Re: [Haskell-cafe] Unicode Haskell source -- Yippie!

On 26/04/2014, at 1:30 AM, Rustom Mody wrote:

On Fri, Apr 25, 2014 at 6:32 PM, Chris Warburton wrote: Rustom Mody writes:

...

As for APL, it failed for various reasons eg - mixing up assembly language (straight line code with gotos) with functional idioms - the character set was a major hurdle in the 60s. Thats not an issue today when most OSes/editors are unicode compliant

I strongly suspect that the failure of APL had very little to do with the character set. When APL was introduced, the character set was just a matter of dropping in a different golf-ball. Later, it was just bits on a screen. Heck in 1984 I was using C and LaTeX on an IBM mainframe where the terminals displayed curly braces as spaces, and oddly enough that didn't kill C... In any case, it was possible to enter any arbitrary APL text using straight ASCII, so that was no great problem. There were a number of much more serious issues with APL. (1) In "classic" APL everything is an n-dimensional array, either an array of characters or an array of (complex) numbers. An absolutely regular array. Want to process a collection of records where some of the fields are strings? No can do. Want to process a collection of strings of different length? No can do: you must use a 2-dimensional array, padding all the strings to the same length. Want type checking? Hysterical laughter. APL2 "fixed" this by introducing nested arrays. This is powerful, but occasionally clumsy. And it is positional, not named. You *can* represent trees, you can represent records with mixed fields, you can do all sorts of stuff. But it's positional, not named. (2) There aren't _that_ many APL symbols, and it didn't take too long to learn them, and once you did, they weren't that hard to remember. (Although the use of the horseshoe symbols in APL2 strikes me as *ab*use.) Problem is, a whole lot of other things were done with numbers. Here's the trig functions: 0 ◦ x sqrt(1-x**2) 1 ◦ x sin x ¯1 ◦ x arcsin x 2 ◦ x cos x ¯2 ◦ x arccos x 3 ◦ x tan x ¯3 ◦ x arctan x 4 ◦ x sqrt(x**2+1) ¯4 ◦ x sqrt(x**2-1) 5 ◦ x sinh x ¯5 ◦ x arcsinh x 6 ◦ x cosh x ¯6 ◦ x arccosh x 7 ◦ x tanh x ¯7 ◦ x arctanh x Who thought _that_ was a good idea? Well, presumably it was the same person who introduced the "I-beam functions". A range of system functions (time of day, cpu time used, space available, ...) were distinguished by *numbers*. (3) Which brings me to the dialect problem. No two systems had the *same* set of I-beam functions. You couldn't even rely on two systems having the same *kind* of approach to files. There were several commercial APL systems, and they weren't priced for the hobbyist or student.