Prepare use of R^d -> (R) function for P0 vector interpolation

src/scheme/DiscreteFunctionVectorInterpoler.cpp

@@ -96,11 +96,7 @@ template <size_t Dimension>
 DiscreteFunctionVariant
 DiscreteFunctionVectorInterpoler::_interpolate() const
 {
-  for (const auto& function_id : m_function_id_list) {
-    const auto& function_descriptor = function_id.descriptor();
-    Assert(function_descriptor.domainMappingNode().children[1]->m_data_type == ASTNodeDataType::typename_t);
-    const ASTNodeDataType& data_type = function_descriptor.domainMappingNode().children[1]->m_data_type.contentType();
-
+  auto check_data_type = [](const ASTNodeDataType& data_type) {
     switch (data_type) {
     case ASTNodeDataType::bool_t:
     case ASTNodeDataType::unsigned_int_t:
@@ -115,7 +111,32 @@ DiscreteFunctionVectorInterpoler::_interpolate() const
       throw NormalError(os.str());
     }
     }
+  };
+
+  if (m_function_id_list.size() == 1) {
+    const auto& function_descriptor = m_function_id_list[0].descriptor();
+    if ((function_descriptor.domainMappingNode().children[1]->m_data_type == ASTNodeDataType::typename_t) or
+        (function_descriptor.domainMappingNode().children[1]->m_data_type == ASTNodeDataType::tuple_t)) {
+      const ASTNodeDataType& data_type = function_descriptor.domainMappingNode().children[1]->m_data_type.contentType();
+
+      check_data_type(data_type);
+    } else {
+      throw UnexpectedError("incorrect function");
+    }
+  } else {
+    for (const auto& function_id : m_function_id_list) {
+      const auto& function_descriptor = function_id.descriptor();
+      if (function_descriptor.domainMappingNode().children[1]->m_data_type == ASTNodeDataType::typename_t) {
+        const ASTNodeDataType& data_type =
+          function_descriptor.domainMappingNode().children[1]->m_data_type.contentType();
+
+        check_data_type(data_type);
+      } else {
+        throw UnexpectedError("incorrect function");
+      }
+    }
   }
+
   return this->_interpolate<Dimension, double>();
 }