lib/parse-sexp: support regular expressions

[notmuch] / doc / man7 / notmuch-sexp-queries.rst

diff --git a/doc/man7/notmuch-sexp-queries.rst b/doc/man7/notmuch-sexp-queries.rst
index c83ce3d0603650eda1a5bf92448ff2a89b85a08d..7eaffe569f0ea42a8f8c8a44c9489547f1e27322 100644 (file)
--- a/doc/man7/notmuch-sexp-queries.rst
+++ b/doc/man7/notmuch-sexp-queries.rst
@@ -36,8 +36,11 @@ An s-expression query is either an atom, the empty list, or a
 a *field*, *logical operation*, or *modifier*, and 0 or more
 subqueries.
 
-``*`` ``()``
-    Match all messages.
+``*``
+   "*" matches any non-empty string in the current field.
+
+``()``
+    The empty list matches all messages
 
 *term*
 
@@ -138,6 +141,20 @@ from terms, operators, and modifiers, but not other fields.
 MODIFIERS
 `````````
 
+*Modifiers* refer to any prefixes (first elements of compound queries)
+that are neither operators nor fields.
+
+``(regex`` *atom* ``)`` ``(rx`` *atom* ``)``
+    Interpret *atom* as a POSIX.2 regular expression (see
+    :manpage:`regex(7)`). This applies in term fields and a subset [#not-phrase]_ of
+    phrase fields (see :any:`field-table`).
+
+``(starts-with`` *subword* ``)``
+    Matches any term starting with *subword*.  This applies in either
+    phrase or term :any:`fields <fields>`, or outside of fields [#not-body]_. Note that
+    a ``starts-with`` query cannot be part of a phrase. The
+    atom ``*`` is a synonym for ``(starts-with "")``.
+
 EXAMPLES
 ========
 
@@ -181,6 +198,9 @@ EXAMPLES
     "mallory@example.org", and also "bob@example.com.au" since it
     contains the adjacent triple "bob", "example", "com".
 
+``(not (to *))``
+    Match messages with an empty or invalid 'To' and 'Cc' field.
+
 NOTES
 =====
 
@@ -190,6 +210,9 @@ NOTES
 
 .. [#aka-bool] a.k.a. boolean prefixes
 
+.. [#not-phrase] Due to the implemention of phrase fields in Xapian,
+                 regex queries could only match individual words.
+
 .. [#not-body] Due the the way ``body`` is implemented in notmuch,
                this modifier is not supported in the ``body`` field.