thrift/lib/hs

Haskell Thrift Bindings

License

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.

Compile

Use Cabal to compile and install; ./configure uses Cabal underneath, and that path is not yet well tested. Thrift's library and generated code should compile with pretty much any GHC extensions or warnings you enable (or disable). Please report this not being the case as a bug on https://issues.apache.org/jira/secure/CreateIssue!default.jspa

Chances you'll need to muck a bit with Cabal flags to install Thrift:

CABAL_CONFIGURE_FLAGS="--user" ./configure

Base Types

The mapping from Thrift types to Haskell's is:

• double -> Double
• byte -> Data.Int.Int8
• i16 -> Data.Int.Int16
• i32 -> Data.Int.Int32
• i64 -> Data.Int.Int64
• string -> Text
• binary -> Data.ByteString.Lazy
• bool -> Boolean

Enums

Become Haskell 'data' types. Use fromEnum to get out the int value.

Lists

Become Data.Vector.Vector from the vector package.

Maps and Sets

Become Data.HashMap.Strict.Map and Data.HashSet.Set from the unordered-containers package.

Structs

Become records. Field labels are ugly, of the form f_STRUCTNAME_FIELDNAME. All fields are Maybe types.

Exceptions

Identical to structs. Use them with throw and catch from Control.Exception.

Client

Just a bunch of functions. You may have to import a bunch of client files to deal with inheritance.

Interface

You should only have to import the last one in the chain of inheritors. To make an interface, declare a label:

data MyIface = MyIface

and then declare it an instance of each iface class, starting with the superest class and proceeding down (all the while defining the methods). Then pass your label to process as the handler.

Processor

Just a function that takes a handler label, protocols. It calls the superclasses process if there is a superclass.