Error.Last

OpenTuring

Error.LastPart of Error module

Syntax   Error.Last : int

Description   Error.Last is a function that returns the error code set by the last called predefined subprogram. If there is no error, then it returns eNoError (which is 0). If there is an error, you can use Error.LastMsg to obtain a textual form of the error or Error.LastStr to obtain a string version of the error constant.

The fact that Error.Last is not eNoError does not necessarily mean that the previous predefined function failed or failed completely. Error.Last also returns a number of warning codes. For example, if a user specifies a number larger than maxcolor for the color parameter of the Draw.Line procedure, the line is still drawn, only in color maxcolor. However, Error.Last will return a code that warns the user of the fact.

Example   This program creates the directory called information. If the creation fails, it prints out the error number and an error message.

        var f : int
        open : f, "testdata/information.txt", get
        if f <= 0 then
            put "File opened"
        else
            put "Could not open file."
            put "Error Number: ", Error.Last
            put "Error Message: ", Error.LastMsg
            put "Error Constant: ", Error.LastStr
        end if

Execute  

Status   Exported qualified.

This means that you can only call the function by calling Error.Last, not by calling Last.