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

Richard A. O'Keefe ok at cs.otago.ac.nz
Mon Apr 28 02:33:26 UTC 2014

On 27/04/2014, at 9:30 PM, Ben Franksen wrote:
> The main problem with special Unicode characters, as I see it, is that it is 
> no longer possible to distinguish characters unambiguously just by looking 
> at them.

"No longer"?
Hands up all the people old enough to have used "coding forms".

Yes, children, there was a time when programmers wrote their
programs on printed paper forms (sort of like A4 tipped sideways)
so that the keypunch girls (not my sexism, historical accuracy)
knew exactly which column each character went in.  And at the
top of each sheet was a row of boxes for you to show how you wrote
2 Z 7
1 I !
0 O
and the like.

For that matter, I recall a PhD thesis from the 80s in which the
author spent a page grumbling about the difficulty of telling
commas and semicolons apart...

> Apart from questions of maintainability, this is also a potential 
> security problem: it enables an attacker to slip in malicious code simply by 
> importing a module whose name looks like a well known safe module. In a big 
> and complex piece of software, such an attack might not be spotted for some 
> time.

Again, considering the possibilities of "1" "i" "l", I don't
think we actually have a new problem here.

Presumably this can be addressed by tools:	
"here is are some modules, tell me what exactly they depend on"
not entirely unlike ldd(1).

Of course, the gotofail bug shows that it's not enough to _have_
tools like that, you have to use them and review the results

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