type Tristate = num

/// Tristate Constants
declare {
    // True
    const vbTrue: Tristate = -1

    // False
    const vbFalse: Tristate = 0

    // Use default from computer's regional settings.
    const vbUseDefault: Tristate = -2
}

// Returns an expression formatted as a currency value using the currency symbol defined in the system control panel.
declare fn FormatCurrency(
    // Expression to be formatted.
    Expression: num,
    NumDigitsAfterDecimal?: num,
    IncludeLeadingDigit?: Tristate,
    UseParensForNegativeNumbers?: Tristate,
    GroupDigits?: Tristate
) -> String

// Returns an expression formatted as a date or time.
declare fn FormatDateTime(Date: Date, NamedFormat: DateFormat = vbGeneralDate) -> Date

// Returns an expression formatted as a number.
declare fn FormatNumber(Expression: num, NumDigitsAfterDecimal: num = -1, IncludeLeadingDigit: Tristate, UseParensForNegativeNumbers: Tristate, GroupDigits: Tristate) -> num

// Returns an expression formatted as a percentage (multiplied by 100) with a trailing % character.
declare fn FormatPercent(Expression: num, NumDigitsAfterDecimal: num = -1, IncludeLeadingDigit: Tristate, UseParensForNegativeNumbers: Tristate, GroupDigits: Tristate) -> str