Tuesday, 15 November 2011

Smalltalk head space

At the last Toronto Smalltalk User Group meeting we had a basic introduction to Seaside. It had been requested by some of the members, especially by the two profs that sponsor our group at Ryerson University. They teach an OO course with a Smalltalk component and felt it would be of interest to their students. A few did show up and the feedback was very positive. A bit surprising, given how basic the demo was (here is a link to the PDF), but it got me thinking about how easy it is to get out of touch with how other people see things. There is something to be said about baby steps.

After the talk we spent a while talking about the sad sate of computer science education; how it's become a C syntax programming training school. Way back in my day (early 80's) there was no dominant computer language. Intro to comp. sci. was taught in FORTAN. We learned BASIC, PL/I, COBOL, SNOBOL, Lisp, 360 Assembler, Prolog and Smalltalk. My OS course was taught as a history lesson, explaining why and how each OS concept was introduced, and why some were abandoned. There was a big focus on 'why', not just 'how'. That does not seem to be the case today.

During the conversation, I talked a bit about how selling Smalltalk can be a challenge. Smalltalk is different. If all you know is C and Java, it's really different. Why learn something different if it will not help you get a job? I made the case that learning Smalltalk helps you learn how to think in objects. A perspective that may be helpful when dealing with the other object hybrid languages (it would also be good to learn Lisp, Prolog and assembler). You can't help thinking that a Java-centric education gives students only one tool: a hammer, and they then view every task as a nail.

But how do you communicate the value of a "Smalltalk head space"? A world where everything is a live object that you can see and change. A place where delegating behaviour to Integer and String makes perfect sense; where the language is minimalist and the libraries add the complexity; where working with a debugger feels natural. And how do you explain how sending messages is different than calling a function? The mechanics are simple enough, but the mental model is harder.

I see functions as a handing off of total control of the world to something else. Within a function you change whatever data you need to. The world is a large, porous bit universe that you manipulate. Whereas sending a message is asking another object to do something for you. You don't think about tickling the bits of another object. You do your job, send messages to other objects, and maybe answer something. You work in a  local scope, not the whole world.

Every professional Smalltalk developer I know can tell talk about their "aha" moment, the point where object-think made sense. In my case it was a course at The Object People where Paul White was explaining how to model a transfer between a chequing and savings account: asking either account to do the transfer smelled wrong, so instead you could model the transaction. Really? You can do that? A 'transction' can be an object? Cool. A more whimsical example is modelling the milking of a cow. Do you ask the cow to milk itself? Do you ask the milk to un-cow itself? No. You model a farmer to do the milking 'transaction'.

The problem is that those "aha" moments take time to learn. And who has time for that? As Dave Thomas said in his recent SPLASH video interview, the complexity that we've added to the development tools is not always a benefit to someone building a simple application. Do you really need to know about objects if a BASIC program will do? Is learning about classes and instances to big a hurdle? Would a prototype object model be easier to learn? I don't know, but we really have to find a better way to communicate the up side of using Smalltalk. Waiting for each student to experience their own "aha" moment is not good enough.

Simple things should be simple. Complex things should be possible.

1 comment:

  1. As a Java developer trying to get up to speed on Smalltalk / Seaside, I can attest it is a challenge. Not just learning Smalltalk but web development in Seaside is quite different from the web dev model I am used to. Hoping for an aha moment ASAP!