86. LotusScript中的数组函数

R6对LotusScript有一些改进和增强，自那之后。Notes对象的接口时有补充和更新，但语言本身没有变化。那些改进就包括添加诸如ArrayGetIndex、ArrayUnique的实用函数。

但在编程实践中，另一些对数组的操作LotusScript没有提供原生的函数，好在基本上都能自己编写。以下的函数中用到的常数都在lsconst.lss或lserr.lss里定义，在脚本前要附加

%INCLUDE"lsconst.lss"

%INCLUDE"lserr.lss"

推断数组是否包括某个元素。

%REM
	Checks if an array contains a value.
	The ArrayGetIndex function returns null if the value is not found.
%END REM
Public Function ArrayContains(source As Variant, value As Variant) As Boolean
	'the data type of source is not checked intentionally
	ArrayContains=Not IsNull(ArrayGetIndex(source,value))
End Function

LotusScript中的数组最多能够有八维（dimension），以下这个函数利用执行时错误（run-time error）ErrSubscriptOutOfRange获得维数。

'Returns the number of an array's dimensions
Function ArrayDimension(array As Variant) As Integer
	If Not IsArray(array) Then
		ArrayDimension=0
		Exit Function
	End If

	On Error ErrSubscriptOutOfRange GoTo RESULT
	Dim d As Integer, lb As Integer
	For d=1 To 9
		lb=LBound(array, d)
	Next

RESULT:
	ArrayDimension=d-1
	Exit Function
End Function

返回多维数组的大小，即全部元素的个数。

Function ArraySize(array As Variant) As Integer
	If Not IsArray(array) Then
		ArraySize=0
		Exit Function
	End If

	ArraySize=1
	Dim d As Integer
	d=ArrayDimension(array)
	Dim i As Integer
	For i=1 To d
		ArraySize=ArraySize*(UBound(array, i)-LBound(array,i)+1)
	Next
End Function

推断两个数组的“形状”。也就是维数和每一维的上下限是否相同。这个函数在今后比較数组是否相等时实用。

Function ArrayBoundsEquals(a1 As Variant, a2 As Variant) As Boolean
	If (Not IsArray(a1)) Or (Not IsArray(a2)) Then
		ArrayBoundsEquals=False
		Exit Function
	End If

	Dim d1 As Integer, d2 As Integer
	d1=ArrayDimension(a1)
	d2=ArrayDimension(a2)
	If d1<>d2 Then
		ArrayBoundsEquals=False
		Exit Function
	End If

	Dim d As Integer
	For d=1 To d1
		If LBound(a1)><LBound(a2) Or UBound(a1)><UBound(a2) Then
			ArrayBoundsEquals=False
			Exit Function
		End If
	Next

	ArrayBoundsEquals=True
End Function

将多维数组转换成一维数组。这个函数相同用于比較两个数组是否相等。

Function ArrayToOneDimension(array As Variant) As Variant
	If Not IsArray(array) Then
		Call SetValue(ArrayToOneDimension, array)
		Exit Function
	End If

	Dim d As Integer
	d=ArrayDimension(array)
	If d=1 Then
		ArrayToOneDimension=array
		Exit Function
	End If

	Dim size As Integer
	size=ArraySize(array)
	Dim result() As Variant
	ReDim result(size-1)
	Dim i As Integer
	ForAll e In array
		result(i)=e
		i=i+1
	End ForAll

	ArrayToOneDimension=result
End Function