mog project: Class of the variable-length array with initialization in VBScript

VBScript: クラスの初期化を行う可変長配列クラス

VBScriptでオブジェクトの可変長配列を実現するクラス。C++のSTL, vectorと名前を揃えている。
スカラー変数はサポート対象外。

Execute()メソッドを使って動的にコードを生成しているのが特徴。

・Class ObjectVector

   1: '// A class manages mutable object array.   2: Const kErrorNotInitialized     = 1  '// Class name is not defined.   3: Const kErrorAlreadyInitialized = 2  '// Class name is already defined.   4: Const kErrorInvalidInitParam   = 3  '// Initialize parameter is invalid.   5: Const kErrorOutOfRange         = 9  '// Specified index is out of range.   6:     7: Class ObjectVector   8:   Private items_()   9:   Private size_  10:   Private class_name_  11:    12:   '// Constructor  13:   Private Sub Class_Initialize()  14:     ReDim items_(7)  15:     size_ = 0  16:     class_name_ = ""  17:   End Sub  18:    19:   '// Initializer  20:   Public Sub Init(ByVal class_name)  21:     If "" <> class_name_ Then  22:       Call Err.Raise(kErrorAlreadyInitialized, "ObjectVector.Init()")  23:     End If  24:     class_name_ = class_name  25:   End Sub  26:    27:   '// Subscript sequence with checking.  28:   Public Default Property Get at(ByVal index)  29:     If IsOutOfRange(index) Then  30:       Call Err.Raise(kErrorOutOfRange, "ObjectVector.at()")  31:     End If  32:     Set at = items_(index)  33:   End Property  34:    35:   '// Return length of sequense.  36:   Public Property Get size()  37:     size = size_  38:   End Property  39:    40:   '// Test if sequense is empty.  41:   Public Property Get is_empty()  42:     is_empty = (0 = size_)  43:   End Property  44:    45:   '// Return first element of sequense.  46:   Public Property Get front()  47:     Set front = Me.at(0)  48:   End Property  49:    50:   '// Return last element of sequense.  51:   Public Property Get back()  52:     Set back = Me.at(size_ - 1)  53:   End Property  54:    55:   '// Insert element at end.  56:   '//   When the parameter "init_array" is not "Null",  57:   '//   execute Init() function of the created object with "init_array".  58:   Public Sub push_back(ByVal init_array)  59:     If "" = class_name_ Then  60:       Call Err.Raise(kErrorNotInitialized, "ObjectVector.push_back()")  61:     End If  62:     If Not (IsNull(init_array) Or IsArray(init_array)) Then  63:       Call Err.Raise(kErrorInvalidInitParam, "ObjectVector.push_back()")  64:     End If  65:    66:     If UBound(items_) >= size_ Then  67:       ReDim Preserve items_(size_ * 2 + 1)  68:     End If  69:     Call Execute("Set items_(size_) = New " & class_name_)  70:     If IsArray(init_array) Then  71:       Dim i, arr()  72:       ReDim arr(UBound(init_array))  73:       For i = 0 To UBound(arr)  74:         arr(i) = "init_array(" & i & ")"  75:       Next  76:       Call Execute("Call items_(size_).Init(" & Join(arr, ",") & ")")  77:     End If  78:     size_ = size_ + 1  79:   End Sub  80:    81:   '// Erase element at end.  82:   Public Sub pop_back()  83:     If IsOutOfRange(size_ - 1) Then  84:       Call Err.Raise(kErrorOutOfRange, "ObjectVector.pop_back()")  85:     End If  86:     Set items_(size_ - 1) = Nothing  87:     size_ = size_ - 1  88:   End Sub  89:    90:   '// Test if index is valid.  91:   Private Function IsOutOfRange(ByVal index)  92:     IsOutOfRange = True  93:     If Not IsNumeric(index) Then Exit Function  94:     If (index >= size_) Or (index < 0) Then Exit Function  95:     IsOutOfRange = False  96:   End Function  97: End Class

使い方は、Set obj = New ObjectVector
とインスタンスを生成してから、Init()関数で子クラス名を登録する。
push_back()関数はやや特殊な構文となっている。

push_back(Null)　：　子クラスの生成のみ
push_back(Array(prm1, prm2, …))　：　渡されたパラメータで、子クラスのInit()関数を実行する。
　　※あらかじめ子クラスでのInit()関数の準備が必須
　　※子クラスのInit()関数が引数を取らない場合は、以下の構文を使用する
　　push_back(Array())

・使用例

   1: '// Some class.   2: Class Nullary   3:   Public x   4:   Public Sub Init()   5:     x = 1   6:   End Sub   7: End Class   8:     9: Class Unary  10:   Public x  11:   Public Sub Init(ByVal value)  12:     x = value  13:   End Sub  14: End Class  15:    16: Set obj1 = New ObjectVector  17: Call obj1.Init("Nullary")  18: obj1.push_back(Array())   ' Execute Nullary.Init().  19: WScript.Echo obj1.back.x  ' Print obj1.at(0).x (=1)  20:    21: Set obj2 = New ObjectVector  22: Call obj2.Init("Unary")  23: obj2.push_back(Null)      ' Not execute Init().  24: obj2.push_back(Array(2))  ' Execute Unary.Init(2).  25: WScript.Echo obj2(0).x    ' Print obj2.at(0).x (=Empty)  26: WScript.Echo obj2(1).x    ' Print obj2.at(1).x (=2)