octagon | Semantic-UI-React Themed Component Library | User Interface library

I am not sure exactly what you are trying to do but why not have an if condition around the NavigationLink

You don't need to use filter on a CoreData FetchRequest ever.

It is best to do the filtering by NSPredicate

https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CoreData/index.html

But in this case all the user's friends are in a variable. If you have the individual user all you need to do is something like this...

A possible approach would involve the calculation of some blob descriptors and filter blobs according to those properties. For example, you can compute the blob's aspect ratio, the (approximated) number of vertices and area. The steps are very straightforward:

1. Load the image and convert it to grayscale.
2. (Invert) Threshold the image. Let’s make sure the blobs are colored in white.
3. Get the binary image’s contours.
4. Compute two features: aspect ratio and number of vertices
5. Filter the blobs based on those features

Let’s see the code:

Say you have your data in dat, then:

It seems you are simply replacing repeatedly the content of your error message display area: the

You want to show possibly messages A, B, and C. Instead of writing the three messages on the same display area, like A B C

You write A, then erase it and write B, then erase it and write C. So you see only C.

When you add a debugger; line, you see the newly placed content, before it gets erased and replaced by a new content. But when you remove it, the content is immediately replaced by a new one, hence your problem.

If you want to see all possible messages, each message should not replace the previous one, but be added at a list of message.

Since you are showing a modal, you should first get all the messages to be displayed, add them to your display element, and at the end show your modal.

But I don't think that using a Modal for form validation is a good idea. You should probably have a look at client side form validation best practices, and see if what you are trying to achieve is not already supported by a library, like jquery-validate.

Just to give you a rough idea of what could correct your code: (not tested). I would not personnaly use this.

The modal HTML

In order to simply not allow a new routine until the previous one has finished simply introduce a bool flag

You could try a list comprehension with a generator:

Looking at the traceback, Line 186 ("/Users/halled/Documents/polys.py") seems to be the problem.

This is not the sort of problem for which you would typically use (f)lex, since the base lexical analysis is trivial (it could be done by simply splitting the line at the space) and detailed error analysis is a bit outside of (f)lex's comfort zone, specifically because there's no way to match "a string containing the same character twice" using a regular expression.

Still, as shown by the question asked by one of your classmates, it can be done with (f)lex by taking advantage of the scanner's ordering rules:

1. Always use the longest possible match.
2. If two or more rules would qualify, choose the first one.

That doesn't get around the question of duplicate characters. The only way to solve that is to enumerate all possibilities, of which there are eight in this case. A simpler way of doing that than that proposed in the linked question is [A-H]*A[A-H]*A[A-H]*|[A-H]*B[A-H]*B[A-H]*|[A-H]*C[A-H]*C[A-H]*....

That let's you create an ordered set of rules something like this:

1. Match lines with duplicate characters
2. Match lines with too many characters
3. Match lines with exactly the right number of characters
4. Anything else is an error. (Too few characters, invalid shape name, invalid letter, etc.)

So that might include this (leaving out the definitions of the two macros, which is straightforward but tedious):