xcbgen: sumof with nested expression

Add parser support for sumof with a nested expression.
For example:
	<sumof ref="mylist1">
		<fieldref>bar</fieldref>
	</sumof>

The nested expression is added as the "rhs"-field of the
expression.object.

Message-ID: <1409743080-302-4-git-send-email-chris@demorecorder.com>
Patch-Thread-Subject: [Xcb] xinput: make ListInputDevices work, sumof with nested expr, ...
Patch-Set: ListInputDevices
Patch-Number: proto 4/7
Patch-Version: V1
Signed-off-by: Christian Linhart <chris@DemoRecorder.com>

diff --git a/xcbgen/expr.py b/xcbgen/expr.py
index 51e738f..a03703f 100644 (file)
--- a/xcbgen/expr.py
+++ b/xcbgen/expr.py
@@ -104,6 +104,12 @@ class Expression(object):
         elif elt.tag == 'sumof':
             self.op = 'sumof'
             self.lenfield_name = elt.get('ref')
+            subexpressions = list(elt)
+            if len(subexpressions) > 0:
+                # sumof with a nested expression which is to be evaluated
+                # for each list-element in the context of that list-element.
+                # sumof then returns the sum of the results of these evaluations
+                self.rhs = Expression(subexpressions[0], parent)
 
         else:
             # Notreached