+#if HAVE_SFSEXP
+#include <sexp.h>
+#endif
+
+/* Bit masks for _notmuch_database::features. Features are named,
+ * independent aspects of the database schema.
+ *
+ * A database stores the set of features that it "uses" (implicitly
+ * before database version 3 and explicitly as of version 3).
+ *
+ * A given library version will "recognize" a particular set of
+ * features; if a database uses a feature that the library does not
+ * recognize, the library will refuse to open it. It is assumed the
+ * set of recognized features grows monotonically over time. A
+ * library version will "implement" some subset of the recognized
+ * features: some operations may require that the database use (or not
+ * use) some feature, while other operations may support both
+ * databases that use and that don't use some feature.
+ *
+ * On disk, the database stores string names for these features (see
+ * the feature_names array). These enum bit values are never
+ * persisted to disk and may change freely.
+ */
+enum _notmuch_features {
+ /* If set, file names are stored in "file-direntry" terms. If
+ * unset, file names are stored in document data.
+ *
+ * Introduced: version 1. */
+ NOTMUCH_FEATURE_FILE_TERMS = 1 << 0,
+
+ /* If set, directory timestamps are stored in documents with
+ * XDIRECTORY terms and relative paths. If unset, directory
+ * timestamps are stored in documents with XTIMESTAMP terms and
+ * absolute paths.
+ *
+ * Introduced: version 1. */
+ NOTMUCH_FEATURE_DIRECTORY_DOCS = 1 << 1,
+
+ /* If set, the from, subject, and message-id headers are stored in
+ * message document values. If unset, message documents *may*
+ * have these values, but if the value is empty, it must be
+ * retrieved from the message file.
+ *
+ * Introduced: optional in version 1, required as of version 3.
+ */
+ NOTMUCH_FEATURE_FROM_SUBJECT_ID_VALUES = 1 << 2,
+
+ /* If set, folder terms are boolean and path terms exist. If
+ * unset, folder terms are probabilistic and stemmed and path
+ * terms do not exist.
+ *
+ * Introduced: version 2. */
+ NOTMUCH_FEATURE_BOOL_FOLDER = 1 << 3,
+
+ /* If set, missing messages are stored in ghost mail documents.
+ * If unset, thread IDs of ghost messages are stored as database
+ * metadata instead of in ghost documents.
+ *
+ * Introduced: version 3. */
+ NOTMUCH_FEATURE_GHOSTS = 1 << 4,
+
+
+ /* If set, then the database was created after the introduction of
+ * indexed mime types. If unset, then the database may contain a
+ * mixture of messages with indexed and non-indexed mime types.
+ *
+ * Introduced: version 3. */
+ NOTMUCH_FEATURE_INDEXED_MIMETYPES = 1 << 5,
+
+ /* If set, messages store the revision number of the last
+ * modification in NOTMUCH_VALUE_LAST_MOD.
+ *
+ * Introduced: version 3. */
+ NOTMUCH_FEATURE_LAST_MOD = 1 << 6,
+
+ /* If set, unprefixed terms are stored only for the message body,
+ * not for headers.
+ *
+ * Introduced: version 3. */
+ NOTMUCH_FEATURE_UNPREFIX_BODY_ONLY = 1 << 7,
+};
+
+/* In C++, a named enum is its own type, so define bitwise operators
+ * on _notmuch_features. */
+inline _notmuch_features
+operator| (_notmuch_features a, _notmuch_features b)
+{
+ return static_cast<_notmuch_features>(
+ static_cast<unsigned>(a) | static_cast<unsigned>(b));
+}
+
+inline _notmuch_features
+operator& (_notmuch_features a, _notmuch_features b)
+{
+ return static_cast<_notmuch_features>(
+ static_cast<unsigned>(a) & static_cast<unsigned>(b));
+}
+
+inline _notmuch_features
+operator~ (_notmuch_features a)
+{
+ return static_cast<_notmuch_features>(~static_cast<unsigned>(a));
+}
+
+inline _notmuch_features&
+operator|= (_notmuch_features &a, _notmuch_features b)
+{
+ a = a | b;
+ return a;
+}
+
+inline _notmuch_features&
+operator&= (_notmuch_features &a, _notmuch_features b)
+{
+ a = a & b;
+ return a;
+}
+
+/*
+ * Configuration options for xapian database fields */
+typedef enum {
+ NOTMUCH_FIELD_NO_FLAGS = 0,
+ NOTMUCH_FIELD_EXTERNAL = 1 << 0,
+ NOTMUCH_FIELD_PROBABILISTIC = 1 << 1,
+ NOTMUCH_FIELD_PROCESSOR = 1 << 2,
+ NOTMUCH_FIELD_STRIP_TRAILING_SLASH = 1 << 3,
+} notmuch_field_flag_t;
+
+/*
+ * define bitwise operators to hide casts */
+inline notmuch_field_flag_t
+operator| (notmuch_field_flag_t a, notmuch_field_flag_t b)
+{
+ return static_cast<notmuch_field_flag_t>(
+ static_cast<unsigned>(a) | static_cast<unsigned>(b));
+}
+
+inline notmuch_field_flag_t
+operator& (notmuch_field_flag_t a, notmuch_field_flag_t b)
+{
+ return static_cast<notmuch_field_flag_t>(
+ static_cast<unsigned>(a) & static_cast<unsigned>(b));
+}
+
+#define NOTMUCH_QUERY_PARSER_FLAGS (Xapian::QueryParser::FLAG_BOOLEAN | \
+ Xapian::QueryParser::FLAG_PHRASE | \
+ Xapian::QueryParser::FLAG_LOVEHATE | \
+ Xapian::QueryParser::FLAG_BOOLEAN_ANY_CASE | \
+ Xapian::QueryParser::FLAG_WILDCARD | \
+ Xapian::QueryParser::FLAG_PURE_NOT)
+
+/*
+ * explicit and implied parameters to open */
+typedef enum {
+ NOTMUCH_PARAM_NONE = 0,
+ /* database passed explicitely */
+ NOTMUCH_PARAM_DATABASE = 1 << 0,
+ /* config file passed explicitely */
+ NOTMUCH_PARAM_CONFIG = 1 << 1,
+ /* profile name passed explicitely */
+ NOTMUCH_PARAM_PROFILE = 1 << 2,
+ /* split (e.g. XDG) configuration */
+ NOTMUCH_PARAM_SPLIT = 1 << 3,
+} notmuch_open_param_t;
+
+/*
+ * define bitwise operators to hide casts */
+
+inline notmuch_open_param_t
+operator| (notmuch_open_param_t a, notmuch_open_param_t b)
+{
+ return static_cast<notmuch_open_param_t>(
+ static_cast<unsigned>(a) | static_cast<unsigned>(b));
+}
+
+inline notmuch_open_param_t&
+operator|= (notmuch_open_param_t &a, notmuch_open_param_t b)
+{
+ a = a | b;
+ return a;
+}
+
+inline notmuch_open_param_t
+operator& (notmuch_open_param_t a, notmuch_open_param_t b)
+{
+ return static_cast<notmuch_open_param_t>(
+ static_cast<unsigned>(a) & static_cast<unsigned>(b));
+}
+