replace _deep_flatten_consts

nutils/evaluable.py

@@ -295,7 +295,7 @@ def dependencies(self):
         for func in self.__args:
             funcdeps = func.dependencies
             deps.update(funcdeps)
-            deps[func] = len(funcdeps)
+            deps[func] = not func.isconstant, len(funcdeps)
         return types.frozendict(deps)
 
     @cached_property
@@ -336,11 +336,9 @@ def serialized(self):
     # property should be treated as if it is immutable.
     @cached_property
     def _serialized_evalf_head(self):
-        return tuple(op.evalf for op in self.ordereddeps[1:])
-
-    @property
-    def _serialized_evalf(self):
-        return zip(itertools.chain(self._serialized_evalf_head, (self.evalf,)), self.dependencytree[1:])
+        serialized = tuple(zip((op.evalf for op in self.ordereddeps[1:]), self.dependencytree[1:-1]))
+        nconsts = builtins.sum(itertools.takewhile(lambda v: v, map(operator.attrgetter('isconstant'), self.ordereddeps[1:])))
+        return serialized, nconsts
 
     def _node(self, cache, subgraph, times):
         if self in cache:
@@ -366,14 +364,25 @@ def eval(self, **evalargs):
         '''Evaluate function on a specified element, point set.'''
 
         values = [evalargs]
+        serialized_head, nconsts = self._serialized_evalf_head
+        if nconsts and (consts := getattr(self, '_eval_consts', None)):
+            assert len(consts) == nconsts
+            if len(serialized_head) + 1 == nconsts:
+                # self is constant
+                return consts[-1]
+            values.extend(consts)
+            serialized_head = serialized_head[nconsts:]
         try:
-            values.extend(op_evalf(*[values[i] for i in indices]) for op_evalf, indices in self._serialized_evalf)
+            values.extend(op_evalf(*[values[i] for i in indices]) for op_evalf, indices in serialized_head)
+            values.append(self.evalf(*[values[i] for i in self.dependencytree[-1]]))
         except KeyboardInterrupt:
             raise
         except Exception as e:
             log.error(self._format_stack(values, e))
             raise
         else:
+            if nconsts and consts is None:
+                self._eval_consts = values[1:1 + nconsts]
             return values[-1]
 
     def eval_withtimes(self, times, **evalargs):
@@ -449,7 +458,6 @@ def _simplified(self):
     @cached_property
     def optimized_for_numpy(self):
         retval = self.simplified._optimized_for_numpy1() or self
-        retval = retval._deep_flatten_constants() or retval
         return retval._combine_loop_concatenates(frozenset())
 
     @replace(depthfirst=True, recursive=True)
@@ -463,11 +471,6 @@ def _optimized_for_numpy1(obj):
     def _optimized_for_numpy(self):
         return
 
-    @replace(depthfirst=False, recursive=False)
-    def _deep_flatten_constants(self):
-        if isinstance(self, Array):
-            return self._flatten_constant()
-
     @cached_property
     def _loop_concatenate_deps(self):
         deps = []
@@ -1003,10 +1006,6 @@ def _const_uniform(self):
             lower, upper = self._intbounds
             return lower if lower == upper else None
 
-    def _flatten_constant(self):
-        if self.isconstant:
-            return constant(self.eval())
-
 
 class Orthonormal(Array):
     'make a vector orthonormal to a subspace'
@@ -1187,9 +1186,6 @@ def _const_uniform(self):
         if self.ndim == 0:
             return self.dtype(self.value[()])
 
-    def _flatten_constant(self):
-        pass
-
 
 class InsertAxis(Array):
 
@@ -1309,9 +1305,6 @@ def _intbounds_impl(self):
     def _const_uniform(self):
         return self.func._const_uniform
 
-    def _flatten_constant(self):
-        pass
-
 
 class Transpose(Array):
 
@@ -1507,9 +1500,6 @@ def _intbounds_impl(self):
     def _const_uniform(self):
         return self.func._const_uniform
 
-    def _flatten_constant(self):
-        pass
-
 
 class Product(Array):