Install Guide

Installation

macOS

brew install flipez/homebrew-tap/rocket-lang

APT

echo "deb [trusted=yes] https://apt.rocket-lang.org/ /" > \
/etc/apt/sources.list.d/fury.list

RPM

[fury]
name=RocketLang Repo
baseurl=https://rpm.rocket-lang.org
enabled=1
gpgcheck=0

Manual

Download from releases.

There is also a Visual Studio Code Extension available. Just search for rocket-lang in the extension menu.

Running a program

rocket-lang program.rl        # run a file
rocket-lang -e 'print("hi")'  # run the code given
rocket-lang                   # start the REPL

Exit codes

👉 Before 0.24 everything exited 0, including a crash

	Exit code
the program ran	0
an error nothing handled	1
the program did not parse	1
the file could not be read	1
OS.exit(n)	n

So rocket-lang build.rl && deploy.sh no longer runs the deploy after a crash.

An error the program handles is not a failure — begin/rescue succeeding exits 0, and so does a conversion answering nil, which is what nil is for:

begin
  1 / 0
rescue e
  print("handled")
end
# exits 0

Diagnostics — a parse error, an unreadable file, an uncaught error — go to standard error. Only the program's own output goes to standard output: a script does not print the value it ends on, unlike the REPL, which echoes it.