[4094] Added evaluate function

1 files changed, 41 insertions, 0 deletions

diff --git a/src/lib/eval/evaluate.cc b/src/lib/eval/evaluate.cc
new file mode 100644
index 0000000000..593a8c9541
--- /dev/null
+++ b/src/lib/eval/evaluate.cc
@@ -0,0 +1,41 @@
+// Copyright (C) 2015 Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <eval/evaluate.h>
+
+namespace isc {
+namespace dhcp {
+
+bool evaluate(const Expression& expr, const Pkt& pkt) {
+    ValueStack values;
+    for (Expression::const_iterator it = expr.begin();
+         it != expr.end(); ++it) {
+        (*it)->evaluate(pkt, values);
+    }
+    if (values.size() != 1) {
+        isc_throw(EvalBadStack, "Incorrect stack order. Expected exactly "
+                  "1 value at the end of evaluatuion, got " << values.size());
+    }
+    if (values.top() == "false") {
+        return (false);
+    } else if (values.top() == "true") {
+        return (true);
+    } else {
+        isc_throw(EvalNotBoolError, "Incorrect evaluation type. Expected "
+                  "\"false\" or \"true\", got \"" << values.top() << "\"");
+    }
+}
+
+}; // end of isc::dhcp namespace
+}; // end of isc namespace