Changes from Rockstar 1

In 2024, Rockstar was ported from JavaScript to C#/.NET, so that we could publish native binaries for Windows, Linux and macOS, and a web-based interpreter using WebAssembly.

The old JavaScript interpreter powered by Satriani is still online at old.codewithrockstar.com but all future development will be on the .NET engine, which is codenamed “Starship” for reasons that will become obvious.

Breaking Changes

End blocks with oh, yeah, baby

In Rockstar 1, the only way to end a block was with a blank line, which got very confused if you had loops inside conditionals inside functions inside functions.

In Rockstar 2, you can end a block with the keywords oh, yeah and baby. Ooh ends two nested blocks, oooh ends three nested blocks, and so on.

See flow control: this is the end, oh yeah baby.

End-of-block keywords (EOBs) must either be prefixed with a comma , or appear at the start of a new line.

New pronouns you, i, me

As well as the existing pronouns it, he, she, and so on, Rockstar 2 adds the pronouns you, i and me. Among other things, this will break programs which use i as an index variable in a loop.

Comparisons update the pronoun subject

Consider this program:

My variable is 1
Your variable is 2
If my variable is 1
shout it

In Rockstar 1, it always points at the most recently assigned variable – your variable here – so the program prints 2.

In Rockstar 2, the pronoun subject is also updated whenever a variable is the left-hand side of a comparison expression, so after evaluating if my variable is 1, any pronoun will resolve to my variable, and the program prints 1.

Poetic literals can’t start with an expression keyword.

In Rockstar 1, this:

The heartbreak is with the night 

would initialise The heartbreak with the value 435, by parsing with the night as a poetic literal.

In Rockstar 2, if the right-hand side of an is assignment starts with an expression keyword, it is evaluated as an expression, not as a poetic literal, so The heartbreak is with the night is equivalent to The heartbreak += the night

Expression keywords are:

• Arithmetic operators: plus with minus without times of divided by over
• Logical operators and or not non
• Null literal null nothing nowhere nobody gone
• Boolean literal true yes ok right false no lies wrong
• String literal empty silent silence
• Undefined literal mysterious

Decimal poetic literals - ... replaces .

In Rockstar 2, a single period . followed by a non-period character can be used to indicate the end of a statement, including assigning a poetic literal.

To initialise a decimal poetic literal, use three dots ...or the Unicode ellipsis U+2026 …)

like, so and now

In Rockstar 2, you can use a poetic literal anywhere by prefixing it with the like or so keywords:

Heartbreak is 456
If heartbreak is like such sweet sorrow (hearbreak == 456)
Shout heartbreak, yeah

Ricky is so so wrong
Shout Ricky (prints: 25)

Conversely, you can force the right-hand side of an assignment to be evaluated as an expression by using the now keyword:

My heart is a kaleidoscope lit with dying embers
Whisper my heart (prints: 123456)

The answer is my heart (interprets 'my heart' as a poetic literal)
Whisper it (prints: 25)
The answer is now my heart (interprets 'my heart' as an expression)
Whisper it (prints: 123456)

the world, the outside

In Rockstar 2, the world and the outside always refer to the command-line arguments array, and cannot be reassigned.

New Language Features

Ninja Strings

Rockstar 1 used rock <list> with <value> to append values to a list expression.

In Rockstar 2, rock is overloaded for strings:

• rock <string> with <string> - concatenate strings
• rock <string> with <number> - convert <number> to the corresponding character based on the Unicode code point, and append the result to <string>

The with keyword is optional, so you can just write:

My string is empty
Rock my string 65, 67, 47, 68, 67
Shout my string

and because numbers can be represented with poetic literals using the like keyword, you can build obfuscated strings that don’t appear anywhere in the program source code:

My world is empty
Rock it like guitar shred
Rock it like vocals soaring
Rock it like drum thunder
Rock it like boomin' bassline
Rock it like smooth bourbon 
Shout it

Hence ‘ninja strings’ - because they’re frikkin’ awesome, and you don’t see them coming.

Ending statements with punctuation

In Rockstar 1, the only way to end a statement was with a newline:

Shout 1
Shout 2
Shout 3
Shout 4

In Rockstar 2, you can also end a statement with punctuation marks ., ?, !, ;:

Shout 1! Shout 2. Shout 3? Shout 4; shout 5

Note that you can use a comma , between a statement and and end-of-block keyword oh yeah baby, but a comma does not end a statement.

For-each and for-every loops

Rockstar now supports for each and for every - see looping over arrays.

Strict equality

Rockstar 2 supports strict equality:

if 1 is true shout "yeah" otherwise shout "no" (prints: yeah)
if 1 is really true shout "yeah" otherwise shout "no" (prints: no)

Nested comments

Rockstar 2 can have nested comments (like this (see?))

Arithmetic

Rockstar 1 would return NaN for operations like subtracting or multiplying strings.

Rockstar 2 never returns NaN: every arithmetic operator is defined for any combination of argument types.

shout "rockstar" - "star" (prints: star)
shout "ratskcor" times -1 (prints: rockstar)
shout true / "t" (prints: 1)
shout "ad" times "c" (prints: acdc)

See arithmetic for detailed examples of how various operations apply to various types.

Wildcard keywords

Rockstar 1 used take it to the top as a continue statement, but you might want to take it somewhere else (the limit, perhaps?), so in Rockstar 2, break, take and continue are wildcard keywords; everything up until the next end of statement is ignored.

While true, break me off a piece of chocolate, baby, shout "hello"