To illustrate: there used to be this subject called "Systems Analysis" that folks heading for programming jobs used to get taught. You could probably be a lot older than me and have been taught it, but not be much younger and not have. Which I suspect is why there was any interest at all in this book. To quote Nat Pryce,
Until I started working in "enterprise IT" I didn't realise that people didn't do this.Well, back in the day I was taught with examples that pretty much sent the message that, say, a "bank account" was a terribly terribly asbtract thing, and an (as it was then) OMT box denoting a class representing bank accounts was a bit more concrete, and that a C++ class definition representing the OMT class was more concrete than that, more concrete still was an object that was an instance of that class. And most concrete of all was the bit pattern in memory that implemented that object. OK. Imagine the embarrassment of trying to explain this view of the world to someone with a crippling overdraft. "No, you see, a bank account is a terribly abstract thing..."
In space, no-one can hear you screamAnother exemplar: This page is clearly a labour of love, and quite impressive in itself. I'm not sure it does anything to make monads any more tractable, however. What it does do is express very clearly this interesting aspect of programmers' thinking, albeit through the reverse mechanism of trying to avoid abstraction.
- "I shall use a metaphor of space stations and astronauts to cut down on the degree of abstraction"
- "A space station is just a metaphor for a function"
- "These astronauts could be anything, Americans, Frenchmen, dogs, gorillas, whales, whatever"
- "The other thing is to note that is our space stations are typed"
"A space station is just a metaphor for a function" But I have zero personal experience of space stations, whereas I do have personal experience of functions, so I struggle to find the former more concrete than the latter. Thinks: "the typed space station takes a whale in a space suit..."
I highlight this not to mock Eric (to whom more power and good luck), but because of the crystal clarity with which this language highlights the deep, deep strangeness of how programmers (including myself) communicate with each other as regards what is abstract, never mind with real people.
"What do you read, my lord?"This sort of thing wouldn't matter so much if the notions of the world convenient to us as programmers didn't keep leaching into the real word. Here's a story that turns out to be about time, identitiy and state (more ideas that we have some sometimes fishy ideas about): I was in a particular bookshop, since gone out of business and this story might partially explain why, and I saw a copy of a Chris Ware book that I didn't have. The copy on the shelf was pretty badly beaten up, so I took it to the till and asked the woman there "do you have another one of these that's in better condition?"
Ware's books sometimes have the unusual feature that the barcode is on a wrapper and not on the book proper, and this copy had lost such wrapper. Well, she searched every surface of the book that she reasonably could to find a bar code to scan, but failed. She handed the book back to me with an apologetic shrug and said "I'm sorry, I don't know what this is". I'll repeat that: "I don't know what this is." A state of profound confusion for someone who works in the book trade, standing in a bookshop, with a book in her hand.
What was meant was something like "the IT system foisted upon me by the senior management of his retail chain will not allow me to perform any actions with this object because I cannot scan it". But what she said was "I don't know what this is" which is perhaps less explicit but more telling. The truth is that the IT system of that shop is not able to distinguish books. It likely has some sort of idea of how many items with a particular barcode have been scanned in, and how many scanned out and therefore how many may reasonably be expected to be found in the shop at any given time. But actual books are beyond it. In the world of this stock control system, rows in a database table are more real, more concrete, than the items on the shelves, and woe betide you if you try to do anything to the latter without the former. It seemes as if the history of this object had rendered it (in the context of the bookshop) without an identity. Remarkable!
And so the person working in the shop has been placed in a world where the tangible objects that are the essence of that business cannot be worked with for want of that key. A book, you see, is a terribly abstract thing...