Re: Modifing try-catch statement

[Ted Unangst <ted.unangst@...>]

On Fri, Sep 17, 2010 at 11:28 PM, Quae Quack <quae@daurnimator.com> wrote:
> Looks like you just made xpcall:
>
> xpcall( function()
>    -- try code
>    if getvar() then
>    else
>         error(setmetatable({"an","error","object"},{__type="err"}))
>    end
> end , function ( err )
>    -- catch code, you can dispatch/swicth on err:
>    if (getmetatable(err) or {}).__type == "err" then
>        print(table.concat(err))
>    else --propgate error
>        error(err)
>    end
> end )

Calling error in xpcall results in a stack overflow, because the error
handler is still in effect while it's running.  This is arguably a
bug.  The manual says it calls f in protected mode, but doesn't say
the same about err.