Re: an infinate loop

[Ted Dennison<dennison@telepath.com>]

In article <tks6i2llqcla15@corp.supernews.com>, Beau says...
>
>Hey I am in an infinate loop and don't understand why. here is my problem to

Look for a big red sign that says "EXIT".

Oh, you mean your *code*? :-)

For one thing, you have 4 nested loops in one big honking routine. For some
people that may be no big deal, but to me its unspeakably ugly. Consider at
least putting the 2 inner loops in their own routine.

For another, it is generally considered very bad form to use an unnamed exit
statement inside of a nested loop. Its too easy for the reader to loose track of
which loop is being broken out of, particularly on a largish set of loops like
you have here. 

For another, most of your "exit" statements are all at the tops of the loops. In
those cases you should probably reverse the test logic and use "while" loops
instead. 

For another, the innermost loop seems to have no code to handle the end of the
file:

>--another nested post-test loop to catch the end of a word. The end of
>--a word can be found by looking for blank spaces
>       LOOP
>     CASE Letter IS --if the character variable was a actual letter
>        --then add one to wordlength
>
>        WHEN 'a'..'z' |'A'..'Z' =>
>           WordLength := WordLength + 1;
>        WHEN OTHERS =>
>           NULL;
>          END CASE;
>
>     Get(File => Infile, Item => Letter);
>
>     EXIT WHEN Letter = ' ' OR ELSE Letter = '.'
>           OR ELSE Letter = '?' OR ELSE Letter = '!';
>
>  END LOOP;


Lastly, and most importantly, you are going through *way* too much work for this
task. You could be doing this entire job with one loop. It looks like you are
trying to somehow code a state machine using each loop to reperesent a state.
Loops are a pretty poor mechanism for representing state machine states. Instead
you should just encode the state in some variable, and do an "if" or "case" on
it inside your main character processing loop. Actually, the variable that keeps
track of which character in the word you are on could probably be made to do the
job. The other way to do state machines is to use "goto" for the state
transitions, but this looks like a school assignment, and I doubt your
instructor wants to see that (although some might like it).

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