🍒 Value News – Luttons Contre la Violence de toute Sorte

but what if the caller want to deal with the error? it can be done by case expression or function. but i feel some oddities on erlang's exception and that is the concept of class. it's too verbose and ugly but i think alternatives are worse. well, it's not bad. we have to use the patter match for the conditional execution. the erlang has three class of exception: error, exit, and throw. suppose, the users forget the query parameters. you can use try expression or catch expression try expression is strightforward, if you ignore the awkward erlang grammer that is. whichever you use, it became quite verbose and boilar-plate. but if you care, that is, you want to run some code on the condition of exception, things get verbose. walkthrough of hello world http server with erlang, cowboy, and rebar3 instead of returning the hello world, we're going to return the sum of two query parameter a, b. but i want to deal the the error. another type of error is although the query paramters are present, it has a string that cannot be parsed as an integer. try expression can have of section and it will be evaluated only on no exception in exprs. well, at least, i understand the error handling of erlang.{/INSERTKEYS}{/PARAGRAPH} putting it all togather, it's very verbose to handle errors in erlang. catch exprs catch expression evaluate exprs and return its value on no exception. we can do condional branching with either case expression or function pattern match. the simplest code that assume no error will be like this. {PARAGRAPH}{INSERTKEYS}so hopefully, the higher framework catch these exceptions and restart the process. erlang has exception like many other langauges. for exceptions of class throw, that is the code called throw term , term is returned. after consdering the various code, i come up with this code. if you don't care about exception, you need to do nothing. use try expression's of section to pattern match the error value. here is the verbose code. the catch expression. my guess is to keep the backward compatibility. let's quickly borrow a code from the hello world http server i explained in the previous article.