ManifoldSubset: Change some methods to generators

[mkoeppe]

This ticket proposes to change some methods that currently return lists to generators - like the method open_supersets added in #31677. This is in line with the changes in the Python standard library when we moved from Python 2 to 3.

ManifoldSubset:

• open_covers() currently returns a list of lists

  • change to generator of ManifoldSubsetFiniteFamily instances
  • add optional argument trivial to simplify the common use case that only needs the nontrivial open covers

• subsets() currently returns a frozenset

  • change to generator of ManifoldSubset instances

These API changes will probably make some updates to sage.manifolds worksheets that are maintained outside of the Sage tree necessary.

Follow-up for some methods of Manifold in #31720.

Depends on #31680

CC: @mjungmath @egourgoulhon @tscrim

Component: manifolds

Author: Matthias Koeppe

Branch/Commit: e026e7a

Reviewer: Eric Gourgoulhon

Issue created by migration from https://trac.sagemath.org/ticket/31718

[mkoeppe]

Branch: u/mkoeppe/manifoldsubset__manifold__change_some_methods_to_generators

[mkoeppe]

Description changed:

--- 
+++ 
@@ -2,7 +2,7 @@
 
 `ManifoldSubset`:
 - `open_covers()` currently returns a list of lists
-  - change to generator of `FiniteManifoldSubsetFamily` instances 
+  - change to generator of `ManifoldSubsetFiniteFamily` instances 
 
 - `subsets()` currently returns a `frozenset`
   - change to generator of `ManifoldSubset` instances

[mkoeppe]

New commits:

186707b

ManifoldSubset.subsets: Change to generator

[mkoeppe]

Commit: 186707b

[mkoeppe]

Description changed:

--- 
+++ 
@@ -3,6 +3,7 @@
 `ManifoldSubset`:
 - `open_covers()` currently returns a list of lists
   - change to generator of `ManifoldSubsetFiniteFamily` instances 
+  - add optional argument `trivial` to simplify the common use case that only needs nontrivial open covers
 
 - `subsets()` currently returns a `frozenset`
   - change to generator of `ManifoldSubset` instances

[sagetrac-git]

Changed commit from 186707b to 78cc27a

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. Last 10 new commits:

42abda7	Adding `__bool__` for other families.
1f21a8f	Merge #31717
f095988	FiniteManifoldObjectFamily.__bool__: Remove, inherited from superclass after #31717
5d87cee	Manifold{Object,Subset}FiniteFamily: Rename from FiniteManifold{Object,Subset}Family
2f2ace2	src/doc/en/reference/manifolds/manifold.rst: Add sage.manifolds.family
1aff58a	Fix up docstring markup
b922066	ManifoldSubsetFiniteFamily: If all subsets are open, include 'open' in repr
30271af	Fixup doctest
adac07a	Merge #31680
78cc27a	ManifoldSubset.open_covers: Change to generator, add optional arg 'trivial'; update uses

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Description changed:

--- 
+++ 
@@ -3,14 +3,10 @@
 `ManifoldSubset`:
 - `open_covers()` currently returns a list of lists
   - change to generator of `ManifoldSubsetFiniteFamily` instances 
-  - add optional argument `trivial` to simplify the common use case that only needs nontrivial open covers
+  - add optional argument `trivial` to simplify the common use case that only needs the nontrivial open covers
 
 - `subsets()` currently returns a `frozenset`
   - change to generator of `ManifoldSubset` instances
 
-`Manifold`:
-- `top_charts()` currently returns a list
-  - change to generator of charts
-- `coord_changes()` currently returns a copy
-  - change to generator of pairs `((from, to), map)` ... so that `dict(M.coord_changes())` will create the copy
-     
+Follow-up for some methods of `Manifold` in #31720.
+

[sagetrac-git]

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

e026e7a

ManifoldSubset.subset_digraph: Use open_covers method

[sagetrac-git]

Changed commit from 78cc27a to e026e7a

[mkoeppe]

Description changed:

--- 
+++ 
@@ -8,5 +8,8 @@
 - `subsets()` currently returns a `frozenset`
   - change to generator of `ManifoldSubset` instances
 
+These API changes will probably make some updates to sage.manifolds worksheets that are maintained outside of the Sage tree necessary.
+
+
 Follow-up for some methods of `Manifold` in #31720.
 

[egourgoulhon]

Reviewer: Eric Gourgoulhon

[egourgoulhon]

comment:8

LGTM. Thanks!