dylanbeattie / rockstar
- вторник, 24 июля 2018 г. в 00:15:57
The Rockstar programming language specification
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.
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'?
Rockstar is intended to give the programmer an unprecedented degree of poetic license when it comes to the composition and structure of their programs.
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)
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, them, they always refer to the most recently named variable, determined at parse time.
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.
mysteriousnothing, nowhere and nobody are defined as aliases for nulltrue and false. (The keywords maybe and definitely maybe are reserved for future use)right, yes and ok are valid aliases for truewrong, no and lies are valid aliases for falseString literals in Rockstar use double quotes.
"Hello World"The single quote character in Rockstar is treated as a letter of the alphabet. This seems unusual until you remember that I ain't talkin' 'bout love is a perfectly valid rock'n'roll sentence.
Numeric literals in Rockstar are written as decimal numbers
1233.141592654Assignment is denoted by the put/into keyword combination:
Put 123 into X will assign the value 123 to the variable XPut "Hello World" into the message will assign the value "Hello World" to the variable the messageIncrement and decrement are supported by the Build {variable} up and Knock {variable} down keywords.
Build my world up will increment the value stored in my world by 1.Knock the walls down will decrement the value stored in the walls by 1Basic arithmetic is provided by the plus, minus, times, over, and by keywords.
Arithmetic expressions:
{a} plus {b} - addition. Alias with{a} minus {b} - subtraction. Alias without{a} times {b} - multiplication. Alias of{a} over {b} - division. Alias byExamples:
Put the whole of your heart into my hands - multiply your heart by the whole and assign the result to my hands
My world is nothing without your love - Initialize my world with the result of subtracting your love from 0
If the tears of a child is nothing - check whether the tears * a child = 0
My love by your eyes - Returns my love divided by your eyes
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.
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 variable my heart with the Boolean value trueTommy is nobody - initialises the variable Tommy with the value null using the nobody aliasA 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.
Billy says hello world!\n will initialise the variable Billy with the string literal "hello world!"The world says hello back\n will initialise the variable the world with the string literal hello backA 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 initialises Tommy with the value 100Sweet Lucy was a dancer - initialises Sweet Lucy with the value 16A killer is on the loose - initialises a killer with the value 235.My dreams were ice. A life unfulfilled; wakin' everybody up, taking booze and pills - initialises my dreams with the value 3.1415926535taking in this example.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 variable Tommy with the value nobodyIf Tommy is nobody - will execute the following block if, and only if, the variable Tommy is equal to nobodyThe modifier not will invert the meaning of the comparison, similar to IS NULL / IS NOT NULL in SQL. The keyword ain't 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'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 from STDIN and store it in your heartUse the Say keyword to write the value of a variable to SDTOUT.
Say Tommy - will output the value stored in Tommy to STDOUTRockstar defines Shout, Whisper and Scream as aliases for Say
Conditional expressions start with the If keyword, followed by an expression. If the expression evaluates to true, then the subsequent code block is executed.
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
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 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 YSearch takes Needle and HaystackThe 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"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
composer.