robinson | A toy web rendering engine

Think of the brackets syntax [] for the destructing operation as an index to a property of an object, not an array that you pass in. It's analogous to calling for example obj["a"] vs obj.a to access the a field on obj.

So knowing this, you need to pass in 3 arguments to extract the values that you want to remove. For null and undefined I had to put them in separate variables, it wasn't working when putting them directly in the brackets:

As per this github issue, this is expected behaviour since PlateCarree is a projected coordinate system.

The PlateCarree coordinate system is Cartesian where a line between two points is straight (in that coordinate system). The Cartesian system has no knowledge of datelines/antimeridians and so when you ask for a line between -170 and +170 you get a line of length 340. It can never be the case that the PlateCarree projection interprets these numbers and chooses to draw a non-cartesian line

One solution is to use the Geodetic transform in your plot calls:

You're so close!

Group is an int (int group = row.getInt("Group");), not a String, hence the conditions will look like:

The easiest way is to use pandas directly:

This might be because you are not returning anything from the pizzaMenu.render() function.

I have changed your code a little bit to make it work.

Check out this repl I made https://replit.com/@beesperester/RichBelovedApplicationstack

app.js

Because the addValueFactory and updateValueFactory delegates are invoked by the ConcurrentDictionary without any locks, it is possible for another thread to change the contents of the dictionary whilst the add/updateValueFactory code is running. To deal with this scenario, if the addValueFactory was invoked (because the key didn't exist in the dictionary) it will only add the returned value if the key still doesn't exist in the dictionary. Similarly if the updateValueFactory was invoked, it will only update the value for the key if the current value is still oldValue.

If there's a mismatch as a result of another thread adding/updating/deleting the same key while the add/updateValueFactory code was running, it will simply try invoking the appropriate delegate again based on the latest contents of the dictionary (the delegates aren't "interrupted", and it's the dictionary itself that calls them again the value for the key being added/updated has changed). This explains why you still need the success = false assignments within the lambdas, even though success is initialized to false. The following example might help visualize the behavior:

Initial dictionary state: _stock["X"] = 1

Step Thread 1 Thread 2 1 Calls _stock.AddOrUpdate("X", ...) 2 updateValueFactory invoked (oldValue = 1) 3 Calls _stock.AddOrUpdate("X", ...) 4 updateValueFactory invoked (oldValue = 1) 5 Sets success = true, returns oldValue - 1 = 0 6 Dictionary checks that the value for key "X" is still = 1 (true) 7 Value for key "X" is updated to 0 8 Sets success = true, returns oldValue - 1 = 0 9 Dictionary checks that the value for key "X" is still = 1 (false) 10 updateValueFactory invoked again (oldValue = 0) 11 Sets success = false, returns 0 12 Dictionary checks that the value for key "X" is still = 0 (true) 13 Value for key "X" is updated to 0 14 Final value of success is false Final value of success is true

Note that without the explicit setting of success = false within the oldValue == 0 branch of the if, Thread 1 would've thought that it had still successfully sold the item, even though there was no longer any stock because Thread 2 sold the last one.

The technique in your question therefore works as intended.

Negative lookaheads may be a solution.

The following replaces sequences of a single . with .\n but only when it's not followed by any of . or new line (\n), and not followed by an end-of-sequence ($):

A new state in the SelectItem component is not needed.

The value or defaultValue must be an object from the list that is used for options.

Here's the updated CSB.

As the check is fairly complex I would recommend braking it out into a separate paragraph coded somethin like: