# HG changeset patch
# User Drew Perttula <drewp@bigasterisk.com>
# Date 1370771015 0
# Node ID aaf1f182500979a7cee3ad7032b0c1990fcb3dcf
# Parent  21974e0ef0c4cbc6519be19231144a05a406a7f2
error if we have multiple expressions on one subterm
Ignore-this: f2f7f687ce0cf1f01df300a523f78243

diff -r 21974e0ef0c4 -r aaf1f1825009 light9/curvecalc/subterm.py
--- a/light9/curvecalc/subterm.py	Sun Jun 09 09:43:22 2013 +0000
+++ b/light9/curvecalc/subterm.py	Sun Jun 09 09:43:35 2013 +0000
@@ -113,7 +113,10 @@
         """current graph is being passed as an optimization. It should be
         equivalent to use self.graph in here."""
 
-        expr = current.value(self.uri, L9['expression'])
+        objs = list(current.objects(self.uri, L9.expression))
+        if len(objs) > 1:
+            raise ValueError("found multiple expressions for %s: %s" %
+                             (self.uri, objs))
         
         expr = current.value(self.uri, L9['expression'])
         if not expr: