From: Michael Orlitzky <michael@orlitzky.com>
Date: Sat, 13 Mar 2021 15:37:44 +0000 (-0500)
Subject: eja: speed up _all2list().
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=e8599960ef47e5a5af8aca360a041d30584f6c3f;p=sage.d.git

eja: speed up _all2list().
---

diff --git a/mjo/eja/eja_utils.py b/mjo/eja/eja_utils.py
index 1cf13bc..a432861 100644
--- a/mjo/eja/eja_utils.py
+++ b/mjo/eja/eja_utils.py
@@ -1,4 +1,5 @@
 from sage.functions.other import sqrt
+from sage.structure.element import is_Matrix
 from sage.matrix.constructor import matrix
 from sage.modules.free_module_element import vector
 
@@ -147,9 +148,16 @@ def _all2list(x):
         # first needing to convert them to a list of octonions and
         # then recursing down into the list. It also avoids the wonky
         # list(x) when x is an element of a CFM. I don't know what it
-        # returns but it aint the coordinates. This will fall through
-        # to the iterable case the next time around.
-        return _all2list(x.to_vector())
+        # returns but it aint the coordinates. We don't recurse
+        # because vectors can only contain ring elements as entries.
+        return x.to_vector().list()
+
+    if is_Matrix(x):
+        # This sucks, but for performance reasons we don't want to
+        # call _all2list recursively on the contents of a matrix
+        # when we don't have to (they only contain ring elements
+        # as entries)
+        return x.list()
 
     try:
         xl = list(x)
@@ -160,7 +168,7 @@ def _all2list(x):
         # Avoid the retardation of list(QQ(1)) == [1].
         return [x]
 
-    return sum(list( map(_all2list, xl) ), [])
+    return sum( map(_all2list, xl) , [])