Racket: execute file and stay in interactive mode - racket

Question

Is there a way from a command line to run Racket file and stay in the interactive mode afterwards?
E.g. same in Python it would be:
python -i <file.py>

Answer 1

Assuming a foo.rkt that's this:
#lang racket
(provide x)
(define x 42)
(define y 4242)
Then you can use -i to specify interactive mode (= REPL), together with -t to require the file:
$ racket -it foo.rkt
Welcome to Racket vX.X.X.
> x
42
> y
y: undefined; ...
> (exit)
Note that y is not bound since it's in the module and not provided out. More likely you want a REPL that is "inside" the foo module, which can be done using enter! to go into the module's namespace, either in the REPL:
$ racket
> (enter! "foo.rkt")
> x
42
> y
4242
> (exit)
or on the command-line, using -e (and also -i to request a REPL):
$ racket -i -e '(enter! "foo.rkt")'
Welcome to Racket vX.X.X.
> x
42
> (+ x 12)
54
> (exit)
xrepl
If you do this a lot, you'll probably like xrepl. In your ~/.racketrc simply add:
(require xrepl)
Now the example becomes:
$ racket
Welcome to Racket vX.X.X.
-> ,en foo.rkt
42
"foo.rkt"> x
42
"foo.rkt"> (+ x 12)
54
"foo.rkt"> ,ex
Aside from ,en, XREPL has a bunch of goodness -- like the prompt indication of the module you're currently in, as well as a bunch of other useful commands:
$ racket
Welcome to Racket vX.X.X.
-> ,h
; Available commands:
; help (h ?): display available commands
; exit (quit ex): exit racket
; cd: change the current directory
; pwd: display the current directory
; shell (sh ls cp mv rm md rd git svn): run a shell command
; edit (e): edit files in your $EDITOR
; drracket (dr drr): edit files in DrRacket
; apropos (ap): look for a binding
; describe (desc id): describe a (bound) identifier
; doc: browse the racket documentation
; require (req r): require a module
; require-reloadable (reqr rr): require a module, make it reloadable
; enter (en): require a module and go into its namespace
; toplevel (top): go back to the toplevel
; load (ld): load a file
; backtrace (bt): see a backtrace of the last exception
; time: time an expression
; trace (tr): trace a function
; untrace (untr): untrace a function
; errortrace (errt inst): errortrace instrumentation control
; profile (prof): profiler control
; execution-counts: execution counts
; coverage (cover): coverage information via a sandbox
; switch-namespace (switch): switch to a different repl namespace
; syntax (stx st): set syntax object to inspect, and control it
; check-requires (ckreq): check the `require's of a module
; log: control log output
; install!: install xrepl in your Racket init file
Emacs
However if you're an Emacs user you might prefer using something like:
Geiser
Quack minor mode for scheme-mode
racket-mode (shameless self-promotion)

Answer 2

If you are using Visual Studio Code as an editor, you may want to use the "Code Runner extension"
make sure it's installed from the vs code marketplace
then enter Preferences: Open Settings (JSON) and past the following:
"code-runner.executorMap": {
"racket": "(exit); racket -i -e '(enter! \"$fileName\")'",
},
You will be able to run directly your file by clicking the Run Code icon or by pressing Ctrl+Alt+N
NB: the same manouvre goes for "scheme" since it's interpreted by racket as well, however putting #lang racket in the top of your file is necessary

Answer 3

It can be done with
racket -if <file.rkt>
However it will not work as expected if the file starts with
#lang racket