# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1488298728 -3600
# Node ID ba53413ad5de163d7084653a95fd958411844812
# Parent  f0fb5ec36d9911ef44a5434876b928c73e4965e7
Remove temporary names used by negation operands.

diff -r f0fb5ec36d99 -r ba53413ad5de tests/logical_simple.py
--- a/tests/logical_simple.py	Tue Feb 28 17:00:26 2017 +0100
+++ b/tests/logical_simple.py	Tue Feb 28 17:18:48 2017 +0100
@@ -1,3 +1,6 @@
+def no_temp(a, b):
+    return not (a and b)
+
 a = 1
 b = 2
 c = a and b
@@ -11,6 +14,9 @@
 
 f = 0
 
+g = no_temp(a, b)
+print g                             # False
+
 if a and b:
     print "a and b"                 # a and b
 else:
diff -r f0fb5ec36d99 -r ba53413ad5de translator.py
--- a/translator.py	Tue Feb 28 17:00:26 2017 +0100
+++ b/translator.py	Tue Feb 28 17:18:48 2017 +0100
@@ -1396,7 +1396,7 @@
 
         "Process the given operator node 'n'."
 
-        return NegationResult(self.process_structure_node(n.expr))
+        return self.make_negation(self.process_structure_node(n.expr))
 
     def process_raise_node(self, n):
 
@@ -1610,7 +1610,7 @@
 
             # Emit a negated test of the continuation condition.
 
-            self.start_if(True, NegationResult(test))
+            self.start_if(True, self.make_negation(test))
             if n.else_:
                 self.process_structure_node(n.else_)
             self.writestmt("break;")
@@ -1676,6 +1676,20 @@
 
         return self.temp_usage.has_key(path) and name in self.temp_usage[path]
 
+    def make_negation(self, expr):
+
+        "Return a negated form of 'expr'."
+
+        result = NegationResult(expr)
+
+        # Negation discards the temporary results of its operand.
+
+        temps = expr.discards_temporary()
+        if temps:
+            self.remove_temps(temps)
+
+        return result
+
     # Output generation.
 
     def start_output(self):
diff -r f0fb5ec36d99 -r ba53413ad5de transresults.py
--- a/transresults.py	Tue Feb 28 17:00:26 2017 +0100
+++ b/transresults.py	Tue Feb 28 17:18:48 2017 +0100
@@ -280,11 +280,11 @@
     def discards_temporary(self, test=True):
 
         """
-        Return a list of temporary names that can be discarded if 'test' is
-        specified as a true value (or omitted).
+        Negations should have discarded their operand's temporary names when
+        being instantiated.
         """
 
-        return self.expr.discards_temporary(test)
+        return None
 
     def __str__(self):
         return "(%s ? %s : %s)" % (