2 Running Top-Level Programs

To run a top-level program, either:

• Use the plt-r6rs executable, supplying the file that contains the program on the command line:

    plt-r6rs ‹program-file›

  Additional command-line arguments are propagated as command-line arguments to the program (accessed via command-line).

  To compile the file to bytecode (to speed future runs of the program), use plt-r6rs with the --compile flag:

    plt-r6rs --compile ‹program-file›

  The bytecode file is written in a "compiled" sub-directory next to ‹program-file›.

  For example, if "hi.sps" contains

  (import (rnrs))

  (display "hello\n")

  then

    plt-r6rs hi.sps

  prints “hello.”

• Prefix the program with #!r6rs, which counts as a comment from the R6RS perspective, but is a synonym for #lang r6rs from the Racket perspective. Such files can be run like any other Racket module, such as using racket:

    racket ‹program-file›

  or using DrRacket. The file can also be compiled to bytecode using raco make:

    raco make ‹program-file›

  For example, if "hi.sps" contains

  #!r6rs

  (import (rnrs))

  (display "hello\n")

  then

    racket hi.sps

  prints “hello.” Similarly, opening "hi.sps" in DrRacket and clicking Run prints “hello” within the DrRacket interactions window.