- Add db/table/index drop, index rename/wait to CE - Add DU for index rename opt args |
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README.md |
RethinkDb.Driver.FSharp
Idiomatic F# extensions for the C# RethinkDB driver
Using
Install the NuGet package RethinkDb.Driver.FSharp
. You will need to specify pre-release, as the package has an alpha designation at this time.
Goals
The goal is to provide:
- A composable pipeline for creating ReQL statements:
/// string -> (IConnection -> Task<Post>)
let fetchPost (postId : string) =
fromDb "Blog"
|> table "Post"
|> get postId
|> runResult<Post>
|> withRetryDefault
- An F# domain-specific language (DSL) using a
rethink
computation expression (CE):
/// string -> (IConnection -> Task<Post>)
let fetchPost (postId : string) =
rethink<Post> {
withTable "Blog.Post"
get postId
result
withRetryDefault
}
- A standard way to translate JSON into a strongly-typed configuration:
/// type: DataConfig
let config = DataConfig.fromJsonFile "data-config.json"
// OR
let config = DataConfig.fromConfiguration (config.GetSection "RethinkDB")
/// type: IConnection
let conn = config.Connect ()
/// type: Post (utilizing either example above)
// (within a task CE)
let! post = fetchPost "the-post-id" conn
- Robust queries
The RethinkDB connection is generally stored as a singleton. Over time, this connection can lose its connection to the server. Both the CE and functions have withRetryDefault
, which will retry a failed command up to 3 times (4 counting the initial try), waiting 200ms, 500ms, and 1 second between the respective attempts. There are other options as well; withRetryOnce
will retry one time immediately. withRetry
takes a list of float
s, which will be interpreted as seconds to delay between each retry; it will retry until it has exhausted the delays.
The examples above both use the default retry logic.
- Only rename functions/methods where required
Within the CE, there are a few differing names, mostly notably at the start (selecting databases and tables); this is to allow for a more natural language flow. Its names may change in the 0.8.x series; it is the most alpha part of the project at this point.
The functions do have to change a bit, since they do not support overloading; an example for filter
is below.
// Function names cannot be polymorphic the way object-oriented methods can, so filter's three overloads become
filter (r.HashMap ("age", 30))
// and
filterFunc (fun row -> row.["age"].Eq(30))
// and
filterJS "function (row) { return 30 == row['age'] }"
Licensing
While no specific additional license restrictions exist for this project, there are modifications to the Apache v2 license on this project's dependencies. Please see the heading on the C# driver page for details.
If you are using the project, feel free to file issues about your pain points; there is no substitute for real-world feedback!