search: more granular message body searching

"bs:" and "b:" are adapted from mairix(1)

We will also support searching explicitly for quoted vs
non-quoted text via "q:" and "nq:" prefixes since sometimes
readers will not care for quoted text.

In the future, we will support parsing diffs (perhaps when
repobrowse integration is complete).

Note: this roughly doubles the size of the Xapian database due
to the additional information; so this change may not be worth
it.

1 files changed, 12 insertions, 6 deletions

diff --git a/lib/PublicInbox/Search.pm b/lib/PublicInbox/Search.pm
index 3b25b662..f74129d5 100644
--- a/lib/PublicInbox/Search.pm
+++ b/lib/PublicInbox/Search.pm
@@ -58,16 +58,22 @@ my %bool_pfx_external = (
 );
 
 my %prob_prefix = (
-        s => 'S', # for mairix compatibility
+        # for mairix compatibility
+        s => 'S',
         m => 'Q', # 'mid' is exact, 'm' can do partial
-        f => 'A', # for mairix compatibility
-        t => 'XTO', # for mairix compatibility
-        tc => 'XTC', # for mairix compatibility
-        c => 'XCC', # for mairix compatibility
-        tcf => 'XTCF', # for mairix compatibility
+        f => 'A',
+        t => 'XTO',
+        tc => 'XTC',
+        c => 'XCC',
+        tcf => 'XTCF',
+        b => 'XBODY',
+        bs => 'XBS',
+
         # n.b.: leaving out "a:" alias for "tcf:" even though
         # mairix supports it.  It is only mentioned in passing in mairix(1)
         # and the extra two letters are not significantly longer.
+        q => 'XQUOT',
+        nq => 'XNQ',
 );
 
 # not documenting m: and mid: for now, the using the URLs works w/o Xapian