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Rocky - Rockstar Java interpreter

Rocky is a 100% Rockstar compatible RockStar Interpreter, written in Java. Have fun and play with it! I like to receive feedbacks, should you have any issues, requests, wishes or troubles, open a ticket for it and I'll help you to resolve.

Features include:

  • Fully compliant Rockstar implementation to date (all of the new test are OK, except the reported bugs)
  • Advanced Debugger mode (Step into/over/return/run, Breakpoints, watches, examine variable, trace expression evaluation!)
  • Interactive terminal mode (REPL - Read - Eval - Print Loop)
  • List command (parse a file without running it)
  • Detailed help with options explanation
  • IEEE754 maths (double precision), or optionally Dec64 (with option --dec64)

It requires at least Java8 JRE to run. The rockstar.bat and rockstar wrappers make it easy to execute on Windows and Unix.


To install and run, you only need the ./rocky.jar file, and one of the wrappers (rockstar.bat or rockstar, depending on your OS). Everything else is for development.

There are some Rockstar program in the programs folder and its subfolders, you may want to check them, too. They're mostly for test purposes, though.


To run a program, it's simple:

$ ./rockstar programs/modulus.rock 
Enter Dividend:
Enter Divisor:
The modulus is 2

To list (and parse) a program, try list (note, that it is the parsed version, with indentations, to help better understanding. Whitespaces do not count in Rockstar)

$ ./rockstar list programs/modulus.rock

  Modulus takes Number and Divisor
    Put Divisor into Big Divisor
    While Big Divisor is less than Number
      Put Big Divisor times 2 into Big Divisor

    While Big Divisor is as high as Divisor
      If Number is as high as Big Divisor
        Put Number minus Big Divisor into Number

      Put Big Divisor over 2 into Big Divisor

    Give back Number

  say "Enter Dividend:"
  Listen to X
  say "Enter Divisor:"
  Listen to Y
  say "The modulus is " with Modulus taking X and Y

Time to get acquainted with Rockstar? Try the REPL (interactive) mode, start Rockstar with - option:

$ ./rockstar -
Rockstar Java by gaborsch, Version 0.99
Type 'exit' to quit, 'show' to get more info.
> My name is Gabor
> What's your name?
> Say my name
> show var
what = 44
my name = 5
> exit

There are other possibilities as well, like debug mode (detailed description coming soon) or help for each command:

$ ./rockstar help
Rockstar Java by gaborsch, Version 0.99
rockstar <filename> ...
rockstar run [--options ...] <filename> ...
    Execute a program. Input is taken from standard input, output is printed to standard output.
rockstar debug [--options ...] <filename> ...
    Debug a program interactively. Stop at breakpoints, lines, display and watch variables.
rockstar list [--options ...] <filename> ...
    Parse and list a program. Useful for syntax checking.
rockstar - [<filename> ...]
rockstar repl [<filename> ...]
    Start an interactive session (Read-Evaluate-Print Loop). Enter commands and execute them immediately.
    The specified programs are pre-run (e.g. defining functions, etc). Special commands are available.
rockstar test [--options ...] <file-or-dirname> ...
    Execute unit tests. Special rules apply, check `rockstar help test` for details
rockstar [-h|--help]
rockstar help
    Print this help.
rockstar help <command>
    Print more detailed help about the given command.

Each command has a more detailed help with options, so try rockstar help run, rockstar help debug, rockstar help repl, etc.

Test results

100% of the tests have passed! With some buggy test cases fixed locally ( and ), everything works!

$ ./rockstar test programs/tests/ -v
PARSE_ERROR tests in programs/tests/failures
   [ OK ] invalid_comments.rock
CORRECT tests in programs/tests/fixtures/assignment
   [ OK ] compound_assignments.rock
   [ OK ] lets.rock
CORRECT tests in programs/tests/fixtures/comments
   [ OK ] complex_comments.rock
   [ OK ] simpleComments.rock
   [ OK ] simple_comment.rock
CORRECT tests in programs/tests/fixtures/conditionals
   [ OK ] empty_if.rock
   [ OK ] simpleConditionals.rock
   [ OK ] truthinessTest.rock
CORRECT tests in programs/tests/fixtures/constants
   [ OK ] constants.rock
CORRECT tests in programs/tests/fixtures/control-flow
   [ OK ] nested_loops.rock
   [ OK ] simpleLoops.rock
CORRECT tests in programs/tests/fixtures/equality
   [ OK ] booleans.rock
   [ OK ] equalityComparison.rock
   [ OK ] mysterious.rock
   [ OK ] negation.rock
   [ OK ] nothing.rock
   [ OK ] null.rock
   [ OK ] numbers.rock
   [ OK ] strings.rock
CORRECT tests in programs/tests/fixtures/examples
   [ OK ] 99_beers.rock
   [ OK ] factorial.rock
   [ OK ] fibonacci.rock
   [ OK ] fizzbuzz-idiomatic.rock
   [ OK ] fizzbuzz-minimalist.rock
CORRECT tests in programs/tests/fixtures/functions
   [ OK ] functionCalls.rock
   [ OK ] nested_functions.rock
   [ OK ] nested_function_scopes.rock
   [ OK ] recursion.rock
   [ OK ] simpleFunctions.rock
CORRECT tests in programs/tests/fixtures/io
   [ OK ] hello_number.rock
   [ OK ] hello_world.rock
   [ OK ] inputTest.rock
   [ OK ] inputTest2.rock
CORRECT tests in programs/tests/fixtures/literals
   [ OK ] literalAliases.rock
   [ OK ] literalstrings.rock
   [ OK ] poeticLiterals.rock
   [ OK ] poeticNumbers.rock
CORRECT tests in programs/tests/fixtures/math
   [ OK ] operators.rock
   [ OK ] operator_aliases.rock
   [ OK ] operator_precedence.rock
CORRECT tests in programs/tests/fixtures/operators
   [ OK ] addOperator.rock
   [ OK ] andTest.rock
   [ OK ] booleans.rock
   [ OK ] divisionOperator.rock
   [ OK ] incrementAndDecrement.rock
   [ OK ] list_expressions_arithmetic.rock
   [ OK ] multiplicationOperator.rock
   [ OK ] notTest.rock
   [ OK ] orderingComparison.rock
   [ OK ] orNorTest.rock
   [ OK ] subtractOperator.rock
CORRECT tests in programs/tests/fixtures/variables
   [ OK ] common_variables.rock
   [ OK ] globalVariables.rock
   [ OK ] poeticStrings.rock
   [ OK ] pronouns.rock
   [ OK ] proper_variables.rock
   [ OK ] simple_pronouns.rock
   [ OK ] simple_variables.rock
   [ OK ] umlauts.rock
CORRECT tests in programs/tests/fixtures/whitespace
   [ OK ] apostrophesIgnored.rock
   [ OK ] leading_blank_lines.rock
   [ OK ] leading_empty_lines.rock
   [ OK ] leading_whitespace.rock
   [ OK ] no_newline_at_eof.rock
   [ OK ] trailing_blank_lines.rock
   [ OK ] trailing_empty_lines.rock

Test results for programs/tests/:
All tests:    67
Failed tests: 0
Passed tests: 67
Pass ratio:   100.00%

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