# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1488297626 -3600
# Node ID f0fb5ec36d9911ef44a5434876b928c73e4965e7
# Parent  11c6d30e098da863d9b28b69b3b3c45747f41a58
Added a means of discarding temporary variables from directly-tested results.

diff -r 11c6d30e098d -r f0fb5ec36d99 results.py
--- a/results.py	Tue Feb 28 00:00:09 2017 +0100
+++ b/results.py	Tue Feb 28 17:00:26 2017 +0100
@@ -45,6 +45,9 @@
     def context_identity(self):
         return None
 
+    def discards_temporary(self, test=True):
+        return None
+
     def get_name(self):
         return None
 
diff -r 11c6d30e098d -r f0fb5ec36d99 tests/logical_simple.py
--- a/tests/logical_simple.py	Tue Feb 28 00:00:09 2017 +0100
+++ b/tests/logical_simple.py	Tue Feb 28 17:00:26 2017 +0100
@@ -9,20 +9,44 @@
 e = not a
 print e                             # False
 
+f = 0
+
 if a and b:
     print "a and b"                 # a and b
+else:
+    print "! (a and b)"
+
+if a and f:
+    print "a and f"
+else:
+    print "! (a and f)"             # ! (a and f)
 
 if not (a and b):
-    print "not (a and b)"           #
+    print "not (a and b)"
+else:
+    print "! (not (a and b))"       # ! (not (a and b))
 
 if not not (a and b):
     print "not not (a and b)"       # not not (a and b)
+else:
+    print "! (not not (a and b))"
 
 if a or b:
     print "a or b"                  # a or b
+else:
+    print "! (a or b)"
 
 if not (a or b):
-    print "not (a or b)"            #
+    print "not (a or b)"
+else:
+    print "! (not (a or b))"        # ! (not (a or b))
 
 if not not (a or b):
     print "not not (a or b)"        # not not (a or b)
+else:
+    print "! (not not (a or b))"
+
+if a and b or f:
+    print "a and b or f"            # a and b or f
+else:
+    print "! (a and b or f)"
diff -r 11c6d30e098d -r f0fb5ec36d99 translator.py
--- a/translator.py	Tue Feb 28 00:00:09 2017 +0100
+++ b/translator.py	Tue Feb 28 17:00:26 2017 +0100
@@ -1627,6 +1627,18 @@
 
     # Special variable usage.
 
+    def get_temp_path(self):
+
+        """
+        Return the appropriate namespace path for temporary names in the current
+        namespace.
+        """
+
+        if self.in_function:
+            return self.get_namespace_path()
+        else:
+            return self.name
+
     def record_temp(self, name):
 
         """
@@ -1636,13 +1648,23 @@
         program.
         """
 
-        if self.in_function:
-            path = self.get_namespace_path()
-        else:
-            path = self.name
-
-        init_item(self.temp_usage, path, set)
-        self.temp_usage[path].add(name)
+        path = self.get_temp_path()
+
+        init_item(self.temp_usage, path, list)
+        self.temp_usage[path].append(name)
+
+    def remove_temps(self, names):
+
+        """
+        Remove 'names' from temporary storage allocations, each instance
+        removing each request for storage.
+        """
+
+        path = self.get_temp_path()
+
+        for name in names:
+            if self.uses_temp(path, name):
+                self.temp_usage[path].remove(name)
 
     def uses_temp(self, path, name):
 
@@ -1816,6 +1838,9 @@
 
         if isinstance(test_ref, LogicalResult):
             self.writeline("%s %s" % (statement, test_ref.apply_test()))
+            temps = test_ref.discards_temporary()
+            if temps:
+                self.remove_temps(temps)
         else:
             self.writeline("%s (__BOOL(%s))" % (statement, test_ref))
 
diff -r 11c6d30e098d -r f0fb5ec36d99 transresults.py
--- a/transresults.py	Tue Feb 28 00:00:09 2017 +0100
+++ b/transresults.py	Tue Feb 28 17:00:26 2017 +0100
@@ -37,9 +37,25 @@
     "A general expression."
 
     def __init__(self, s):
-        self.s = s
+        if isinstance(s, Result):
+            self.s = str(s)
+            self.expr = s
+        else:
+            self.s = s
+            self.expr = None
+
+    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).
+        """
+
+        return self.expr and self.expr.discards_temporary(False)
+
     def __str__(self):
         return self.s
+
     def __repr__(self):
         return "Expression(%r)" % self.s
 
@@ -261,6 +277,15 @@
         expr = self._convert(self.expr)
         return "(!%s)" % expr
 
+    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).
+        """
+
+        return self.expr.discards_temporary(test)
+
     def __str__(self):
         return "(%s ? %s : %s)" % (
             self._convert(self.expr),
@@ -301,6 +326,25 @@
         else:
             return "(%s)" % " || ".join(results)
 
+    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).
+        """
+
+        if not test:
+            return None
+
+        temps = ["__tmp_result"]
+
+        for expr in self.exprs:
+            t = expr.discards_temporary(test)
+            if t:
+                temps += t
+
+        return temps
+
     def __str__(self):
 
         """