lib/parse-sexp: support and, not, and or.

All operations and (Xapian) fields will eventually have an entry in
the prefixes table. The flags field is just a placeholder for now, but
will eventually distinguish between various kinds of prefixes.

1 files changed, 71 insertions, 5 deletions

diff --git a/lib/parse-sexp.cc b/lib/parse-sexp.cc
index f031d790..0d2c0ba8 100644
--- a/lib/parse-sexp.cc
+++ b/lib/parse-sexp.cc
@@ -7,12 +7,69 @@
 /* _sexp is used for file scope symbols to avoid clashing with
  * definitions from sexp.h */
 
+typedef enum {
+    SEXP_FLAG_NONE = 0,
+} _sexp_flag_t;
+
+typedef struct  {
+    const char *name;
+    Xapian::Query::op xapian_op;
+    Xapian::Query initial;
+    _sexp_flag_t flags;
+} _sexp_prefix_t;
+
+static _sexp_prefix_t prefixes[] =
+{
+    { "and",            Xapian::Query::OP_AND,          Xapian::Query::MatchAll,
+      SEXP_FLAG_NONE },
+    { "not",            Xapian::Query::OP_AND_NOT,      Xapian::Query::MatchAll,
+      SEXP_FLAG_NONE },
+    { "or",             Xapian::Query::OP_OR,           Xapian::Query::MatchNothing,
+      SEXP_FLAG_NONE },
+    { }
+};
+
+static notmuch_status_t _sexp_to_xapian_query (notmuch_database_t *notmuch,
+					       const _sexp_prefix_t *parent,
+					       const sexp_t *sx,
+					       Xapian::Query &output);
+
+static notmuch_status_t
+_sexp_combine_query (notmuch_database_t *notmuch,
+		     const _sexp_prefix_t *parent,
+		     Xapian::Query::op operation,
+		     Xapian::Query left,
+		     const sexp_t *sx,
+		     Xapian::Query &output)
+{
+    Xapian::Query subquery;
+
+    notmuch_status_t status;
+
+    /* if we run out elements, return accumulator */
+
+    if (! sx) {
+	output = left;
+	return NOTMUCH_STATUS_SUCCESS;
+    }
+
+    status = _sexp_to_xapian_query (notmuch, parent, sx, subquery);
+    if (status)
+	return status;
+
+    return _sexp_combine_query (notmuch,
+				parent,
+				operation,
+				Xapian::Query (operation, left, subquery),
+				sx->next, output);
+}
+
 /* 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 */
 
 static notmuch_status_t
-_sexp_to_xapian_query (notmuch_database_t *notmuch, const sexp_t *sx,
+_sexp_to_xapian_query (notmuch_database_t *notmuch, const _sexp_prefix_t *parent, const sexp_t *sx,
 		       Xapian::Query &output)
 {
 
@@ -32,11 +89,20 @@ _sexp_to_xapian_query (notmuch_database_t *notmuch, const sexp_t *sx,
 	return NOTMUCH_STATUS_SUCCESS;
     }
 
-    if (sx->list->ty == SEXP_VALUE)
-	_notmuch_database_log (notmuch, "unknown prefix '%s'\n", sx->list->val);
-    else
+    if (sx->list->ty == SEXP_LIST) {
 	_notmuch_database_log (notmuch, "unexpected list in field/operation position\n",
 			       sx->list->val);
+	return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
+    }
+
+    for (_sexp_prefix_t *prefix = prefixes; prefix && prefix->name; prefix++) {
+	if (strcmp (prefix->name, sx->list->val) == 0) {
+	    return _sexp_combine_query (notmuch, parent, prefix->xapian_op, prefix->initial,
+					sx->list->next, output);
+	}
+    }
+
+    _notmuch_database_log (notmuch, "unknown prefix '%s'\n", sx->list->val);
 
     return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 }
@@ -54,6 +120,6 @@ _notmuch_sexp_string_to_xapian_query (notmuch_database_t *notmuch, const char *q
 	return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
     }
 
-    return _sexp_to_xapian_query (notmuch, sx, output);
+    return _sexp_to_xapian_query (notmuch, NULL, sx, output);
 }
 #endif