ifstate | Manage host interface settings in a declarative manner | Networking library

The first issue I see is that there is no visitReturnStatement in your Visitor class.

This method would need to be responsible for pulling the return value from the result of visiting its expr() child and getting it's value.

The more interesting issue is that you might be anywhere within the functionDeclaration's statementBlock child sub-tree when the return is encountered. However, whenever it's encountered, it needs to "return" immediately from the function, without bothering with any more of the logic in the statementBlock.

Off hand, a fairly simple solution it to use exception handling for this (even though it's not really an exception, you need the "jump out of here up to the first place that's ready to handle me" behavior that exceptions do well).

If you set up something like a FunctionReturnResultException that has a Value member in it's definition, you could wrap your code to evaluate the statements in the statement block in visitFunctionCall:

Getting this right is surprisingly difficult, so I've tried to annotate the steps. There are a lot of annoying details.

At its core, this is just a manifestation of the dangling else ambiguity, whose resolution is pretty well-known (force the parser to always shift the else). The solution below resolves the ambiguity in the grammar itself, which is unambiguous.

The basic principle that I've used here is the one outlined several decades ago in Principles of Compiler Design by Alfred Aho and Jeffrey Ullman (the so-called "Dragon book", which I mention since its authors were recently granted the Turing award precisely for that and their other influential works). In particular, I use the terms "matched" and "unmatched" (rather than "open" and "closed", which are also popular) because that's the way I learned it.

It is also possible to solve this grammar problem using precedence declarations; indeed, that often turns out to be much simpler. But in this particular case, it's not easy to work with operator precedence because the relevant token (the else) can be preceded by an arbitrary number of newline tokens. I'm pretty sure you could still construct a precedence-based solution, but there are advantages to using an unambiguous grammar, including the ease of porting to a parser generator which doesn't use the same precedence algorithm, and the fact that it is possible to analyze mechanically.

The basic outline of the solution is to divide all statements into two categories:

• "matched" (or "closed") statements, which are complete in the sense that it is not possible to extend the statement with an else clause. (In other words, every if…then is matched by a corresponding else.) These
• "unmatched" (or "open") statements, which could have been extended with an else clause. (In other words, at least one if…then clause is not matched by an else.) Since the unmatched statement is a complete statement, it cannot be immediately followed by an else token; had an else token appeared, it would have served to extend the statement.

Once we manage to construct grammars for these two categories of statement, it's only necessary to figure out which uses of statement in the ambiguous grammar can be followed by else. In all of these contexts, the non-terminal statement must be replaced with the non-terminal matched-statement, because only matched statements can be followed by else without interacting with it. In other contexts, where else could not be the next token, either category of statement is valid.

So the essential grammar style is (taken from the Dragon book):

(Still... not a Python programmer)

This took quite a bit of hacking around on my part just to pick up modifications. (For example, on my system, scripts/antlr4.sh (BTW, docs say script/antlr4, so... off to a great start.) doesn't execute properly)

That said, in the solidity_antlr4 directory is a parser.py source file.

It is missing a visitThrowStatement method.

I added:

Usually you would do this with an "embedded" action:

Found what was happening! both (input)="textinputreceived($event)" and (keydown.enter)="sendTextMessage($event)"> trigger a 'enter press', so in debug mode, enterpress get registered, text cleared, message send. If not in debug the enterpress is probably registered after the field has been cleared, hence the whitespace.

simple solution: event.preventDefault() on both methods!

You should write it this way:

This is `r if(nrow(Data)>1000) {"higher than"} else if (nrow(Data) <900) {"lower than"} else {"similar to"}` previous years response levels.

You don't need a print statement.

The solution with print doesn't work because print(x) shows the x in console and returns x invisibly.

If you want to use print in your solution but you want to make it work, you need to apply (...) parentheses around your if-statement so to force visibility on invisible returns. Check out ?invisible if you don't know what it means.

This is how to get your expected result retaining the print function:

This is `r (if(nrow(Data)>1000) {print("higher than")} else if (nrow(Data) <900) {print("lower than")} else {print("similar to")})` previous years response levels.

I write software for HTML Scraping. My tools are for generating translations of foreign news-services. This is being mentioned to explain the background information in this answer - so you may understand where HTML Scrape is most useful, and when it is better avoided (and likely inefficient and 'kind of' unnecessary).

In cases where a REST API is provided, it almost always "wiser" to use the REST API. This Wikipedia Article about REST API's contains this below copied (cut and paste) description of what they are. Almost all of the REST's that I have seen or read about provide JSON as a response to a web-server query.

Web service APIs that adhere to the REST architectural constraints are called RESTful APIs.[14] HTTP-based RESTful APIs are defined with the following aspects:[15]

• a base URI, such as http://api.example.com/collection/; standard HTTP methods (e.g., GET, POST, PUT, PATCH and DELETE);
• a media type that defines state transition data elements (e.g., Atom, microformats, application/vnd.collection+json,[15]:91–99 etc.).
• The current representation tells the client how to compose requests for transitions to all the next available application states. This could be as simple as a URI or as complex as a Java applet.[16]

Generally understanding how to use a JSON API requires using one of two different JSON Parser's that Java has at its disposal. One of them is buried in the javax.json package hierarchy-tree, and the other is in the android.JSON development platform package. Either one is will help you parse the responses to REST API's, and those are nearly always better than trying to run Java-Script on web-sites that are filled with Java-Script.

Here are the documentation sites for JSON Parsing - again Java has two that are popularly used:

• javax.json (Old Java Package)
• org.json (Newer, for Android)

I mention the HTML Parser I use precisely because I try to explain that there are circumstances where the only way to obtain the data one needs is by HTML Parsing (and even Java-Script execution), however, when an actual API is provided to the "Internet at Large" it is much better to use those instead.

A quick search on Google reveals dozens of REST API's for BitCoin Traders - and experimenting with parsing those responses using either of the JSON libraries I have mentioned would be smarter. These links were copied directly from entering "BitCount REST API" into the Google Search Bar

• Blockchain.com
• rest.bitcoin.com
• coindesk.com

The page you are trying to scrape using Selenium is one of the more complicated Java-Script / AJAX laden pages I have seen. It might be difficult for Selenium to execute that script easily. I have been wrong many times in my life, but I thought I might suggest using a different Web URL for BitCoin Prices

This looks like Eclipse bug 564329 which is marked as fixed in Eclipse core 4.17 M1 (Milestone 1). So this fix will be in the 2020-09 release scheduled for September 2020.

###object###.constructor.name does the trick, however, ive heard minifying may cause issues with this. Then cast itself as whatever it is so intellisense works