AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Once again problems with wildcards/generic methods          AppletTalk.com Forum Index -> Java Help View previous topic :: View next topic   Author Message Hendrik Maryns Guest Posted: Mon Feb 27, 2006 1:12 pm    Post subject: Once again problems with wildcards/generic methods -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hi, I have successfully applied generics a few times now, but once again, it gets a bit more complicated, and Eclipse?s error messages are a bit too cryptic. So I have this method public <T extends State> List<Set<List<T>>> arrangeStates(Set<T> states) Here, I need the parameter T, because I want to be able to give subtypes of State to the method, and get a result with the same subtypes (as in Sun?s Generics Tutorial: parametrised methods should be used if you want to express a relation between the types of the arguments and/or return type.) I had to introduce the T, because I want to invoke the method with a subtype of State (worked fine with State before). Now another method, public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State> states) invokes arrangeStates like so: List<Set<List<State>>> arrangedStates = this.arrangeStates(states); and then goes on doing stuff with it. Here, I did not use a type parameter, as wildcards are sufficient. But as the knowledgeable will have noticed, the above line does not compile. How can I change it such that I can invoke arrangeStates on Set<? extends State>? The compiler message is this: Error Type mismatch: cannot convert from List<Set<List<capture-of ? extends State>>> to List<Set<List<State>>> Signature.java Eclipse?s Quick Fix proposes to change the type of arrangedStates to List<Set<List<? extends State>>>, but that gives another warning, and its suggestions stay the same... Thanks, H. -- Hendrik Maryns ================== www.lieverleven.be http://aouw.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEAvBve+7xMGD3itQRAtKbAJ9LndQNzjU5xU2G6mrO59KiLEFiAwCaAzOd eleelq3y0WRZgU1sdBOSo9E= =fwXP -----END PGP SIGNATURE----- Back to top Hendrik Maryns Guest Posted: Mon Feb 27, 2006 1:12 pm    Post subject: Re: Once again problems with wildcards/generic methods -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hendrik Maryns schreef: Quote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hi, I have successfully applied generics a few times now, but once again, it gets a bit more complicated, and Eclipse?s error messages are a bit too cryptic. So I have this method public <T extends State> List<Set<List<T>>> arrangeStates(Set<T> states) Here, I need the parameter T, because I want to be able to give subtypes of State to the method, and get a result with the same subtypes (as in Sun?s Generics Tutorial: parametrised methods should be used if you want to express a relation between the types of the arguments and/or return type.) I had to introduce the T, because I want to invoke the method with a subtype of State (worked fine with State before). Now another method, public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State states) invokes arrangeStates like so: List<Set<List<State>>> arrangedStates = this.arrangeStates(states); and then goes on doing stuff with it. Here, I did not use a type parameter, as wildcards are sufficient. But as the knowledgeable will have noticed, the above line does not compile. How can I change it such that I can invoke arrangeStates on Set<? extends State>? The compiler message is this: Error Type mismatch: cannot convert from List<Set<List<capture-of ? extends State>>> to List<Set<List<State>>> Signature.java Eclipse?s Quick Fix proposes to change the type of arrangedStates to List<Set<List<? extends State>>>, but that gives another warning, and its suggestions stay the same... I should add to this that I do not need arrangedStates to be anything more specific than a list of sets of lists of states (indeed, this is something cartesian-product like). Whether they are a subtype of states is not important. H. -- Hendrik Maryns ================== www.lieverleven.be http://aouw.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEAvF0e+7xMGD3itQRAkkKAJ9T3+JG2Q9lRJpFb6lv/a3wKdEpcQCeMSl3 9u/qmOqz2PvfvQSXrqq7AHw= =rjT1 -----END PGP SIGNATURE----- Back to top Hendrik Maryns Guest Posted: Tue Feb 28, 2006 1:12 pm    Post subject: No Solution? (Was: Once again problems with wildcards/generi -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Is there no Knowledgeable Person (TM), that can give me a hand here? Please, I?ve been reading FAQs about generics for some hours now, and did not find anything helpful (yet). TIA, H. Quote: Hi, I have successfully applied generics a few times now, but once again, it gets a bit more complicated, and Eclipse?s error messages are a bit too cryptic. So I have this method public <T extends State> List<Set<List<T>>> arrangeStates(Set<T> states) Here, I need the parameter T, because I want to be able to give subtypes of State to the method, and get a result with the same subtypes (as in Sun?s Generics Tutorial: parametrised methods should be used if you want to express a relation between the types of the arguments and/or return type.) I had to introduce the T, because I want to invoke the method with a subtype of State (worked fine with State before). Now another method, public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State states) invokes arrangeStates like so: List<Set<List<State>>> arrangedStates = this.arrangeStates(states); and then goes on doing stuff with it. Here, I did not use a type parameter, as wildcards are sufficient. But as the knowledgeable will have noticed, the above line does not compile. How can I change it such that I can invoke arrangeStates on Set<? extends State>? The compiler message is this: Error Type mismatch: cannot convert from List<Set<List<capture-of ? extends State>>> to List<Set<List<State>>> Signature.java Eclipse?s Quick Fix proposes to change the type of arrangedStates to List<Set<List<? extends State>>>, but that gives another warning, and its suggestions stay the same... I should add to this that I do not need arrangedStates to be anything more specific than a list of sets of lists of states (indeed, this is something cartesian-product like). Whether they are a subtype of states is not important. H. -- Hendrik Maryns ================== www.lieverleven.be http://aouw.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEBEfye+7xMGD3itQRAkzDAJ4kYN3MuDxVQUhqFgcJlKf5w+EOAwCffd20 s1NSm6MYGk5bPbhmw/VChM0= =xR30 -----END PGP SIGNATURE----- Back to top Bart Cremers Guest Posted: Tue Feb 28, 2006 2:12 pm    Post subject: Re: No Solution? (Was: Once again problems with wildcards/ge List<Set<List<? extends State>>> arrangedStates = this.arrangeStates(states); Bart Back to top Bart Cremers Guest Posted: Tue Feb 28, 2006 2:12 pm    Post subject: Re: No Solution? (Was: Once again problems with wildcards/ge Oops, didn't read carefull enough. Could you post a complete code example? Bart Back to top Roedy Green Guest Posted: Tue Feb 28, 2006 6:12 pm    Post subject: Re: Once again problems with wildcards/generic methods On Mon, 27 Feb 2006 13:28:31 +0100, Hendrik Maryns <hendrik_maryns (AT) despammed (DOT) com> wrote, quoted or indirectly quoted someone who said : Quote: public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State states) invokes arrangeStates like so: To better understand what you are doing, please define State, FunctionTuple and tell us what is a subset of what. -- Canadian Mind Products, Roedy Green. http://mindprod.com Java custom programming, consulting and coaching. Back to top Hendrik Maryns Guest Posted: Wed Mar 01, 2006 11:12 am    Post subject: Re: No Solution? (Was: Once again problems with wildcards/ge -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Bart Cremers schreef: Quote: Oops, didn't read careful enough. Indeed:-) Could you post a complete code Quote: example? My pleasure, should?ve done that from the start, I guess. The additional class SignatureSymbol is just a wrapper around a String (getName) and an int (getArity), whereas FunctionInputTuple is a wrapper around a SignatureSymbol and a list of States, which checks that the length of the list is the same as the symbol?s arity. State is a class that does nothing special except existing. FunctionInputTuple.getInstance(symbol, states) is a factory method. It returns the single instance with the given symbol and states. (Sort of cache management). import java.util.*; /** * A class representing a signature of an automaton. It holds the alphabet of * symbols on which the automaton works. Signatures are immutable. */ public class Signature implements Iterable<SignatureSymbol> { /** * Initialise a new signature, with given set of symbols. * * @param symbols */ public Signature(Set<SignatureSymbol> symbols) { this.symbols = new ArrayList<SignatureSymbol>(symbols); Collections.sort(this.symbols, new Comparator<SignatureSymbol>() { public int compare(SignatureSymbol sym1, SignatureSymbol sym2) { return sym1.getArity() - sym2.getArity(); } }); } /** * The symbols of the signature. They are stored in a list, sorted by * arity. */ final private List<SignatureSymbol> symbols; /** * Return a list of sets, where every symbol in the ith set has arity i. * * @return Every symbol with arity i belongs to the ith set. * | for each symbol in this * | result.get(symbol.getArity()).contains(symbol) * @return The ith set in the list contains only elements of arity i. * | for 0 <= i < result.size() * | for each symbol in result.get(i) * | symbol.getArity() == i */ public List<Set<SignatureSymbol>> getSymbolsSorted() { List<Set<SignatureSymbol>> result = new ArrayList<Set<SignatureSymbol>>(); for (int i = 0; i <= getMaximalArity(); i++) { result.add(i, new HashSet<SignatureSymbol>()); } for (SignatureSymbol symbol : this) { result.get(symbol.getArity()).add(symbol); } // make all sets unmodifiable for (int i = 0; i < result.size(); i++) { result.set(i, Collections.unmodifiableSet(result.get(i))); } return result; // TODO: improve/remove this for list } /** * Return the maximal arity of an element in this signature. */ public int getMaximalArity() { return symbols.get(symbols.size()-1).getArity(); } /** * Arrange the states in lists, such that every combination of i states is * in a list in the ith set. * THIS FUNCTION WORKS FINE (I THINK) * @param states * The states to arrange. * @return The ith set represents the ith power of the set of states * (cartesian product). It goes on until getMaximalArity(). */ public <T extends State> List<Set<List<T>>> arrangeStates(Set<T> states) { List<Set<List<T>>> result = new ArrayList<Set<List<T>>>(); Set<List<T>> setI = new HashSet<List<T>>(); setI.add(new ArrayList<T>()); result.add(0, setI); for (int i = 1; i <= getMaximalArity(); i++) { setI = new HashSet<List<T>>(); result.add(i, setI); for (T state : states) { for (List<T> list : result.get(i - 1)) { List<T> newList = new ArrayList<T>(); newList.add(0, state); // copy list into newList from position 1 newList.addAll(1, list); setI.add(newList); } } } return result; } /** * Sort the given states such that for each symbol of this signature, if its * arity is i, all possible FunctionInputTuples with combinations of states * of length i are in the ith set in the resulting list. * * @param states * The states to sort. * @return Every tuple in set i has a symbol of arity i. * | for each 0 < i <= result.size() * | for each tuple in result.get(i) * | tuple.getSymbol().getArity() == i * @return Every possible combination of i states is in set i for each * symbol of arity i. * | for each 0 < i <= result.size() * | for each symbol in this * | if (symbol.getArity() == i) * | then for each s_1 ... s_i in states * | result.get(i).contains( * | FunctionInputTuple.getInstance(symbol, s_1, ... s_i) */ public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State> states) { List<Set<SignatureSymbol>> sortSyms = getSymbolsSorted(); List<Set<FunctionInputTuple>> result = new ArrayList<Set<FunctionInputTuple>>(); // HERE IS THE PROBLEM List<Set<List<State>>> arrangedStates = this.arrangeStates(states); for (Set<SignatureSymbol> set : sortSyms) { Set<FunctionInputTuple> aritySet = new HashSet<FunctionInputTuple>(); result.add(aritySet); // to the end! for (SignatureSymbol symbol : set) { for (List<State> stateArr : arrangedStates.get(symbol.getArity())) { try { aritySet.add(FunctionInputTuple.getInstance(symbol, stateArr)); } catch (FunctionArgumentsMismatchException e) { // should not occur } } } } return result; } } I hope it is readable, if necessary, I can trim down some more. Thanks for any help, H. -- Hendrik Maryns ================== www.lieverleven.be http://aouw.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEBXR7e+7xMGD3itQRAmnqAJ9UooyXy6Vrt2MXiGChTHKlTfPKvwCfVTXh xnz6iX4JyjI2gy9WkmAN26c= =Qk77 -----END PGP SIGNATURE----- Back to top Hendrik Maryns Guest Posted: Wed Mar 01, 2006 11:12 am    Post subject: Re: Once again problems with wildcards/generic methods -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Roedy Green schreef: Quote: On Mon, 27 Feb 2006 13:28:31 +0100, Hendrik Maryns hendrik_maryns (AT) despammed (DOT) com> wrote, quoted or indirectly quoted someone who said : public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State states) invokes arrangeStates like so: To better understand what you are doing, please define State, FunctionTuple and tell us what is a subset of what. Ok, sorry. As I answered to Bart?s post: State is just a dummy class that represents a state of an automaton, but does nothing. It just registers a name. It does have a subclass, not mentioned here, which I want to be able to use the method with, too. (StateSet, a state which contains other states.) FunctionInputTuple is a wrapper around a SignatureSymbol and a list of states. It checks that the length of the list is the same as the arity of the symbol. A SignatureSymbol is a wrapper around a String (its name) and an int (its arity), with appropriate getters. It also does nothing. Hope this helps, the whole class can be seen in the other post. TIA, H. -- Hendrik Maryns ================== www.lieverleven.be http://aouw.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEBXWve+7xMGD3itQRAiR/AJ9K8vbAnuFX1qdzmEjW2t3VJ4K9KgCfXhNh yJGRTW/cS+obw6CGWix6/vo= =br8g -----END PGP SIGNATURE----- Back to top Hendrik Maryns Guest Posted: Wed Mar 01, 2006 1:12 pm    Post subject: SOLVED! (Once again problems with wildcards/generic methods) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hendrik Maryns schreef: Quote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hendrik Maryns schreef: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hi, I have successfully applied generics a few times now, but once again, it gets a bit more complicated, and Eclipse?s error messages are a bit too cryptic. So I have this method public <T extends State> List<Set<List<T>>> arrangeStates(Set<T> states) Here, I need the parameter T, because I want to be able to give subtypes of State to the method, and get a result with the same subtypes (as in Sun?s Generics Tutorial: parametrised methods should be used if you want to express a relation between the types of the arguments and/or return type.) I had to introduce the T, because I want to invoke the method with a subtype of State (worked fine with State before). Now another method, public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State states) invokes arrangeStates like so: List<Set<List<State>>> arrangedStates = this.arrangeStates(states); and then goes on doing stuff with it. Here, I did not use a type parameter, as wildcards are sufficient. But as the knowledgeable will have noticed, the above line does not compile. How can I change it such that I can invoke arrangeStates on Set<? extends State>? The compiler message is this: Error Type mismatch: cannot convert from List<Set<List<capture-of ? extends State>>> to List<Set<List<State>>> Signature.java Eclipse?s Quick Fix proposes to change the type of arrangedStates to List<Set<List<? extends State>>>, but that gives another warning, and its suggestions stay the same... I should add to this that I do not need arrangedStates to be anything more specific than a list of sets of lists of states (indeed, this is something cartesian-product like). Whether they are a subtype of states is not important. Hi all, After reading in the very interesting Java Generics FAQ from Angelika Langer, I finally found the answer in the article about multilevel wildcards: http://www.angelikalanger.com/GenericsFAQ/FAQSections/TypeArguments.html#What%20do%20multilevel%20wildcards%20mean? or http://tinyurl.com/h3j8y. Also the part about Type System http://www.angelikalanger.com/GenericsFAQ/FAQSections/TechnicalDetails.html#Type%20System explains what happens in nested type arguments (stuff like List<? extends Set<? super Long>>). Roedy, might be something interesting to link to... The problem is that the type arguments are nested, and wildcard capturing. Anyway, the solution was to make sortForArities a parametrised method, like this: public <T extends State> List<Set<FunctionInputTuple>> sortForArities( Set<T> states) { List<Set<SignatureSymbol>> sortSyms = getSymbolsSorted(); List<Set<FunctionInputTuple>> result = new ArrayList<Set<FunctionInputTuple>>(); List<Set<List<T>>> arrangedStates = this.arrangeStates(states); for (Set<SignatureSymbol> set : sortSyms) { Set<FunctionInputTuple> aritySet = new HashSet<FunctionInputTuple>(); result.add(aritySet); // to the end! for (SignatureSymbol symbol : set) { for (List<T> stateArr : arrangedStates.get(symbol .getArity())) { try { aritySet.add(FunctionInputTuple.getInstance(symbol, stateArr)); } catch (FunctionArgumentsMismatchException e) { // should not occur } } } } return result; } That works. I have to think a bit more about why exactly this is necessary and whether this would be possible with wildcards, because only seeing the method signature, it seems unnecessary to use the generic method form. This should be possible with wildcards. This breaks encapsulation: by changing this into a generic method, I give away that I cannot implement it with wildcards, which says something about the constructs used. Thanks to all, and to Angelika Langer specifically. H. -- Hendrik Maryns ================== www.lieverleven.be http://aouw.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEBZOne+7xMGD3itQRAjTYAJ9JpNWDHik2fxjBOcXOw0gRhbdWGQCeM3w1 leyL7dHb3KP2LRPZGZc5F30= =Sy7a -----END PGP SIGNATURE----- Back to top Hendrik Maryns Guest Posted: Thu Mar 02, 2006 9:12 pm    Post subject: Re: SOLVED! (Once again problems with wildcards/generic meth -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hendrik Maryns uitte de volgende tekst op 03/01/2006 01:29 PM: Quote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hendrik Maryns schreef: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hendrik Maryns schreef: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NotDashEscaped: You need GnuPG to verify this message Hi, I have successfully applied generics a few times now, but once again, it gets a bit more complicated, and Eclipse?s error messages are a bit too cryptic. So I have this method public <T extends State> List<Set<List<T>>> arrangeStates(Set<T> states) Here, I need the parameter T, because I want to be able to give subtypes of State to the method, and get a result with the same subtypes (as in Sun?s Generics Tutorial: parametrised methods should be used if you want to express a relation between the types of the arguments and/or return type.) I had to introduce the T, because I want to invoke the method with a subtype of State (worked fine with State before). Now another method, public List<Set<FunctionInputTuple>> sortForArities(Set<? extends State states) invokes arrangeStates like so: List<Set<List<State>>> arrangedStates = this.arrangeStates(states); and then goes on doing stuff with it. Here, I did not use a type parameter, as wildcards are sufficient. But as the knowledgeable will have noticed, the above line does not compile. How can I change it such that I can invoke arrangeStates on Set<? extends State>? The compiler message is this: Error Type mismatch: cannot convert from List<Set<List<capture-of ? extends State>>> to List<Set<List<State>>> Signature.java Eclipse?s Quick Fix proposes to change the type of arrangedStates to List<Set<List<? extends State>>>, but that gives another warning, and its suggestions stay the same... I should add to this that I do not need arrangedStates to be anything more specific than a list of sets of lists of states (indeed, this is something cartesian-product like). Whether they are a subtype of states is not important. Hi all, After reading in the very interesting Java Generics FAQ from Angelika Langer, I finally found the answer in the article about multilevel wildcards: http://www.angelikalanger.com/GenericsFAQ/FAQSections/TypeArguments.html#What%20do%20multilevel%20wildcards%20mean? or http://tinyurl.com/h3j8y. Also the part about Type System http://www.angelikalanger.com/GenericsFAQ/FAQSections/TechnicalDetails.html#Type%20System explains what happens in nested type arguments (stuff like List<? extends Set<? super Long>>). Roedy, might be something interesting to link to... The problem is that the type arguments are nested, and wildcard capturing. Anyway, the solution was to make sortForArities a parametrised method, like this: public <T extends State> List<Set<FunctionInputTuple>> sortForArities( Set<T> states) { List<Set<SignatureSymbol>> sortSyms = getSymbolsSorted(); List<Set<FunctionInputTuple>> result = new ArrayList<Set<FunctionInputTuple>>(); List<Set<List<T>>> arrangedStates = this.arrangeStates(states); for (Set<SignatureSymbol> set : sortSyms) { Set<FunctionInputTuple> aritySet = new HashSet<FunctionInputTuple>(); result.add(aritySet); // to the end! for (SignatureSymbol symbol : set) { for (List<T> stateArr : arrangedStates.get(symbol .getArity())) { try { aritySet.add(FunctionInputTuple.getInstance(symbol, stateArr)); } catch (FunctionArgumentsMismatchException e) { // should not occur } } } } return result; } That works. I have to think a bit more about why exactly this is necessary and whether this would be possible with wildcards, because only seeing the method signature, it seems unnecessary to use the generic method form. This should be possible with wildcards. This breaks encapsulation: by changing this into a generic method, I give away that I cannot implement it with wildcards, which says something about the constructs used. Forget that. The trick is, to make the method above private, then invoke that one from the public one which uses wildcards. A bit unclean, but works and the only way. See http://tinyurl.com/o4a82, in Angelika?s FAQ again. Quote: Thanks to all, and to Angelika Langer specifically. again. H. -- Hendrik Maryns ================== www.lieverleven.be http://aouw.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEB1b5iOEY3xKMFEERAmSwAKCKKjEuc1rLy1IrPEtxcoYc2VYM0QCgkuBf 0eZg4i3JZS4e6Fr6jC2Zlgs= =rPKM -----END PGP SIGNATURE----- Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AppletTalk.com Forum Index -> Java Help All times are GMT Page 1 of 1   Jump to: Select a forum Java Newsgroups----------------Java DiscussionsWeb-based java games comp.lang.java 3D Graphics API's for Java Java: Support and criticism Java System Announcements comp.lang.java.api JavaBeans Java and CORBA Java and Databases comp.lang.java.developer Java GUI Toolkits Java Help comp.lang.java.javascript JVM, native methods and hardware comp.lang.java.misc Java Language Programming Security and Java comp.lang.java.setup Java Software Tools comp.lang.java.tech ibm.software.java.linux  Non-English Java Newsgroups----------------Java Language (German)Language Java (Français)Java (Italian)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.