X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=NEWS;h=da87a2bbcc9cf27bfe7cd2aaf96a1a5a2c376405;hp=333f226838240f5422be0034f1f45e2631eac749;hb=dae96ef0fb9f0f7eccf1940136cd28808db9f47d;hpb=8fed79e08b39660fcc4471584ceff4722e2d3a06;ds=sidebyside diff --git a/NEWS b/NEWS index 333f2268..da87a2bb 100644 --- a/NEWS +++ b/NEWS @@ -3,22 +3,33 @@ This file records noteworthy changes. 1.2.0 () * Added a structure template class for the easy creation of user-defined algebraic classes. -* -* -* -* Improved the speed of subs() and normal() by the use of maps instead of - lists. +* Added support for (acyclic) visitors, to allow cleaner implementations of + algebraic algorithms. +* +* Completely revamped the implementation of expression output. It is now + possible to add new output formats, to change the behavior of predefined + formats at run-time, and to have different output styles for algebraic + functions. +* Symbols can be made non-commutative. +* Improved the speed of subs(), normal(), to_rational() and to_polynomial() + by the use of maps instead of lists. The old forms + subs(const lst & ls, const lst & lr, unsigned options) + to_rational/to_polynomial(lst & repl) + are still available for compatibility, but using the new forms + subs(const exmap & m, unsigned options) + to_rational/to_polynomial(exmap & repl) + is more efficient, especially when the number of replacements is large. * quo(), rem(), prem(), sprem(), decomp_rational(), unit(), content(), primpart() and matrix::charpoly() now take a "const ex &" instead of a "const symbol &". * -* Many internal reorganizations and optimizations. +* Lots of internal streamlining and optimizations. * Caveats for class implementors: - basic::copy() and basic::destroy() are gone; classes derived from basic can use the defaults for the assignment operator and copy constructor. - - basic::subs() and basic::normal() take an 'exmap &' instead of two - 'lst &'. + - basic::subs(), basic::normal(), basic::to_rational() and + basic::to_polynomial() take 'exmap' objects instead of lists. - basic::subs() now descends into subexpressions (if accessible via nops()/op()/let_op()). If you have a custom implementation of subs() that calls basic::subs() after substituting subexpressions, this needs