Instana tracer implementation

vendor/github.com/looplab/fsm/errors.go

@@ -0,0 +1,100 @@
+// Copyright (c) 2013 - Max Persson <max@looplab.se>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fsm
+
+// InvalidEventError is returned by FSM.Event() when the event cannot be called
+// in the current state.
+type InvalidEventError struct {
+	Event string
+	State string
+}
+
+func (e InvalidEventError) Error() string {
+	return "event " + e.Event + " inappropriate in current state " + e.State
+}
+
+// UnknownEventError is returned by FSM.Event() when the event is not defined.
+type UnknownEventError struct {
+	Event string
+}
+
+func (e UnknownEventError) Error() string {
+	return "event " + e.Event + " does not exist"
+}
+
+// InTransitionError is returned by FSM.Event() when an asynchronous transition
+// is already in progress.
+type InTransitionError struct {
+	Event string
+}
+
+func (e InTransitionError) Error() string {
+	return "event " + e.Event + " inappropriate because previous transition did not complete"
+}
+
+// NotInTransitionError is returned by FSM.Transition() when an asynchronous
+// transition is not in progress.
+type NotInTransitionError struct{}
+
+func (e NotInTransitionError) Error() string {
+	return "transition inappropriate because no state change in progress"
+}
+
+// NoTransitionError is returned by FSM.Event() when no transition have happened,
+// for example if the source and destination states are the same.
+type NoTransitionError struct {
+	Err error
+}
+
+func (e NoTransitionError) Error() string {
+	if e.Err != nil {
+		return "no transition with error: " + e.Err.Error()
+	}
+	return "no transition"
+}
+
+// CanceledError is returned by FSM.Event() when a callback have canceled a
+// transition.
+type CanceledError struct {
+	Err error
+}
+
+func (e CanceledError) Error() string {
+	if e.Err != nil {
+		return "transition canceled with error: " + e.Err.Error()
+	}
+	return "transition canceled"
+}
+
+// AsyncError is returned by FSM.Event() when a callback have initiated an
+// asynchronous state transition.
+type AsyncError struct {
+	Err error
+}
+
+func (e AsyncError) Error() string {
+	if e.Err != nil {
+		return "async started with error: " + e.Err.Error()
+	}
+	return "async started"
+}
+
+// InternalError is returned by FSM.Event() and should never occur. It is a
+// probably because of a bug.
+type InternalError struct{}
+
+func (e InternalError) Error() string {
+	return "internal error on state transition"
+}