bitsets - Developer IT

Are Bitsets actually Bools?

- by cam

In C++, are bitsets actually a set of bools? Doesn't this defeat the purpose of using a BitSet because bools are 32 bits (I think...)?

Groovy on Grails: GORM and BitSets?

- by Visionary Software Solutions

I don't see anything in the official documentation about unsupported persistence data types, so I'm working under the assumption that types available in the Groovy language should be handled. However, for the following domain class: class DocGroupPermissions { Workgroup workgroup; Document document; BitSet permissions = new BitSet(2) public DocGroupPermissions() {} void setPermissions(boolean canRead, boolean canWrite){ setReadPermissions(canRead) setWritePermissions(canWrite) } BitSet getPermissions() { return permissions } void setReadPermissions(boolean canRead) { permissions.set(0,canRead) } void setWritePermissions(boolean canWrite) { permissions.set(1,canWrite) } boolean getReadPermissions() { return permissions.get(0) } boolean getWritePermissions() { return permissions.get(1) } static belongsTo = [workgroup:Workgroup, document:Document] static constraints = { workgroup(nullable:false, blank:false) document(nullable:false, blank:false) } } I'm getting: 2009-11-15 16:46:12,298 [main] ERROR context.ContextLoader - Context initialization failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'messageSource': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.MappingException: An association from the table doc_group_permissions refers to an unmapped class: java.util.BitSet Has anyone run into this before?

Read the article

Null Pointer Exception with an array of bitsets

- by p0ny

could someone explain to me why the following results in a Null pointer Exception? And how to set a value for bitarray[0]? BitSet[] bitarray; bitarray= new BitSet[10]; bitarray[0].set(1); Also, why something like this work and not result in a pointer exception? BitSet[] bitarray = new BitSet[10]; BitSet bits = new BitSet(32); bits.set(1); bitarray[0] = bits; Thanks

Read the article

How do I change the value of a dynamic_bitset?

- by R S

I am using C++ boost's dynamic_bitset. I have already allocated a variable and I just want to change its value - to construct it anew from an 'unsigned long' like from the constructor, but I don't want to allocate the memory again or to create a temporary variable. What can I do?

Read the article

Easy way to convert a string of 0's and 1's into a character? Plain C

- by Nick

I'm doing a steganography project where I read in bytes from a ppm file and add the least significant bit to an array. So once 8 bytes are read in, I would have 8 bits in my array, which should equal some character in a hidden message. Is there an easy way to convert an array of 0's and 1's into an ascii value? For example, the array: char bits[] = "0,1,1,1,0,1,0,0" would equal 't'. Plain C

Read the article

Easy way to convert a string of 0's and 1's into a character? C language

- by Nick

I'm doing a steganography project where I read in bytes from a ppm file and add the least significant bit to an array. So once 8 bytes are read in, I would have 8 bits in my array, which should equal some character in a hidden message. Is there an easy way to convert an array of 0's and 1's into an ascii value? For example, the array: char bits[] = "0,1,1,1,0,1,0,0" would equal 't'.

Read the article

Concatenate boost::dynamic_bitset or std::bitset

- by MOnsDaR

Hey, what is the best way to concatenate 2 bitsets? For example i've got boost::dynamic_bitset<> test1( std::string("1111") ); boost::dynamic_bitset<> test2( std::string("00") ); they should be concatenated into a thrid Bitset test3 which then holds 111100 Solutions should use boost::dynamic_bitset. If the solution works with std::bitset, it would be nice too. There should be a focus on performance when concatenating the bits.

Read the article

ANTLR JavaScript Target

- by kunalsawlani

Hello, I have been using ANTLR to generate a parser + tree grammar for a mark up language with Java target which works fine. Now I am trying to get the target in JavaScript to use it in my web browser. However, I have not been able to locate any good documentation on how to go about doing this. I am using eclipse with ANTLR IDE, and when i specify the language as JavaScript, I get the following errors. Multiple markers at this line (10): internal error: group JavaScript does not satisfy interface ANTLRCore: mismatched arguments on these templates [treeParser(grammar, name, scopes, tokens, tokenNames, globalAction, rules, numRules, bitsets, labelType, ASTLabelType, superClass, members, filterMode)] (10): internal error: java.util.NoSuchElementException: no such attribute: filterMode in template context [treeParser] If anyone could help me out with this or point me to some material which I could read about the JavaScript target with ANTLR, it would be great. Thanks

Read the article

Assign bitset member to char

- by RedX

I have some code here that uses bitsets to store many 1 bit values into a char. Basically struct BITS_8 { char _1:1; (...) char _8:1; } Now i was trying to pass one of these bits as a parameter into a function void func(char bit){ if(bit){ // do something }else{ // do something else } // and the call was struct BITS_8 bits; // all bits were set to 0 before bits._7 = 1; bits._8 = 1; func(bits._8); The solution was to single the bit out when calling the function: func(bits._8 & 0x128); But i kept going into //do something because other bits were set. I was wondering if this is the correct behaviour or if my compiler is broken. The compiler is an embedded compiler that produces code for freescale ASICs.

Read the article

Data structure to build and lookup set of integer ranges

- by actual

I have a set of uint32 integers, there may be millions of items in the set. 50-70% of them are consecutive, but in input stream they appear in unpredictable order. I need to: Compress this set into ranges to achieve space efficient representation. Already implemented this using trivial algorithm, since ranges computed only once speed is not important here. After this transformation number of resulting ranges is typically within 5 000-10 000, many of them are single-item, of course. Test membership of some integer, information about specific range in the set is not required. This one must be very fast -- O(1). Was thinking about minimal perfect hash functions, but they do not play well with ranges. Bitsets are very space inefficient. Other structures, like binary trees, has complexity of O(log n), worst thing with them that implementation make many conditional jumps and processor can not predict them well giving poor performance. Is there any data structure or algorithm specialized in integer ranges to solve this task?

Read the article

Optimizing C++ Tree Generation

- by cam

Hi, I'm generating a Tic-Tac-Toe game tree (9 seconds after the first move), and I'm told it should take only a few milliseconds. So I'm trying to optimize it, I ran it through CodeAnalyst and these are the top 5 calls being made (I used bitsets to represent the Tic-Tac-Toe board): std::_Iterator_base::_Orphan_me std::bitset<9::test std::_Iterator_base::_Adopt std::bitset<9::reference::operator bool std::_Iterator_base::~_Iterator_base void BuildTreeToDepth(Node &nNode, const int& nextPlayer, int depth) { if (depth > 0) { //Calculate gameboard states int evalBoard = nNode.m_board.CalculateBoardState(); bool isFinished = nNode.m_board.isFinished(); if (isFinished || (nNode.m_board.isWinner() > 0)) { nNode.m_winCount = evalBoard; } else { Ticboard tBoard = nNode.m_board; do { int validMove = tBoard.FirstValidMove(); if (validMove != -1) { Node f; Ticboard tempBoard = nNode.m_board; tempBoard.Move(validMove, nextPlayer); tBoard.Move(validMove, nextPlayer); f.m_board = tempBoard; f.m_winCount = 0; f.m_Move = validMove; int currPlay = (nextPlayer == 1 ? 2 : 1); BuildTreeToDepth(f,currPlay, depth - 1); nNode.m_winCount += f.m_board.CalculateBoardState(); nNode.m_branches.push_back(f); } else { break; } }while(true); } } } Where should I be looking to optimize it? How should I optimize these 5 calls (I don't recognize them=.

Developer IT