Console
I can't enter the print statement.
It can't be used in nested structures. Use it at the top level instead.
How can I enter more the one statement into the console?
Enter an opening curly brace (starts a new statement list in baselanguage) and enter your statements.
How can I find all System.out.println statements?
#nodes,#models, #usages etc. don't show any result. What did I do wrong
Make sure that your query is correct. You also have to set I scope for these statements in square brackets such as #nodes<scope = global> to find all the nodes in the global scope.
Is the console a regular root node?
Yes, it is of concept ConsoleRoot and is located in a temporary model. It is possible to open it in a normal tab. Right click in the console (for example at the top) and click "Show Node in Explorer". Click the ConsoleRoot and it will open in a new tab (Keyboard shortcuts such as run line won't work here).
After executing the current line I get an error that the console class was not found?
This can happen when the compilation of the model of the console was not successful. It can happen if you import a custom generation plan into the console that disables some generators. It can also happen if you import a solution that doesn't has the Java Facet checked or has a different solution kind such as "Other".
What does the expression #internalMode do?
It tells you if the internal mode is activated which can be achieved by calling RuntimeFlags.setInternalMode(true) or by setting a system variable. The exact functionality of this flag can be found by looking at the MPS source code. One of the new action groups that it adds, is called Internal. There is also an Internal Actions Menu in Intellij IDE's. Consolute the documentation for more info.