after-delete in drscheme:unit:program-editor-mixin

Called after a given range is deleted from the editor (and after the display is refreshed; use on-delete and begin-edit-sequence to avoid extra refreshes when after-delete modifies the editor).

See also can-delete? and on-edit-sequence.

No internals locks are set when this method is called.

• (send a-drscheme:unit:program-editor-mixin after-delete start len void
     start : number
     len : number

  Calls the super method.

  Resets an error highlighting.