This blog is updated daily.
A general description is here.
PCRE has been upgraded to version 8.20 with bug fixes and greater Perl
compatibility. This adds a JIT pattern compiler, about which PCRE's
news says ‘large performance benefits can be had in many situations’.
(It is supported on most but not all platforms that run R.)
The internal ‘untar()’ (as used by default by ‘R CMD INSTALL’) now
knows about some ‘pax’ headers which ‘bsdtar’ (e.g., the default ‘tar’
for Mac OS >= 10.6) can incorrectly include in ‘tar’ files, and will
skip them with a warning.
‘serialize()’ has a new option ‘xdr = FALSE’ which will use the native byte-order for binary serializations. In scenarios where only little-endian machines are involved (these days, close to universal) and (un)serialization takes an appreciable amount of time this may speed up noticeably transferring data between systems.
The namespace import code was warning when identical S4 generic functions were imported more than once, but should not (reported by Brian Ripley, then Martin Morgan).
The internal ‘untar()’ (as used by default by ‘R CMD INSTALL’) now knows about some ‘pax’ headers which ‘bsdtar’ (e.g., the default ‘tar’ for Mac OS >= 10.6) can incorrectly include in ‘tar’ files, and will skip them with a warning.
PCRE has been upgraded to version 8.21: as well as bug fixes and greater Perl compatibility, this adds a JIT pattern compiler, about which PCRE's news says ‘large performance benefits can be had in many situations’.