Delete emitter implementations

This deletes the Zap and Tally emitter implementations from cff to
reduce the dependency footprint.
We'll keep copies of these for use internally.

This also warns users away from using WithEmitter because the API is
expected to change significantly with #11.

Resolves #2

cff.go

@@ -46,16 +46,11 @@ func Results(results ...interface{}) Option {
 //
 //	cff.Flow(ctx,
 //	  ...
-//	  cff.WithEmitter(cff.TallyEmitter(scope)),
+//	  cff.WithEmitter(em),
 //	)
 //
-// Provide this option multiple times to connect multiple emitters.
-//
-//	cff.Flow(ctx,
-//	  ...
-//	  cff.WithEmitter(cff.TallyEmitter(scope)),
-//	  cff.WithEmitter(cff.LogEmitter(logger)),
-//	)
+// WARNING: Do not use this API.
+// We intend to replace it in an upcoming release.
 //
 // This is a code generation directive.
 func WithEmitter(Emitter) Option {

emitter.go

@@ -8,6 +8,9 @@ import (
 )
 
 // Emitter initializes Task, Flow, and Parallel emitters.
+//
+// WARNING: Do not use this API.
+// We intend to replace it in an upcoming release.
 type Emitter interface {
 	// TaskInit returns a TaskEmitter which could be memoized based on task name.
 	TaskInit(*TaskInfo, *DirectiveInfo) TaskEmitter
@@ -25,6 +28,9 @@ type SchedulerState = scheduler.State
 
 // SchedulerEmitter provides observability into the state of the CFF
 // scheduler.
+//
+// WARNING: Do not use this API.
+// We intend to replace it in an upcoming release.
 type SchedulerEmitter interface {
 	// EmitScheduler emits the state of the CFF scheduler.
 	EmitScheduler(s SchedulerState)
@@ -74,6 +80,9 @@ type ParallelInfo struct {
 
 // FlowEmitter receives events for when flow events occur, for the purpose of
 // emitting metrics.
+//
+// WARNING: Do not use this API.
+// We intend to replace it in an upcoming release.
 type FlowEmitter interface {
 	// FlowSuccess is called when a flow runs successfully.
 	FlowSuccess(context.Context)
@@ -85,6 +94,9 @@ type FlowEmitter interface {
 
 // ParallelEmitter receives events for when parallel events occur, for the
 // purpose of emitting metrics.
+//
+// WARNING: Do not use this API.
+// We intend to replace it in an upcoming release.
 type ParallelEmitter interface {
 	// ParallelSuccess is called when a parallel runs successfully.
 	ParallelSuccess(context.Context)
@@ -96,6 +108,9 @@ type ParallelEmitter interface {
 
 // TaskEmitter receives events for when task events occur, for the purpose of
 // emitting metrics.
+//
+// WARNING: Do not use this API.
+// We intend to replace it in an upcoming release.
 type TaskEmitter interface {
 	// TaskSuccess is called when a task runs successfully.
 	TaskSuccess(context.Context)

emitter_stack_test.go

@@ -7,10 +7,8 @@ import (
 	"time"
 
 	"github.com/golang/mock/gomock"
-	"github.com/uber-go/tally"
 	. "go.uber.org/cff"
 	"go.uber.org/cff/internal/emittertest"
-	"go.uber.org/zap"
 )
 
 func TestEmitterStackConstruction(t *testing.T) {
@@ -22,24 +20,24 @@ func TestEmitterStackConstruction(t *testing.T) {
 		{
 			desc: "single",
 			give: []Emitter{
-				LogEmitter(zap.NewNop()),
+				NopEmitter(),
 			},
 		},
 		{
 			desc: "multiple",
 			give: []Emitter{
-				LogEmitter(zap.NewNop()),
 				NopEmitter(),
-				TallyEmitter(tally.NoopScope),
+				NopEmitter(),
+				NopEmitter(),
 			},
 		},
 		{
 			desc: "nested",
 			give: []Emitter{
-				LogEmitter(zap.NewNop()),
+				NopEmitter(),
 				EmitterStack(
 					NopEmitter(),
-					TallyEmitter(tally.NoopScope),
+					NopEmitter(),
 				),
 			},
 		},

examples/go.mod

@@ -4,15 +4,12 @@ go 1.19
 
 require (
 	github.com/stretchr/testify v1.8.0
-	github.com/uber-go/tally v3.5.0+incompatible
 	go.uber.org/cff v0.1.0
-	go.uber.org/zap v1.23.0
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/twmb/murmur3 v1.1.6 // indirect
 	go.uber.org/atomic v1.10.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

examples/go.sum

@@ -1,9 +1,7 @@
-github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLju8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/golang/mock v1.6.0 h1:ErTB+efbowRARo13NNdxyJji2egdxLGQhRaY+DUumQc=
-github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
@@ -13,18 +11,12 @@ github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/twmb/murmur3 v1.1.6 h1:mqrRot1BRxm+Yct+vavLMou2/iJt0tNVTTC0QoIjaZg=
-github.com/twmb/murmur3 v1.1.6/go.mod h1:Qq/R7NUyOfr65zD+6Q5IHKsJLwP7exErjN6lyyq3OSQ=
-github.com/uber-go/tally v3.5.0+incompatible h1:2vIkqVrSaspifqcJh2yQjQqqpfavvmfj/ognDrBxuSg=
-github.com/uber-go/tally v3.5.0+incompatible/go.mod h1:YDTIBxdXyOU/sCWilKB4bgyufu1cEi0jdVnRdxvjnmU=
 go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/atomic v1.10.0 h1:9qC72Qh0+3MqyJbAn8YU5xVq1frD8bn3JtD2oXtafVQ=
 go.uber.org/atomic v1.10.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/goleak v1.2.0 h1:xqgm/S+aQvhWFTtR0XK3Jvg7z8kGV8P4X14IzwN3Eqk=
 go.uber.org/multierr v1.8.0 h1:dg6GjLku4EH+249NNmoIciG9N/jURbDG+pFlTkhzIC8=
 go.uber.org/multierr v1.8.0/go.mod h1:7EAYxJLBy9rStEaz58O2t4Uvip6FSURkq8/ppBp95ak=
-go.uber.org/zap v1.23.0 h1:OjGQ5KQDEUawVHxNwQgPpiypGHOxo2mNZsOqTak4fFY=
-go.uber.org/zap v1.23.0/go.mod h1:D+nX8jyLsMHMYrln8A0rJjFt/T/9/bGgIhAqxv5URuY=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

examples/magic.go

@@ -8,9 +8,7 @@ import (
 	"fmt"
 	"strconv"
 
-	"github.com/uber-go/tally"
 	"go.uber.org/cff"
-	"go.uber.org/zap"
 )
 
 // Request TODO
@@ -24,11 +22,9 @@ type Response struct {
 }
 
 type fooHandler struct {
-	mgr    *ManagerRepository
-	users  *UserRepository
-	ses    *SESClient
-	scope  tally.Scope
-	logger *zap.Logger
+	mgr   *ManagerRepository
+	users *UserRepository
+	ses   *SESClient
 }
 
 func (h *fooHandler) HandleFoo(ctx context.Context, req *Request) (*Response, error) {
@@ -37,9 +33,6 @@ func (h *fooHandler) HandleFoo(ctx context.Context, req *Request) (*Response, er
 		cff.Params(req),
 		cff.Results(&res),
 		cff.Concurrency(8),
-		cff.WithEmitter(cff.TallyEmitter(h.scope)),
-		cff.WithEmitter(cff.LogEmitter(h.logger)),
-		cff.InstrumentFlow("HandleFoo"),
 
 		cff.Task(
 			func(req *Request) (*GetManagerRequest, *ListUsersRequest) {
@@ -67,7 +60,6 @@ func (h *fooHandler) HandleFoo(ctx context.Context, req *Request) (*Response, er
 				return req.LDAPGroup != "everyone"
 			}),
 			cff.FallbackWith(&ListUsersResponse{}),
-			cff.Instrument("FormSendEmailRequest"),
 		),
 		cff.Task(
 			func(mgr *GetManagerResponse, users *ListUsersResponse) []*SendEmailRequest {
@@ -80,16 +72,12 @@ func (h *fooHandler) HandleFoo(ctx context.Context, req *Request) (*Response, er
 			cff.Predicate(func(req *GetManagerRequest) bool {
 				return req.LDAPGroup != "everyone"
 			}),
-			cff.Instrument("FormSendEmailRequest"),
 		),
 	)
 
 	err = cff.Parallel(
 		ctx,
 		cff.Concurrency(2),
-		cff.WithEmitter(cff.TallyEmitter(h.scope)),
-		cff.WithEmitter(cff.LogEmitter(h.logger)),
-		cff.InstrumentParallel("SendParallel"),
 		cff.ContinueOnError(true),
 		cff.Tasks(
 			func(_ context.Context) error {
@@ -101,7 +89,6 @@ func (h *fooHandler) HandleFoo(ctx context.Context, req *Request) (*Response, er
 			func() error {
 				return SendMessage()
 			},
-			cff.Instrument("SendMsg"),
 		),
 		cff.Slice(
 			func(ctx context.Context, idx int, s string) error {