bkmgit commented on a change in pull request #10296: URL: https://github.com/apache/arrow/pull/10296#discussion_r776177694
########## File path: docs/source/cpp/authoring_compute_functions.rst ########## @@ -0,0 +1,423 @@ +.. 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. + +.. default-domain:: cpp +.. highlight:: cpp +.. cpp:namespace:: arrow::compute + +=========================== +Authoring Compute Functions +=========================== + +Compute Functions +================= + +An introduction to compute functions is provided in https://arrow.apache.org/docs/cpp/compute.html. + +The [compute submodule](https://github.com/edponce/arrow/tree/master/cpp/src/arrow/compute) contains analytical functions that process primarily columnar data for either scalar or Arrow-based array inputs. These are intended for use inside query engines, data frame libraries, etc. + +Many functions have SQL-like semantics in that they perform element-wise or scalar operations on whole arrays at a time. Other functions are not SQL-like and compute results that may be a different length or whose results depend on the order of the values. + +Terminology: +* The term compute "function" refers to a particular general operation that may have many different implementations corresponding to different combinations of types or function behavior options. +* A specific implementation of a function is a "kernel". Selecting a viable kernel for executing a function is referred to as "dispatching". When executing a function on inputs, we must first select a suitable kernel corresponding to the value types of the inputs is selected. +* Functions along with their kernel implementations are collected in a "function registry". Given a function name and argument types, we can look up that function and dispatch to a compatible kernel. + +[Compute functions](https://github.com/apache/arrow/blob/master/cpp/src/arrow/compute/function.h) have the following principal attributes: +* A unique ["name"](https://arrow.apache.org/docs/cpp/api/compute.html#_CPPv4NK5arrow7compute8Function4nameEv) used for function invocation and language bindings Review comment: ```suggestion * A unique :doc:`name <.compute>` used for function invocation and language bindings ``` Adding a section heading to the approriate part of the compute documentation will give a better link. See [restructured text documentation](https://www.sphinx-doc.org/en/master/usage/restructuredtext/roles.html#cross-referencing-arbitrary-locations) -- 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]
