[ERLANG37]ERROR/1 exit/1 EXIT/2 THROW/1 the difference

1. ERROR/1

The system is primarily used to define internal errors: There are 10 types of run time error built into Erlang:

Function_clause/case_clause/if_clause/badmatch/badarg/undef/badarith/badfun/badarity/system_limit, For example:          

1> erlang:binary_to_list (1).     * * exception Error:bad argument in       function  binary_to_list/1       called as Binary_to_list (1)

This is triggered by the ERROR/1, we can also manually trigger a bit.

2> Erlang:error (badarg).         * * Exception Error:bad  argument

Note that Erlang directly Badarg this built-in error into a more detailed bad argument,

Further, we can also use ERROR/1 to define our own errors.

3> Erlang:error ("This is my own error").    * * Exception Error: "This is my own error"

This time, the custom error is not recognized by the Erlang shell.

2. EXIT/1 EXIT/2

Exit has the difference between internal exits and external exits, we can use Exit (Pid,reason) to let a process exit.

EXIT/1 and ERROR/1 are very similar, many times can be common, that is, exit context is a withdrawal, more suitable for the process of exit situations, there is a difference is

EXIT/1 does not bring the stack trace information that is called (it is easier for other processes to exit without having to take very large call information, lighter). But ERROR/1 will take.

Catch exit (test).  {' EXIT ', test}catch  error (test).   {' EXIT ', {test,[{erl_eval,do_apply,6,           [{file,' Erl_eval.erl '},{line,674}]},            {Erl_ eval,expr,5,[{file, "Erl_eval.erl"},{line,431}]},            {Shell,exprs,7,[{file, "Shell.erl"},{ line,686}]},            {Shell,eval_exprs,7,[{file, "Shell.erl"},{line,641}]},            {shell,eval_loop, 3,[{file, "Shell.erl"},{line,626}]}]}}

3. THROW/1

THROW/1 It is most commonly used with try...of catch processing nested case (which can jump out quickly) and it carries the least amount of information (a ' EXIT ' less than EXIT/1):

catch throw (+/-). catch 2+24 

The above 2 case catch, can not tell whether the result is a throw out, or normal calculation results, so it is recommended to use try. Reasons for the catch:

Try of 8> V, {OK, v}catch8>  throw:v , {error, v}end . {error,4} 

4. Summary :

Process exits using EXIT/1 or EXIT/2, want to quickly jump out of recursion or jump back to top-level function with THROW/1, try not to use ERROR/1,

If you need to get the stack trace information for the call, you can explicitly call erlang:get_stacktrace () yourself. Gets the stacktrace of the current process when the latest exception.

5. References:

5.1. Erlang Official document:http://erlang.org/doc/reference_manual/errors.html

5.2. Learnyousomeerlang's introduction to Exceptions: http://learnyousomeerlang.com/errors-and-exceptions

[ERLANG37]ERROR/1 exit/1 EXIT/2 THROW/1 the difference