mbeckerle commented on a change in pull request #273: WIP: Add User Defined Functions Capability URL: https://github.com/apache/incubator-daffodil/pull/273#discussion_r336030672
########## File path: daffodil-runtime1/src/main/scala/org/apache/daffodil/dpath/UserDefinedFunctionBase.scala ########## @@ -0,0 +1,35 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.daffodil.dpath + +import org.apache.daffodil.exceptions.Assert +import java.lang.reflect.Method +import org.apache.daffodil.udf.UserDefinedFunction + +/** + * Both the evaluate method and the User Defined Function instance are passed in, as both are needed by the Method.invoke + * function. + */ +case class UserDefinedFunctionCall(recipes: List[CompiledDPath], userDefinedFunction: UserDefinedFunction, evaluateFxn: Method) + extends FNArgsList(recipes) { + override def computeValue(values: List[Any], dstate: DState) = { + val jValues = values.map { _.asInstanceOf[Object] } + val res = evaluateFxn.invoke(userDefinedFunction, jValues: _*) Review comment: The DFDL constructors with the hex strings you mention, ... strings and numeric ranges really are pretty different. In this particular case, those functions have this artificial hex syntax feature intended to be used with literal constants e.g., dfdl:int("xA1B2C3D4"). They *could* be used with the argument coming direct from data, but how likely is it that data would use this prefix "x" convention to indicate a value expressed in hex? This is clearly for use with human authored constants, and that's why this is an SDE, not a PE. Fact is, it *should* be a PE, and we should be able to rely on Daffodil to detect this PE at compile time for literal constants. I'm not sure we can do that right now. I think we eval expressions at compile time, but if they cause an error we just assume they can't be successfully evaluated at compile time, and so are not constants. So I think if we made these PE, then dfdl:int("foobar") would end up a PE at runtime, which we don't want. This is just a limitation of our expression compiler though. It *could* tell the difference between an error evaluating an expression due to constant args, vs. accessing the infoset (which doesn't exist at compile time). I just don't think it does right now. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
