dedicated syntax for specific effects

Imperative programming languages nowadays often have async/await for concurrency. Though strictly less general than do notation it is kind of nice that it explicitly specifies which effect is being managed at the use site whereas otherwise effects could be harder to notice visually. Another example of this is Swift’s try/throws syntax for Either like exceptions.

Consider this Swift example:

async let access1 = readFileAsync(url: url1)
async let access2 = readFileAsync(url: url2)
let (contents1, contents2) = try await (access1, access2)
let newContents = contents1 + contents2
try await writeFileAsync(url: url3)

try/async/await clearly de-mark where effects occur. In a naive Haskell implementation of this they might not be.