Array Subroutines

Public Low As Single
Public High As Single

' Filters source array with predicateName.
Public Function Where(source() As Variant, predicateName As String) As Variant()
    Const PredicateNameIsEmpty As Integer = 513

    If predicateName = "" Then
        Call Err.Raise(PredicateNameIsEmpty, "predicateName", _
            "empty predicate name can't be used")
    End If

    Dim Result() As Variant

    Dim isFirst As Boolean
    isFirst = True
    For i = 0 To UBound(source)
        Dim suites As Boolean
        suites = Application.Run(predicateName, source(i))
        If suites Then
            If isFirst Then
                ReDim Preserve Result(0)
                isFirst = False
            Else
                ReDim Preserve Result(UBound(Result) + 1)
            End If
            Result(UBound(Result)) = source(i)
        End If
    Next i
    Where = Result
End Function

' Converts array to string.
Public Function ArrayToString(source() As Variant, Optional delimiter As String = ", ", _
    Optional startDelimiter As String = "[", Optional endDelimiter As String = "]")
    Dim Result As String
    Result = startDelimiter
    On Error Resume Next
    If UBound(source) >= LBound(source) Then
        For Each Item In source
            Result = Result & CStr(Item) & delimiter
        Next
    End If
    ArrayToString = Left(Result, Len(Result) - Len(delimiter)) & endDelimiter
End Function

Public Function IsGreaterZeroPredicate(value As Single) As Boolean
    IsGreaterZeroPredicate = value > 0
End Function

Public Function IsLessZeroPredicate(value As Single) As Boolean
    IsLessZeroPredicate = value < 0
End Function

Public Function IsInRangePredicate(value As Single) As Boolean
    IsInRangePredicate = value >= Low And value <= High
End Function