> On May 3, 2009, at 4:51 PM, Steve Willoughby wrote:
>
> AGSCalabrese wrote:
>> What I am really after is a tutorial that describes string
>> operations.  I am
>> teaching some students about strings.
>> I wanted to find some tutorial that explained concatenation,
>> string length, getting a character at position "n", 8 bit and 16 bit
>
> But right there you have implementation-dependent concepts.  Take  
> string
> length.  All you can say without looking at an implementation is
> "strings consist of a number of characters (whatever a character might
> or might not BE on a particular platform), and you can do something
> language-specific to see what the number of characters is."  Beyond
> that, what, exactly, could you say without knowing what characters are
> and how the strings are represented?
I don't see a problem with simply stating that characters can be 8 bit  
or
16 bit and that a string might start with a header and might end with a
trailer which would affect the value of "n". ( and that there might be
variations where characters were 6,7, 9 or whatever bits. )
Gus
>
>
> Getting a character at position N is the same.  What "position N" even
> means is language dependent.  How to "get" a "character" is also.
>
>> characters, capitalization and capitalization not.  Also string to
>> <--> hex conversion, string <--> decimal conversion , character
>>  <--> ASCII value and more.  These things can be explained without
>> requiring a specific implementation.
>
> I'd love to see how they can be explained in any useful way without
> assuming a particular implementation.  (Silently assuming one and just
> not calling out what it is doesn't count.)
I am confident I can write a tutorial.  I just wanted to steal one  
from someone
else.  I would do what you are suggesting ( silently assuming and mixing
various implementations without mentioning them explicitly )
Gus
>
>
> I've taught no small number of programming classes myself, and I'm a
> little mystified by what's driving you to take this angle.  I'd  
> explain
> strings very briefly in abstract but from there I think anything
> meaningful would better be done by picking a sample implementation  
> (ANY
> one) and showing concrete examples and actually working with them.
> -- 

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