From f4fd104afdd67c0bf0bbcd34d3524e0b4f91ae10 Mon Sep 17 00:00:00 2001
From: Michael Desa <mjdesa@gmail.com>
Date: Fri, 19 May 2017 11:38:46 -0400
Subject: [PATCH] Add unixNano built in function

---
 tick/stateful/functions.go | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/tick/stateful/functions.go b/tick/stateful/functions.go
index 4bf1f3993..066f5288c 100644
--- a/tick/stateful/functions.go
+++ b/tick/stateful/functions.go
@@ -168,6 +168,7 @@ func init() {
 	statelessFuncs["isPresent"] = isPresent{}
 
 	// Time functions
+	statelessFuncs["unixNano"] = unixNano{}
 	statelessFuncs["minute"] = minute{}
 	statelessFuncs["hour"] = hour{}
 	statelessFuncs["weekday"] = weekday{}
@@ -1135,6 +1136,30 @@ func init() {
 	timeFuncSignature[d] = ast.TInt
 }
 
+type unixNano struct {
+}
+
+func (unixNano) Reset() {
+}
+
+// Return the nanosecond unix timestamp for the given time.
+func (unixNano) Call(args ...interface{}) (v interface{}, err error) {
+	if len(args) != 1 {
+		return 0, errors.New("unixNano expects exactly one argument")
+	}
+	switch a := args[0].(type) {
+	case time.Time:
+		v = int64(a.UnixNano())
+	default:
+		err = fmt.Errorf("cannot convert %T to time.Time", a)
+	}
+	return
+}
+
+func (unixNano) Signature() map[Domain]ast.ValueType {
+	return timeFuncSignature
+}
+
 type minute struct {
 }