error_handler
Default System Error Handler
The error handler module defines what happens when certain types of errors occur.
Functions
undefined_function(Module, Function, Args) -> term()
Module = Function = atom()
Args = [term()]
Arg1,..,ArgN
This function is evaluated if a call is made to
Module:Function(Arg1,.., ArgN)
and
Module:Function/N
is undefined. Note that
undefined_function/3
is evaluated inside the process
making the original call.
If Module
is interpreted, the interpreter is invoked
and the return value of the interpreted
Function(Arg1,.., ArgN)
call is returned.
Otherwise, it returns, if possible, the value of
apply(Module, Function, Args)
after an attempt has been
made to autoload Module
. If this is not possible, the
call to Module:Function(Arg1,.., ArgN)
fails with
exit reason undef
.
undefined_lambda(Module, Fun, Args) -> term()
Module = Function = atom()
Args = [term()]
Arg1,..,ArgN
This function is evaluated if a call is made to
Fun(Arg1,.., ArgN)
when the module defining the fun is
not loaded. The function is evaluated inside the process
making the original call.
If Module
is interpreted, the interpreter is invoked
and the return value of the interpreted
Fun(Arg1,.., ArgN)
call is returned.
Otherwise, it returns, if possible, the value of
apply(Fun, Args)
after an attempt has been made to
autoload Module
. If this is not possible, the call
fails with exit reason undef
.
Notes
The code in error_handler
is complex and should not be
changed without fully understanding the interaction between
the error handler, the init
process of the code server,
and the I/O mechanism of the code.
Changes in the code which may seem small can cause a deadlock
as unforeseen consequences may occur. The use of input
is
dangerous in this type of code.