Re: StringBuilder Difficulties
On 07/02/2011 02:29 AM, Gene Wirchenko wrote:
On 1 Jul 2011 20:47:47 GMT, blmblm@myrealbox.com
<blmblm.myrealbox@gmail.com> wrote:
In article<6cqp07tiug2nu8u6ififvvek1694fkpfi1@4ax.com>,
Gene Wirchenko<genew@ocis.net> wrote:
On 30 Jun 2011 20:30:00 GMT, blmblm@myrealbox.com
<blmblm.myrealbox@gmail.com> wrote:
[snip]
A general comment: I'm inclined to agree with the people who are
saying that in general it seems like you're trying to write [name
of your favorite language] programs in Java, and in the long term
that seems less optimal than trying to grok the Java mindset.
My mindset is that I want to get my work done. I do not care
about the Java mindset except as it helps me get my work done.
Yes, and if you were going to do a lot of programming in Java it
would seem to make sense to adapt to the local customs, so to speak.
Not to do so seems to me like fighting with your tools, which, well,
I do it too sometimes, but it does get in the way of getting stuff
done.
My tools include manyyears of experience programming. I do not
think that Java is such a precious snowflake -- the same is true of
any language -- that I should have to throw all that experience away
in order to use the language.
As far as I can see nobody asked you to do that. If adjusting to a new
language's mindset requires you to throw away everything you've learned
so far then you probably better stick with the previous experience and
tools. That will be much more efficient and beneficial.
If, on the other hand, you want to use a new language then you typically
get best results (or results at all) if you adjust to the environment
you find. You may have noticed that your issues with StringBuilder seem
to be quite unique - others posting here do not seem to have those
issues. In my experience this is usually an indication that I am doing
something wrong or haven't properly understood the new environment yet.
I think part of it may be struggling with the object-oriented
paradigm, but part of it may just be coming to terms with the fact
No, I am experienced with OOP.
Huh. Well, with all due respect ....
I'd have said otherwise given that all of the variables and methods
in your TimingTesting program (the version I tried revising) seem
to be static (except the local variables). I'm also puzzled by why
that program duplicates so much code, when you could have factored
out the parts that are different using objects-as-code-wrappers.
But maybe the O-O languages you've used before don't make you do
that, and adapting to that particular Java idiom seemed not worth
the trouble.
Oh, I asked about that. One apparently can not pass a function
pointer parameter as in C. The ways that were posted involved lookup
every time AFIACS and I judged that it might swamp what I was
measuring (checking if a character were in a set). So, to my chagrin,
I had to go with cut-and-paste.
The usual solution in Java is to factor out an API into an interface and
have several implementations of that interface. See Callable for
example - this basically encapsulates a "function" with no arguments and
a single return value:
http://download.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/Callable.html
In your TimingTesting program you could define a private interface like this
private interface Search {
boolean search(char c);
}
Then you create inner classes
private final class SequentialSearch implements Search {
@Override
boolean search(char c) {
for ( int i = 0; i < chars.length(); ++i ) {
if (chars.charAt(i) == c) {
return true;
}
}
return false;
}
}
public void parseSequentialSearch() {
parse(new SequentialSearch());
}
private void parse(Search s) {
int xScan=0;
boolean fBuildingIdent=false;
boolean fInIdentChars;
String cIdent=""; // fussy init
while (xScan<cParseString.length())
{
char CurrChar=cParseString.charAt(xScan);
fInIdentChars=s.search(CurrChar);
....
}
etc.
This would be the _minimal_ refactoring to get what you want but you
also need to switch from having all the state static in TimingTesting to
instance. Chances are that a more thorough refactoring yields a
significantly better (in terms of OO and modularity) solution.
Btw, if you want to create a parser in Java then I recommend looking
into ANTLR. There is even a graphical UI (ANTLRWorks) which helps get
results quickly and even has grammar debugging. Cool stuff!
http://www.antlr.org/works/index.html
Cheers
robert