IntelliJ IDEA 2017.2 Help

Working with Type-Aware Highlighting

The following is only valid when Scala Plugin is installed and enabled!

Scala type-aware highlighting lets you get an error analysis based on the Scala type system before you start the compilation process.

Enabling or Disabling Type-Aware Highlighting on the Project Level

  • Enable or disable the type-aware highlighting for your project by clicking type aware highlighting icon or T disabled icon on the status bar. You can also use the Ctrl+Shift+Alt+E shortcut.
    T toolbar

Enabling or Disabling Type-Aware Highlighting on the File Level

  • Open the file and on the status bar click hector Hector icon. If you disable Hector, then the type-aware highlighting will also be disabled. Each time you enable or disable the type-aware highlighting, you can see the notification of the status's change in the Event log.

Working with Type-Aware Highlighting in Editor

  • Let's see how it works:
    T editor highlighting
    As you can see, the expression is wrong and the value is highlighted.
    If the type-aware highlighting is disabled, the error is not highlighted and it might be quite difficult to spot:
    T when disabled
  • You can also enable the highlighting based on expression type inference.
    Consider the following example:
    T editor function highlighting
    As the pop-up message suggests, the expression type is wrong and is highlighted.

Disabling Type-Aware Highlighting Locally

  • Highlight the code and on the main menu select Code | Surround With.
  • When Surround With window opens, select the / * _ * /.../ * _ * / option from the list.
    T surround with action
    After you've selected the appropriate option your code looks like this:
    T surround with action result
    As a result, the error is not highlighted.
Last modified: 29 November 2017