A Fortran language anticipation and prompting system

An experimental interactive system has been developed on an intelligent terminal which accepts only syntactically correct Fortran statements and otherwise assists the user in preparing Fortran programs. Whenever possible the system anticipates the syntax of statements which is implied by an initial input and supplies the general form of the statement directly beneath the line on which input is being accepted. In some cases (the function heading) decisions are inverted from the language and in others (statement numbers) inputs are automatically positioned. In general, only syntax within the statements is checked, but some global checking (multiple main programs) is performed. Alternate forms of statements are often displayed with the unwanted ones being eliminated as entries are made. The techniques used demonstrate pedagogic as well as productive potential.