A couple helper functions are also used here and there in the class' code - I'm not asking for a review of those, but if you are interested to see more, StringFormat
is a custom C#-style VB6/VBA implementation of string.Format()
covered here here, StringMatchesAny
is a custom string helper function covered here here, and Coalesce
is a simple null-replacement function that considers an empty string as a null value.
A couple helper functions are also used here and there in the class' code - I'm not asking for a review of those, but if you are interested to see more, StringFormat
is a custom C#-style VB6/VBA implementation of string.Format()
covered here, StringMatchesAny
is a custom string helper function covered here, and Coalesce
is a simple null-replacement function that considers an empty string as a null value.
A couple helper functions are also used here and there in the class' code - I'm not asking for a review of those, but if you are interested to see more, StringFormat
is a custom C#-style VB6/VBA implementation of string.Format()
covered here, StringMatchesAny
is a custom string helper function covered here, and Coalesce
is a simple null-replacement function that considers an empty string as a null value.
I'm including the raw notepad-view class because there are procedure attributes involved :)
VERSION 1.0 CLASS
BEGIN
MultiUse = -1 'True
Persistable = 0 'NotPersistable
DataBindingBehavior = 0 'vbNone
DataSourceBehavior = 0 'vbNone
MTSTransactionMode = 0 'NotAnMTSObject
END
Attribute VB_Name = "List"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Private Type tList
Encapsulated As Collection
ItemTypeName As String
End Type
Private this As tList
Option Explicit
Private Function IsReferenceType() As Boolean
If Count = 0 Then Exit Function
IsReferenceType = IsObject(this.Encapsulated(1))
End Function
Private Function IsComparable() As Boolean
If IsReferenceType Then
IsComparable = TypeOf First Is IComparable
End If
End Function
Private Function CompareReferenceTypes(value As Variant, other As Variant) As Integer
Dim comparable As IComparable
If IsComparable Then
Set comparable = value
CompareReferenceTypes = comparable.CompareTo(other)
Else
RaiseErrorMustImplementIComparable "CompareReferenceTypes()"
End If
End Function
Private Function CompareValueTypes(value As Variant, other As Variant) As Integer
If value < other Then
CompareValueTypes = -1
ElseIf value > other Then
CompareValueTypes = 1
End If
End Function
Private Function IsEquatable() As Boolean
If IsReferenceType Then
IsEquatable = TypeOf First Is IEquatable
End If
End Function
Private Function EquateReferenceTypes(value As Variant, other As Variant) As Boolean
Dim equatable As IEquatable
If IsEquatable Then
Set equatable = value
EquateReferenceTypes = equatable.Equals(other)
Else
Debug.Print "WARNING: Reference type doesn't implement IEquatable, using reference equality."
EquateReferenceTypes = (ObjPtr(value) = ObjPtr(other))
End If
End Function
Private Function EquateValueTypes(value As Variant, other As Variant) As Boolean
EquateValueTypes = (value = other)
End Function
Private Function ValidateItemType(value As Variant)
If this.ItemTypeName = vbNullString Then this.ItemTypeName = TypeName(value)
ValidateItemType = IsTypeSafe(value)
End Function
Private Sub RaiseErrorUnsafeType(member As String, suppliedType As String)
Err.Raise 13, StringFormat("{0}.{1}", ToString, member), _
StringFormat("Type Mismatch. Expected: '{0}', '{1}' was supplied.", this.ItemTypeName, suppliedType)
End Sub
Private Sub RaiseErrorMustImplementIComparable(member As String)
Err.Raise 5, StringFormat("{0}.{1}", ToString, member), "Invalid operation: method requires a list of numeric, date or string values, or a list of objects implementing the IComparable interface."
End Sub
Private Sub Class_Initialize()
Set this.Encapsulated = New Collection
End Sub
Private Sub Class_Terminate()
Set this.Encapsulated = Nothing
End Sub
Public Property Get Item(ByVal Index As Long) As Variant
Attribute Item.VB_Description = "Gets or sets the element at the specified index."
Attribute Item.VB_UserMemId = 0
'Gets the element at the specified index.
If IsReferenceType Then
Set Item = this.Encapsulated(Index)
Else
Item = this.Encapsulated(Index)
End If
End Property
Public Property Let Item(ByVal Index As Long, ByVal value As Variant)
'Sets the element at the specified index.
If Not IsTypeSafe(value) Then RaiseErrorUnsafeType "Item(Let)", TypeName(value)
RemoveAt Index
If Index = Count Then
Add value
Else
Insert Index, value
End If
End Property
Public Property Set Item(ByVal Index As Long, ByVal value As Variant)
'Sets the element at the specified index.
If Not IsTypeSafe(value) Then RaiseErrorUnsafeType "Item(Set)", TypeName(value)
RemoveAt Index
If Index = Count Then
Add value
Else
Insert Index, value
End If
End Property
Public Property Get NewEnum() As IUnknown
Attribute NewEnum.VB_Description = "Gets an enumerator that iterates through the List."
Attribute NewEnum.VB_UserMemId = -4
Attribute NewEnum.VB_MemberFlags = "40"
'Gets an enumerator that iterates through the List.
Set NewEnum = this.Encapsulated.[_NewEnum]
End Property
Public Property Get Count() As Long
Attribute Count.VB_Description = "Gets the number of elements contained in the List."
'Gets the number of elements contained in the List.
Count = this.Encapsulated.Count
End Property
Attribute Add.VB_Description = "Adds an object to the end of the List."Attribute AddArray.VB_Description = "Adds the specified elements to the end of the List."Attribute AddRange.VB_Description = "Adds the elements of the specified List to the end of the List."Attribute AddValues.VB_Description = "Adds the specified elements to the end of the List."Attribute Clear.VB_Description = "Removes all elements from the List."Attribute Contains.VB_Description = "Determines whether an element is in the List."Attribute First.VB_Description = "Returns the first element of the List."Attribute GetRange.VB_Description = "Creates a copy of a range of elements in the source List."Attribute IndexOf.VB_Description = "Searches for the specified object and returns the 1-based index of the first occurrence within the entire List." If Count = 0 Then IndexOf = -1: Exit Function
For i = 1 To Count
If isRef Then
found = EquateReferenceTypes(value, Item(i))
Else
found = EquateValueTypes(value, Item(i))
End If
If found Then IndexOf = i: Exit Function
Next
IndexOf = -1
End Function
Public Sub Insert(ByVal Index As Long, value As Variant)
Attribute Insert.VB_Description = "Inserts an element into the List at the specified index."
'Inserts an element into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
Add value
AddRange tmp
End Sub
Public Sub InsertArray(ByVal Index As Long, values() As Variant)
Attribute InsertArray.VB_Description = "Inserts the specified elements into the List at the specified index."
'Inserts the specified elements into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
AddArray values
AddRange tmp
End Sub
Public Sub InsertRange(ByVal Index As Long, values As List)
Attribute InsertRange.VB_Description = "Inserts the specified elements into the List at the specified index."
'Inserts the specified elements into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
AddRange values
AddRange tmp
End Sub
Public Sub InsertValues(ByVal Index As Long, ParamArray values())
Attribute InsertValues.VB_Description = "Inserts the specified elements into the List at the specified index."
'Inserts the specified elements into the List at the specified index.
Dim valuesArray() As Variant
valuesArray = values
InsertArray Index, valuesArray
End Sub
Public Function IsSortable() As Boolean
Attribute IsSortable.VB_Description = "Determines whether the List can be sorted."
'Determines whether the List can be sorted.
If Count = 0 Then Exit Function
Dim firstItem As Variant
If IsReferenceType Then
Set firstItem = First
Else
firstItem = First
End If
IsSortable = IsNumeric(firstItem) _
Or IsDate(firstItem) _
Or this.ItemTypeName = "String" _
Or IsComparable
End Function
Public Function IsTypeSafe(value As Variant) As Boolean
Attribute IsTypeSafe.VB_Description = "Determines whether a value can be safely added to the List."
'Determines whether a value can be safely added to the List.
'Returns true if the type of specified value matches the type of items already in the list,
'or it the type of specified value is a numeric type smaller than the type of items already in the list.
'This means a List<Long> can contain Integer values, but a List<Integer> cannot contain Long values.
Dim result As Boolean
'most common cases: this.ItemTypeName isn't yet defined, or matches TypeName(value):
result = this.ItemTypeName = vbNullString Or this.ItemTypeName = TypeName(value)
If result Then IsTypeSafe = result: Exit Function
'all other cases demand more processing:
IsTypeSafe = result _
Or this.ItemTypeName = "Integer" And StringMatchesAny(TypeName(value), "Byte") _
Or this.ItemTypeName = "Long" And StringMatchesAny(TypeName(value), "Integer", "Byte") _
Or this.ItemTypeName = "Single" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte") _
Or this.ItemTypeName = "Double" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte", "Single") _
Or this.ItemTypeName = "Currency" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte", "Single", "Double")
End Function
Public Function Last() As Variant
Attribute Last.VB_Description = "Returns the last element of the List."
'Returns the last element of the List.
If Count = 0 Then Exit Function
If IsReferenceType Then
Set Last = Item(Count)
Else
Last = Item(Count)
End If
End Function
Public Function LastIndexOf(value As Variant) As Long
Attribute LastIndexOf.VB_Description = "Searches for the specified object and returns the 1-based index of the last occurrence within the entire List."
'Searches for the specified object and returns the 1-based index of the last occurrence within the entire List.
Dim found As Boolean
Dim isRef As Boolean
isRef = IsReferenceType
LastIndexOf = -1
If Count = 0 Then Exit Function
Dim i As Long
For i = 1 To Count
If isRef Then
found = EquateReferenceTypes(value, Item(i))
Else
found = EquateValueTypes(value, Item(i))
End If
If found Then LastIndexOf = i
Next
End Function
Public Function Max() As Variant
Attribute Max.VB_Description = "Returns the maximum value in the List."
'Returns the maximum value in the List.
Dim isRef As Boolean
isRef = IsReferenceType
Dim largest As Variant
Dim isLarger As Boolean
Dim i As Long
For i = 1 To Count
If isRef Then
If IsEmpty(largest) Then Set largest = Item(i)
isLarger = CompareReferenceTypes(Item(i), largest) > 0
If isLarger Or IsEmpty(Max) Then
Set largest = Item(i)
Set Max = largest
End If
Else
If IsEmpty(largest) Then largest = Item(i)
isLarger = CompareValueTypes(Item(i), largest) > 0
If isLarger Or IsEmpty(Max) Then
largest = Item(i)
Max = largest
End If
End If
Next
End Function
Public Function Min() As Variant
Attribute Min.VB_Description = "Returns the minimum value in the List."
'Returns the minimum value in the List.
Dim isRef As Boolean
isRef = IsReferenceType
Dim smallest As Variant
Dim isSmaller As Boolean
Dim i As Long
For i = 1 To Count
If isRef Then
If IsEmpty(smallest) Then Set smallest = Item(i)
isSmaller = CompareReferenceTypes(Item(i), smallest) < 0
If isSmaller Or IsEmpty(Min) Then
Set smallest = Item(i)
Set Min = smallest
End If
Else
If IsEmpty(smallest) Then smallest = Item(i)
isSmaller = CompareValueTypes(Item(i), smallest) < 0
If isSmaller Or IsEmpty(Min) Then
smallest = Item(i)
Min = smallest
End If
End If
Next
End Function
Public Sub Reverse()
Attribute Reverse.VB_Description = "Reverses the order of the elements in the entire List."
'Reverses the order of the elements in the entire List.
Dim tmp As New List
Do Until Count = 0
tmp.Add Item(Count)
RemoveAt Count
Loop
AddRange tmp
End Sub
Public Sub Remove(ParamArray values())
Attribute Remove.VB_Description = "Removes the first occurrence of specified object(s) from the List."
'Removes the first occurrence of specified object(s) from the List.
Dim i As Long
Dim Index As Long
For i = LBound(values) To UBound(values)
Index = IndexOf(values(i))
If Index <> -1 Then RemoveAt Index
Next
End Sub
Public Sub RemoveAt(ByVal Index As Long)
Attribute RemoveAt.VB_Description = "Removes the element at the specified index of the List."
'Removes the element at the specified index of the List.
this.Encapsulated.Remove Index
End Sub
Public Sub RemoveRange(ByVal Index As Long, ByVal valuesCount As Long)
Attribute RemoveRange.VB_Description = "Removes a range of elements from the List."
'Removes a range of elements from the List.
Dim i As Long
For i = Index To Index + valuesCount - 1
RemoveAt Index
Next
End Sub
Public Sub Sort()
Attribute Sort.VB_Description = "Sorts the elements in the entire List."
'Sorts the elements in the entire List.
Dim tmp As List
Dim minValue As Variant
If Not IsSortable Then RaiseErrorMustImplementIComparable "Sort()"
Dim isRef As Boolean
isRef = IsReferenceType
Set tmp = New List
Do Until Count = 0
If isRef Then
Set minValue = Min
Else
minValue = Min
End If
tmp.Add minValue
Remove minValue
Loop
AddRange tmp
End Sub
Public Sub SortDescending()
Attribute SortDescending.VB_Description = "Sorts the elements in the entire List, in descending order."
'Sorts the elements in the entire List, in descending order.
Dim tmp As List
Dim maxValue As Variant
If Not IsSortable Then RaiseErrorMustImplementIComparable "SortDescending()"
Dim isRef As Boolean
isRef = IsReferenceType
Set tmp = New List
Do Until Count = 0
If isRef Then
Set maxValue = Max
Else
maxValue = Max
End If
tmp.Add maxValue
Remove maxValue
Loop
AddRange tmp
End Sub
Public Function ToArray() As Variant()
Attribute ToArray.VB_Description = "Copies the elements of the List to a new array."
'Copies the elements of the List to a new array.
Dim result() As Variant
ReDim result(1 To Count)
Dim i As Long
If Count = 0 Then Exit Function
If IsReferenceType Then
For i = 1 To Count
Set result(i) = Item(i)
Next
Else
For i = 1 To Count
result(i) = Item(i)
Next
End If
ToArray = result
End Function
Public Function ToString() As String
Attribute ToString.VB_Description = "Returns a string that represents the current List object."
'Returns a string that represents the current List object.
ToString = StringFormat("{0}<{1}>", TypeName(Me), Coalesce(this.ItemTypeName, "Variant"))
End Function
IComparable:
VERSION 1.0 CLASS
BEGIN
MultiUse = -1 'True
Persistable = 0 'NotPersistable
DataBindingBehavior = 0 'vbNone
DataSourceBehavior = 0 'vbNone
MTSTransactionMode = 0 'NotAnMTSObject
END
Attribute VB_Name = "IComparable"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Option Explicit
Public Function CompareTo(other As Variant) As Integer
Attribute CompareTo.VB_Description = "Compares the current instance with another object of the same type and returns an integer that indicates whether the current instance precedes, follows, or occurs in the same position in the sort order as the other object."
End Function
VERSION 1.0 CLASS
BEGIN
MultiUse = -1 'True
Persistable = 0 'NotPersistable
DataBindingBehavior = 0 'vbNone
DataSourceBehavior = 0 'vbNone
MTSTransactionMode = 0 'NotAnMTSObject
END
Attribute VB_Name = "IEquatable"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Option Explicit
Public Function Equals(other As Variant) As Boolean
End Function
IEquatable:
Option Explicit
Public Function Equals(other As Variant) As Boolean
End Function
I'm including the raw notepad-view class because there are procedure attributes involved :)
VERSION 1.0 CLASS
BEGIN
MultiUse = -1 'True
Persistable = 0 'NotPersistable
DataBindingBehavior = 0 'vbNone
DataSourceBehavior = 0 'vbNone
MTSTransactionMode = 0 'NotAnMTSObject
END
Attribute VB_Name = "List"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Private Type tList
Encapsulated As Collection
ItemTypeName As String
End Type
Private this As tList
Option Explicit
Private Function IsReferenceType() As Boolean
If Count = 0 Then Exit Function
IsReferenceType = IsObject(this.Encapsulated(1))
End Function
Private Function IsComparable() As Boolean
If IsReferenceType Then
IsComparable = TypeOf First Is IComparable
End If
End Function
Private Function CompareReferenceTypes(value As Variant, other As Variant) As Integer
Dim comparable As IComparable
If IsComparable Then
Set comparable = value
CompareReferenceTypes = comparable.CompareTo(other)
Else
RaiseErrorMustImplementIComparable "CompareReferenceTypes()"
End If
End Function
Private Function CompareValueTypes(value As Variant, other As Variant) As Integer
If value < other Then
CompareValueTypes = -1
ElseIf value > other Then
CompareValueTypes = 1
End If
End Function
Private Function IsEquatable() As Boolean
If IsReferenceType Then
IsEquatable = TypeOf First Is IEquatable
End If
End Function
Private Function EquateReferenceTypes(value As Variant, other As Variant) As Boolean
Dim equatable As IEquatable
If IsEquatable Then
Set equatable = value
EquateReferenceTypes = equatable.Equals(other)
Else
Debug.Print "WARNING: Reference type doesn't implement IEquatable, using reference equality."
EquateReferenceTypes = (ObjPtr(value) = ObjPtr(other))
End If
End Function
Private Function EquateValueTypes(value As Variant, other As Variant) As Boolean
EquateValueTypes = (value = other)
End Function
Private Function ValidateItemType(value As Variant)
If this.ItemTypeName = vbNullString Then this.ItemTypeName = TypeName(value)
ValidateItemType = IsTypeSafe(value)
End Function
Private Sub RaiseErrorUnsafeType(member As String, suppliedType As String)
Err.Raise 13, StringFormat("{0}.{1}", ToString, member), _
StringFormat("Type Mismatch. Expected: '{0}', '{1}' was supplied.", this.ItemTypeName, suppliedType)
End Sub
Private Sub RaiseErrorMustImplementIComparable(member As String)
Err.Raise 5, StringFormat("{0}.{1}", ToString, member), "Invalid operation: method requires a list of numeric, date or string values, or a list of objects implementing the IComparable interface."
End Sub
Private Sub Class_Initialize()
Set this.Encapsulated = New Collection
End Sub
Private Sub Class_Terminate()
Set this.Encapsulated = Nothing
End Sub
Public Property Get Item(ByVal Index As Long) As Variant
Attribute Item.VB_Description = "Gets or sets the element at the specified index."
Attribute Item.VB_UserMemId = 0
'Gets the element at the specified index.
If IsReferenceType Then
Set Item = this.Encapsulated(Index)
Else
Item = this.Encapsulated(Index)
End If
End Property
Public Property Let Item(ByVal Index As Long, ByVal value As Variant)
'Sets the element at the specified index.
If Not IsTypeSafe(value) Then RaiseErrorUnsafeType "Item(Let)", TypeName(value)
RemoveAt Index
If Index = Count Then
Add value
Else
Insert Index, value
End If
End Property
Public Property Set Item(ByVal Index As Long, ByVal value As Variant)
'Sets the element at the specified index.
If Not IsTypeSafe(value) Then RaiseErrorUnsafeType "Item(Set)", TypeName(value)
RemoveAt Index
If Index = Count Then
Add value
Else
Insert Index, value
End If
End Property
Public Property Get NewEnum() As IUnknown
Attribute NewEnum.VB_Description = "Gets an enumerator that iterates through the List."
Attribute NewEnum.VB_UserMemId = -4
Attribute NewEnum.VB_MemberFlags = "40"
'Gets an enumerator that iterates through the List.
Set NewEnum = this.Encapsulated.[_NewEnum]
End Property
Public Property Get Count() As Long
Attribute Count.VB_Description = "Gets the number of elements contained in the List."
'Gets the number of elements contained in the List.
Count = this.Encapsulated.Count
End Property
Attribute Add.VB_Description = "Adds an object to the end of the List."Attribute AddArray.VB_Description = "Adds the specified elements to the end of the List."Attribute AddRange.VB_Description = "Adds the elements of the specified List to the end of the List."Attribute AddValues.VB_Description = "Adds the specified elements to the end of the List."Attribute Clear.VB_Description = "Removes all elements from the List."Attribute Contains.VB_Description = "Determines whether an element is in the List."Attribute First.VB_Description = "Returns the first element of the List."Attribute GetRange.VB_Description = "Creates a copy of a range of elements in the source List."Attribute IndexOf.VB_Description = "Searches for the specified object and returns the 1-based index of the first occurrence within the entire List." If Count = 0 Then IndexOf = -1: Exit Function
For i = 1 To Count
If isRef Then
found = EquateReferenceTypes(value, Item(i))
Else
found = EquateValueTypes(value, Item(i))
End If
If found Then IndexOf = i: Exit Function
Next
IndexOf = -1
End Function
Public Sub Insert(ByVal Index As Long, value As Variant)
Attribute Insert.VB_Description = "Inserts an element into the List at the specified index."
'Inserts an element into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
Add value
AddRange tmp
End Sub
Public Sub InsertArray(ByVal Index As Long, values() As Variant)
Attribute InsertArray.VB_Description = "Inserts the specified elements into the List at the specified index."
'Inserts the specified elements into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
AddArray values
AddRange tmp
End Sub
Public Sub InsertRange(ByVal Index As Long, values As List)
Attribute InsertRange.VB_Description = "Inserts the specified elements into the List at the specified index."
'Inserts the specified elements into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
AddRange values
AddRange tmp
End Sub
Public Sub InsertValues(ByVal Index As Long, ParamArray values())
Attribute InsertValues.VB_Description = "Inserts the specified elements into the List at the specified index."
'Inserts the specified elements into the List at the specified index.
Dim valuesArray() As Variant
valuesArray = values
InsertArray Index, valuesArray
End Sub
Public Function IsSortable() As Boolean
Attribute IsSortable.VB_Description = "Determines whether the List can be sorted."
'Determines whether the List can be sorted.
If Count = 0 Then Exit Function
Dim firstItem As Variant
If IsReferenceType Then
Set firstItem = First
Else
firstItem = First
End If
IsSortable = IsNumeric(firstItem) _
Or IsDate(firstItem) _
Or this.ItemTypeName = "String" _
Or IsComparable
End Function
Public Function IsTypeSafe(value As Variant) As Boolean
Attribute IsTypeSafe.VB_Description = "Determines whether a value can be safely added to the List."
'Determines whether a value can be safely added to the List.
'Returns true if the type of specified value matches the type of items already in the list,
'or it the type of specified value is a numeric type smaller than the type of items already in the list.
'This means a List<Long> can contain Integer values, but a List<Integer> cannot contain Long values.
Dim result As Boolean
'most common cases: this.ItemTypeName isn't yet defined, or matches TypeName(value):
result = this.ItemTypeName = vbNullString Or this.ItemTypeName = TypeName(value)
If result Then IsTypeSafe = result: Exit Function
'all other cases demand more processing:
IsTypeSafe = result _
Or this.ItemTypeName = "Integer" And StringMatchesAny(TypeName(value), "Byte") _
Or this.ItemTypeName = "Long" And StringMatchesAny(TypeName(value), "Integer", "Byte") _
Or this.ItemTypeName = "Single" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte") _
Or this.ItemTypeName = "Double" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte", "Single") _
Or this.ItemTypeName = "Currency" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte", "Single", "Double")
End Function
Public Function Last() As Variant
Attribute Last.VB_Description = "Returns the last element of the List."
'Returns the last element of the List.
If Count = 0 Then Exit Function
If IsReferenceType Then
Set Last = Item(Count)
Else
Last = Item(Count)
End If
End Function
Public Function LastIndexOf(value As Variant) As Long
Attribute LastIndexOf.VB_Description = "Searches for the specified object and returns the 1-based index of the last occurrence within the entire List."
'Searches for the specified object and returns the 1-based index of the last occurrence within the entire List.
Dim found As Boolean
Dim isRef As Boolean
isRef = IsReferenceType
LastIndexOf = -1
If Count = 0 Then Exit Function
Dim i As Long
For i = 1 To Count
If isRef Then
found = EquateReferenceTypes(value, Item(i))
Else
found = EquateValueTypes(value, Item(i))
End If
If found Then LastIndexOf = i
Next
End Function
Public Function Max() As Variant
Attribute Max.VB_Description = "Returns the maximum value in the List."
'Returns the maximum value in the List.
Dim isRef As Boolean
isRef = IsReferenceType
Dim largest As Variant
Dim isLarger As Boolean
Dim i As Long
For i = 1 To Count
If isRef Then
If IsEmpty(largest) Then Set largest = Item(i)
isLarger = CompareReferenceTypes(Item(i), largest) > 0
If isLarger Or IsEmpty(Max) Then
Set largest = Item(i)
Set Max = largest
End If
Else
If IsEmpty(largest) Then largest = Item(i)
isLarger = CompareValueTypes(Item(i), largest) > 0
If isLarger Or IsEmpty(Max) Then
largest = Item(i)
Max = largest
End If
End If
Next
End Function
Public Function Min() As Variant
Attribute Min.VB_Description = "Returns the minimum value in the List."
'Returns the minimum value in the List.
Dim isRef As Boolean
isRef = IsReferenceType
Dim smallest As Variant
Dim isSmaller As Boolean
Dim i As Long
For i = 1 To Count
If isRef Then
If IsEmpty(smallest) Then Set smallest = Item(i)
isSmaller = CompareReferenceTypes(Item(i), smallest) < 0
If isSmaller Or IsEmpty(Min) Then
Set smallest = Item(i)
Set Min = smallest
End If
Else
If IsEmpty(smallest) Then smallest = Item(i)
isSmaller = CompareValueTypes(Item(i), smallest) < 0
If isSmaller Or IsEmpty(Min) Then
smallest = Item(i)
Min = smallest
End If
End If
Next
End Function
Public Sub Reverse()
Attribute Reverse.VB_Description = "Reverses the order of the elements in the entire List."
'Reverses the order of the elements in the entire List.
Dim tmp As New List
Do Until Count = 0
tmp.Add Item(Count)
RemoveAt Count
Loop
AddRange tmp
End Sub
Public Sub Remove(ParamArray values())
Attribute Remove.VB_Description = "Removes the first occurrence of specified object(s) from the List."
'Removes the first occurrence of specified object(s) from the List.
Dim i As Long
Dim Index As Long
For i = LBound(values) To UBound(values)
Index = IndexOf(values(i))
If Index <> -1 Then RemoveAt Index
Next
End Sub
Public Sub RemoveAt(ByVal Index As Long)
Attribute RemoveAt.VB_Description = "Removes the element at the specified index of the List."
'Removes the element at the specified index of the List.
this.Encapsulated.Remove Index
End Sub
Public Sub RemoveRange(ByVal Index As Long, ByVal valuesCount As Long)
Attribute RemoveRange.VB_Description = "Removes a range of elements from the List."
'Removes a range of elements from the List.
Dim i As Long
For i = Index To Index + valuesCount - 1
RemoveAt Index
Next
End Sub
Public Sub Sort()
Attribute Sort.VB_Description = "Sorts the elements in the entire List."
'Sorts the elements in the entire List.
Dim tmp As List
Dim minValue As Variant
If Not IsSortable Then RaiseErrorMustImplementIComparable "Sort()"
Dim isRef As Boolean
isRef = IsReferenceType
Set tmp = New List
Do Until Count = 0
If isRef Then
Set minValue = Min
Else
minValue = Min
End If
tmp.Add minValue
Remove minValue
Loop
AddRange tmp
End Sub
Public Sub SortDescending()
Attribute SortDescending.VB_Description = "Sorts the elements in the entire List, in descending order."
'Sorts the elements in the entire List, in descending order.
Dim tmp As List
Dim maxValue As Variant
If Not IsSortable Then RaiseErrorMustImplementIComparable "SortDescending()"
Dim isRef As Boolean
isRef = IsReferenceType
Set tmp = New List
Do Until Count = 0
If isRef Then
Set maxValue = Max
Else
maxValue = Max
End If
tmp.Add maxValue
Remove maxValue
Loop
AddRange tmp
End Sub
Public Function ToArray() As Variant()
Attribute ToArray.VB_Description = "Copies the elements of the List to a new array."
'Copies the elements of the List to a new array.
Dim result() As Variant
ReDim result(1 To Count)
Dim i As Long
If Count = 0 Then Exit Function
If IsReferenceType Then
For i = 1 To Count
Set result(i) = Item(i)
Next
Else
For i = 1 To Count
result(i) = Item(i)
Next
End If
ToArray = result
End Function
Public Function ToString() As String
Attribute ToString.VB_Description = "Returns a string that represents the current List object."
'Returns a string that represents the current List object.
ToString = StringFormat("{0}<{1}>", TypeName(Me), Coalesce(this.ItemTypeName, "Variant"))
End Function
VERSION 1.0 CLASS
BEGIN
MultiUse = -1 'True
Persistable = 0 'NotPersistable
DataBindingBehavior = 0 'vbNone
DataSourceBehavior = 0 'vbNone
MTSTransactionMode = 0 'NotAnMTSObject
END
Attribute VB_Name = "IComparable"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Option Explicit
Public Function CompareTo(other As Variant) As Integer
Attribute CompareTo.VB_Description = "Compares the current instance with another object of the same type and returns an integer that indicates whether the current instance precedes, follows, or occurs in the same position in the sort order as the other object."
End Function
VERSION 1.0 CLASS
BEGIN
MultiUse = -1 'True
Persistable = 0 'NotPersistable
DataBindingBehavior = 0 'vbNone
DataSourceBehavior = 0 'vbNone
MTSTransactionMode = 0 'NotAnMTSObject
END
Attribute VB_Name = "IEquatable"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Option Explicit
Public Function Equals(other As Variant) As Boolean
End Function
Attribute VB_Name = "List"
Private Type tList
Encapsulated As Collection
ItemTypeName As String
End Type
Private this As tList
Option Explicit
Private Function IsReferenceType() As Boolean
If Count = 0 Then Exit Function
IsReferenceType = IsObject(this.Encapsulated(1))
End Function
Private Function IsComparable() As Boolean
If IsReferenceType Then
IsComparable = TypeOf First Is IComparable
End If
End Function
Private Function CompareReferenceTypes(value As Variant, other As Variant) As Integer
Dim comparable As IComparable
If IsComparable Then
Set comparable = value
CompareReferenceTypes = comparable.CompareTo(other)
Else
RaiseErrorMustImplementIComparable "CompareReferenceTypes()"
End If
End Function
Private Function CompareValueTypes(value As Variant, other As Variant) As Integer
If value < other Then
CompareValueTypes = -1
ElseIf value > other Then
CompareValueTypes = 1
End If
End Function
Private Function IsEquatable() As Boolean
If IsReferenceType Then
IsEquatable = TypeOf First Is IEquatable
End If
End Function
Private Function EquateReferenceTypes(value As Variant, other As Variant) As Boolean
Dim equatable As IEquatable
If IsEquatable Then
Set equatable = value
EquateReferenceTypes = equatable.Equals(other)
Else
Debug.Print "WARNING: Reference type doesn't implement IEquatable, using reference equality."
EquateReferenceTypes = (ObjPtr(value) = ObjPtr(other))
End If
End Function
Private Function EquateValueTypes(value As Variant, other As Variant) As Boolean
EquateValueTypes = (value = other)
End Function
Private Function ValidateItemType(value As Variant)
If this.ItemTypeName = vbNullString Then this.ItemTypeName = TypeName(value)
ValidateItemType = IsTypeSafe(value)
End Function
Private Sub RaiseErrorUnsafeType(member As String, suppliedType As String)
Err.Raise 13, StringFormat("{0}.{1}", ToString, member), _
StringFormat("Type Mismatch. Expected: '{0}', '{1}' was supplied.", this.ItemTypeName, suppliedType)
End Sub
Private Sub RaiseErrorMustImplementIComparable(member As String)
Err.Raise 5, StringFormat("{0}.{1}", ToString, member), "Invalid operation: method requires a list of numeric, date or string values, or a list of objects implementing the IComparable interface."
End Sub
Private Sub Class_Initialize()
Set this.Encapsulated = New Collection
End Sub
Private Sub Class_Terminate()
Set this.Encapsulated = Nothing
End Sub
Public Property Get Item(ByVal Index As Long) As Variant
Attribute Item.VB_UserMemId = 0
'Gets the element at the specified index.
If IsReferenceType Then
Set Item = this.Encapsulated(Index)
Else
Item = this.Encapsulated(Index)
End If
End Property
Public Property Let Item(ByVal Index As Long, ByVal value As Variant)
'Sets the element at the specified index.
If Not IsTypeSafe(value) Then RaiseErrorUnsafeType "Item(Let)", TypeName(value)
RemoveAt Index
If Index = Count Then
Add value
Else
Insert Index, value
End If
End Property
Public Property Set Item(ByVal Index As Long, ByVal value As Variant)
'Sets the element at the specified index.
If Not IsTypeSafe(value) Then RaiseErrorUnsafeType "Item(Set)", TypeName(value)
RemoveAt Index
If Index = Count Then
Add value
Else
Insert Index, value
End If
End Property
Public Property Get NewEnum() As IUnknown
Attribute NewEnum.VB_UserMemId = -4
Attribute NewEnum.VB_MemberFlags = "40"
'Gets an enumerator that iterates through the List.
Set NewEnum = this.Encapsulated.[_NewEnum]
End Property
Public Property Get Count() As Long
Count = this.Encapsulated.Count
End Property
If Count = 0 Then IndexOf = -1: Exit Function
For i = 1 To Count
If isRef Then
found = EquateReferenceTypes(value, Item(i))
Else
found = EquateValueTypes(value, Item(i))
End If
If found Then IndexOf = i: Exit Function
Next
IndexOf = -1
End Function
Public Sub Insert(ByVal Index As Long, value As Variant)
'Inserts an element into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
Add value
AddRange tmp
End Sub
Public Sub InsertArray(ByVal Index As Long, values() As Variant)
'Inserts the specified elements into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
AddArray values
AddRange tmp
End Sub
Public Sub InsertRange(ByVal Index As Long, values As List)
'Inserts the specified elements into the List at the specified index.
Dim tmp As List
Set tmp = GetRange(Index, Count)
RemoveRange Index, Count
AddRange values
AddRange tmp
End Sub
Public Sub InsertValues(ByVal Index As Long, ParamArray values())
'Inserts the specified elements into the List at the specified index.
Dim valuesArray() As Variant
valuesArray = values
InsertArray Index, valuesArray
End Sub
Public Function IsSortable() As Boolean
'Determines whether the List can be sorted.
If Count = 0 Then Exit Function
Dim firstItem As Variant
If IsReferenceType Then
Set firstItem = First
Else
firstItem = First
End If
IsSortable = IsNumeric(firstItem) _
Or IsDate(firstItem) _
Or this.ItemTypeName = "String" _
Or IsComparable
End Function
Public Function IsTypeSafe(value As Variant) As Boolean
'Determines whether a value can be safely added to the List.
'Returns true if the type of specified value matches the type of items already in the list,
'or it the type of specified value is a numeric type smaller than the type of items already in the list.
'This means a List<Long> can contain Integer values, but a List<Integer> cannot contain Long values.
Dim result As Boolean
'most common cases: this.ItemTypeName isn't yet defined, or matches TypeName(value):
result = this.ItemTypeName = vbNullString Or this.ItemTypeName = TypeName(value)
If result Then IsTypeSafe = result: Exit Function
'all other cases demand more processing:
IsTypeSafe = result _
Or this.ItemTypeName = "Integer" And StringMatchesAny(TypeName(value), "Byte") _
Or this.ItemTypeName = "Long" And StringMatchesAny(TypeName(value), "Integer", "Byte") _
Or this.ItemTypeName = "Single" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte") _
Or this.ItemTypeName = "Double" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte", "Single") _
Or this.ItemTypeName = "Currency" And StringMatchesAny(TypeName(value), "Long", "Integer", "Byte", "Single", "Double")
End Function
Public Function Last() As Variant
'Returns the last element of the List.
If Count = 0 Then Exit Function
If IsReferenceType Then
Set Last = Item(Count)
Else
Last = Item(Count)
End If
End Function
Public Function LastIndexOf(value As Variant) As Long
'Searches for the specified object and returns the 1-based index of the last occurrence within the entire List.
Dim found As Boolean
Dim isRef As Boolean
isRef = IsReferenceType
LastIndexOf = -1
If Count = 0 Then Exit Function
Dim i As Long
For i = 1 To Count
If isRef Then
found = EquateReferenceTypes(value, Item(i))
Else
found = EquateValueTypes(value, Item(i))
End If
If found Then LastIndexOf = i
Next
End Function
Public Function Max() As Variant
'Returns the maximum value in the List.
Dim isRef As Boolean
isRef = IsReferenceType
Dim largest As Variant
Dim isLarger As Boolean
Dim i As Long
For i = 1 To Count
If isRef Then
If IsEmpty(largest) Then Set largest = Item(i)
isLarger = CompareReferenceTypes(Item(i), largest) > 0
If isLarger Or IsEmpty(Max) Then
Set largest = Item(i)
Set Max = largest
End If
Else
If IsEmpty(largest) Then largest = Item(i)
isLarger = CompareValueTypes(Item(i), largest) > 0
If isLarger Or IsEmpty(Max) Then
largest = Item(i)
Max = largest
End If
End If
Next
End Function
Public Function Min() As Variant
'Returns the minimum value in the List.
Dim isRef As Boolean
isRef = IsReferenceType
Dim smallest As Variant
Dim isSmaller As Boolean
Dim i As Long
For i = 1 To Count
If isRef Then
If IsEmpty(smallest) Then Set smallest = Item(i)
isSmaller = CompareReferenceTypes(Item(i), smallest) < 0
If isSmaller Or IsEmpty(Min) Then
Set smallest = Item(i)
Set Min = smallest
End If
Else
If IsEmpty(smallest) Then smallest = Item(i)
isSmaller = CompareValueTypes(Item(i), smallest) < 0
If isSmaller Or IsEmpty(Min) Then
smallest = Item(i)
Min = smallest
End If
End If
Next
End Function
Public Sub Reverse()
'Reverses the order of the elements in the entire List.
Dim tmp As New List
Do Until Count = 0
tmp.Add Item(Count)
RemoveAt Count
Loop
AddRange tmp
End Sub
Public Sub Remove(ParamArray values())
'Removes the first occurrence of specified object(s) from the List.
Dim i As Long
Dim Index As Long
For i = LBound(values) To UBound(values)
Index = IndexOf(values(i))
If Index <> -1 Then RemoveAt Index
Next
End Sub
Public Sub RemoveAt(ByVal Index As Long)
'Removes the element at the specified index of the List.
this.Encapsulated.Remove Index
End Sub
Public Sub RemoveRange(ByVal Index As Long, ByVal valuesCount As Long)
'Removes a range of elements from the List.
Dim i As Long
For i = Index To Index + valuesCount - 1
RemoveAt Index
Next
End Sub
Public Sub Sort()
'Sorts the elements in the entire List.
Dim tmp As List
Dim minValue As Variant
If Not IsSortable Then RaiseErrorMustImplementIComparable "Sort()"
Dim isRef As Boolean
isRef = IsReferenceType
Set tmp = New List
Do Until Count = 0
If isRef Then
Set minValue = Min
Else
minValue = Min
End If
tmp.Add minValue
Remove minValue
Loop
AddRange tmp
End Sub
Public Sub SortDescending()
'Sorts the elements in the entire List, in descending order.
Dim tmp As List
Dim maxValue As Variant
If Not IsSortable Then RaiseErrorMustImplementIComparable "SortDescending()"
Dim isRef As Boolean
isRef = IsReferenceType
Set tmp = New List
Do Until Count = 0
If isRef Then
Set maxValue = Max
Else
maxValue = Max
End If
tmp.Add maxValue
Remove maxValue
Loop
AddRange tmp
End Sub
Public Function ToArray() As Variant()
'Copies the elements of the List to a new array.
Dim result() As Variant
ReDim result(1 To Count)
Dim i As Long
If Count = 0 Then Exit Function
If IsReferenceType Then
For i = 1 To Count
Set result(i) = Item(i)
Next
Else
For i = 1 To Count
result(i) = Item(i)
Next
End If
ToArray = result
End Function
Public Function ToString() As String
'Returns a string that represents the current List object.
ToString = StringFormat("{0}<{1}>", TypeName(Me), Coalesce(this.ItemTypeName, "Variant"))
End Function
IComparable:
Option Explicit
Public Function CompareTo(other As Variant) As Integer
End Function
IEquatable:
Option Explicit
Public Function Equals(other As Variant) As Boolean
End Function
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- 75.5k
- 18
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- 467
- 75.5k
- 18
- 194
- 467