use libgap in simplicial_complex

[dimpase]

this is just a 1-line change.

A part of #26902

CC: @jhpalmieri

Component: algebraic topology

Author: Dima Pasechnik

Branch/Commit: 1867190

Reviewer: John Palmieri

Issue created by migration from https://trac.sagemath.org/ticket/34769

[jhpalmieri]

comment:2

Would it make sense to make it a 2-line change instead?

diff --git a/src/sage/topology/simplicial_complex.py b/src/sage/topology/simplicial_complex.py
index fe237895d8..857430769a 100644
--- a/src/sage/topology/simplicial_complex.py
+++ b/src/sage/topology/simplicial_complex.py
@@ -4081,7 +4081,7 @@ class SimplicialComplex(Parent, GenericCellComplex):
             return self.connected_component(Simplex([base_point])).fundamental_group(simplify=simplify)

         from sage.groups.free_group import FreeGroup
-        from sage.libs.gap.libgap import libgap as gap
+        from sage.libs.gap.libgap import libgap
         G = self.graph()
         # If the vertices and edges of G are not sortable, e.g., a mix
         # of str and int, Sage+Python 3 may raise a TypeError when
@@ -4098,7 +4098,7 @@ class SimplicialComplex(Parent, GenericCellComplex):
                 for e in G2.edges(sort=True)
                 if e not in spanning_tree]
         if len(gens) == 0:
-            return gap.TrivialGroup()
+            return libgap.TrivialGroup()

         # Edges in the graph may be sorted differently than in the
         # simplicial complex, so convert the edges to frozensets so we

[dimpase]

comment:3

We have imported libgap as gap, thus gap is the right thing in the scope, no?

[jhpalmieri]

comment:4

Your proposed change is this:

diff --git a/src/sage/topology/simplicial_complex.py b/src/sage/topology/simplicial_complex.py
index 736df96..fe23789 100644
--- a/src/sage/topology/simplicial_complex.py
+++ b/src/sage/topology/simplicial_complex.py
@@ -4081,7 +4081,7 @@ class SimplicialComplex(Parent, GenericCellComplex):
             return self.connected_component(Simplex([base_point])).fundamental_group(simplify=simplify)

         from sage.groups.free_group import FreeGroup
-        from sage.interfaces.gap import gap
+        from sage.libs.gap.libgap import libgap as gap
         G = self.graph()
         # If the vertices and edges of G are not sortable, e.g., a mix
         # of str and int, Sage+Python 3 may raise a TypeError when

I'm suggesting just doing from ... import libgap and also changing the one other line that uses gap.

[jhpalmieri]

comment:5

The Sage library tends to use from ... import libgap rather than from ... import libgap as gap, and consistency might be good.

[dimpase]

comment:6

as our aim is to drop pexpect gap, and rename libgap -> gap, I don't see why we should keep the convention you mentioned. It is less changes yo be done at the final stage this way (with your proposal,we will then have to change back all libgap. to gap.

[jhpalmieri]

Reviewer: John Palmieri

[jhpalmieri]

comment:7

It's fine, we can leave this as is, but currently searching for "import libgap as gap" (that is, git grep "import.*libgap.*as.*gap) comes up empty in the Sage library. I didn't know there was a proposal to rename libgap to gap.

[vbraun]

Changed branch from u/dimpase/topology/use_libgap to 1867190