SysError

Usage

use SysError;

or

import SysError;

This module helps handle system errors.

This module defines the type syserr, which can encode an error code or error message and be returned from routines generating an error. Additional routines are provided to print a useful error message from a syserr.

The IO module uses these routines in a way that supports error inspection and rapid prototyping. Most routines in the IO module have two forms. In one form, a SystemError is thrown when an error occurs. In the second form, a syserr is returned in an out error argument.

class SystemError: Error

SystemError is a base class for Errors.Error s generated from syserr. It provides factory methods to create different subtypes based on the syserr that is passed.

var err: syserr

var details: string

proc init(err: syserr, details: string = "")

override proc message()

Provides a formatted string output for SystemError, generated from the internal err and the details string.

proc type fromSyserr(err: syserr, details: string = "")

Return the matching SystemError subtype for a given syserr, with an optional string containing extra details.

Arguments

• err – the syserr to generate from

• details – extra information to include with the error

proc type fromSyserr(err: int, details: string = "")

Return the matching SystemError subtype for a given error number, with an optional string containing extra details.

Arguments

• err – the number to generate from

• details – extra information to include with the error

class BlockingIOError: SystemError

BlockingIOError is the subclass of SystemError corresponding to SysBasic.EAGAIN, SysBasic.EALREADY, SysBasic.EWOULDBLOCK, and SysBasic.EINPROGRESS.

proc init(details: string = "", err: syserr = EWOULDBLOCK: syserr)

class ChildProcessError: SystemError

ChildProcessError is the subclass of SystemError corresponding to SysBasic.ECHILD.

proc init(details: string = "", err: syserr = ECHILD: syserr)

class ConnectionError: SystemError

ConnectionError is the subclass of SystemError that serves as the base class for all system errors regarding connections.

proc init(err: syserr, details: string = "")

class BrokenPipeError: ConnectionError

BrokenPipeError is the subclass of ConnectionError corresponding to SysBasic.EPIPE and SysBasic.ESHUTDOWN.

proc init(details: string = "", err: syserr = EPIPE: syserr)

class ConnectionAbortedError: ConnectionError

ConnectionAbortedError is the subclass of ConnectionError corresponding to SysBasic.ECONNABORTED.

proc init(details: string = "", err: syserr = ECONNABORTED: syserr)

class ConnectionRefusedError: ConnectionError

ConnectionRefusedError is the subclass of ConnectionError corresponding to SysBasic.ECONNREFUSED.

proc init(details: string = "", err: syserr = ECONNREFUSED: syserr)

class ConnectionResetError: ConnectionError

ConnectionResetError is the subclass of ConnectionError corresponding to SysBasic.ECONNRESET.

proc init(details: string = "", err: syserr = ECONNRESET: syserr)

class FileExistsError: SystemError

FileExistsError is the subclass of SystemError corresponding to SysBasic.EEXIST.

proc init(details: string = "", err: syserr = EEXIST: syserr)

class FileNotFoundError: SystemError

FileNotFoundError is the subclass of SystemError corresponding to SysBasic.ENOENT.

proc init(details: string = "", err: syserr = ENOENT: syserr)

class InterruptedError: SystemError

InterruptedError is the subclass of SystemError corresponding to SysBasic.EINTR.

proc init(details: string = "", err: syserr = EINTR: syserr)

class IsADirectoryError: SystemError

IsADirectoryError is the subclass of SystemError corresponding to SysBasic.EISDIR.

proc init(details: string = "", err: syserr = EISDIR: syserr)

class NotADirectoryError: SystemError

NotADirectoryError is the subclass of SystemError corresponding to SysBasic.ENOTDIR.

proc init(details: string = "", err: syserr = ENOTDIR: syserr)

class PermissionError: SystemError

PermissionError is the subclass of SystemError corresponding to SysBasic.EACCES and SysBasic.EPERM.

proc init(details: string = "", err: syserr = EPERM: syserr)

class ProcessLookupError: SystemError

ProcessLookupError is the subclass of SystemError corresponding to SysBasic.ESRCH.

proc init(details: string = "", err: syserr = ESRCH: syserr)

class TimeoutError: SystemError

TimeoutError is the subclass of SystemError corresponding to SysBasic.ETIMEDOUT.

proc init(details: string = "", err: syserr = ETIMEDOUT: syserr)

class IOError: SystemError

IOError is the subclass of SystemError that serves as the base class for all errors regarding inputs and their formatting. They are typically not directly generated by the OS, but they are used and emitted by the IO module.

proc init(err: syserr, details: string = "")

class EOFError: IOError

EOFError is the subclass of IOError corresponding to SysBasic.EEOF.

proc init(details: string = "", err: syserr = EEOF: syserr)

class UnexpectedEOFError: IOError

UnexpectedEOFError is the subclass of IOError corresponding to SysBasic.ESHORT.

proc init(details: string = "", err: syserr = ESHORT: syserr)

class BadFormatError: IOError

BadFormatError is the subclass of IOError corresponding to SysBasic.EFORMAT.

proc init(details: string = "", err: syserr = EFORMAT: syserr)

proc ioerror(error: syserr, msg: string, path: string, offset: int(64)) throws

Create and throw a SystemError if an error occurred, formatting a useful message based on the provided arguments. Do nothing if the error argument does not indicate an error occurred.

Arguments

• error – the error code

• msg – extra information to include in the thrown error

• path – optionally, a path to include in the thrown error

• offset – optionally, an offset to include in the thrown error

Throws

SystemError – A subtype is thrown when the error argument indicates an error occurred

proc ioerror(errstr: string, msg: string, path: string, offset: int(64)) throws

Create and throw an IOError and include a formatted message based on the provided arguments.

Arguments

• errstr – the error string

• msg – extra information to print after the error description

• path – a path to print out that is related to the error

• offset – an offset to print out that is related to the error

Throws

IOError – always throws an IOError

proc errorToString(error: syserr): string

Convert a syserr code to a human-readable string describing the error.

Arguments

error – the error code

Returns

a string describing the error