| I programed in Smalltalk-80 from 1990-1995. I used it at Morgan Stanley to build a derivative trading system that was distributed between London and NYC. It was running on networed Sun Sparcstations. Traders would collaborate on the same trading "book" across different machines. One of the big battles of getting the system installed was persuading traders to make room and to use a mouse to control the system. St-80 was a great system and by way my favorite programming experience. I remember visiting Jim Gosling to hear about Oak (which subsequently became Java) and thinking that it was neat but a pale imitation of Smalltalk. What "killed" Smalltak were a thousand cuts. A huge problem was the fact that hardware in those days was slow. Our production machines had a 25 Megahertz processor which had problems with the interpreted language that was also painting a GUI. For a long time St-80 would just take 100% of the puny cpu even when there was nothing going on. Eventually there was 4-line event driven patch that cleared that up but that did not help when the program actually did some work. For finance double-dispatch arithmetic made things worse since even a simple addition would result in a bunch of message sending that was cute and pure but slow. The monolithic image was an issue too since shipping and delivering production code was hard. There were source control system but ultimately the image was a hug blob that had to be shipped around. Another issue was the windowing system. Smalltalk was its own universe and basically grew out of being the whole environment for a machine (e.g. Xerox Star). There were no namespaces so it was hard to segments certain kinds of code and you'd end up fiddling with the innards of St which may have unintended consequences. It did not integrate with the window managers of the day (e.g. Motif) and could not use native widgets so we had to try to style our widgets to look like the window manager. I think the folks at ParcPlace were great inventors and engineers (Peter Deutsch is a god) but they were not fast enough to respond to the pressures of the market. I wonder what would happen if Gigahertz machines were avaible for Smalltalk and if ParcPlace had managed to make their system have a decent package manager and to call native widgets. It was also hard to find engineers since C/C++ was there flavor de jour. At Morgan Stanley there was also APL/A+/J but ultimately Java took the world over and now then Javascript which started off as an interpreted language with a lot less that St-80 but some times timing is everything. Moore's law helps too. With all that said St-80 is still the gold standard of my programming life which included other fun systems such as Interlisp-D and NextStep. |
Why would there be double-dispatch of 2 + 4 ?
Why would that require numeric coercion ?