Features of Scheme

[bnewman]

Batya Wittenberg's Creatures of Dream is a haunting rap ballad about Dream, Faery, and the power of Fantasy.  Scheme is a simplified dialect of the LISP programming language, often used in academic settings (at least back when I was in school).  The idea for this parody did come to me just because of the sound of the refrain, but to do it justice I wanted to capture not just the facts about Scheme but my own very real sense of computer programming as a kind of magical gift.

Batya and I have now each parodied the other's best song, but I think her parody of mine isn't posted yet.

lyrics by Benjamin Newman

ttto: "Creatures of Dream" by Batya Wittenberg

listen to this song

You're at the head of my list, kid, so get in the car

I know where you've been, 'cause I've been where you are

You looked into the machine, and where the rest found confusion

You saw something unseen — is it real or illusion? 

 

You're not the best in your class, others are smarter or faster

But you can surpass them, you have a gift, you can master

What's truly essential about computation

Believe in your potential, not this examination

 

Where every missed paren feels like a terrible blunder

They see a means to an end, you feel the power and wonder

They learned the structure, but you grokked the interpretation

They found the key to a job, you found the keys to creation

 

You found some kind of magic, and you can make it do nearly

Anything you imagine, if you imagine it clearly

And that clarity comes when your tools are simple to know

Open up the Purple Book, kid, I got something to show you

 

Features of Scheme

These are the features of Scheme

 

The first thing about Scheme is that the language is small

There's just a few moving parts, so you can master them all

Wish you could weave a working world inside a sliver of sand?

Here's a loom that fits completely in the palm of your hand

 

If this machine has a heart, then it's the lambda expression

To forge your own moving parts, you just express your intention

And it creates a procedure that'll carry it out

On whatever raw material you're thinking about

 

Those raw materials could be procedures as well

Stir them up in the cauldron and invent a new spell

Pass them one into each to alter each one's behavior

Search this tree for a peach?  Sure, but you choose the flavor!

 

Each procedure you make has something else up its sleeve

It remembers the context in which it was conceived

Lexical scope is what lets you buy procedures at retail

Where they share the same structure, but they differ in detail

 

All these features together add up to be something greater

Sure, procedures are code, but these procedures are data

You can store and compose them, just like numbers and strings

They're verbs, but they're nouns; they're people, places and things

 

You can fill up a world with them, a planet that sings

You can build a machine with cranks and axles and springs

Where electricity runs along invisible wires

Here's the foundation — now build whatever your heart desires

 

Features of Scheme

These are the features of Scheme

 

One thing you won't find in this language's core

Is an iterative primitive like while or for

But we have what you need to roll your very own version

Scheme comes out of the box with proper tail recursion

 

A call returns a value to the context that called it

But if there's no more to do there, don't worry, we solved it

Tail calls pay a value forward without sending it back

We're done here, no need to push a frame on the stack

 

Another thing that Scheme won't do is frequently crash

Because you don't have to tell it how to take out the trash

When your objects are dead they'll be garbage-collected

And it can tell that they're toast no matter how they're connected

 

And speaking of loops, you're gonna learn if you're wise

A coder's work is a loop, you write and test and revise

And one feature of Scheme that helps keep the loop tight

Is that the code that it runs is the code that you write

 

The interpreter takes the very code that it's given

And parses and runs it in the form that it's written

So you can see your code run almost as quick as you think it

Without waiting around for a compiler to link it

 

Once the ink has flowed, you'll know you wrote in style

And if you write that code, then you can load that file

It's a long, long road, it's gonna take a while

But you won't spend it waiting for your Scheme to compile

 

Features of Scheme

These are the features of Scheme

 

Scheme seems ancient now, and the world keeps turning

But if you're just starting out, it's still good for the learning

And in any post or project where the future may find you

Any language you learn, you'll learn with this one behind you

 

Write in Java or Python, write in Haskell or Go

There'll be some surprises, but you'll already know

More than half of what you need to be a hacker and geek

'Cause Scheme's no longer alone in what makes it unique

 

Look in any modern language for these features, you'll find some

'Cause folks who started as Schemers went on to design them

The keys you find here will open multiple doors

You'll take on those other tools and you'll make them all yours

 

You're not just learning a language here, you're learning a craft

A discipline you'll hone with each revision and draft

And it's not just a craft, it's a living tradition

Congratulations, kid, you're gonna be a magician!

 

Features of Scheme

These are the features of Scheme

 

Features of Scheme

These are the features of Scheme

Comments

[mdlbear]

Love it! A worthy addition to the somewhat specialized category* of Lisp filk.

(I was writing in Lisp 1.6 at Stanford a year or two before Scheme was developed at MIT.)

• makes me wonder whether there's any Haskell filk.

[bnewman]

I don't know of any filk specifically about Haskell, the language, but two songs about an imaginary dragon friend named Haskell are coming towards the end of this batch of updates.

And then there's this from the Shabbat morning liturgy, which finally settles the question of which programming language G!d used to create the universe: יְצָרָם בְּדַעַת בְּבִינָה וּבְהַשְׂכֵּל y'tzaram b'da'at b'vinah uv'haskel "G!d made them (the sun, moon, and stars) with knowledge and understanding, in Haskell."