Awesome
UPDATE 2018-07-31
Hey rockstar developers.
So... this thing has completely exploded. 3,000+ stars, half-a-dozen implementations, loads of issues and ideas and PRs. It is AMAZING and you are all wonderful. Only problem is... I'm in the middle of moving house right now so I'm going to have to put the whole thing on hold for a week or two. Doesn't mean it's dead - there's loads of really cool stuff still to come. But please, hang in there for a couple of weeks whilst I pack my life into a few dozen small boxes and lug it halfway across London.
By all means keep filing issues and opening PRs. But don't get discouraged if they don't get an immediate response.
Rock on. \m/
@dylanbeattie
Rockstar
Rockstar is a dynamically typed Turing-complete programming language.
Rockstar is designed for creating computer programs that are also song lyrics, and is heavily influenced by the lyrical conventions of 1980s hard rock and power ballads.
But why?
Mainly because if we make Rockstar a real (and completely pointless) programming language, then recruiters and hiring managers won't be able to talk about 'rockstar developers' any more.
Also 'cos it's kinda fun and any language based on the idea of compiling Meatloaf lyrics has to be worth a look, right?
Also we can make stickers. Who doesn't want a sticker on their laptop saying 'CERTIFIED ROCKSTAR DEVELOPER'?
The Rockstar Language Specification
Rockstar is intended to give the programmer an unprecedented degree of poetic license when it comes to the composition and structure of their programs.
File format
Rockstar programs are UTF-8 files with the .rock
file extension. (Given that for everything included in the current Rockstar specification, UTF-8 is indistinguishable from 7-bit ASCII, that's a fancy way of saying they're plain text files.)
Comments
The use of comments in Rockstar programs is strongly discouraged. This is rock'n'roll; it's up to the audience to find their own meaning. If you absolutely insist on commenting your Rockstar programs, comments should be contained in parentheses (). Yes, this means you can't use brackets in arithmetic expressions and may need to decompose complex expressions into multiple evaluations and assignments.
Rockstar developers are not into that whole brevity thing.
Tommy was a lean mean wrecking machine. (initialises Tommy with the value 14487)
Variables
There's two ways to declare and use variables in Rockstar.
Common variables consist of one of the keywords a
, an
, the
, my
or your
followed by a unique variable name, which must contain only lowercase ASCII letters a-z.
Proper variables are proper nouns - any word that isn't a reserved keyword and starts with an uppercase letter. Proper variable names can contain spaces as long as each space is followed by an uppercase letter. Whilst some developers may use this feature to create variables with names like Customer ID
, Tax Rate
or Distance In KM
, we recommend you favour idiomatic variable names such as Tommy
, Gina
, Doctor Feelgood
, Mister Crowley
, Kayleigh
, Tom Sawyer
, Billie Jean
and Janie
.
(Although not strictly idiomatic, Eleanor Rigby
, Peggy Sue
, Black Betty
, Layla
and Johnny B Goode
would also all be valid variable names in Rockstar.)
As in Ruby, Python and VBScript, variables are dynamically typed and you don't need to declare variables before use.
Pronouns
The keywords it
, he
, she
, him
, her
, they
, them
, ze
, hir
, zie
, zir
, xe
, xem
, ve
, and ver
refer to the last named variable determined by parsing order.
(Please don't file issues pointing out that 80s rockers were a bunch of misogynists and gender-inclusive pronouns aren't really idiomatic. You're right, we know, and we've all learned a lot since then. Besides, Look What The Cat Dragged In was recorded by four cishet guys who spent more money on lipgloss and hairspray than they did on studio time, and it's an absolute classic.)
Types
Rockstar uses a very similar type system to that defined by the ECMAScript type system, except undefined
doesn't sound very rock'n'roll so we use mysterious
instead.
- Mysterious - the value of any variable that hasn't been assigned a value, denoted by the keyword
mysterious
- Null - the null type. Evaluates as equal to zero and equal to false. The keywords
nothing
,nowhere
,nobody
,empty
andgone
are defined as aliases fornull
- Boolean - a logical entity having two values
true
andfalse
. (The keywordsmaybe
anddefinitely maybe
are reserved for future use) right
,yes
andok
are valid aliases fortrue
wrong
,no
andlies
are valid aliases forfalse
- Number - Numbers in Rockstar are stored using the DEC64 numeric type.
- String - Rockstar strings are sequences of 16-bit unsigned integer values representing UTF-16 code units.
- Object - a collection of named data properties, as in ECMAScript.
Literals and Assignment
String literals in Rockstar use double quotes.
"Hello San Francisco"
Numeric literals in Rockstar are written as decimal numbers
123
3.141592654
Assignment is denoted by the put/into
keyword combination:
Put 123 into X
will assign the value123
to the variableX
Put "Hello San Francisco" into the message
will assign the value"Hello San Francisco"
to the variablethe message
Single Quotes
Given Rockstar's intriguing ancestral mixture of computer programming, creative English and idiomatic rock'n'roll, the single quote character presents all sorts of challenges.
Most programming languages use the single quote for quoting literal strings - 'like this'
. English, when written using the basic ASCII character set, often uses the single quote to stand in for the apostrophe to denote contractions or possessives - you're, she's, he's, shouldn't, rock'n'roll
. Rock'n'roll uses the apostrophe apparently at random - sweet child o' mine
, ain't talkin' 'bout love
, guns n' roses
.
Given three such dramatically different influences, here's how Rockstar interprets single quotes.
- The sequence
's\W+
- a single quote followed by a lowercase 's' and one or more whitespace characters - should be replaced withis
(space, is, space)
- This allows
Janie's got a gun
(initialisesJanie
with the value313
) andUnion's been on strike
(initialiseUnion
with the value426
) as valid variable declarations.
- All other single quotes are then ignored.
ain't
is equivalent toaint
,wakin'
has five letters, and'''''
is equal to the empty string. This means you can use single quotes freely throughout your program to punctuate, adjust word lengths and generally channel the spirit of rock'n'roll without worrying about compiler errors.
Increment and Decrement
Increment and decrement are supported by the Build {variable} up
and Knock {variable} down
keywords.
Build my world up
will increment the value stored inmy world
by 1.Knock the walls down
will decrement the value stored inthe walls
by 1
Arithmetic
Basic arithmetic is provided by the plus
, minus
, times
and over
keywords.
Arithmetic expressions:
{a} plus {b}
- addition. Aliaswith
{a} minus {b}
- subtraction. Aliaswithout
{a} times {b}
- multiplication. Aliasof
{a} over {b}
- division. Aliases TBC.
The alias by
has been explicitly rejected because of disagreements between the colloquial English ten by four
(i.e. 10*4 = 40
) and ten (divided) by four
(i.e. 10/4 = 2.5
)
Examples:
-
Put the whole of your heart into my hands
- multiplyyour heart
bythe whole
and assign the result tomy hands
-
My world is nothing without your love
- Initializemy world
with the result of subtractingyour love
from 0 -
If the tears of a child is nothing
- check whetherthe tears
*a child
= 0 -
My heart over the moon
- Returnsmy heart
divided bythe moon
Poetic Literals
Rockstar also supports a unique language feature known as poetic literals. Inspired by the here-document syntax supported by many scripting languages, poetic literals allow the programmer to simultaneously initialize a variable and express their innermost angst.
Poetic Type Literals
For the keywords true
, false
, nothing
, nobody
and nowhere
, a poetic assignment is a single line consisting of a variable name, the is
keyword and the required value literal
My heart is true
- initialises the variablemy heart
with the Boolean valuetrue
Tommy is nobody
- initialises the variableTommy
with the valuenull
using thenobody
alias
Poetic String Literals
A poetic string literal assignment starts with a variable name, followed by one of the keywords says
followed by a single space. The rest of the line up to the \n
terminator is treated as an unquoted string literal.
Peter says Hello San Francisco!\n
will initialise the variablePeter
with the string literal"Hello San Francisco!"
San Francisco says Hello back\n
will initialise the variableSan Francisco
with the string literalHello back
Poetic Number Literals
A poetic number literal begins with a variable name, followed by the keyword is
, or the aliases was
or were
. As long as the next symbol is not a reserved keyword, the rest of the line is treated as a decimal number in which the values of consecutive digits are given by the lengths of the subsequent barewords, up until the end of the line. To allow the digit zero, and to compensate for a lack of suitably rock'n'roll 1- and 2-letter words, word lengths are parsed modulo 10. A period (.) character denotes a decimal place. Other than the first period, any non-alphabetical characters are ignored.
Tommy was a lovestruck ladykiller
initialisesTommy
with the value100
Sweet Lucy was a dancer
- initialisesSweet Lucy
with the value 16A killer is on the loose
- initialisesa killer
with the value 235.My dreams were ice. A life unfulfilled; wakin' everybody up, taking booze and pills
- initialisesmy dreams
with the value3.1415926535
- Note that poetic literals can include reserved keywords, as with
taking
in this example. - The semi-colon, comma, apostrophe and any other non-alphabetical characters are ignored.
Comparison
Similar to the single-equals operator in Visual Basic and some scripting languages, the is
keyword in Rockstar is interepreted differently depending whether it appears as part of a statement or as part of an expression.
Comparison in Rockstar can only be done within an expression.
Tommy is nobody
initialises the variableTommy
with the valuenobody
If Tommy is nobody
- will execute the following block if, and only if, the variableTommy
is equal tonobody
The modifier not
will invert the meaning of the comparison, similar to IS NULL / IS NOT NULL
in SQL. The keyword ain't
(which is reduced to aint
by Rockstar) is an alias for is not
. This usage runs contrary to idiomatic English, where "Tommy isn't anybody", "Tommy ain't nobody" and "Tommy ain't not nobody" somehow mean exactly the same thing.
Rockstar also supports the following comparison syntax:
is higher/greater/bigger/stronger than
to denote 'greater than'is lower/less/smaller/weaker than
to denote 'less than'is as high/great/big/strong as
to denote 'greater than or equal to'is as low/little/small/weak as
to denote 'less than or equal to'
Input/Output
Use the Listen
keyword to read one line of input from STDIN
. Use Listen to
to capture the input into a named variable.
Listen to your heart
- read one line of input fromSTDIN
and store it inyour heart
Use the Say
keyword to write the value of a variable to STDOUT
.
Say Tommy
- will output the value stored inTommy
toSTDOUT
Rockstar defines Shout
, Whisper
and Scream
as aliases for Say
Flow Control and Block Syntax
Conditionals
Conditional expressions start with the If
keyword, followed by an expression. If the expression evaluates to true
, then the subsequent code block is executed. Optionally, an Else
block can be written after an If
block. The code block following the Else
keyword would be executed if the If
expression evaluated to false
.
Loops
Similar to the If
statement, a loop is denoted by the While
or Until
keyword, which will cause the subsequent code block to be executed repeatedly whilst the expression is satisfied:
Tommy was a dancer
While Tommy ain't nothing,
Knock Tommy down
That'll initialize Tommy with the value 16 (using the poetic number literal syntax) and then loop, decrementing Tommy by 1 each time until Tommy equals zero (i.e ain't nothing
returns false).
The break
and continue
statements work as they do in most block-based languages. Rockstar defines Break it down
as an alias for break
and Take it to the top
as an alias for continue
Blocks
A block in Rockstar starts with an If
, Else
, While
or Until
statement, and is terminated by a blank line or the end-of-file. EOF ends all open code blocks
Tommy was a dancer
While Tommy ain't nothing
Shout it
Knock it down
Functions
Functions are declared with a variable name followed by the takes
keyword and a list of argument separated by the and
keyword.
Multiply takes X and Y
Search takes Needle and Haystack
The function body is a list of statements with no separating blank lines. A blank line denotes the end of a function body. Functions in Rockstar always have a return value, indicated by the Give back
keyword.
Functions are called using the 'taking' keyword:
Multiply taking 3, 5
is an expression returning (presumably) 15Search taking "hands", "lay your hands on me"
Examples
Here's FizzBuzz in minimalist Rockstar, with block scope indented for clarity:
Modulus takes Number and Divisor
While Number is as high as Divisor
Put Number minus Divisor into Number
(blank line ending While block)
Give back Number
(blank line ending function declaration)
Limit is 100
Counter is 0
Fizz is 3
Buzz is 5
Until Counter is Limit
Build Counter up
If Modulus taking Counter, Fizz is 0 and Modulus taking Counter, Buzz is 0
Say "FizzBuzz!"
Continue
(blank line ending 'If' Block)
If Modulus taking Counter and Fizz is 0
Say "Fizz!"
Continue
(blank line ending 'If' Block)
If Modulus taking Counter and Buzz is 0
Say "Buzz!"
Continue
(blank line ending 'If' Block)
Say Counter
(EOL ending Until block)
And here's the same thing in idiomatic Rockstar, using poetic literals and no indentation
Midnight takes your heart and your soul
While your heart is as high as your soul
Put your heart without your soul into your heart
Give back your heart
Desire is a lovestruck ladykiller
My world is nothing
Fire is ice
Hate is water
Until my world is Desire,
Build my world up
If Midnight taking my world, Fire is nothing and Midnight taking my world, Hate is nothing
Shout "FizzBuzz!"
Take it to the top
If Midnight taking my world, Fire is nothing
Shout "Fizz!"
Take it to the top
If Midnight taking my world, Hate is nothing
Say "Buzz!"
Take it to the top
Whisper my world
Ideas
- Work out if this is even remotely implementable. I'm not sold on the idea of continuation prefixes for block syntax - for starters it won't let you implement nested blocks.
- Explore other ideas for Turing-complete rock ballad compilers. Maybe something based on BF where we use word length or initial letters or something to compile lyrics down to BF or some other very minimalist but Turing-complete language
- Make 'Certified Rockstar Developer' stickers and give them out to anybody who can write even one line of Rockstar.
- Generate a score for the lyrics using a component called a
composer
.
Implementations
- rockstar-js - Rockstar-to-JavaScript transpiler
- rockstar-lexer - Rockstar lexer written in Haskell with Alex
- rockstar-java - Rockstar interpreter in Java
- rockstar-ml - Rockstar interpreter in OCaml
- rockstar-py - Rockstar-to-Python transpiler
- kaiser-ruby - Rockstar to Ruby transpiler
- sublime-rockstar-syntax - Syntax highlighter for Sublime Text 3
- language-rockstar - Syntax highlighter for Atom
- maiden - Rockstar interpreter in Rust
- rockstar-webpiler - Online Rockstar Parser and Transpiler. rockstar.connorwfitzgerald.com
- vim-rockstar - Syntax highlighting for vim
- vscode-rockstar-language - Syntax highlighting for VSCode
Social Spaces
- /r/RockstarDevs - Subreddit
- Rockstar Developers - Discord Group