        CHANGES IN bit VERSION 4.5.0

USER VISIBLE CHANGES

    o still.identical now throws an error when called with Strings
      (and previously threw when called with Lists) 
      Inofficial calls to STRING_PTR and VECTOR_PTR were removed.

BUG FIXES

    o Now works with _R_USE_STRICT_R_HEADERS_=true 
    o Replaced Calloc and Free with R_Calloc and R_Free
    o Replaced SETLENGTH with Rf_lengthgets



        CHANGES IN bit VERSION 4.0.5

BUG FIXES

    o C functions () without parameters
      are now declared (void) to avoid
      prototype warning
    o getAttrib is now PROTECTed



        CHANGES IN bit VERSION 4.0.4

USER VISIBLE CHANGES

    o copy() and reverse() have been renamed to 
    copy_vector() and reverse_vector() to avoid
    naming conflict with data.table



        CHANGES IN bit VERSION 4.0.3

BUG FIXES

    o temporarily removed link to clone.ff 
      to satisfy CRAN checks



        CHANGES IN bit VERSION 4.0.2

USER VISIBLE CHANGES

    o Vignettes nolonger execute ff code 
      for ff-version prior 4.0.0

BUG FIXES

    o NA could crash bit_extract_unsorted 
    o now DESCRIPTION URL points to github
    
    

        CHANGES IN bit VERSION 4.0.1

USER VISIBLE CHANGES

    o bbatch now checks input N >= 0, B > 0
      and returns batchsize b in 1..N

BUG FIXES

    o NA could crash bit_extract_unsorted 


 
        CHANGES IN bit VERSION 4.0.0
 
NEW FEATURES

    o new superclass ?booltype now allows proper method 
      dispatch even for two user defined booleans, e.g. (bit | bitwhich)
    o new ordinal 'booltypes' nobool < logical < bit < bitwhich < which < ri
      and diagnostic functions booltype() and is.booltype() 
    o bitwhich now has methods for [[ [ [[<- and [<-
    o new functions 'c', '==', '!=', '|', '&', 'xor' for .booltype 
    o new function bitwhich_representation() to inspect the bitwhich 
      representation without the cost of unclass() 
    o new method 'is' for .which, .ri, .hi (and .booltype)
    o new coercion generic as.booltype with .default method
    o new coercion method as.logical.which
    o new generic as.ri with methods for .ri and .default (lossy)
    o new methods rep, rev, as.character and str for .bit and .bitwhich
    o new methods all, any, min, max, range, sum, summary for .booltype, .which
    o new method anyNA for all booltypes
    o new dummy method 'is.na' for .bit, .bitwhich
    o new function in.bitwhich much faster than %in%
    o new integer sorting function bitsort() using bit_sort() or bit_sort_unique() 
      which can be by an order of magnitude faster than radix sorts 
      or falling back to one of countsort(), quicksort2(), quicksort3() 
    o new symmetric set function symdiff 
    o new functions copy(), reverse() for copying and reversing integer vectors
    o new helper functions range_na(), range_nanozero(), range_sortna() 
      join multiple tasks in one go
    o new fast unary functions for integers: bit_unique, bit_duplicated,
      bit_anyDuplicated, bit_sumDuplicated
    o new fast binary functions for integers: bit_in, bit_intersect, bit_union, 
      bit_setequal, bit_symdiff, bit_setdiff, bit_rangediff
    o new fast unary functions for sorted integers: merge_rev, 
      merge_unique, merge_duplicated, merge_anyDuplicated, merge_sumDuplicated,
      merge_first, merge_last, 
    o new fast binary functions for sorted integers: 
      merge_firstin, merge_firstnotin, merge_lastin, merge_lastnotin,
      merge_match, merge_in, merge_notin, 
      merge_union, merge_intersect, merge_setdiff, merge_symdiff,
      merge_setequal
    o new even faster binary functions when the first argument is a range of integers: 
      merge_rangein, merge_rangenotin, merge_rangesect, merge_rangediff
    o new function firstNA substantially faster than which.max(is.na(x))
    o new function getsetattr() does setattr() but returns the old attr()
    o new function get_length() directly returns LENGTH(SEXP) 
      circumventing all method dispatch for length()
    o new methods rlepack.integer, rleunpack.rlepack anyDuplicated.rlepack   

USER VISIBLE CHANGES

    o license has been extendend from GPL-2 to GPL-2 | GPL-3
    o S3methods are no longer exported in NAMESPACE
      (except for .booltype)
    o class bitwhich 
    - now is a fully functional alternative to bit vectors  
    - has argument order changed to (maxindex, x, poslength) 
    - its internal representation of bitwhich(0) has been changed 
      from FALSE to logical() and from unsorted to sorted integers
    o class 'which' now carries an attribute 'maxindex' if available  
    o as.which() and bitwhich() now filter zeroes and store data unique(sort(x))
    o as.which() now has methods for .which, .logical, .integer and .numeric 
      instead of .default.
    o bit() and bitwhich() now behave more like logical(), without 
      arguments they return objects of length zero
    o as.bit, as.bitwhich and as.which now have methods for class NULL
      such that for example as.bit(c()) will return bit(0)
      (wish of Martijn Schuemle)
    o binary operators now allow for different lengths 
      and recycle instead of throwing an error
    o xor.default now keeps the original definition of xor() and uses 
      a new method xor.logical to speed-up logicals
    o the generics poslength and maxindex have been moved from package ff
      with methods now for .default, .logical, .bit, .bitwhich, .which, .ri
    o old method chunk.default has been renamed to chunks and now returns with names
      (for backward compatibility chunk() with named arguments behaves as before)
    o new method chunk.default calls chunks() along the length(x) 
      using typeof(x) or vmode(x), this replaces chunk.bit from package ff
    o clone.default now uses R's C-function duplicate()
      and clone.list has been removed
    o intisasc() and intisdesc() have a new argument 
      na.method=c("none","break","skip") to specify tie handling
      
TESTING and DOCUMENTATION

    o there are much more regression tests now
    o testing uses package testthat
    o documentation uses package roxygen2 now
    o new vignettes bit-demo, bit-usage and bit-performance

BUG FIXES

    o assignment functions '[<-.bit' now behave like '[<-.logical' when it 
      comes to NAs or ZEROs in subscripts
    o length<-.bit no longer tries to access memory before it is allocated
    o as.bit.bitwhich now handles non-positive bitwhich correctly
    o declare as static many functions/variables in bit.c. (Thanks to Brian Ripley)
    
    

        CHANGES IN bit VERSION 1.1-14

BUG FIXES

    o bit[i] and bit[i]<-v now check for non-positive integers
      which prevents a segfault when bit[NA] or bit[NA]<-v   

      

        CHANGES IN bit VERSION 1.1-13

USER VISIBLE CHANGES

    o logical NA is now mapped to bit FALSE as in ff booleans
    o extractor function '[.bit' with positive numeric subscripts
	  (integer, double, bitwhich) now behaves like '[.logical' and returns 
	  NA for out-of-bound requests and no element for 0
    o extractor function '[[.bit' with positive numeric (integer, double, 
      bitwhich) subscripts now behaves like '[[.logical' and throws an error
      for out-of-bound requests
    o extractor function '[.bit' with range index subscripts (ri)
      subscripts now behaves like '[[.bit' and throws an error
      for out-of-bound requests
    o assignment functions '[<-.bit' and '[[<-.bit' with positive numeric 
      (integer, double, bitwhich) subscripts now behave like '[<-.logical' and
      '[[<-.logical' and silently increase vector length if necessary
    o assignment function '[<-.bit' with range index subscripts (ri) now 
      behaves like '[[<-.bit' and silently increases vector length if necessary
    o rlepack() is now a generic with a method for class 'integer'
    o rleunpack() is now a generic with a method for class 'rlepack'
    o unique.rlepack() now gives correct results for unordered sequences
    o anyDuplicated.rlepack() now returns the position of the first
	  duplicate and gives correct results for unordered sequences

TUNING

    o The package can now compiled with 64bit words instead of 32bit words,
      since we only measured a minor speedup, we left 32bit as the default.

BUG FIXES

    o extractor and assignment functions now check for legal (positive) 
      subscript bounds, hence illegally large subscripts or zero no longer 
      cause memory violations

    
    
CHANGES IN bit VERSION 1.1-12

NEW FEATURES

    o function still.identical() has been moved to here from package bit64
    o generic 'clone' and methods clone.default and clone.list have been moved to here from package ff

BUG FIXES

    o bit[bitwhich] is now subscripting properly (VALGRIND)
    o UBSAN should no longer complain about left shift of int
      (although that never was a problem)

    
    
    CHANGES IN bit VERSION 1.1-10


TUNING

    o function 'vecseq' now calls C-code when calling with the default 
      parameters 'concat=TRUE, eval=TRUE' (wish of Matthew Dowle)

BUG FIXES

    o all.bit no longer ignores TRUE values in the second and following words
      (spotted by Nelson Chen)

    
    
    CHANGES IN bit VERSION 1.1-9


NEW FEATURES

    o new function 'repeat.time' for adaptive timing

    
CODE ORGANIZATION

    o generics for sorting and ordering have been moved from 'ff' to 'bit'
    
    
    
    CHANGES IN bit VERSION 1.1-7


USER VISIBLE CHANGES

    o all calls to 'seq.int' have been replaced by 'seq_along' or 'seq_len'
    o most calls to 'cat' have been replaced by 'message'


BUG FIXES

    o chunk.default now works with chunk(from=2, to=3, by=1) thanks to Edwin de Jonge



    CHANGES IN bit VERSION 1.1-5


NEW FEATURES

    o new utility functions setattr() and setattributes() allow to set attributes 
      by reference (unlike attr()<- attributes()<- without copying the object)

    o new utility unattr() returns copy of input with attributes removed


USER VISIBLE CHANGES

    o certain operations like creating a bit object are even faster now: need 
      half the time and RAM through the use of setattr() instead of attr()<-

    o [.bit now decorates its logical return vector with attr(,'vmode')='boolean',
      i.e. we retain the information that there are no NAs.


BUG FIXES

    o .onLoad() no longer calls installed.packages() which substantially 
      improves startup time (thanks to Brian Ripley)



    CHANGES IN bit VERSION 1.1-2


USER VISIBLE CHANGES

    o The package now has a namespace




    CHANGES IN bit VERSION 1.1-1


USER VISIBLE CHANGES

    o Function 'chunk' has been made generic, the default method
      provides the previous behavior.

    o New method to increase length of bitwhich objects.

    o Added further coercion methods.
      provides the previous behavior.


BUG FIXES

    o as.bitwhich.ri now generates correct negative subscripts.




    CHANGES IN bit VERSION 1.1-0


NEW FEATURES

    o New class 'bitwhich' stores subscript positions in most efficient way:
      TRUE for all()==TRUE, FALSE for !any()==TRUE. otherwise positive or
      negative subscripts, whatever needs less RAM. Coercion functions and 
      logical operators are available, the latter being efficient for very
      asymetric (skewed) distributions: selecting or exlcuding small factions
      of the data.
    
    o New class 'ri' (range index) allows to select ranges of positions for 
      chunked processing: all three classes 'bit', 'bitwhich' and 'ri' can be 
      used for subsetting 'ff' objects (ff-2.1.0 and higher).
    
    o New c() method for 'bit' and 'bitwhich' objects which behaves like 
      c(logical).

    o The bit methods sum(), any(), all(), min(), max(), range(), summary() 
      and which() now support a range argument that allows to restrict the 
      range of evaluation for chunked processing.

    o New utilities for chunked processing: bbatch, repfromto, chunk, vecseq.


USER VISIBLE CHANGES

    o reducing length of bit objects will now set hidden bits to FALSE, 
      such that subsequent length increase behaves consistent with bit
      objects that had never been reduced in length: new bits are FALSE

    o 'which' is no longer turned into a generic. Use 'bitwhich' instead, 
      or, 'as.which' if you need strictly positive subscripts. 
      
    o 'which.bit' has been renamed to 'as.which.bit'. It no longer has 
      parameter 'negative' and always returns positive subscripts (wish of 
      Stavros Macrakis). It now has second parameter 'range' in order to return
      subscripts for chunked processing (note that the bitwhich representation 
      is not suitable for chunked processing). In order to facilitate coercion, 
      the return vector of 'as.which' now has class 'which'.
      
    o the internal structure of a bit object has been changed to align with ff 
      ram objects: the bitlength of a bit object is no longer stored in 
      attr(bit, "n"), instead in attr(attr(bit, "physical"), "Length"),
      which is accessible via physical(bit)$Length, but should be accessed
      usually via length(bit). 

    o the semantics of 'min', 'max' and 'range' have been changed. They now 
      refer to the positions of TRUE in the bit vector (and thus are consistent
      with bitwhich rather than with logical. The 'summary' method now returns 
      four elements c("FALSE"=, "TRUE"=, "Min."=, "Max."=).


BUG FIXES

    o which.bit no longer returns integer() for a bit vector that has all TRUE


KNOWN PROBLEMS / TODOs

    o NAs are mapped to TRUE in 'bit' and to FALSE in 'ff' booleans. Might be aligned 
      in a future release. Don't use bit if you have NAs - or map NAs explicitely.

