From my extension, how can I access the abstract syntax tree that VS Code has for the active file? I have been looking through the API docs but haven't been able to find anything. I also came across this SO question but both the question and answer are pretty opaque to me.
There's no thing like a common AST for files loaded into an editor. In fact, many file aren't even parsed at all, unless an extension is installed which does that.
The linked answer describes a way to implement language support (via a language server), which is not the same as getting a fictional AST from vscode.
Related
I'm looking to improve my own productivity by trying to figure out how to provide cmd+click functionality for variables declared at runtime. I work with a library that allows you to register objects to it at runtime to be accessed later — it would be great if I could cmd+click to definitions of these! How do you think I could achieve this? I'm open to any ideas. Thanks!
Edit:
Thoughts I have so far inspired by feedback from various Slack communities:
There is no such thing as 'runtime' when providing functionality in IDEs
We need to be able to teach the IDE about what definitions to expect. Whether this means writing an extension to use the VS Code API specifically for my use-case, or otherwise working within a system that generates files that the IDE already knows to look for, which allows it to connect the dots and provide the precious peek / goto definition functionality
Edit:
I'm starting work on a VS Code extension that reads a dotfile for configuration — I'll share what I find out as I go!
Is it possible to write an extension which will do code analysis? I looked at the api and I didnt see how I can get all variables that are declared in the document/xref on specific variable and get it flow in the code. If someone know api in visual studio code which actually helps with it, it will be great.
Creating such an extension is certainly possible, however you have to do your own language processing. AFAIK there's no way to access the internal structures (syntax tree, symbol table etc.) of the existing JS/TS (or other language for that matter) extensions.
I did my best to overcome this problem but it was in vain. I am developing tests in Robot Framework (RF) in Visual Studio Code and I want it to either show "signatures" of keywords from standard libraries or to be able to go to their definitions. Go to definition and signature displaying when hovering with Ctrl key are behaving this way:
works for my keywords written in RF (hoorah!)
works for my keywords written in Python only if a keyword consists of one word (I think conversion between undescores and spaces is failing)
does not work for keywords from standard libraries even if the keyword is one-word (e.g. "Fail"), regardless whether the keyword comes from built-in libraries or other ones (e.g. SeleniumLibrary)
When failing, Robot Framework Intellisense Server gives me message "Keyword definition 'Blah Blah' not found from the workspace".
I am using plugins Robot Framework Intellisense FORK and/or Robot Framework Language Server. I tried to configure them carefully according their documentation (Details), but the best state I reached is described above.
Can you help me please? I do not need to use a specific plugin, I just need to have the signature or documentation (or implementation) of every keyword in my code to be one click far.
According to their documentation they support
Goto definition
For variables
For user keywords
I was able to partially solve this when I not only open the folder with source code, but create a workspace and add the folder containing standard libraries to it as well (Add Folder to Workspace). I do not know exactly which folder is the best to add, it seems ...\Python\Python37\Lib\site-packages\ to me.
I am totally new to creating extensions in VS Code, and all the official examples of extensions are written in Typescript/Javascript, which I have no experience with. Is it possible to create VS Code extensions in other languages, such as Python or C++?
If so, could anyone point me to any resources to get me started?
It is possible by creating a C++ module for Node.js, which can then be loaded like any other node module. Of course, some glue code written in JS or TS is necessary to register the extension and translate calls to/from vscode.
I've gone this way in my ANTLR4 extension, but gave up eventually, because of the troubles I had due to incompatible dependencies (you have to make sure the extension uses the exact same V8 version, which was used to build the underlying Node.js used by vscode, on all supported platforms).
This situation might have change, I don't know, but with that in the background I don't recommend it.
If you want to add support for a new language in vscode you can also write a separate language server, as is mentioned in the linked SO answer. For other type of work, I'm afraid, you have no alternative to use.
No, as #rioV8 said, since VSCode is an electron app and runs on Javascript.
I am creating an Eclipse plug-in for it to support a new language. The problem I have is with the content type/file association and its respective editor.
The language has no base in Java or XML and let's say its extension is '.xyz'
From what I understood of research online, I would need to create a new Content Type with file extension '.xyz'. But all the information I have found online has related to either associating a new extension with java (for java syntax highlighting) or creating a new type of file which can be a variant of XML, hence having a lot of details about the describer.
Basically, I am confused about the content describer, am I also to create a new describer for a new language? And what base-type would I give for a language not related to XML or JAVA at all?
Also, since I will be adding my own syntax highlighting, would I need to create my own editor or can I just open such a file in the pre-set editorArea (editors).
The package I am looking at for content types is org.eclipse.core.contenttype.contentTypes.
I realised that I never really picked an answer for this question and eventually I found some useful information on it, so I thought I would share it.
This is the information I understood and used; I apologize if there are any errors or I have misunderstood, and I am open to any corrections.
It was actually a lot simpler than I expected.
To create a new file extension, you just need to extend
org.eclipse.core.contenttype.contentTypes
If you are using the PDE, then you can just right click on the extension (once it is added in the extensions tab) and choose New... -> content-type
Here is the xml code for it,
<extension
id="com.newLanguage.XYZ.contentType"
point="org.eclipse.core.contenttype.contentTypes">
<content-type
file-extensions="xyz,xyzz"
id="com.newLanguage.XYZ.contenttypeMod"
name="XYZ File"
priority="normal">
</content-type>
</extension>
Here you can set the properties of this content-type by defining a unique id, a human-readable name and the extension. You can also give multiple extensions for this content type. For example, my XYZ language can have 2 types of extension '.xyz, and '.xyzz'.
The content describer comes in when I have one generic file-extension: '.xy' but the content or format of the file may differentiate and so I need a describer for the editor to be able to go through the content of the file and recognize the difference. This is handy for syntax highlighting where I need to know the differences.
Since I am not very good at explaining this, this link was extremely useful to me.
But all in all, this tutorial is what set me on my pace and has actually taken me far in understanding how to implement an IDE plug-in for Eclipse. I think it is a very ideal place to start, especially for someone new.
Another place that kept my work going is the Eclipse FAQs but I would specifically like to point out to section 3.5 Implementing Support for Your Own Language which has many tutorial links.
Note: this (new language support, custom syntax highlighting, ...) is the kind of feature provided with XText.
Xtext - Language Development Framework
With Xtext you can easily create your own programming languages and domain-specific languages (DSLs).
The framework supports the development of language infrastructures including compilers and interpreters as well as full blown Eclipse-based IDE integration.
Since the sources are available, you might have a lots of clues to illustrate the usage of the packages you are currently looking.