A worksheet is a Scala file that is evaluated on save, and the result of each expression is shown in a column to the right of your program. Worksheets are like a REPL session on steroids, and enjoy 1st class editor support: completion, hyperlinking, interactive errors-as-you-type, etc. Worksheet use the extension
The only supported client for the Worksheet mode is Visual Studio Code.
To use the worksheets, start Dotty IDE by following the instruction and create a new file
MyWorksheet.sc and write some code:
val xyz = 123 println("Hello, worksheets!") 456 + xyz
On top of the buffer, the message
Run this worksheet appears. Click it to evaluate the code of the worksheet. Each line of output is printed on the right of the expression that produced it. The worksheets run with the classes of your project and its dependencies on their classpath.
By default, the worksheets are also run when the file is saved. This can be configured in VSCode preferences:
Note that the worksheet are fully integrated with the rest of Dotty IDE: While typing, errors are shown, completions are suggested, and you can use all the other features of Dotty IDE such as go to definition, find all references, etc.
The implementation details of the worksheet mode and the information necessary to add support for other clients are available in Worksheet mode - Implementation details.