEX)) {
+	_notmuch_database_log (notmuch, "'%s' not supported in field '%s'\n",
+			       prefix->name, parent->name);
+	return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
+    }
+
+    std::string msg; /* ignored */
+
+    return _notmuch_regexp_to_query (notmuch, Xapian::BAD_VALUENO, parent->name,
+				     val, output, msg);
+}
+
 /* Here we expect the s-expression to be a proper list, with first
  * element defining and operation, or as a special case the empty
  * list */
@@ -254,6 +284,10 @@ _sexp_to_xapian_query (notmuch_database_t *notmuch, const _sexp_prefix_t *parent
 	    if (prefix->xapian_op == Xapian::Query::OP_WILDCARD)
 		return _sexp_parse_wildcard (notmuch, parent, sx->list->next->val, output);
 
+	    if (prefix->flags & SEXP_FLAG_DO_REGEX) {
+		return _sexp_parse_regex (notmuch, prefix, parent, sx->list->next->val, output);
+	    }
+
 	    return _sexp_combine_query (notmuch, parent, prefix->xapian_op, prefix->initial,
 					sx->list->next, output);
 	}