(drracket:modes:add-mode name surrogate repl-submit matches-language) → drracket:modes:mode? name : string? surrogate : (or/c #f (is-a?/c mode:surrogate-text<%>)) repl-submit : (-> (is-a?/c drracket:rep:text%) number? boolean?) matches-language : (-> (or/c #f (listof string?)) boolean?)
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.
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.
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.