From b818799800520bcba5538b03da727d135bd43664 Mon Sep 17 00:00:00 2001
From: Glen Fraser <holaglen@gmail.com>
Date: Mon, 4 May 2015 19:40:57 +0200
Subject: [PATCH 1/2] Added getTimeInSeconds() helper to chai executable

---
 src/main.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/main.cpp b/src/main.cpp
index 6dcfa2b..fcb41d5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -249,6 +249,15 @@ void interactive(chaiscript::ChaiScript& chai)
   }
 }
 
+double getTimeInSeconds()
+{
+  using namespace std::chrono;
+  static time_point<high_resolution_clock> start = high_resolution_clock::now();
+
+  duration<double> elapsed_seconds = high_resolution_clock::now() - start;
+  return elapsed_seconds.count();
+}
+
 int main(int argc, char *argv[])
 {
 
@@ -288,6 +297,8 @@ int main(int argc, char *argv[])
   chai.add(chaiscript::fun(&help), "help");
   chai.add(chaiscript::fun(&throws_exception), "throws_exception");
   chai.add(chaiscript::fun(&get_eval_error), "get_eval_error");
+  chai.add(chaiscript::fun(&getTimeInSeconds), "getTimeInSeconds");
+
 
   for (int i = 0; i < argc; ++i) {
     if ( i == 0 && argc > 1 ) {

From bd176cfde2ba66505771c37c88fcf39a89b2b4a3 Mon Sep 17 00:00:00 2001
From: Glen Fraser <holaglen@gmail.com>
Date: Wed, 6 May 2015 11:37:37 +0200
Subject: [PATCH 2/2] Renamed timer function to now(), added perf unit test

---
 src/main.cpp               | 10 ++++------
 unittests/performance.chai | 13 +++++++++++++
 2 files changed, 17 insertions(+), 6 deletions(-)
 create mode 100644 unittests/performance.chai

diff --git a/src/main.cpp b/src/main.cpp
index fcb41d5..3a72df1 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -249,13 +249,11 @@ void interactive(chaiscript::ChaiScript& chai)
   }
 }
 
-double getTimeInSeconds()
+double now()
 {
   using namespace std::chrono;
-  static time_point<high_resolution_clock> start = high_resolution_clock::now();
-
-  duration<double> elapsed_seconds = high_resolution_clock::now() - start;
-  return elapsed_seconds.count();
+  auto now = high_resolution_clock::now();
+  return duration_cast<duration<double>>(now.time_since_epoch()).count();
 }
 
 int main(int argc, char *argv[])
@@ -297,7 +295,7 @@ int main(int argc, char *argv[])
   chai.add(chaiscript::fun(&help), "help");
   chai.add(chaiscript::fun(&throws_exception), "throws_exception");
   chai.add(chaiscript::fun(&get_eval_error), "get_eval_error");
-  chai.add(chaiscript::fun(&getTimeInSeconds), "getTimeInSeconds");
+  chai.add(chaiscript::fun(&now), "now");
 
 
   for (int i = 0; i < argc; ++i) {
diff --git a/unittests/performance.chai b/unittests/performance.chai
new file mode 100644
index 0000000..1345c74
--- /dev/null
+++ b/unittests/performance.chai
@@ -0,0 +1,13 @@
+var sum = 0.0
+var start = now()
+for (var i = 1; i <= 100000; ++i) {
+  if (i % 2 == 0) {
+    sum += 1.0 / i;
+  }
+  else {
+    sum += 1.0 / (double(i) * i);
+  }
+}
+var end = now()
+print("Elapsed time: " + to_string(end - start) + " sum: " + to_string(sum))
+assert_equal(to_string(sum), "6.9322")