From c73467caf524a885e73d8d86d91d89a9eced7036 Mon Sep 17 00:00:00 2001
From: "Dr. Carsten Leue" <carsten.leue@de.ibm.com>
Date: Fri, 26 Jan 2024 10:09:39 +0100
Subject: [PATCH] fix: add WithTime and WithDuration

Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com>
---
 io/generic/io.go | 21 +++++++++++++++++++++
 io/io.go         | 11 +++++++++++
 2 files changed, 32 insertions(+)

diff --git a/io/generic/io.go b/io/generic/io.go
index e5a8612..159184f 100644
--- a/io/generic/io.go
+++ b/io/generic/io.go
@@ -22,6 +22,7 @@ import (
 	C "github.com/IBM/fp-go/internal/chain"
 	FC "github.com/IBM/fp-go/internal/functor"
 	L "github.com/IBM/fp-go/internal/lazy"
+	T "github.com/IBM/fp-go/tuple"
 )
 
 // type IO[A any] = func() A
@@ -175,3 +176,23 @@ func MonadFlap[FAB ~func(A) B, GFAB ~func() FAB, GB ~func() B, A, B any](fab GFA
 func Flap[FAB ~func(A) B, GFAB ~func() FAB, GB ~func() B, A, B any](a A) func(GFAB) GB {
 	return F.Bind2nd(MonadFlap[FAB, GFAB, GB, A, B], a)
 }
+
+// WithTime returns an operation that measures the start and end timestamp of the operation
+func WithTime[GTA ~func() T.Tuple3[A, time.Time, time.Time], GA ~func() A, A any](a GA) GTA {
+	return MakeIO[GTA](func() T.Tuple3[A, time.Time, time.Time] {
+		t0 := time.Now()
+		res := a()
+		t1 := time.Now()
+		return T.MakeTuple3(res, t0, t1)
+	})
+}
+
+// WithDuration returns an operation that measures the duration of the operation
+func WithDuration[GTA ~func() T.Tuple2[A, time.Duration], GA ~func() A, A any](a GA) GTA {
+	return MakeIO[GTA](func() T.Tuple2[A, time.Duration] {
+		t0 := time.Now()
+		res := a()
+		t1 := time.Now()
+		return T.MakeTuple2(res, t1.Sub(t0))
+	})
+}
diff --git a/io/io.go b/io/io.go
index 2d35926..0a9c74f 100644
--- a/io/io.go
+++ b/io/io.go
@@ -19,6 +19,7 @@ import (
 	"time"
 
 	G "github.com/IBM/fp-go/io/generic"
+	T "github.com/IBM/fp-go/tuple"
 )
 
 // IO represents a synchronous computation that cannot fail
@@ -156,3 +157,13 @@ func Delay[A any](delay time.Duration) func(IO[A]) IO[A] {
 func After[A any](timestamp time.Time) func(IO[A]) IO[A] {
 	return G.After[IO[A]](timestamp)
 }
+
+// WithTime returns an operation that measures the start and end [time.Time] of the operation
+func WithTime[A any](a IO[A]) IO[T.Tuple3[A, time.Time, time.Time]] {
+	return G.WithTime[IO[T.Tuple3[A, time.Time, time.Time]], IO[A]](a)
+}
+
+// WithDuration returns an operation that measures the [time.Duration]
+func WithDuration[A any](a IO[A]) IO[T.Tuple2[A, time.Duration]] {
+	return G.WithDuration[IO[T.Tuple2[A, time.Duration]], IO[A]](a)
+}