(no subject)

[vlion]

The well-known QUIKTRAN system is based on interpretation of FORTRAN statements. The FORTRAN program under debugging may be modified freely by insertion and deletion of statements. A form of nonconditional breakpoint capability is included in the sense that a statement can be inserted at any point in the program which, when reached, has the effect of transferring control to the user. Capability for examining and modifying variables is present, as well as a variety of modes of tracing (print all assignments to variables in a given portion of the program, all assignments to selected variables, all control transfers within a specified region, etc.). Furthermore, extensive run-time diagnostics made possible by the interpretive mode are provided, and several unusual "bookkeeping" features, similarly based on interpretation, are available, such as the AUDIT command, which generates information as to which portions of the program were never executed, which variables were never set, or set but never used, during a given execution of the program.

from Evans and Darley, AFIPS 1966