December 2021 - GiNaC-devel

[SCM] GiNaC -- a C++ library for symbolic computations branch, master, updated. release_1-4-0-724-gcb885a6f
by Richard B. Kreckel 21 Dec '21

21 Dec '21

This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "GiNaC -- a C++ library for symbolic computations". The branch, master has been updated via cb885a6f05aa4f93518c9ab7ee161c0a1b9f39d8 (commit) from 98424bb9699756d1eaf77f8a17b936f640c4083f (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit cb885a6f05aa4f93518c9ab7ee161c0a1b9f39d8 Author: Oleg Finkelshteyn <olegfink(a)gmail.com> Date: Tue Dec 21 10:02:29 2021 +0100 Fix relational::compare_same_type. A hash collision was needed to elicit this bug because basic::compare returns early without calling compare_same_type if hashes differ. Reported by Feng Feng <f.feng(a)outlook.com>. ----------------------------------------------------------------------- Summary of changes: check/exam_relational.cpp | 16 ++++++++++++++++ ginac/relational.cpp | 4 ++-- 2 files changed, 18 insertions(+), 2 deletions(-) hooks/post-receive -- GiNaC -- a C++ library for symbolic computations

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[PATCH] Fix comparison ordering in relational.
by ovf 20 Dec '21

20 Dec '21

Reported by Feng Feng <f.feng(a)outlook.com> in https://www.ginac.de/pipermail/ginac-list/2021-December/002368.html --- check/exam_relational.cpp | 17 +++++++++++++++++ ginac/relational.cpp | 4 ++-- 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/check/exam_relational.cpp b/check/exam_relational.cpp index 3b652b05..f66911f3 100644 --- a/check/exam_relational.cpp +++ b/check/exam_relational.cpp @@ -94,6 +94,21 @@ static unsigned exam_relational_possymbol() return result; } +// Comparisons should maintain ordering invariants +static unsigned exam_relational_order() +{ + unsigned result = 0; + numeric i = 1ll<<32, j = i+1; + symbol a; + relational x = i==a, y = j==a; + if (x.compare(y) != -y.compare(x)) { + clog << "comparison should be antisymmetric." << endl; + result += 1; + } + + return result; +} + // Very simple arithmetic should be supported, too. static unsigned exam_relational_arith() { @@ -125,10 +140,12 @@ unsigned exam_relational() result += exam_relational_elementary(); cout << '.' << flush; result += exam_relational_possymbol(); cout << '.' << flush; result += exam_relational_arith(); cout << '.' << flush; + result += exam_relational_order(); cout << '.' << flush; return result; } + int main(int argc, char** argv) { return exam_relational(); diff --git a/ginac/relational.cpp b/ginac/relational.cpp index 599a2635..dbc541a3 100644 --- a/ginac/relational.cpp +++ b/ginac/relational.cpp @@ -223,8 +223,8 @@ int relational::compare_same_type(const basic & other) const return (o < oth.o) ? -1 : 1; break; } - const int lcmpval = lh.compare(oth.rh); - return (lcmpval!=0) ? lcmpval : rh.compare(oth.lh); + const int lcmpval = lh.compare(oth.lh); + return (lcmpval!=0) ? lcmpval : rh.compare(oth.rh); } bool relational::match_same_type(const basic & other) const -- 2.34.1

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Re: [GiNaC-devel] [GiNaC-list] A strange behaviour while implementing archive in a user-defined class
by Vladimir V. Kisil 20 Dec '21

20 Dec '21

>>>>> On Mon, 20 Dec 2021 08:57:42 +0000, Oleg Finkelshteyn <olegfink(a)gmail.com> said: OF> i suspect this is actually due to a typo in OF> relational::compare_same_type. Thanks for spotting the source. It is worth to cross-post your patch to GiNaC-devel list. -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Maps https://doi.org/10.1142/p835 Soft: Geometry of cycles http://moebinv.sourceforge.net/ Jupyter notebooks: https://github.com/vvkisil?tab=repositories ==================================================== diff --git a/ginac/relational.cpp b/ginac/relational.cpp index 599a2635..dbc541a3 100644 --- a/ginac/relational.cpp +++ b/ginac/relational.cpp @@ -223,8 +223,8 @@ int relational::compare_same_type(const basic & other) const return (o < oth.o) ? -1 : 1; break; } - const int lcmpval = lh.compare(oth.rh); - return (lcmpval!=0) ? lcmpval : rh.compare(oth.lh); + const int lcmpval = lh.compare(oth.lh); + return (lcmpval!=0) ? lcmpval : rh.compare(oth.rh); }

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