TweetFollow Us on Twitter

December 95 - The Veteran Neophyte: The Right Tool for the Job

The Veteran Neophyte: The Right Tool for the Job

Dave Johnson

Dynamic programming languages are cool. Once you've tasted dynamic programming, it's hard to go back to the old, crusty, static way of doing things. But the fact remains that almost all commercial software is still written with static languages. Why?

Recently I took a class in Newton programming. For me personally the Newton isn't a very useful device, only because I never carry around a notepad or calendar or address book or to-do list and I don't have a need to collect any sort of data out in the field. But even though it's not terribly useful to me, it is very useful to a lot of people -- and useful or not, it's a really cool device. Programming the Newton, for those of you who haven't had the pleasure, is very, very different from programming the Macintosh in C or C++ or Pascal, and is incredibly attractive in a lot of ways.

The language that you use to program the Newton, NewtonScript, is an example of an object-oriented dynamic language, or OODL. (See? Even the acronym is cool.) This means a number of things, but the upshot is that it's very programmer-friendly and very flexible. Now, I don't pretend to be an expert in languages, not by a long shot, so I can't offer any incisive comparisons with other "modern" languages, but I can tell you what it feels like for a dyed-in-the-wool C programmer to leap into this new and different world. It feels great.

One well-known feature of dynamic languages is garbage collection, the automatic management of memory. Objects in memory that are no longer needed are automatically freed, and in fact there is no way to explicitly free them other than making sure that there are no references to them any more, so that the garbage collector can do its thing. I didn't fully realize how much time and effort and code it takes to deal with memory management until I didn't have to do it anymore. There's something almost naughty about it, going around cavalierly creating objects in memory without worrying about what to do with them later. After a lifetime of living in mortal fear of memory leaks, it feels deliciously irresponsible. I like it. I like it a lot.

NewtonScript's object model is refreshingly simple and consistent. There are the usual "simple" data types -- integers, real numbers, Booleans, strings, and so on -- and only two kinds of compound objects: arrays and frames. An array, as you might expect, is simply a linear, ordered group of objects, and the individual objects are referenced by their index (their position in the array). Frames are an unordered collection of items in named slots; you refer to a particular item by the name of its slot. Frames are also the only NewtonScript objects that can be sent messages, and the message is simply the name of a slot that contains a function.

Because NewtonScript is dynamic, variables or frame slots or array members can hold any kind of data, including other arrays or frames, or even functions, and the kind of data can be changed at any time. The size of the array or frame can be changed anytime, too; you can add or delete items as needed, without worrying about managing the changing memory requirements. This kind of flexibility is a big chunk of what makes dynamic languages so, well, dynamic. Such a thing is of course unimaginable in a static language, where each byte must be explicitly allocated before it's needed, carefully tracked while used, and explicitly deallocated when you're done with it.

NewtonScript is also introspective, meaning that all objects "know" all about themselves. (Isn't that a nice term? I like the idea of a language being introspective -- sitting there, chin in hand, pondering itself.) The type of a piece of data is stored with the data, and named items keep their names. In fact, everything in memory is coherent, with a well-defined identity; there is no possibility of undifferentiated bits getting schlepped around, no possibility of a dangling pointer or a string being interpreted as a real number. In static languages, of course, all that design-level information is thrown out at compile time, and doesn't exist in the running program at all. There's nothing but undifferentiated bits, really. What a mess.

And that means that debugging, for the most part, has to take place at the machine level. By the time the program is running, it's just a maze of pointers and bytes and instructions, fine for a machine but nasty for humans. Of course, to combat this we have elaborate, complex programs called source-level debuggers. They give you the sense that the names still exist, thank goodness, but it's just a trick, and depends on an external file that correlates symbols with locations in memory. If you don't have the symbol file, you're out of luck. (Confession time: In my regular C programming I avoid low-level debugging like the plague. Usually I'd rather spend an hour in a source-level debugger than spend five minutes in MacsBug -- I know, I know, I'm a wimp -- precisely because all the information that helps me to think about my program, the names and so on, still "exist" in the source-level debugger. In NewtonScript, there isn't even such a thing as low-level debugging! All that design information is right there in the guts of the running program. Hallelujah!)

With dynamic languages like NewtonScript, you can let go of the details of the machine's operation, and deal with your program's operation instead -- you can think at the design level, not the machine level. And it's an incredible relief to float free of the bits and bytes and pointers and handles and memory leaks and messy bookkeeping. Most of the ponderous baggage that comes along with writing a computer program goes away. I mean really, how much longer must we approach the machine on its terms when we want to build something on it? Users were released from that kind of bondage to the machine's way of doing things long ago. So what are we waiting for? Obviously we can't program the Macintosh in NewtonScript (more's the pity) but why aren't we all chucking our C++ compilers in exchange for Prograph or Lisp or Smalltalk or Dylan? Well, some of us are. But I think there are two major hurdles to overcome before dynamic languages become mainstream: the need for speed, and inertia.

Dynamic languages carry their own baggage, of course. In the same way that making the Macintosh easier for people to use made it harder to program because the complexity and bookkeeping were shunted behind the scenes, making programming languages easier to use also requires new behind-the-scenes infrastructure and complexity. (Somebody has to do the memory management, after all.) This usually results in a bigger memory footprint and slower execution. For "normal" operations, we're long past the point where that mattered: the hardware is beefy enough to handle it without blinking. But software always pushes the limits of the hardware. Consequently, there are still times when it's important to squeeze every drop of performance out of the machine. And dynamic languages are just not very good at that. (I don't think you'd want to write your QuickDraw 3D renderer in Lisp.) So any dynamic language that hopes for mainstream commercial acceptance had better have a facility for running hunks of "external" code. That way you could write the bulk of your program in a dynamic language, but still be able to write any time-critical parts in your favorite static language and plug them in. You'd lose the protection of the dynamic language when running the external code, but that's a reasonable tradeoff.

Inertia is the other big problem. People, once they know one way to do something, are often loath to change it, especially if they've been doing it that way for a long time. I'm guilty of this in my own small way: every time I learn a spiffy, liberating new way to program I think I'll never go back to the "old" way. But the next time I set off to write some code I automatically reach for the familiar tools, not the new ones. (Lucky for me, the only way to program the Newton is in NewtonScript.) Fortunately, neither one of these hurdles will stop the evolution of our tools. It's unstoppable, if perhaps slower than we might like. There's already a whole spectrum of tools available. From Assembler to AppleScript, Pascal to Prograph, there are tools that allow anyone with enough interest to teach their computers to do new things. The line between users and programmers continues to blur, and dynamic languages can only help that process. I love the thought of putting programming tools into the hands of "nonprogrammers" -- kids, artists, hobbyists -- and seeing what they come up with. You can bet it will be something new, something that people tied to the machine would never have thought of. I can't wait.


    • Unleashed: Poems by Writers' Dogs, edited by Amy Hempel and Jim Shepard (Crown, 1995).

    DAVE JOHNSON recently enrolled his smallest dog -- named Io (eye-oh) but affectionately called The Stinklet -- in an agility class. Dog agility is a sort of obstacle course for dogs, with ramps and jumps and tunnels and poles to climb and leap over and crawl and weave through. Dave got so involved that he started building agility courses in the living room. He came to his senses, thankfully, before creating any permanent installations.

    Dave is easing up on his working life: beginning with the next issue, he'll be working 3/4 time. He had to give up some things, and it was decided (reasonably enough) that helping to edit the rest of develop was more important than writing this column. Look for guest Neophytes in coming issues, with perhaps the occasional installment from Dave.

    Thanks to Lorraine Anderson, Jeff Barbose, Paul Dreyfus, Bo3b Johnson, Lisa Jongewaard, and Ned van Alstyne for their always enlightening review comments.

    Dave welcomes feedback on his musings. He can be reached at JOHNSON.DK on AppleLink or eWorld, or on the Internet.


Community Search:
MacTech Search:

Software Updates via MacUpdate

World of Tanks Generals guide - Tips and...
World of Tanks Generals is a brand new card game by the developer behind the World of Tanks shooter franchise. It plays like a cross between chess and your typical card game. You have to keep in consideration where you place your tanks on the board... | Read more »
TruckSimulation 16 guide: How to succeed...
Remember those strangely enjoyable truck missions in Grand Theft Auto V whereit was a disturbing amount of fun to deliver cargo? TruckSimulation 16 is reminiscent of that, and has you play the role of a truck driver who has to deliver various... | Read more »
The best GIF making apps
Animated GIFs have exploded in popularity recently which is likely thanks to a combination of Tumblr, our shorter attention spans, and the simple fact they’re a lot of fun. [Read more] | Read more »
The best remote desktop apps for iOS
We've been sifting through the App Store to find the best ways to do computer tasks on a tablet. That gave us a thought - what if we could just do computer tasks from our tablets? Here's a list of the best remote desktop apps to help you use your... | Read more »
Warhammer 40,000: Freeblade guide - How...
Warhammer 40,000: Freebladejust launched in the App Store and it lets you live your childhood dream of blowing up and slashing a bunch of enemies as a massive, hulking Space Marine. It's not easy being a Space Marine though - and particularly if... | Read more »
Gopogo guide - How to bounce like the be...
Nitrome just launched a new game and, as to be expected, it's a lot of addictive fun. It's called Gopogo, and it challenges you to hoparound a bunch of platforms, avoiding enemies and picking up shiny stuff. It's not easy though - just like the... | Read more »
Sago Mini Superhero (Education)
Sago Mini Superhero 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: KAPOW! Jack the rabbit bursts into the sky as the Sago Mini Superhero! Fly with Jack as he lifts impossible weights,... | Read more »
Star Wars: Galaxy of Heroes guide - How...
Star Wars: Galaxy of Heroes is all about collecting heroes, powering them up, and using them together to defeat your foes. It's pretty straightforward stuff for the most part, but increasing your characters' stats can be a bit confusing because it... | Read more »
The best cooking apps (just in time for...
It’s that time of year again, where you’ll be gathering around the dinner table with your family and a huge feast in front of you. [Read more] | Read more »
Square Rave guide - How to grab those te...
Square Rave is an awesome little music-oriented puzzle game that smacks of games like Lumines, but with its own unique sense of gameplay. To help wrap your head around the game, keep the following tips and tricks in mind. [Read more] | Read more »

Price Scanner via

Cyber Monday: Apple MacBooks on sale for up t...
Apple resellers have MacBook Pros, MacBook Airs, and MacBooks on sale for up to $250 off MSRP for Cyber Monday 2015. The following is a roundup of the lowest prices available for new models from any... Read more
Cyber Monday: 15% off Apple products, and sto...
Use code CYBER15 on Cyber Monday only to take 15% on Apple products at Target, and store-wide. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-... Read more
iPad Air 2 And iPad mini Among Top Five Black...
Adobe has released its 2015 online shopping data for Black Friday and Thanksgiving Day. The five best selling electronic products on Black Friday were Samsung 4K TVs, Apple iPad Air 2, Microsoft Xbox... Read more
All-in-one PC Shipments Projected To Drop Ove...
Digitimes’ Aaron Lee and Joseph Tsai report that all-in-one (AIO) PC shipments may drop a double-digit percentage on-year in 2015 due to weaker-than-expected demand, although second-largest AIO make... Read more
Sprint Offers iPad Pro
Sprint now offers Apple’s new iPad Pro with Wi-Fi + Cellular, featuring a 12.9-inch Retina display with 5.6 million pixels. Customers can pick up iPad Pro at select Sprint retail locations. It can... Read more
Cyber Monday: Target offers 15% discount on A...
Target has discounted Apple Watches by 15% for Cyber Monday. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-store prices may vary: - Apple... Read more
Sunday roundup of Holiday weekend Mac sales:...
Take up to $500 off MSRP on the price of a new Mac at B&H Photo today as part of their Black Friday/Holiday weekend sale. Shipping is free, and B&H charges NY tax only. These prices are... Read more
Holiday weekend: Apple Watch on sale for $50-...
B&H Photo has the Apple Watch on sale today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - Apple Watch Sport: $50 off - Apple Watch: $50-$100 off Read more
Holiday weekend: iPad Air 2s on sale for up t...
B&H Photo has iPad Air 2s on sale for up to $80 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $459 $40 off - 64GB iPad Air 2 WiFi: $569 $30 off - 128GB iPad Air... Read more
Holiday weekend Mac sales roundup: B&H Ph...
B&H Photo continues to have all new Macs on sale for up to $500 off MSRP as part of their Black Friday/Holiday weekend sale. Shipping is free, and B&H charges NY tax only: - 15″ 2.2GHz Retina... Read more

Jobs Board

Technical Program Manager, Strategic Merchant...
# Technical Program Manager, Strategic Merchants - Apple Pay Job Number: 44001177 Santa Clara Valley, Califo ia, United States Posted: Oct. 30, 2015 Weekly Hours: 40.00 Read more
Frameworks Engineer, *Apple* Watch - Apple...
# Frameworks Engineer, Apple Watch Job Number: 41403122 Santa Clara Valley, Califo ia, United States Posted: Jul. 1, 2015 Weekly Hours: 40.00 **Job Summary** Join the Read more
Software Engineer - *Apple* Pay - Apple (Un...
# Software Engineer - Apple Pay Job Number: 44003246 Santa Clara Valley, Califo ia, United States Posted: Nov. 16, 2015 Weekly Hours: 40.00 **Job Summary** Apple Pay Read more
Merchant Operations Manager: *Apple* Pay -...
# Merchant Operations Manager: Apple Pay Job Number: 43593822 Santa Clara Valley, Califo ia, United States Posted: Nov. 10, 2015 Weekly Hours: 40.00 **Job Summary** The Read more
Product Design Engineer - *Apple* Watch - A...
# Product Design Engineer - Apple Watch Job Number: 41727161 Santa Clara Valley, Califo ia, United States Posted: Jul. 22, 2015 Weekly Hours: 40.00 **Job Summary** Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.