create project

collections/ArrayList.go

@@ -0,0 +1,129 @@
+package collections
+
+import "collections/exceptions"
+
+type ArrayList struct {
+	array []interface{}
+	used  uint32
+}
+
+func NewArrayList() *ArrayList {
+	return &ArrayList{
+		make([]interface{}, 16),
+		0,
+	}
+}
+
+func (a ArrayList) Iterator() Iterator {
+	return a.MutableIterator()
+}
+
+func (a ArrayList) Size() uint32 {
+	return a.used
+}
+
+func (a ArrayList) IsEmpty() bool {
+	return a.Size() == 0
+}
+
+func (a ArrayList) Contains(element interface{}) bool {
+	return Contains(a, element)
+}
+
+func (a ArrayList) ContainsAll(c Collection) bool {
+	return ContainsAll(a, c)
+}
+
+func (a *ArrayList) MutableIterator() MutableIterator {
+	panic("implement me")
+}
+
+func (a *ArrayList) Add(element interface{}) bool {
+	if a.used >= uint32(len(a.array)) {
+		oldArray := a.array
+		a.array = make([]interface{}, a.used*2)
+		copy(a.array, oldArray)
+	}
+	a.array[a.used] = element
+	a.used++
+	return true
+}
+
+func (a ArrayList) IndexOf(element interface{}) int {
+	var i uint32 = 0
+	for ; i < a.used; i++ {
+		if a.array[i] == element {
+			return int(i)
+		}
+	}
+	return -1
+}
+
+func (a *ArrayList) RemoveIndex(index uint32) error {
+	if index >= a.used {
+		return exceptions.NewIndexOutOfBound("", true)
+	}
+
+	array := a.array
+	for i := index + 1; i < a.used; i++ {
+		array[index-1] = array[index]
+	}
+	return nil
+}
+
+func (a *ArrayList) Remove(element interface{}) error {
+	index := a.IndexOf(element)
+	if index < 0 {
+		return exceptions.NewElementNotFoundException("", true)
+	} else {
+		return a.RemoveIndex(uint32(index))
+	}
+}
+
+func (a *ArrayList) AddAll(c Collection) bool {
+	return AddAll(a, c)
+}
+
+func (a *ArrayList) RemoveAll(c Collection) bool {
+	return RemoveAll(a, c)
+}
+
+func (a *ArrayList) RetainAll(c Collection) bool {
+	return RetainAll(a, c)
+}
+
+func (a *ArrayList) Clear() {
+	a.used = 0
+}
+
+func (a ArrayList) Get(index uint32) (interface{}, error) {
+	if index >= a.used {
+		return nil, exceptions.NewIndexOutOfBound("", true)
+	} else {
+		return a.array[index], nil
+	}
+}
+
+func (a ArrayList) SubList(from, to uint32) List {
+	return NewSubList(a, from, to)
+}
+
+func (a *ArrayList) Set(index uint32, element interface{}) error {
+	if index >= a.used {
+		return exceptions.NewIndexOutOfBound("", true)
+	}
+	a.array[index] = element
+	return nil
+}
+
+func (a *ArrayList) AddAtIndex(index uint32, element interface{}) bool {
+	panic("implement me")
+}
+
+func (a *ArrayList) RemoveAt(index uint32) bool {
+	panic("implement me")
+}
+
+func (a *ArrayList) SubMutableList(from, to uint32) MutableList {
+	panic("implement me")
+}

collections/Collection.go

@@ -24,7 +24,7 @@ type (
 
 		MutableIterator() MutableIterator
 		Add(element interface{}) bool
-		Remove(element interface{}) bool
+		Remove(element interface{}) error
 		AddAll(c Collection) bool
 		RemoveAll(c Collection) bool
 		RetainAll(c Collection) bool
@@ -51,7 +51,7 @@ type (
 
 		MutableIterator() MutableIterator
 		Add(element interface{}) bool
-		Remove(element interface{}) bool
+		Remove(element interface{}) error
 		AddAll(c Collection) bool
 		RemoveAll(c Collection) bool
 		RetainAll(c Collection) bool
@@ -60,7 +60,7 @@ type (
 		Get(index uint32) (interface{}, error)
 		SubList(from, to uint32) List
 
-		Set(index uint32, element interface{}) bool
+		Set(index uint32, element interface{}) error
 		AddAtIndex(index uint32, element interface{}) bool
 		RemoveAt(index uint32) bool
 		SubMutableList(from, to uint32) MutableList
@@ -97,10 +97,7 @@ func AddAll(l MutableCollection, collection Collection) bool {
 
 func RemoveAll(l MutableCollection, collection Collection) bool {
 	return Loop(collection, func(e interface{}) error {
-		if !l.Remove(e) {
+		return l.Remove(e)
-			return exceptions.CollectionLoopFinished
-		}
-		return nil
 	}) == nil
 }
 
@@ -122,11 +119,11 @@ func String(l List) string {
 	builder := strings.Builder{}
 	builder.WriteString("[")
 	iterator := l.Iterator()
-	next := iterator.Next()
+	next, _ := iterator.Next()
 	builder.WriteString(fmt.Sprint(next))
 	for iterator.HasNext() {
 		builder.WriteString(", ")
-		next = iterator.Next()
+		next, _ = iterator.Next()
 		builder.WriteString(fmt.Sprint(next))
 	}
 	builder.WriteString("]")

collections/Iterable.go

@@ -2,7 +2,7 @@ package collections
 
 type Iterator interface {
 	HasNext() bool
-	Next() interface{}
+	Next() (interface{}, error)
 }
 
 type Iterable interface {
@@ -11,7 +11,7 @@ type Iterable interface {
 
 type MutableIterator interface {
 	HasNext() bool
-	Next() interface{}
+	Next() (interface{}, error)
 	Remove() bool
 }
 
@@ -26,7 +26,11 @@ func Loop(iterable Iterable, f func(element interface{}) error) error {
 	}
 	iterator := iterable.Iterator()
 	for iterator.HasNext() {
-		err := f(iterator.Next())
+		next, err := iterator.Next()
+		if err != nil {
+			return err
+		}
+		err = f(next)
 		if err != nil {
 			return err
 		}
@@ -40,7 +44,11 @@ func LoopMutable(iterable MutableIterable, f func(element interface{}, iterator
 	}
 	iterator := iterable.MutableIterator()
 	for iterator.HasNext() {
-		err := f(iterator.Next(), iterator)
+		next, err := iterator.Next()
+		if err != nil {
+			return err
+		}
+		err = f(next, iterator)
 		if err != nil {
 			return err
 		}

collections/LinkedList.go

@@ -50,14 +50,19 @@ func (l *LinkedList) Add(element interface{}) bool {
 	return true
 }
 
-func (l *LinkedList) Remove(element interface{}) bool {
+func (l *LinkedList) Remove(element interface{}) error {
-	return LoopMutable(l, func(e interface{}, iterator MutableIterator) error {
+	err := LoopMutable(l, func(e interface{}, iterator MutableIterator) error {
 		if element == e {
 			iterator.Remove()
 			return exceptions.CollectionLoopFinished
 		}
 		return nil
-	}) != nil
+	})
+	if err != nil {
+		return nil
+	} else {
+		return exceptions.NewElementNotFoundException("", true)
+	}
 }
 
 func (l *LinkedList) AddAll(c Collection) bool {
@@ -81,16 +86,16 @@ func (l LinkedList) SubList(from, to uint32) List {
 	return NewSubList(l, from, to)
 }
 
-func (l *LinkedList) Set(index uint32, element interface{}) bool {
+func (l *LinkedList) Set(index uint32, element interface{}) error {
 	node := l.head
 	for node != l.head {
 		if index == 0 {
 			node.value = element
-			return true
+			return nil
 		}
 		index--
 	}
-	return false
+	return exceptions.NewIndexOutOfBound("", true)
 }
 
 func (l *LinkedList) AddAtIndex(index uint32, element interface{}) bool {
@@ -153,12 +158,12 @@ func (l *linkedListIterator) HasNext() bool {
 	return l.node != l.head
 }
 
-func (l *linkedListIterator) Next() interface{} {
+func (l *linkedListIterator) Next() (interface{}, error) {
 	if l.node == l.head {
-		panic("iterator loop finished")
+		return nil, exceptions.NewIndexOutOfBound("", true)
 	}
 	l.node = l.node.next
-	return l.node.prev.value
+	return l.node.prev.value, nil
 }
 
 func (l *linkedListIterator) Remove() bool {

collections/MutableSubList.go

@@ -1,5 +1,7 @@
 package collections
 
+import "collections/exceptions"
+
 type MutableSubList struct {
 	list     MutableList
 	from, to uint32
@@ -12,7 +14,10 @@ func NewMutableSubList(list MutableList, from, to uint32) *MutableSubList {
 func (s *MutableSubList) Iterator() Iterator {
 	iterator := s.list.Iterator()
 	for i := 0; i < int(s.from); i++ {
-		iterator.Next()
+		_, err := iterator.Next()
+		if err != nil {
+			return nil
+		}
 	}
 	return iterator
 }
@@ -45,41 +50,41 @@ func (s *MutableSubList) MutableIterator() MutableIterator {
 	return nil
 }
 
-func (s *MutableSubList) Add(element interface{}) bool {
+func (s *MutableSubList) Add(_ interface{}) bool {
 	return false
 }
 
-func (s *MutableSubList) Remove(element interface{}) bool {
+func (s *MutableSubList) Remove(element interface{}) error {
+	return nil
+}
+
+func (s *MutableSubList) AddAll(_ Collection) bool {
 	return false
 }
 
-func (s *MutableSubList) AddAll(c Collection) bool {
+func (s *MutableSubList) RemoveAll(_ Collection) bool {
 	return false
 }
 
-func (s *MutableSubList) RemoveAll(c Collection) bool {
+func (s *MutableSubList) RetainAll(_ Collection) bool {
-	return false
-}
-
-func (s *MutableSubList) RetainAll(c Collection) bool {
 	return false
 }
 
 func (s *MutableSubList) Clear() {
 }
 
-func (s *MutableSubList) Set(index uint32, element interface{}) bool {
+func (s *MutableSubList) Set(index uint32, element interface{}) error {
 	if index >= s.to-s.from {
-		return false
+		return exceptions.NewIndexOutOfBound("", true)
 	}
 	return s.list.Set(index+s.from, element)
 }
 
-func (s *MutableSubList) AddAtIndex(index uint32, element interface{}) bool {
+func (s *MutableSubList) AddAtIndex(_ uint32, _ interface{}) bool {
 	return false
 }
 
-func (s *MutableSubList) RemoveAt(index uint32) bool {
+func (s *MutableSubList) RemoveAt(_ uint32) bool {
 	return false
 }
 

collections/SubList.go

@@ -12,7 +12,10 @@ func NewSubList(list List, from, to uint32) *SubList {
 func (s *SubList) Iterator() Iterator {
 	iterator := s.list.Iterator()
 	for i := 0; i < int(s.from); i++ {
-		iterator.Next()
+		_, err := iterator.Next()
+		if err != nil {
+			return nil
+		}
 	}
 	return iterator
 }

exceptions/ElementNotFound.go

@@ -0,0 +1,42 @@
+package exceptions
+
+import (
+	"io"
+	"os"
+)
+
+type ElementNotFoundException struct {
+	message    string
+	stackTrace []StackTrace
+}
+
+func NewElementNotFoundException(message string, getStackTrace bool) *ElementNotFoundException {
+	var stackTrace []StackTrace = nil
+	if getStackTrace {
+		stackTrace = GetStackTrace()
+	}
+	return &ElementNotFoundException{
+		message:    message,
+		stackTrace: stackTrace,
+	}
+}
+
+func (e ElementNotFoundException) Error() string {
+	if len(e.message) == 0 {
+		return "element not found"
+	} else {
+		return e.message
+	}
+}
+
+func (e ElementNotFoundException) StackTrace() []StackTrace {
+	return e.stackTrace
+}
+
+func (e ElementNotFoundException) PrintStackTrace() {
+	e.PrintStackTraceTo(os.Stderr)
+}
+
+func (e ElementNotFoundException) PrintStackTraceTo(writer io.Writer) {
+	PrintStackTrace(writer, e, "exception caused ElementNotFoundException:")
+}

exceptions/Exception.go

@@ -1,6 +1,9 @@
 package exceptions
 
-import "io"
+import (
+	"fmt"
+	"io"
+)
 
 type Exception interface {
 	Error() string
@@ -8,3 +11,29 @@ type Exception interface {
 	PrintStackTrace()
 	PrintStackTraceTo(writer io.Writer)
 }
+
+func PrintStackTrace(writer io.Writer, e Exception, exceptionMsg string) {
+	_, err := fmt.Fprintln(writer, exceptionMsg, e.Error())
+	if err != nil {
+		return
+	}
+	if e.StackTrace() == nil {
+		return
+	}
+	for _, stackTrace := range e.StackTrace() {
+		stackTrace.PrintLn(writer)
+	}
+}
+
+func Try(f func() (interface{}, error), catch func(interface{}) interface{}) (ret interface{}) {
+	defer func() {
+		if r := recover(); r != nil {
+			ret = catch(r)
+		}
+	}()
+	ret, err := f()
+	if err != nil {
+		ret = catch(err)
+	}
+	return
+}

exceptions/IndexOutOfBoundError.go

@@ -1,7 +1,6 @@
 package exceptions
 
 import (
-	"fmt"
 	"io"
 	"os"
 )
@@ -31,16 +30,7 @@ func (i IndexOutOfBound) PrintStackTrace() {
 }
 
 func (i IndexOutOfBound) PrintStackTraceTo(writer io.Writer) {
-	_, err := fmt.Fprintln(writer, "exception caused IndexOutOfBound:", i.Error())
+	PrintStackTrace(writer, i, "exception caused IndexOutOfBound:")
-	if err != nil {
-		return
-	}
-	if i.stackTrace == nil {
-		return
-	}
-	for _, stackTrace := range i.stackTrace {
-		stackTrace.PrintLn(writer)
-	}
 }
 
 func (i IndexOutOfBound) Error() string {

main.go

@@ -2,10 +2,18 @@ package main
 
 import (
 	"collections/collections"
+	"collections/exceptions"
 	"fmt"
 )
 
 func main() {
+	fmt.Println(exceptions.Try(func() (interface{}, error) {
+		panic("test")
+	}, func(r interface{}) interface{} {
+		fmt.Println("recover from panic", r)
+		return exceptions.NewIndexOutOfBound("", true)
+	}))
+
 	list := collections.NewLinkedList()
 	fmt.Println(list)
 	for i := 0; i < 20; i++ {