major improvements to lazy power series

[mwhansen]

Some re-structuring of the streams / series code fixes many issues and makes the code quite a bit simpler.

Fixes #15249, #15248, #10084, #10085, #10086, #13433, #14685, #12648, #12649.

CC: @mantepse @videlec

Component: combinatorics

Keywords: LazyPowerSeries, days57

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/15673

[mwhansen]

Branch: u/mhansen/species_stream

[mwhansen]

comment:2

One thing that should be done (maybe not on this ticket) is to deprecate the code in sage.combinat.species.stream.

---

Last 10 new commits:

b7afcd7	Simplifications to new_stream.py
69b55ab	Add documentation / doctests
13c5a49	Remove TODO in cycle_species.py
bdad7a3	#12648: Species do not support renaming
d2d753e	Fix bug in SeriesStream.is_constant()
fea9eb0	#15248: Convert LazyPowerSeriesRing (and friends) to new coercion model
6525200	Remove dependence on sage.combinat.species.stream
ed19baa	Add doctests to new_stream.py
654a89d	Add doctests to generating_series.py
bd7527c	More work on doctests for series_stream.py

[mwhansen]

Commit: a696708

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

f4157f7

Remove dead code in GenericCombinatorialSpecies._series_helper

[sagetrac-git]

Changed commit from a696708 to f4157f7

[mantepse]

comment:4

Hi Mike! Thank you for uploading the new code!

I have one immediate question: if I understand correctly, you chose to introduce a new class for every operation on streams, eg. SumStream, ProductStream, TailStream, DerivativeStream, etc.

Could you explain why...? I would have thought that these things fit more natural into various generating series classes, but I'm sure you have thought quite a lot about this...

Thanks again,

Martin

[mwhansen]

comment:5

The main idea is to have the streams know about their (approximate) order. That way we don't have to worry about initializing generators with the correct approximate order. We can also do some improvements w.r.t. caching if the streams are a bit more structured.

[mantepse]

comment:6

Thanks for the explanation!

I am currently compiling sage to try your code. In case you have enough time: I recently reviewed ticket #14846, which is based on the old code... Unfortunately, it is still not in the develop branch, so maybe it's better to wait until it is.

[mwhansen]

Description changed:

--- 
+++ 
@@ -1,3 +1,3 @@
 Some re-structuring of the streams / series code fixes many issues and makes the code quite a bit simpler.
 
-Fixes #15249, #15248, #10084, #10085, #10086, #13433, #14685.
+Fixes #15249, #15248, #10084, #10085, #10086, #13433, #14685, #12648, #12659.

[mantepse]

comment:8

Mike, Are you sure that #12659 is related?

[mwhansen]

comment:9

Oops, I meant #12649.