BUG: Rhombus CLI flags (`-e`, `-f`) fail with syntax errors when using `racket -I rhombus`

[sohang3112]

When invoking Rhombus via the Racket CLI wrapper (racket -I rhombus), interaction flags like -e (eval) and -f (load file) fail with syntax errors. The CLI passes expressions directly to Racket's default #%top-interaction macro instead of routing them through Rhombus's parser.

Additionally, the interface mimics standard Racket too closely without actual support:

• The welcome banner incorrectly reads Welcome to Racket instead of Welcome to Rhombus.
• The --help output is identical to racket --help, listing numerous options (like -e, -f, -t) that are currently broken or unsupported under -I rhombus.

Steps to Reproduce

1. Evaluating any expression (-e) fails:

$ racket -I rhombus -e '"Hello, World"'
#%top-interaction: bad syntax
  in: #{(#%top-interaction . "Hello, World")}
  context...:
   /usr/racket/collects/syntax/parse/private/runtime-report.rkt:744:0: error/report
   /usr/racket/collects/syntax/parse/private/runtime-report.rkt:25:0: call-current-failure-handler

2. Running a script also fails (any file, even a simple file with only #lang rhombus and nothing else):

$ racket -I rhombus -f test.rhm
/home/sohang/a.rkt:1:6: #%top-interaction: expected one of these literal symbols: `multi' or `group'
  at: module
  in: #{#%top-interaction} module a #{(lib "rhombus/main.rhm")} #{(#%module-begin (multi (group "Hello, World!")))}
  location...:
   a.rkt:1:6
  context...:
   /usr/racket/collects/syntax/parse/private/runtime-report.rkt:744:0: error/report

Note: The only working CLI mechanism currently is launching the interactive REPL raw via racket -I rhombus with no trailing execution flags).

[mflatt]

The -I flag affects binding, but it cannot affect the reader aspect of racket for flags like -e and -f. That is, the problem is not with #%top-interaction, but with the use of read that's behind -e and -f.

The intent is that you use the rhombus executable for a task like -e, as in rhombus -e '"Hello, World"'.

If you want to run a module, though, don't use -f or -I with racket. Just provide the module to racket, or use -t if you want to be explicit: racket test.rhm or racket -t test.rhm. The -f flag for Racket is more or less a holdover from traditional Scheme/Lisp approaches. The rhombus executable treats -f more like -t, since that's more useful with Racket/Rhombus.

[mflatt]

P.S. — I will update the Rhombus Guide, because I can see how it would give the impression that racket -I is a synonym for rhombus.

[sohang3112]

Thanks @mflatt - -e (eval) and -t (run file) are working with rhombus executable, but running script + interactive mode isn't working (i.e. REPL after script runs).

Here I just put #lang rhombus in the script and tried running it interactively, but any code isn't working in REPL after script is done running:

$ rhombus -i -t /path/to/script.rkt           # same as: racket -i -t /path/to/script.rkt
> "Hello, World!"
#%top-interaction: unbound identifier;
 also, no #%app syntax transformer is bound
  at: #{#%top-interaction}
  in: #{#%top-interaction} multi "Hello, World!"
 [,bt for context]

[mflatt]

The interaction of -i and -t is indeed a bug, and I'll push a repair. It happens that it works as you'd expect without -t, though (i.e., the problem is specific to -t and -f).

[sohang3112]

The interaction of -i and -t is indeed a bug, and I'll push a repair. It happens that it works as you'd expect without -t, though (i.e., the problem is specific to -t and -f).

Interactive mode with file doesn't seem to be working even with just -i FILENAME (without -t, -f). This happened when I tried with a similar #lang racket code so not Rhombus specific.

I put this Rhombus code in a file:

#lang rhombus
println("Hello, World!")
def x = 0

After running with -i the print (hello world) did not run and x also doesn't seem to be defined. But at least Rhombus code works in the REPL after that:

$ racket -i rhombus_racket_language.rkt      # alternative: rhombus -i rhombus_racket_language.rkt
Welcome to Racket v9.2 [cs].
> x
x: undefined;
 cannot reference an identifier before its definition
  in module: top-level
 [,bt for context]
> println "working"
#<procedure:println>
"working"

Importing a script in Rhombus REPL has mixed result - Hello World (from code in script) gets printed, but x doesn't get defined and a further println directly in REPL fails with a weird error:

$ rhombus
Welcome to Rhombus v0.47
> import:
    file("rhombus_racket_language.rkt") open
    
Hello, World!
> x
x: undefined;
 cannot reference an identifier before its definition
  in module: top-level
 [,bt for context]
> 1+1
2
> println "working"
string:1:0: println: misplaced expression;
 the identifier is not bound as a macro, and no infix operator appears afterward
  in: println
  bound in spaces:
   expressions, definitions, and declarations
   space with path rhombus/statinfo
 [,bt for context]

[mflatt]

Sorry — I was confused, and you're right that -i without -t does not load a module provided as an argument, since -i is not merely a "configuration argument". The repair for -t will be available in a new build soon.

The reason x isn't accessible after importing the module is that bindings must be explicitly exported to make them available outside of the defining module. Adding export: x or using export def x = 0 would make the binding visible. Also, println is a function in Rhombus, so println("working") would print.