🍒 Kunimaro KojoさんEPTヘッズアップ優勝 | ポーカー情報満載のポーカー新聞

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

so hopefully, the higher framework catch these exceptions and restart the process. well, at least, i pca poker 2019 the error handling of erlang.

suppose, the users forget the query parameters.