lib: add clarification about the use of "prefix" in the docs.

[notmuch] / lib / database.cc

diff --git a/lib/database.cc b/lib/database.cc
index 02444e09e965c4ce0dbc396d5ed48b5abce5ba0a..f33f0af6a7145a603a7ed9eb42bed44c442deba4 100644 (file)
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -21,6 +21,7 @@
 #include "database-private.h"
 #include "parse-time-vrp.h"
 #include "query-fp.h"
+#include "thread-fp.h"
 #include "regexp-fields.h"
 #include "string-util.h"
 
@@ -62,14 +63,19 @@ typedef struct {
  * We currently have three different types of documents (mail, ghost,
  * and directory) and also some metadata.
  *
+ * There are two kinds of prefixes used in notmuch. There are the
+ * human friendly 'prefix names' like "thread:", which are also used
+ * in the query parser, and the actual prefix terms in the database
+ * (e.g. "G"). The correspondence is maintained in the file scope data
+ * structure 'prefix_table'.
+ *
  * Mail document
  * -------------
  * A mail document is associated with a particular email message. It
- * is stored in one or more files on disk (though only one has its
- * content indexed) and is uniquely identified  by its "id" field
- * (which is generally the message ID). It is indexed with the
- * following prefixed terms which the database uses to construct
- * threads, etc.:
+ * is stored in one or more files on disk and is uniquely identified
+ * by its "id" field (which is generally the message ID). It is
+ * indexed with the following prefixed terms which the database uses
+ * to construct threads, etc.:
  *
  *    Single terms of given prefix:
  *
@@ -258,7 +264,8 @@ prefix_t prefix_table[] = {
     { "directory",             "XDIRECTORY",   NOTMUCH_FIELD_NO_FLAGS },
     { "file-direntry",         "XFDIRENTRY",   NOTMUCH_FIELD_NO_FLAGS },
     { "directory-direntry",    "XDDIRENTRY",   NOTMUCH_FIELD_NO_FLAGS },
-    { "thread",                        "G",            NOTMUCH_FIELD_EXTERNAL },
+    { "thread",                        "G",            NOTMUCH_FIELD_EXTERNAL |
+                                               NOTMUCH_FIELD_PROCESSOR },
     { "tag",                   "K",            NOTMUCH_FIELD_EXTERNAL |
                                                NOTMUCH_FIELD_PROCESSOR },
     { "is",                    "K",            NOTMUCH_FIELD_EXTERNAL |
@@ -317,6 +324,8 @@ _setup_query_field (const prefix_t *prefix, notmuch_database_t *notmuch)
            fp = (new DateFieldProcessor())->release ();
        else if (STRNCMP_LITERAL(prefix->name, "query") == 0)
            fp = (new QueryFieldProcessor (*notmuch->query_parser, notmuch))->release ();
+       else if (STRNCMP_LITERAL(prefix->name, "thread") == 0)
+           fp = (new ThreadFieldProcessor (*notmuch->query_parser, notmuch))->release ();
        else
            fp = (new RegexpFieldProcessor (prefix->name, prefix->flags,
                                            *notmuch->query_parser, notmuch))->release ();