cpcloud commented on a change in pull request #10934: URL: https://github.com/apache/arrow/pull/10934#discussion_r698458633
########## File path: format/experimental/computeir/Expression.fbs ########## @@ -0,0 +1,351 @@ +// 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. + +include "../../Schema.fbs"; +include "Literal.fbs"; +include "InlineBuffer.fbs"; + +namespace org.apache.arrow.computeir.flatbuf; + +/// Access a value for a given map key +table MapKey { + key: string (required); +} + +/// Struct field access +table StructField { + /// The position of the field in the struct schema + position: uint32; +} + +/// Zero-based array index +table ArraySubscript { + position: uint32; +} + +/// Zero-based range of elements in an array +table ArraySlice { + /// The start of an array slice, inclusive + start_inclusive: uint32; + /// The end of an array slice, exclusive + end_exclusive: uint32; +} + +/// Field name in a relation +table FieldName { + position: uint32; +} + +/// A union of possible dereference operations +union Deref { + /// Access a value for a given map key + MapKey, + /// Access the value at a struct field + StructField, + /// Access the element at a given index in an array + ArraySubscript, + /// Access a range of elements in an array + ArraySlice, + /// Access a field of a relation + FieldName, +} + +/// Access the data of a field +table FieldRef { + /// A sequence of field names to allow referencing potentially nested fields + ref: Deref (required); + /// For Expressions which might reference fields in multiple Relations, + /// this index may be provided to indicate which Relation's fields + /// `path` points into. For example in the case of a join, + /// 0 refers to the left relation and 1 to the right relation. + relation_index: int; +} + +/// A canonical (probably SQL equivalent) function +// +// TODO: variadics +enum CanonicalFunctionId : uint32 { Review comment: Are we actually sure this is possible to do for all of the types we want to support? What the key is for, say, the `==` operator for a complex type like list or struct? I don't think a wildcard type is well-defined here without more clarification. For example, `List<T>` can only be compared with `List<U>` if `T == U`, but if `T != U` the operation is undefined. Unnest is another example. With a type system that handles generics, you can't write down the type of all possible instantiations of any type that has a type parameter, such as list, map, and struct. What is the issue with having a list of functions in some structured format, that indicates the canonical name of the function and its arity? If a producer sends over a call to the add function with input types `int32, int32` and output type `int32`, then the consumer would look that up, and if it's able to execute that IR, then it does and if it's not able to do so it returns an error. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
