Multiple items
module List
from Microsoft.FSharp.Collections
--------------------
type List<'T> =
| ( [] )
| ( :: ) of Head: 'T * Tail: 'T list
interface IEnumerable
interface IEnumerable<'T>
member GetSlice : startIndex:int option * endIndex:int option -> 'T list
member Head : 'T
member IsEmpty : bool
member Item : index:int -> 'T with get
member Length : int
member Tail : 'T list
static member Cons : head:'T * tail:'T list -> 'T list
static member Empty : 'T list
Full name: Microsoft.FSharp.Collections.List<_>
union case Option.Some: Value: 'T -> Option<'T>
union case Option.None: Option<'T>
val async : AsyncBuilder
Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.async
Multiple items
type Async
static member AsBeginEnd : computation:('Arg -> Async<'T>) -> ('Arg * AsyncCallback * obj -> IAsyncResult) * (IAsyncResult -> 'T) * (IAsyncResult -> unit)
static member AwaitEvent : event:IEvent<'Del,'T> * ?cancelAction:(unit -> unit) -> Async<'T> (requires delegate and 'Del :> Delegate)
static member AwaitIAsyncResult : iar:IAsyncResult * ?millisecondsTimeout:int -> Async<bool>
static member AwaitTask : task:Task -> Async<unit>
static member AwaitTask : task:Task<'T> -> Async<'T>
static member AwaitWaitHandle : waitHandle:WaitHandle * ?millisecondsTimeout:int -> Async<bool>
static member CancelDefaultToken : unit -> unit
static member Catch : computation:Async<'T> -> Async<Choice<'T,exn>>
static member FromBeginEnd : beginAction:(AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg:'Arg1 * beginAction:('Arg1 * AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * beginAction:('Arg1 * 'Arg2 * AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * arg3:'Arg3 * beginAction:('Arg1 * 'Arg2 * 'Arg3 * AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromContinuations : callback:(('T -> unit) * (exn -> unit) * (OperationCanceledException -> unit) -> unit) -> Async<'T>
static member Ignore : computation:Async<'T> -> Async<unit>
static member OnCancel : interruption:(unit -> unit) -> Async<IDisposable>
static member Parallel : computations:seq<Async<'T>> -> Async<'T []>
static member RunSynchronously : computation:Async<'T> * ?timeout:int * ?cancellationToken:CancellationToken -> 'T
static member Sleep : millisecondsDueTime:int -> Async<unit>
static member Start : computation:Async<unit> * ?cancellationToken:CancellationToken -> unit
static member StartAsTask : computation:Async<'T> * ?taskCreationOptions:TaskCreationOptions * ?cancellationToken:CancellationToken -> Task<'T>
static member StartChild : computation:Async<'T> * ?millisecondsTimeout:int -> Async<Async<'T>>
static member StartChildAsTask : computation:Async<'T> * ?taskCreationOptions:TaskCreationOptions -> Async<Task<'T>>
static member StartImmediate : computation:Async<unit> * ?cancellationToken:CancellationToken -> unit
static member StartWithContinuations : computation:Async<'T> * continuation:('T -> unit) * exceptionContinuation:(exn -> unit) * cancellationContinuation:(OperationCanceledException -> unit) * ?cancellationToken:CancellationToken -> unit
static member SwitchToContext : syncContext:SynchronizationContext -> Async<unit>
static member SwitchToNewThread : unit -> Async<unit>
static member SwitchToThreadPool : unit -> Async<unit>
static member TryCancelled : computation:Async<'T> * compensation:(OperationCanceledException -> unit) -> Async<'T>
static member CancellationToken : Async<CancellationToken>
static member DefaultCancellationToken : CancellationToken
Full name: Microsoft.FSharp.Control.Async
--------------------
type Async<'T>
Full name: Microsoft.FSharp.Control.Async<_>
static member Async.Sleep : millisecondsDueTime:int -> Async<unit>
FUNCTIONAL-FIRST
programming with F#
F# is a mature, open source, cross-platform, functional-first programming language.
It empowers users to tackle complex problems with simple code.
A function from \(A\) to \(B\) is an object \(f\)
such that every \(a\in A\) is uniquely
associated with an object \(f(a)\in B\).
A function is the purpose for which
something is designed or exists.
Transform a value into a new value
using a series of transformations.
DEMO
Transforming 3D shapes
The elimination of ornament
The elimination of language keywords
1:
2:
3:
4:
|
Fun.cylinder
|> Fun.color Colors.yellow
|> Fun.scale (1.0, 3.0, 1.0)
|> Fun.move (0.0, -2.0, 0.0)
|
Navigating through and extracting
information from a data source.
DEMO
JSON type provider in F#
Design conveys the message of simplicity,
using basic geometric forms, simple materials.
1:
2:
3:
4:
5:
|
type W = JsonProvider<"http://...">
let weather = W.GetSample()
for w in weather.List do
printTemp w.Temp.Day w.Temp.Night
|
How far can we go
with a given material?
DEMO
Pivot provider in TheGamma
If dot is concrete, then type providers are reinforced concrete.
Give an alternative meaning
to an ordinary computation.
1:
2:
3:
4:
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7:
|
let tryGetPageLength url =
let wc = WebClient()
try
let html = wc.Download(url)
Some(html.Length)
with e ->
None
|
1:
2:
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|
let tryGetPageLength url = async {
let wc = WebClient()
try
let! html = wc.AsyncDownload(url)
return Some(html.Length)
with e ->
return None }
|
DEMO
Asynchronous computations
Use flexible material and
design with material in mind.
Using the right abstraction
should be either easy or impossible.
1:
2:
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6:
|
type AsyncSeq<'T> =
Async<AsyncSeqResult<'T>>
and AsyncSeqResult<'T> =
| Empty
| Value of 'T * AsyncSeq<'T>
|
DEMO
Asynchronous sequences
Modernism is associated with
- Analytical approach to the function
- Rational use of new materials
- Openness to structural innovation
- The elimination of ornament
Function composition
elimination of ornament
Type providers
structural innovation
Computation expressions
leverage new materials
FUNCTIONAL PROGRAMMING
Function as in purpose
Form follows function
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2:
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|
let whatDoesThisMean () = reactive {
let trumpTweets = getTrumpTweets()
for t in trumpTweets do
if t.Text.Contains("great") then
do! Async.Sleep(1000)
yield t }
|