8 replies

I want an Effect.all() which receives a map

Hi folks,

I'm sort of allergic to the

Effect.gen()

Effect.gen()

syntax.

First, some context. Please forgive my noob questions and hardline fp stance.

My ideal app architecture is that my application, or at least each request is simply a purely-composed

pipe()

pipe()

function, assembled imperatively at the very top level in my

main

main

function, with all errors and effectful behaviour handled at that top level.

Functional core, imperative shell. A classic architecture, and theoretically a no-brainer in

Effect

Effect

.

My questions:

1) given the ubiquity of the
Effect.gen()
Effect.gen()
/ imperative-style syntax, is pipeline-only style Effect even possible?
I remember maestro Ethan being quite explicit in a talk about gen and pipeline syntax being essentially toggleable in the docs, but I no longer see any such thing. It looks like I have to call

gen

gen

, use

yield*

yield*

syntax, and write much more imperative code than I want to.

2) if the answer to #1 is yes, then is there some kind of
Effect.all
Effect.all
which can receive a value, like a map, which is then combined with one or more of the elements in the
all
all
array/object?

Usage:

const myProgram = pipe(
 inputValue,
 Effect.map(someTransformation),
// Hypothetical function here:
 Effect.mapAll(transformationResult => ([
  effect1(transformationResult),
  effect2,
  effect3
 ]),
 Effect.map(([
  effect1WithMappedTransformationResult,
  effect2Result,
  effect3Result
 ]) => {
  // doing cool stuff here
 })
)

const myProgram = pipe(
 inputValue,
 Effect.map(someTransformation),
// Hypothetical function here:
 Effect.mapAll(transformationResult => ([
  effect1(transformationResult),
  effect2,
  effect3
 ]),
 Effect.map(([
  effect1WithMappedTransformationResult,
  effect2Result,
  effect3Result
 ]) => {
  // doing cool stuff here
 })
)

The

Effect.gen

Effect.gen

syntax would make bypassing this issue fairly easy by just having the

transformationResult

transformationResult

in block scope for use by an

Effect.all

Effect.all

, but in a strict pipeline, it doesn't seem to be possible.

I've scoured the docs and can't find any evidence of what I'm after, though the use case seems clear?

Thanks for your time + help!

Edit: SOLVED thanks to @Tim Smart for saving my life:

  Effect.flatMap(
    prev => Effect.all([
      effect1(prev),
      effect2,
      effect3
    ])
  )

  Effect.flatMap(
    prev => Effect.all([
      effect1(prev),
      effect2,
      effect3
    ])
  )

I want an Effect.all() which receives a map

Hi folks,

I'm sort of allergic to the

Effect.gen()

Effect.gen()

syntax.

First, some context. Please forgive my noob questions and hardline fp stance.

My ideal app architecture is that my application, or at least each request is simply a purely-composed

pipe()

pipe()

function, assembled imperatively at the very top level in my

main

main

function, with all errors and effectful behaviour handled at that top level.

Functional core, imperative shell. A classic architecture, and theoretically a no-brainer in

Effect

Effect

gen

gen

, use

yield*

yield*

const myProgram = pipe(
 inputValue,
 Effect.map(someTransformation),
// Hypothetical function here:
 Effect.mapAll(transformationResult => ([
  effect1(transformationResult),
  effect2,
  effect3
 ]),
 Effect.map(([
  effect1WithMappedTransformationResult,
  effect2Result,
  effect3Result
 ]) => {
  // doing cool stuff here
 })
)

const myProgram = pipe(
 inputValue,
 Effect.map(someTransformation),
// Hypothetical function here:
 Effect.mapAll(transformationResult => ([
  effect1(transformationResult),
  effect2,
  effect3
 ]),
 Effect.map(([
  effect1WithMappedTransformationResult,
  effect2Result,
  effect3Result
 ]) => {
  // doing cool stuff here
 })
)

The

Effect.gen

Effect.gen

syntax would make bypassing this issue fairly easy by just having the

transformationResult

transformationResult

in block scope for use by an

Effect.all

Effect.all

  Effect.flatMap(
    prev => Effect.all([
      effect1(prev),
      effect2,
      effect3
    ])
  )

  Effect.flatMap(
    prev => Effect.all([
      effect1(prev),
      effect2,
      effect3
    ])
  )

I want an Effect.all() which receives a map

I want an Effect.all() which receives a map

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