TODO: action and algorithms/formtransformation

ufl/algorithms/checks.py

@@ -15,6 +15,7 @@
 from ufl.form import Form
 from ufl.argument import Argument
 from ufl.coefficient import Coefficient
+from ufl.subspace import Subspace
 from ufl.constantvalue import is_true_ufl_scalar
 
 # UFL algorithms
@@ -52,9 +53,10 @@ def validate_form(form):  # TODO: Can we make this return a list of errors inste
     elif len(cells) > 1:
         errors.append(f"Multiple cell definitions in form: {cells}")
 
-    # Check that no Coefficient or Argument instance have the same
+    # Check that no Coefficient/Subspace or Argument instance have the same
     # count unless they are the same
     coefficients = {}
+    subspaces = {}
     arguments = {}
     for e in iter_expressions(form):
         for f in traverse_unique_terminals(e):
@@ -68,6 +70,16 @@ def validate_form(form):  # TODO: Can we make this return a list of errors inste
                 else:
                     coefficients[c] = f
 
+            if isinstance(f, Subspace):
+                c = f.count()
+                if c in subspaces:
+                    g = subspaces[c]
+                    if f is not g:
+                        errors.append("Found different Subspaces with "
+                                      f"same count: {f} and {g}.")
+                else:
+                    subspaces[c] = f
+
             elif isinstance(f, Argument):
                 n = f.number()
                 p = f.part()

ufl/algorithms/signature.py

@@ -10,7 +10,7 @@
 import hashlib
 from ufl.classes import (Label,
                          Index, MultiIndex,
-                         Coefficient, Argument,
+                         Coefficient, Subspace, Argument,
                          GeometricQuantity, ConstantValue, Constant,
                          ExprList, ExprMapping)
 from ufl.corealg.traversal import traverse_unique_terminals, unique_post_traversal
@@ -58,6 +58,9 @@ def compute_terminal_hashdata(expressions, renumbering):
             elif isinstance(expr, Coefficient):
                 data = expr._ufl_signature_data_(renumbering)
 
+            elif isinstance(expr, Subspace):
+                data = expr._ufl_signature_data_(renumbering)
+
             elif isinstance(expr, Constant):
                 data = expr._ufl_signature_data_(renumbering)
 

ufl/algorithms/strip_terminal_data.py

@@ -3,7 +3,7 @@
 data-carrying objects have been extracted to a mapping."""
 
 from ufl.classes import Form, Integral
-from ufl.classes import Argument, Coefficient, Constant
+from ufl.classes import Argument, Coefficient, Subspace, Constant
 from ufl.classes import FunctionSpace, TensorProductFunctionSpace, MixedFunctionSpace
 from ufl.classes import Mesh, MeshView, TensorProductMesh
 from ufl.algorithms.replace import replace
@@ -26,6 +26,11 @@ def coefficient(self, o):
                             o.count())
         return self.mapping.setdefault(o, o_new)
 
+    def subspace(self, o):
+        o_new = Subspace(strip_function_space(o.ufl_function_space()),
+                            o.count())
+        return self.mapping.setdefault(o, o_new)
+
     def constant(self, o):
         o_new = Constant(strip_domain(o.ufl_domain()), o.ufl_shape,
                          o.count())
@@ -118,4 +123,4 @@ def strip_domain(domain):
         meshes = [strip_domain(mesh) for mesh in domain.ufl_meshes()]
         return TensorProductMesh(meshes, domain.ufl_id())
     else:
-        raise NotImplementedError(f"{type(domain)} cannot be stripped")
+        raise NotImplemen`tedError(f"{type(domain)} cannot be stripped")

ufl/sorting.py

@@ -17,6 +17,7 @@
 from ufl.core.expr import Expr
 from ufl.argument import Argument
 from ufl.coefficient import Coefficient
+from ufl.subspace import Subspace
 from ufl.core.multiindex import FixedIndex, MultiIndex
 from ufl.variable import Label
 
@@ -61,7 +62,7 @@ def _cmp_label(a, b):
 
 
 def _cmp_coefficient(a, b):
-    # It's ok to compare relative counts for Coefficients,
+    # It's ok to compare relative counts for Coefficients/Subspaces,
     # since their ordering is a property of the form
     x, y = a._count, b._count
     if x < y:
@@ -97,6 +98,7 @@ def _cmp_terminal_by_repr(a, b):
 _terminal_cmps[MultiIndex._ufl_typecode_] = _cmp_multi_index
 _terminal_cmps[Argument._ufl_typecode_] = _cmp_argument
 _terminal_cmps[Coefficient._ufl_typecode_] = _cmp_coefficient
+_terminal_cmps[Subspace._ufl_typecode_] = _cmp_coefficient
 _terminal_cmps[Label._ufl_typecode_] = _cmp_label
 
 

ufl/split_functions.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-"Algorithm for splitting a Coefficient or Argument into subfunctions."
+"Algorithm for splitting a Coefficient/Subspace or Argument into subfunctions."
 
 # Copyright (C) 2008-2016 Martin Sandve Alnæs
 #
@@ -18,7 +18,7 @@
 
 
 def split(v):
-    """UFL operator: If v is a Coefficient or Argument in a mixed space, returns
+    """UFL operator: If v is a Coefficient/Subspace or Argument in a mixed space, returns
     a tuple with the function components corresponding to the subelements."""
 
     # Default range is all of v