catch-me | Catch , display and validate emails | Email library
kandi X-RAY | catch-me Summary
kandi X-RAY | catch-me Summary
Catch, display and validate emails
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of catch-me
catch-me Key Features
catch-me Examples and Code Snippets
Community Discussions
Trending Discussions on catch-me
QUESTION
I'm trying to evaluate arbitrary and nested arithmetic expressions in scheme with eval.
The expressions are build up from numbers, operators, constant bindings and parentheses.
For example, (eval (+ 1 1)) or (eval (+ (* 1 2) 3))
The problem is, the expressions could also have unbalanced parentheses, like
(eval ((+ 1 1)), and the reader in scheme would just wait when the expression is entered
till all parentheses are closed and somehow matched.
I looked into quotation in scheme and by using a try-catch-mechanism in scheme (How to implement a try-catch block in scheme?) - but that didn't work. I'm also thinking about implementing in scheme my own version of an evaluator for arithmetic expressions, maybe with brackets as delimiters.
I search for a way to evaluate arbitrary expressions, and if the expression is not valid, to get an error message like 'not valid expression' from eval, and not have the reader waiting for closing parentheses.
Edit: See below for an implementation of a solution.
...ANSWER
Answered 2020-Oct-26 at 01:42Your strategy will not work. Scheme has "try-catch", but just like "try-catch" in most programming languages, it only works on runtime error (the error that occurs as your program runs). The unbalanced parentheses problem, in contrast, is a syntax error (the error the occurs when reading your program).
For example, in Python, you can write:
QUESTION
I am am using the AxWindowsMediaPlayer control to build a small Windows web radio developed in C#.
This works out well. My StatusChange event handler extracts the name of the current radio station:
ANSWER
Answered 2020-Aug-06 at 06:28There seems to be no easy way to extract SHOUTCast/Icecast meta-data from AxWindowsMediaPlayer.
My solution is to replace AxWindowsMediaPlayer by BASS.NET.
BASS is an audio library wrapped by BASS.NET for .Net usage.
It provides a TAG_INFO class which covers more than enough tags.
Code snippet from a BASS C# sample NetRadio.cs
QUESTION
function fetchDog(){
fetch("https://dog.ceo/api/breeds/image/fail")
.then(response => response.json())
.then(data => console.log(data))
.catch(function(err) {
console.log('Fetch problem');
});
};
fetchDog();
ANSWER
Answered 2020-Jul-20 at 20:28When
catchinvariably receives a fulfilled promise, it returnsundefined?
No. Calling .catch() will always return a promise. It does that before even knowing whether the promise that it was called on is fulfilled, rejected or still pending.
I interpret this to mean
catchreturns a promise whose value isundefined.
Yes. You can test this easily with
QUESTION
I'm learning Promises so that I can understand better before I try to use Firebase. I am new and I've been reading the following in regard to catch():
- Link one: An article with some exercises
- Link two: A question in SO in regard to why we always need a
catch()after Promise chain - Link three: A question in SO in regard to the difference of
catch()andthen()
From what I've read, I have taken the following conclusions:
catch()is necessary at in every Promise chaining in case "unexpected exceptions" occurs. It seems like these "unexpected exceptions" can be detected by thefailureHandlerof mythen. However, it cannot distinguish between "normal failure" from these types of failures. I assume that one of those "unexpected exceptions" is when you're trying to access some property of anullelement.- It seems like I can also do chaining of
then(successHandler, failureHandler)and then proceed with acatch()block to allow finer control, as mentioned in link two. This is useful when I want to do something else when something fails ("normal failure" in this case, not the "unexpected exceptions") and pass the rejected Promise to the nextthento process, thus potentially yielding very different results from the result had the failed part succeeded. I can also catch "unexpected exceptions" by usingcatch()at the end of the chain in case something failed inside mysuccessHandlerorfailureHandler.
As you can see from my conclusions, I have very little understanding of what errors might occur. I mentioned null exception as one of the examples of "unexpected exceptions" (is this assumption even correct?). However, what other errors do failureHandler detect and what other "unexpected exceptions" do catch() detect?
I also mentioned above that [then] cannot distinguish between normal failure from these types of failures. Is that correct? If it is, why is it important?
EDIT
After reading some more, it seems like if a Promise is rejected on the top of the chain, the thens following are ignored and I immediately go to the catch() block. This means that my conclusion above: This is useful when I want to do something else when something fails and pass the rejected Promise to the next then to process is incorrect. If that is the case, if I already have a catch() at the end of my chain, I no longer need a failureHandler for each of my then block. However, it is mentioned in link three:
The argument is that usually you want to catch errors in every step of the processing, and that you shouldn't use it in chains. The expectation is that you only have one final handler which handles all errors - while, when you use the "antipattern", errors in some of the then-callbacks are not handled.
However, this pattern is actually very useful: When you want to handle errors that happened in exactly this step, and you want to do something entirely different when no error happened - i.e. when the error is unrecoverable. Be aware that this is branching your control flow. Of course, this is sometimes desired.
I took my conclusion that the rejected Promise will be passed to the next then to process because I read the above. So what does and you want to do something entirely different when no error happened - i.e. when the error is unrecoverable mean?
ANSWER
Answered 2019-Jun-06 at 11:35From the MDN I understand that there is no real difference between the two methods of declaring the rejection handler.
For success, it's obvious that we will get to the fulfillment handler:
QUESTION
I'm working with Laravel and VueJS and for all of my post and put methods server returns the newly created data after submitting the form, in the case of errors, I cannot access them from the browser console. This is what I can see in the newtwork tab.The purpose is to customize form errors according to errors that is being returned by the server
Here is my backend code :
...ANSWER
Answered 2019-Mar-08 at 09:25Laravel returns the HTTP 422 - Unprocessable Entity when the validations you set fail. In your case I would take a closer look at the data you're posting to the server and manually check if it passes the validation cases you wrote.
To get the exact fields that are causing the error you need to handle this in your code, like this for example:
QUESTION
im working on a assignment where I now have to implement the Try & Catch-method too catch inputs other than numbers in my program. I understand the process and explanations in my study-book and have also done some minor examples while trying it out. But when I want to implement this into my assignment I am getting stuck. Can someone please explain to me in a manor as to not spoil anything but try and help me along the way?
Here is my code:
...ANSWER
Answered 2017-Dec-27 at 12:23There is no required try/catch to check valid input. You could use double.TryParse;
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install catch-me
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page
