added SetValue

Minor style and design changes

errorTypes.go

@@ -9,10 +9,18 @@ func (err ErrListEmpty) Error() string {
 	return err.S
 }
 
-type ErrDuplicateElement struct {
+type ErrDuplicateElem struct {
 	S string
 }
 
-func (err ErrDuplicateElement) Error() string {
+func (err ErrDuplicateElem) Error() string {
+	return err.S
+}
+
+type ErrNoElem struct {
+	S string
+}
+
+func (err ErrNoElem) Error() string {
 	return err.S
 }

set.go

@@ -6,6 +6,10 @@ import (
 	"gitlab.com/Pixdigit/uniqueID"
 )
 
+// Set is optimized for Set.Elems() to be fast.
+// This is why it doesnt implement the functionality with a map
+// This of course makes all other operations slow
+
 type Set struct {
 	elems []*setElem
 }
@@ -26,7 +30,7 @@ func (se *setElem) ID() uniqueID.ID {
 func (s *Set) Insert(uElem uniqueElem, value Num) error {
 	for _, elem := range s.elems {
 		if elem.ID() == uElem.ID() {
-			return &ErrDuplicateElement{"element already present in set"}
+			return &ErrDuplicateElem{"element already present in set"}
 		}
 	}
 
@@ -55,6 +59,20 @@ func (s *Set) Insert(uElem uniqueElem, value Num) error {
 	return nil
 }
 
+func (s *Set) SetValue(ID uniqueID.ID, value Num) error {
+	for i, elem := range s.elems {
+		if elem.ID() == ID {
+			elem.value = value
+			//remove elem from array
+			s.elems = append(s.elems[:i], s.elems[i+1:]...)
+			//insert it again at new position
+			s.Insert(elem.elem, elem.value)
+			return nil
+		}
+	}
+    return ErrNoElem{"the list has no item with that ID"}
+}
+
 func (s *Set) Nearest(value Num) (interface{}, error) {
 
 	if len(s.elems) == 0 {
@@ -104,7 +122,7 @@ func (s *Set) String() string {
 func (s *Set) Elems() []interface{} {
 	copy := make([]interface{}, len(s.elems))
 	for i, elem := range s.elems {
-		copy[i] = interface{}(elem)
+		copy[i] = interface{}(elem.elem)
 	}
 	return copy
 }

set_test.go

@@ -12,7 +12,6 @@ type testElem struct {
 	Name string
 }
 
-
 var lastID uniqueID.ID
 
 func NewSampleElem(IDSpace *uniqueID.IDSpace, name string) *testElem {
@@ -27,7 +26,7 @@ func (te *testElem) ID() uniqueID.ID {
 	return te.id
 }
 
-func TestSet(t *testing.T) {
+func TestNearest(t *testing.T) {
 
 	testIDSpace := &uniqueID.IDSpace{}
 	set := Set{}
@@ -50,7 +49,32 @@ func TestSet(t *testing.T) {
 
 	tools.Test(set.Contains(lastID), "set did not contain added element", t)
 
-
 	t.Log(set.String())
+}
+
+func TestSetValue(t *testing.T) {
+	testIDSpace := &uniqueID.IDSpace{}
+	set := Set{}
+
+	a := NewSampleElem(testIDSpace, "a")
+	b := NewSampleElem(testIDSpace, "b")
+	c := NewSampleElem(testIDSpace, "c")
+	d := NewSampleElem(testIDSpace, "d")
+	e := NewSampleElem(testIDSpace, "e")
+
+	err := set.Insert(a, 1);	if err != nil {tools.WrapErr(err, "could not insert test element", t)}
+	err = set.Insert(b, 2);	if err != nil {tools.WrapErr(err, "could not insert test element", t)}
+	err = set.Insert(c, 3);	if err != nil {tools.WrapErr(err, "could not insert test element", t)}
+	err = set.Insert(d, 5);	if err != nil {tools.WrapErr(err, "could not insert test element", t)}
+	err = set.Insert(e, 4);	if err != nil {tools.WrapErr(err, "could not insert test element", t)}
+
+    set.SetValue(a.ID(), 3.5)
+    set.SetValue(e.ID(), -2)
+
+    tools.Test(set.Elems()[0] == e, "did not correctly change position when set new value", t)
+    tools.Test(set.Elems()[1] == b, "did not correctly change position when set new value", t)
+    tools.Test(set.Elems()[2] == c, "did not correctly change position when set new value", t)
+    tools.Test(set.Elems()[3] == a, "did not correctly change position when set new value", t)
+    tools.Test(set.Elems()[4] == d, "did not correctly change position when set new value", t)
 
 }