StringBuilder Difficulties

[Gene Wirchenko]

Dear Java'ers:

I am working with StringBuilder now. I grant that it is faster
in execution, but it is taking a bunch of my time to get it straight.
I decided to change my VRString class (call-by-value-result) to
VRStringB. Complications ensued.

The amount of ornamentation required in my code was nasty, so I
did some simplifying.

How does one assign a String value to a StringBuilder variable?
For the class below (before I defined .Set()), I needed
cParsedWord.Value.replace(
0,cParsedWord.Value.length(),cScan.substring(xStart,xEnd));
With .Set(), I just need
cParsedWord.Value.Set(cScan.substring(xStart,xEnd));

For value equality to a String value, one needs something like
cParsedWord.Value.toString().equals("some value")
(because without the .toString(), the comparison will fail) whereas
with .equals() below, this will do it
cParsedWord.equals("some value")

***** Start of Code *****
// VRStringB Class
// StringBuilder Value-Result Parameter Handling
// Last Modification: 2011-06-28

class VRStringB
{
StringBuilder Value;

VRStringB()
{
this.Value=new StringBuilder("");
}

VRStringB
(
StringBuilder Init
)
{
this.Value=Init;
}

boolean equals
(
String theString
)
{
return this.Value.toString().equals(theString);
}

void Set
(
String theString
)
{
this.Value.replace(0,this.Value.length(),theString);
}
}
***** End of Code *****

Am I missing something about StringBuilder, or is it really this
difficult to play with? It would make a lot more sense to me if
StringBuilder worked more like String does.

Sincerely,

Gene Wirchenko

 

[Eric Sosman]

Dear Java'ers:

I am working with StringBuilder now. I grant that it is faster
in execution, but it is taking a bunch of my time to get it straight.
I decided to change my VRString class (call-by-value-result) to
VRStringB. Complications ensued.

The amount of ornamentation required in my code was nasty, so I
did some simplifying.

How does one assign a String value to a StringBuilder variable?

One does not "assign" a reference of type T1 to a reference
of unrelated type T2. One can, however, create a StringBuilder
whose initial content is the same as that of a given String:

String str = ...; // non-null
StringBuilder sbd = new StringBuilder(str);

These are "the same" in the sense that str.length() == sbc.length()
and str.charAt(k) == sbd.charAt(k) for all 0 <= k < str.length().
Also, str.equals(sbd.toString()) returns true.

[...]
Am I missing something about StringBuilder, or is it really this
difficult to play with?

You've been advised to read some Java tutorials or textbooks,
and (it seems) have chosen not to follow that advice. Under the
circumstances, then, I'd have to say StringBuilder is "really this
difficult to play with."

Perhaps you're "too pressed for time" to learn Java before writing
it. Okay, yeah, that's reality, shit happens. But if so, you've been
"pressed for time" for some weeks now, and (I'll wager) have already
wasted more time chasing blind alleys than you would have spent learning
the rudiments of the language. (A potential infinite regress looms.)

It would make a lot more sense to me if
StringBuilder worked more like String does.

StringBuilder is only of interest because it is mutable, while
String is immutable. From this fact flow many of the necessary
differences that give you so much trouble, but that others take in
stride.

Summary: Fer Crissakes, Gene, read the damn' book!

 

[Lew]

Summary: Fer Crissakes, Gene, read the damn' book!

And don't go plonking everyone who gives you good advice, either, Gene. Eric,
like markspace before him, is giving you good advice. Follow it instead of
copping an attitude like you did before.

Straight, unvarnished, blunt truth can feel bad at first, but it helps you.
It really does.

Also, refusal to learn harms you.

 

[Gene Wirchenko]

^^^^^
One does not "assign" a reference of type T1 to a reference

^^^^^^^^^
I wrote "value".

of unrelated type T2. One can, however, create a StringBuilder
whose initial content is the same as that of a given String:

String str = ...; // non-null
StringBuilder sbd = new StringBuilder(str);

I have found that, but I was wondering about how to do it with
the same StringBuilder object. I thought that part of the advantage
of using StringBuilder was that the amount of object creation got cut
down.

These are "the same" in the sense that str.length() == sbc.length()
and str.charAt(k) == sbd.charAt(k) for all 0 <= k < str.length().
Also, str.equals(sbd.toString()) returns true.

IOW, a String value assigned to a StringBuilder variable.

[...]
Am I missing something about StringBuilder, or is it really this
difficult to play with?

You've been advised to read some Java tutorials or textbooks,
and (it seems) have chosen not to follow that advice. Under the
circumstances, then, I'd have to say StringBuilder is "really this
difficult to play with."

Which I have. I have been referring to the docs for
StringBuilder, but the docs are rather incomplete, and I have to
guess. This takestime.

Perhaps you're "too pressed for time" to learn Java before writing
it. Okay, yeah, that's reality, shit happens. But if so, you've been
"pressed for time" for some weeks now, and (I'll wager) have already

A few and part-time.

wasted more time chasing blind alleys than you would have spent learning
the rudiments of the language. (A potential infinite regress looms.)

I know the rudiments. I am having trouble with the next level.

I have been asking here to try to knock out some of those blind
alleys. I can get something to work, but I would prefer to have
something work well.

StringBuilder is only of interest because it is mutable, while
String is immutable. From this fact flow many of the necessary
differences that give you so much trouble, but that others take in
stride.

Why is the syntax so different? It does not need to be, but it
is. In order to change from String to StringBuilder, I had to modify
a bunch of code apart from changing variable types.

Summary: Fer Crissakes, Gene, read the damn' book!

I have been RTFM. The docs often say what, but without an
example and usually not why. I am paddling the best I can. Please do
not cannonball next to me.

Sincerely,

Gene Wirchenko

 

[Gene Wirchenko]

And don't go plonking everyone who gives you good advice, either, Gene. Eric,

I do not. I plonked one person who called my sanity into
question. As I like to say, disagreeing one thing, but being
disagreeable is quite another. Snarking on sanity is the latter.

like markspace before him, is giving you good advice. Follow it instead of
copping an attitude like you did before.

Straight, unvarnished, blunt truth can feel bad at first, but it helps you.
It really does.

The attitude of some posters is that they are Keepers of the
Truth. I suggest that there are different realities. I have
programmed in quite a few programming languages. I see no need to
jettison what I have learned, because some practice is different with
Java. If it is better, I will consider using it. If it does not meet
my needs, I see no need to use it regardless of what Java practice is.

Also, refusal to learn harms you.

I do not refuse to learn, but I know what I want to accomplish
with my program. A number of the suggestions have been plain
irrelevant. Some of them have been quite useful, but those subthreads
tend to die, because there is no need for further discussion. Thus,
discussion tends to continue only on points of contention. They are
not the only points. There is more agreement than disagreement, but
you would not know that the way some posters keep coming at me.

Sincerely,

Gene Wirchenko

 

[blmblm]

Dear Java'ers:

I am working with StringBuilder now. I grant that it is faster
in execution, but it is taking a bunch of my time to get it straight.
I decided to change my VRString class (call-by-value-result) to
VRStringB. Complications ensued.

The amount of ornamentation required in my code was nasty, so I
did some simplifying.

How does one assign a String value to a StringBuilder variable?
For the class below (before I defined .Set()), I needed
cParsedWord.Value.replace(
0,cParsedWord.Value.length(),cScan.substring(xStart,xEnd));
With .Set(), I just need
cParsedWord.Value.Set(cScan.substring(xStart,xEnd));

For value equality to a String value, one needs something like
cParsedWord.Value.toString().equals("some value")
(because without the .toString(), the comparison will fail) whereas
with .equals() below, this will do it
cParsedWord.equals("some value")

***** Start of Code *****
// VRStringB Class
// StringBuilder Value-Result Parameter Handling
// Last Modification: 2011-06-28

class VRStringB
{
StringBuilder Value;

VRStringB()
{
this.Value=new StringBuilder("");
}

VRStringB
(
StringBuilder Init
)
{
this.Value=Init;
}

boolean equals
(
String theString
)
{
return this.Value.toString().equals(theString);
}

void Set
(
String theString
)
{
this.Value.replace(0,this.Value.length(),theString);
}
}
***** End of Code *****

Am I missing something about StringBuilder, or is it really this
difficult to play with? It would make a lot more sense to me if
StringBuilder worked more like String does.

Well ....

If all you need is something that's like a String but whose value
can change, it seems to me [*] that you might be better off just
writing a simple wrapper class for String -- I'm thinking a class
with one variable of type String, which could even be public if
you don't want to fool with writing getter/setter methods.

[*] The experts may disagree. I'm a journey(wo)man at best
with Java.

Where StringBuilder is useful is in, well, building strings;
a typical use case is a situation in which you want to build
up a string piece by piece. You *could* write something like

String a = "first";
a += " second";
a += " etc";

and my *guess* is that this is not horribly inefficient if the
number of concatenation operations is small. (The conventional
wisdom, as I understand it, is that the Java runtime is pretty
good at managing short-lived objects, so creating new objects is
not invariably something to avoid, though as with anything else
one shouldn't get carried away, maybe. Again the experts may
disagree.)

But if there are a lot of concatenation operations it's said to be
more efficient to use a StringBuilder, e.g.:

StringBuilder sb = new StringBuilder();
sb.append("first");
sb.append(" second");
sb.append(" etc");
String a = sb.toString();

The above is what I mostly use StringBuilder for; there are
undoubtedly other things one can do with it as well, some of
which may be useful to you (I haven't followed carefully all the
threads you've started).

(I'm not optimistic that this commentary will be helpful, or
even that it will be read [*], given that you didn't reply to
my posts in the threads about passing method names to methods,
but I guess I'll try again .... <shrug> )

[*] That's not actually meant as snark; not long ago I changed
the e-mail address I use to post, to a GMail one, and I'm under
the impression that some Usenet participants routinely filter out
anything from a GMail address, so I worry just a bit ....

 

[Gene Wirchenko]

On 6/28/2011 5:54 PM, Gene Wirchenko wrote:
...
...

The main thing you seem to be missing about StringBuilder is that it is
not a string, it is a tool for building strings.

Well, once I have built a string, I want to use it.

Here is some sample code demonstrating comparing a String to the current
contents of a StringBuilder, and replacing the entire contents with a
different String.

public class StringBuilderExample {
public static void main(String[] args) {
StringBuilder sb = new StringBuilder();
sb.append("aaa");
System.out.println(sb);
System.out.println("aaa".equals(sb.toString()));
sb.replace(0, Integer.MAX_VALUE, "bbbbbbb");
System.out.println(sb);
}
}

I find the .replace() line rather ornamental. I have even more
complex parameters so I came up with my .Set() method. I am surprised
that there is no such functionality in StringBuilder.

I understand your example. Either I have learned, you write good
examples, or both.

Sincerely,

Gene Wirchenko

 

[Roedy Green]

How does one assign a String value to a StringBuilder variable?

see http://mindprod.com/jgloss/stringbuilder.html

There is a ton of source code on the net. Googling it looking for
various classes and methods can help you find how other programmers
use them which can help you make sense of the JavaDoc.

I use FastCat now for 95% of my string building work. It is aims to
use memory precisely to reduce the amount of GC. I only use
StringBuilder for character-by-character building.

see http://mindprod.com/products1.html#FASTCAT

--
Roedy Green Canadian Mind Products
http://mindprod.com
One of the curses of the computer age is manufacturers now design
home appliances to die on the very day the warranty expires.
It is deliberate waste in the service of mindless profit.

 

[Gene Wirchenko]

[snip]

Am I missing something about StringBuilder, or is it really this
difficult to play with? It would make a lot more sense to me if
StringBuilder worked more like String does.

[snip]

up a string piece by piece. You *could* write something like

String a = "first";
a += " second";
a += " etc";

and my *guess* is that this is not horribly inefficient if the
number of concatenation operations is small. (The conventional

IOW, who cares if it is only a bit of inefficiency? Agreed.

wisdom, as I understand it, is that the Java runtime is pretty
good at managing short-lived objects, so creating new objects is
not invariably something to avoid, though as with anything else
one shouldn't get carried away, maybe. Again the experts may
disagree.)

But if there are a lot of concatenation operations it's said to be
more efficient to use a StringBuilder, e.g.:

StringBuilder sb = new StringBuilder();
sb.append("first");
sb.append(" second");
sb.append(" etc");
String a = sb.toString();

It is. My test code appends one character at a time. Switching
from String to StringBuilder cut the execution time by about 40%.

The above is what I mostly use StringBuilder for; there are
undoubtedly other things one can do with it as well, some of
which may be useful to you (I haven't followed carefully all the
threads you've started).

I have managed to get to the point where I have found out what
you have posted here, and I agree with it, too.

(I'm not optimistic that this commentary will be helpful, or
even that it will be read [*], given that you didn't reply to
my posts in the threads about passing method names to methods,
but I guess I'll try again .... <shrug> )

[*] That's not actually meant as snark; not long ago I changed
the e-mail address I use to post, to a GMail one, and I'm under
the impression that some Usenet participants routinely filter out
anything from a GMail address, so I worry just a bit ....

Not me. I killfile only the deserving (meaning those undeserving
of my time).

Sincerely,

Gene Wirchenko

 

[Gene Wirchenko]

[snip]

It is relatively rare to decide, part way through a build, to throw away
the work so far and begin again with entirely different contents.

I am going to be doing it in a loop. why create a new object
each iteration?

Sincerely,

Gene Wirchenko

 

[Eric Sosman]

^^^^^^^^^
I wrote "value".

You also wrote "assign." The only values Java can "assign"
are primitives and references -- in particular, Java cannot "assign"
the sequence of characters that make up the content of a String or
a StringBuilder.

I have found that, but I was wondering about how to do it with
the same StringBuilder object. I thought that part of the advantage
of using StringBuilder was that the amount of object creation got cut
down.

Not sure what the "it" you mention is. The efficiency "advantage,"
to the extent that there is one, is illustrated by

String result = "";
for (String s : bigBunchOfStrings)
result += s;

vs.

StringBuilder buff = new StringBuilder();
for (String s : bigBunchOfStrings)
buff.append(s);
String result = buff.toString();

IOW, a String value assigned to a StringBuilder variable.

See above; this is not "assignment."

Which I have. I have been referring to the docs for
StringBuilder, but the docs are rather incomplete, and I have to
guess. This takestime.

Elsethread you mention that you've programmed in "quite a few
programming languages." Did you study them as diligently as you're
studying Java, or are you like the Real Programmer who "can write
FORTRAN in any language?"

Okay, if you've got a distaste for Java and are reluctant to
learn it, that's the way it goes. I've resisted C++ for years and
years on equally flimsy grounds. But if you're just trying to "get
by" and don't intend to learn, then at the very least stop whining!

I know the rudiments. I am having trouble with the next level.

IMHO you do not yet know the rudiments.

 

[blmblm]

[ snip ]

IOW, who cares if it is only a bit of inefficiency? Agreed.


It is. My test code appends one character at a time. Switching

So okay, you probably *do* want to use StringBuilder, and having
that confirmed by experiment is good.

[ snip ]

(I'm not optimistic that this commentary will be helpful, or
even that it will be read [*], given that you didn't reply to
my posts in the threads about passing method names to methods,
but I guess I'll try again .... <shrug> )

[*] That's not actually meant as snark; not long ago I changed
the e-mail address I use to post, to a GMail one, and I'm under
the impression that some Usenet participants routinely filter out
anything from a GMail address, so I worry just a bit ....

Not me. I killfile only the deserving (meaning those undeserving
of my time).

More useful information; thanks for the reply.

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.
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
that Java is, as I think Patricia Shanahan said not long ago
(possibly in another thread), that Java is just plain verbose.

But I have some sympathy with the desire just to get something
running: I spent a number of hours a while back trying to teach
myself some Scheme and in the process trying make it conform to
my strongly-typed-languages-trained mindset, and I'd probably
have done better to get a good introductory book and try to grok
the no-types(?) mindset. (Maybe I'll try again at some point.)

 

[Gene Wirchenko]

On 30 Jun 2011 20:30:00 GMT, (e-mail address removed)

[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.

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.

that Java is, as I think Patricia Shanahan said not long ago
(possibly in another thread), that Java is just plain verbose.

Well, I posted about the verbosity earlier and got flak over it.

But I have some sympathy with the desire just to get something
running: I spent a number of hours a while back trying to teach

And without having to buy into a language religion.

myself some Scheme and in the process trying make it conform to
my strongly-typed-languages-trained mindset, and I'd probably
have done better to get a good introductory book and try to grok
the no-types(?) mindset. (Maybe I'll try again at some point.)

Sincerely,

Gene Wirchenko

 

[Eric Sosman]

On 6/30/2011 1:30 PM, (e-mail address removed) wrote:
...

I've tried several approaches to learning programming languages, and the
one that works best for me is to get an introductory book, and work
through it, reading each chapter and doing the exercises.

To this I'd add (and perhaps this is reflective only of my
own modes of learning): Get hold of some samples of good code in
the language (or "believed to be good," since the learner is in
a poor position to judge), and read the code. With the tutorials
and reference works at one's elbow, of course. "Why didn't he need
to grab a lock here?" "Oh, *that's* how you handle file-not-found!"
And so on, and so on.

I still recall learning SNOBOL years and years ago by studying
the SNOBOL source of the SNOBOL compiler while frantically flipping
pages in the SNOBOL book. My grasp of the language SNOBOLed.

 

[John B. Matthews]

I still recall learning SNOBOL years and years ago by studying
the SNOBOL source of the SNOBOL compiler while frantically flipping
pages in the SNOBOL book. My grasp of the language SNOBOLed.

You might enjoy looking at the SPITBOL operations that are part of the
GNAT Ada Library in the package, GNAT.Spitbol:

<http://gcc.gnu.org/onlinedocs/gnat_rm/The-GNAT-Library.html#The-GNAT-Library>

Much of the documentation is in the corresponding specification (.ads)
files:

<http://gcc.gnu.org/viewcvs/trunk/gcc/ada/>

GNAT.Spitbol.Patterns is an example:

<http://gcc.gnu.org/viewcvs/trunk/gcc/ada/g-spipat.ads?revision=139296&view=markup>

The GPL version is available here:

<http://libre.adacore.com/libre/>

 

[blmblm]

On 30 Jun 2011 20:30:00 GMT, (e-mail address removed)

[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.

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.

Well, I posted about the verbosity earlier and got flak over it.


And without having to buy into a language religion.

Hm. I wouldn't say that adapting to local customs constitutes
buying into a language religion. YMMV, I suppose.

 

[Gene Wirchenko]

On 30 Jun 2011 20:30:00 GMT, (e-mail address removed)

[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.

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.

Hm. I wouldn't say that adapting to local customs constitutes
buying into a language religion. YMMV, I suppose.

Some of the posters have been quite vociferous about it.

I am pretty much past the intro stage and into the pain stage
where there is not so much help.

Sincerely,

Gene Wirchenko

 

[Robert Klemme]

On 30 Jun 2011 20:30:00 GMT, (e-mail address removed)

[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.

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

 

[blmblm]

On 30 Jun 2011 20:30:00 GMT, (e-mail address removed)

[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 another poster has responded, I'm not convinced that's what
you're being asked to do (though you obviously feel otherwise).

It seems to me that one of the things one learns from doing a lot
of coding in a lot of languages is recognizing when something is
the same as what you've done before, just with different syntax,
and when it's different.

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.

Without experimenting to find out, of course ....

It seems to me that virtual method invocations are so common in
Java that they would be well-optimized. But if you want to claim
that the code you eventually hope to produce won't have one, well,
yeah, that's true, so maybe it matters. Then again, wouldn't a
similar argument apply to C with function pointers? Maybe not.
I don't seem to be able to think this through as carefully as
I'd like.

Anyway, I was curious, so I ran your code and my revision [1], and
the results were -- surprising [2]. I noticed, by the way, that
all three of your parse methods make a call to SequentialSearch,
assigning the result to a variable that apparently isn't used.
Thinking that *might* be a mistake, I also tried your code and my
revision with that possibly-extra call removed.

[1] Message-ID: <[email protected]>

[2] I tried this on several different systems, all Fedora Linux
running Java 1.6.0_21 but different hardware and different releases
of Fedora. I was going to include results here, but in trying
the experiment on additional systems I'm less and less convinced
the results would mean anything without my putting more effort
into it than I'm up for. (Usually when I'm timing something
I try it twice, and if results are close enough I don't bother
with additional trials. In this case results of two trials were
just different enough for me to think I'd need to do more to get
meaningful results.) Briefly, though .... :

Your code was fairly (but not 100%!) consistent in showing
treeset-based search to be fastest, followed by binary search and
then sequential search, though sometimes the difference between
sequential and binary was small. My code was -- well, this is where
it's surprising. On most of the systems where I tried it, treeset
search was fastest, but sequential search was faster than binary
search; on one system, however, the order was as for your code.
Your code was pretty consistently faster than mine, though usually
not by a lot (less than 1%).

Some of the posters have been quite vociferous about it.

I've noticed a certain amount of, oh, "contentiousness" maybe, on both
sides. Sort of a , sort of not.

(Aside: I recognize your name from alt.folklore.computers, where
you seem, oh, much more mild-mannered. Hm.)

I am pretty much past the intro stage and into the pain stage
where there is not so much help.

That people are not willing to offer further help when many of their
previous suggestions have been rejected should not be a total surprise.
<shrug>

 

[supercalifragilisticexpialadiamaticonormalizeringe]

(Aside: I recognize your name from alt.folklore.computers, where
you seem, oh, much more mild-mannered. Hm.)

CLJP seems to bring out a contentious streak in people.