Undocumented? socket:connect throws an error on failure about cqueues HOT 3 CLOSED

Yes, this is an unfortunate early design decision and I'd like to change it eventually. Along with returning (return-value, error-string, error-code) instead of (return-value, error-code).

Every socket has an error handler. The default error handler will throw an error for everything except EPIPE and ETIMEDOUT. The idea was that errors would be thrown, except that EPIPE and ETIMEDOUT weren't errors and would usually be handled inline. This is described in the socket:onerror method documentation, and the introduction section on Errors also has a blurb about it (I should make it more explicit). I now find the current default behavior really quite annoying. The original impetus--keep applications from accidentally ignoring errors--is no longer relevant, because errors are repeated until cleared, and will eventually throw after a user-defined count of unsuccessful operations if the error hadn't been cleared.

You can change the current behavior by changing the default error handler using socket.onerror, which is a method on the prototype singleton. All subsequent sockets will then use that error handler.

from cqueues.

Thanks for the note; I didn't realise that was what socket.onerror was for.

This seems a much more reasonable default (at least to me):

local cqueues_socket = require "cqueues.socket"
local cqueues_errno = require "cqueues.errno"
-- Change default error handler to *not* throw.
cqueues_socket.onerror(function(sock, func, errno, level)
    local msg = cqueues_errno.strerror(errno)
    return msg, errno
end)

from cqueues.

On Wed, Oct 22, 2014 at 09:41:30AM -0700, daurnimator wrote:

Thanks for the note; I didn't realise that was what socket.onerror was for.

This seems a much more reasonable default (at least to me):

-- Change default error handler to *not* throw.
cqueues_socket.onerror(function(sock, func, errno, level)
  local msg = cqueues_errno.strerror(errno)
  return msg, errno
end)

I agree it makes more sense. Eventually I want to have a flag day where I
change the default to the above, not just for sockets but for all modules.
But that'll require some planning and a careful refactoring of everything,
including making it easy to get the old behavior, as there's too much code
in production at this point.

FWIW, auxlib.fileresult will convert the existing return values to the more
idiomatic Lua return values.

I've opened two new issues to fix this stuff. You can keep #8 open if you
want.

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