fp-ts TaskEither Async Patterns

TaskEither combines the laziness of Task with the error handling of Either, providing a powerful abstraction for async operations that can fail.

Core Concepts

import * as TE from 'fp-ts/TaskEither'
import * as T from 'fp-ts/Task'
import * as E from 'fp-ts/Either'
import { pipe, flow } from 'fp-ts/function'

TaskEither<E, A> is equivalent to () => Promise<Either<E, A>>

• E = Error type (left)
• A = Success type (right)
• Lazy: nothing executes until you call the function
• Composable: chain operations without try/catch