Epic success \/ failure, refactoring to *real* FP

Epic Success V Failure ? Refactoring to real FP

Eric Torreborre

Why, oh why?

What now?

How hard can it be?

HelloWorldSpec.scala

How hard can it be?

Text

Example

Text

Text

Example

Step

Example

Filtering

by nameby previous

Execution

concurre

ntcondition

al

Reporting

console

html

How hard can it be?

Configuration(s)Resources

FileSystem

“Flow”

State

Composition

Errors

Problem?

Strategy

Strategy

Filtering by name

Filtering by previous

Text Example Example Text

Stats

result

resultresult

resultresult

Monad stacks

Task[A]

AError

AError

A

Future

Monad stacks values

AError

Future

now(a: A)

delay(a: =>A)A

Error

Future

AError

Future

fail(t: Throwable)

and

flatM

ap!

Action in action

Action[A]

AError

AError

A

IO

AError

IO

Reader

Conf => IO[A] => IO[Error]

Error = String | Throwable | (String, Throwable)

Action in action

Action opportunity

Read

everything

!

Filtering by previous

Text Example Example Text

Stats

result

resultresult

resultresult

Filtering by previous

Text Example Example Text

Stats

result

Action[Fragment] => Task[Fragment]

Fragment => Action[Result]Action[Result] => Action[Fragment]

map

Task[Fragment] => Process[Task, Fragment]

eval

Filtering by previous

flatM

ap!

Filtering by previous

On stacks

No big deal

Specialise

Library

Composition?

Integration?

Scalaz-stream

Concurrency with

Easy!

Concurrency with

With state!

Text Example Example Step Example

stop here

Flatmap with

Online

testing!

Flatmap with

Online

testing!

Text1 Example1 Example2 Example3

Text1 Example1 Example2 Example3

Example2.1 Example2.2

Reporting with

“duplicate”stream

Write to console

Accumulatestate

Reporting with

Text1 Example1 Example2 Example3

“t1” “e1” “e2” “e3”

> Console

stats stats stats

Reporting with

Not composable

Reporting with and Folds!

Reporting with and Folds!

Reporting with and Folds!

Opaque

dependent

type

Reporting with and Folds!

Fold Monoid!

Reporting with and Folds!

Conclusion