kandi X-RAY | rascal Summary
kandi X-RAY | rascal Summary
This is the core implementation of the Rascal meta-programming language. It contains the interpreter, the parser generator, the parser run-time, the standard library, the online documentation and the type checker. Rascal is used in practice, but we consider it to be alpha software because we are still improving the language. For questions use the rascal tag on StackOverflow.
Top functions reviewed by kandi - BETA
- Visits a catch clause
- Visit an AnnotationTypeDeclaration node
- Visit a Block
- Visit an ImportDeclaration node
- Visit this node
- Visit a wildcard
- Visit a type parameter
- Visit a Switch Statement
- Visit a single variable declaration
- Visit a NormalAnnotation node
- Visit a Try Statement
- Visit a ParameterizedType
- Visit an array creation
- Visit a field
- Processes the package declaration
- Visit a SuperMethodInvocation node
- Visit InfixExpression
- Visit a VariableDeclarationStatement
- Visit a VariableDeclarationExpression
- Visits an enum constant
- Visit a constructor call
- Visit a compilation unit
- Visit a SuperConstructorInvocation node
- Visit a For Statement
- Visit a method declaration
- Visit a type declaration
- Visit an enum declaration
- Visit a ClassInstanceCreate
- Visit an AnnotationTypeMemberDeclaration node
- Visit an ArrayInitializer node
- Visits a ConditionalExpression
rascal Key Features
rascal Examples and Code Snippets
Trending Discussions on rascal
I am trying to add instrumentation (e.g. logging some information) to methods in a Java file. I am using the following Rascal code which seems to work mostly:...
ANSWERAnswered 2021-Dec-17 at 13:13
Alas, capturing whitespace with a concrete pattern is not a feature of the current version of Rascal. We used to have it, but now it's back on the TODO list. I can point you to papers about the topic if you are interested. So for now you have to deal with this "damage" later.
You could write a Tree to Tree transformation on the generic level (see ParseTree.rsc), to fix indentation issues in a parse tree after your transformation, or to re-insert the comments that you lost. This is about matching the Tree data-type and
appl constructors. The Tree format is a form of reflection on the parse trees of Rascal that allow any kind of transformation, including whitespace and comments.
The parse error you talked about is caused by not using the
start non-terminal. If you use
parse(#start[CompilationUnit], ...) then whitespace and comments before and after the CompilationUnit are accepted.
I am executing a command in Rascal on Windows 10 (some batch file) which in itself works fine:...
ANSWERAnswered 2021-Dec-12 at 14:36
The working dir parameters is a so called "keyword parameter" which you call using this syntax:
I'm using the
eval function to evaluate an abstract list pattern against a list and it keeps coming up with an Undeclared Variable error. Below is included a small reproducible example.
ANSWERAnswered 2021-Sep-01 at 11:55
evalis not an often used function in Rascal; do you really need to dynamically create patterns?
- there is the node pattern:
(str name)()which in this case would match any constructor with no arguments
- the real answer is that if you do
importthe right modules in the call to
evalthose modules will be cached by the interpreter which is used by the
- so that would not be slow
- however, module reloading is not well-supported and you might have to restart the shell to get a fresh version into the eval evaluator.
I'm trying to create an outline for a syntax definition I create in rascal. I've managed to make the various object appear in the outline by simply adding label annotations like recommended in the documentation. However, I would also like to "categorise" these objects so that all the objects of the same type end up under a common collapsible category. Like the way that Rascal's outline is with all the annotations, functions, variables, tests and so on sorted into their own categories. I haven't found anything really in the documentation about it. I've tried applying @Category to the syntax and to the AST, neither really worked...
ANSWERAnswered 2021-Aug-13 at 17:24
You can nest nodes like so:
I have this syntax definition...
ANSWERAnswered 2021-Jul-16 at 09:33
Turns out I was overcomplicating the whole thing. Instead of trying to have a union of types I simply added an additional construction to RULEPART that could accommodate COMMAND. I think I might have been also initially confused about some of the issues because I had bugs in other parts of the code that I was misinterpreting as being caused by this problem.
I'm attempting to create a Socket library in Rascal to operate a Java TCP socket class. For this the following basic setup is used: (src)>(Network)>(Socket.java, Socket.rsc) : https://i.stack.imgur.com/a66RS.png
When attempting to import the Network::Socket module into a Rascal Terminal the following error occurs: "Cannot link method Network.Socket because: class not found"
The Rascal module:...
ANSWERAnswered 2021-Jul-05 at 13:39
The fault laid in some metadeta of the eclipse project being faulty.
Creating a new project with the exact same setup and files made it work.
Edit: Believed cause of error is renaming the project
When defining a syntax, it is possible to match 1 or more times (+) or 0 or more times (*) similarly to how it is done in regex. However, I have not found in the rascal documentation if it is possible to also match a Symbol a specific amount of times. In regex (and Rascal patterns) this is done with an integer between two curly brackets but this doesn't seem to work for syntax definition. Ideally, I'd want something like:...
ANSWERAnswered 2021-Jun-13 at 10:25
No this meta syntax does not exist in Rascal. We did not add it.
You could write an over-estimation like this and have a post-parse filter reject more than 5 items:
I want to show the data of table in a form for updating it.
So I'm using this code :...
ANSWERAnswered 2021-May-26 at 13:56
You can give classes to your
p tags inside your
card .Then , whenever user click on
edit simply use
.find() to get values from
p tags and show them inside modal inputs .
Demo Code :
How can I create a set containing a loc, int and string? In the example below it seems my map is converted to the container type ' value'. I would like to use the characteristics of a set; Only one element should be contained in the set and the order does not matter . In the example below the same elements are contained in what I was hoping to be a set....
ANSWERAnswered 2021-Jan-06 at 14:04
Something weird is going on . First mySet is a map, and then you add a set to it and the variable
mySet is suddenly a set that contains the previous map and the new element you added. It looks to me that
+= has a bug.
If you want to add several elements to a set, you should start with a set and add elements to it like so:
In java I would use: System.getProperty("os.name") to get Java to return the operating system. Is something similar possible in Rascal? My goal is to write a method to write text files to a folder that works OS-independent. Something like;...
ANSWERAnswered 2020-Dec-23 at 17:03
If you just use a home URL like
home:///path/to/file the writeFile function will take care of the rest. There is also
cwd:// for the current working directory and
tmp:/// for the temp folder.
No vulnerabilities reported
You can use rascal like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the rascal component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .
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