Transcript language design.

[Alex Tweedly]

At 18:43 09/06/2004 -0700, Mark Wieder wrote:

>Alex-
>
>Wednesday, June 9, 2004, 4:11:53 PM, you wrote:
>Yup. I think many of us have been here before in starting out. Put
>quotes around any of the runrev objects and you'll stay out of trouble
>here.
>
>  put "something" into field "field1"   --no problem
>  put "something" into "field1"         --error

That's a good tip (from a few people).

>I always have explicitVariables turned on. I've read the warnings and
>I continue to ignore them. Even if I didn't have it turned on, I would
>always explicitly declare my variables. But I do think that whatever
>possible problems explicitVariables may cause are far outweighed by
>having the compiler catch some errors before they cause any real
>trouble.

Cool! I'll turn it on and just keep an eye out for problems.

>AT> I don't think I've ever encountered a language where a valid expression
>AT> could cause unwanted side-effects in an expression using only a single
>AT> instance of an operator. Sigh.
>
>...I may be wrong, but I don't think I've ever encountered a language
>where this wasn't the case.

Ummmmm - Algol ?  FORTRAN ?  Pascal ?  C ?  Python ?   etc.
I can't remember enough about Cobol and RPG, so I'll leave them out.
(Is my age showing ? :-)

>  Take, for example, in C the difference
>between = and ==. How many times have you typed
>
>if (c = 3)   instead of    if (c == 3)  ?

Often. But that's not a counter-example; that's an example of using the 
wrong operator and the language design not helping to spot it;   not an 
example of using the correct operator, which is the problem here. As I said 
- it caught me out mostly because string operations are so unusual.

>I've gotten into the C habit of writing
>
>if (3 == c) just to avoid those kinds of things.

I did that for a year or so - then the difficulty of reading it got too 
much, so I stopped. After another year, I got so tired of making the 
mistake, I started it again. Then it got annoying, so I stopped, ..... 
eventually I just gave up writing C completely and moved into the modern 
world of scripting languages  :-)

-- Alex.
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