22 drracket:modes

The first argument, name, is the name of the mode, used in DrRacket’s GUI to allow the user to select this mode.

The surrogate argument is set to the definitions text and the interactions text (via the mode:host-text set-surrogate<%> method) whenever this mode is enabled.

The repl-submit procedure is called whenever the user types a return in the interactions window. It is passed the interactions editor and the position where the last prompt occurs. If it returns #t, the text after the last prompt is treated as a program fragment and evaluated, according to the language settings. If it returns #f, the text is assumed to be an incomplete program fragment, and the keystroke is not treated specially.

The matches-language predicate is called whenever the language changes. If it returns #t this mode is installed. It is passed the list of strings that correspond to the names of the language in the language dialog.

The intended-to-edit-programs? boolean indicates if this mode is intended to be for editing programs (as opposed to some other kind of file content). If it is #f, online expansion is disabled and DrRacket won’t look for (module at the front of the buffer to try to guess the intended filename.

Modes are tested in the opposite order that they are added. That is, the last mode to be added gets tested first when the filename changes or when the language changes.

See also drracket:modes:get-modes.

Note that the surrogate field of the mode corresponding to the module language does not take into account the definitions-text-surrogate, so it may not be the actual class used directly in DrRacket, even when the mode is active.

See also drracket:modes:add-mode.