Unison language preview

1. Doubling a list

an ability declaration, a function, and a test

horizon-dark

-- doubles every element of a list
structural ability Stream where
  emit : Nat -> ()

use List map

double : [Nat] -> [Nat]
double xs = map (n -> n * 2) xs

test> double.tests.ex1 =
  match double [1, 2, 3] with
    [2, 4, 6] -> ok "matched"
    _ -> fail "no match"

atom-one-dark

-- doubles every element of a list
structural ability Stream where
  emit : Nat -> ()

use List map

double : [Nat] -> [Nat]
double xs = map (n -> n * 2) xs

test> double.tests.ex1 =
  match double [1, 2, 3] with
    [2, 4, 6] -> ok "matched"
    _ -> fail "no match"

github-dark

-- doubles every element of a list
structural ability Stream where
  emit : Nat -> ()

use List map

double : [Nat] -> [Nat]
double xs = map (n -> n * 2) xs

test> double.tests.ex1 =
  match double [1, 2, 3] with
    [2, 4, 6] -> ok "matched"
    _ -> fail "no match"

dracula

-- doubles every element of a list
structural ability Stream where
  emit : Nat -> ()

use List map

double : [Nat] -> [Nat]
double xs = map (n -> n * 2) xs

test> double.tests.ex1 =
  match double [1, 2, 3] with
    [2, 4, 6] -> ok "matched"
    _ -> fail "no match"

nord

-- doubles every element of a list
structural ability Stream where
  emit : Nat -> ()

use List map

double : [Nat] -> [Nat]
double xs = map (n -> n * 2) xs

test> double.tests.ex1 =
  match double [1, 2, 3] with
    [2, 4, 6] -> ok "matched"
    _ -> fail "no match"

github

-- doubles every element of a list
structural ability Stream where
  emit : Nat -> ()

use List map

double : [Nat] -> [Nat]
double xs = map (n -> n * 2) xs

test> double.tests.ex1 =
  match double [1, 2, 3] with
    [2, 4, 6] -> ok "matched"
    _ -> fail "no match"

2. Ability sets

an ability set in a function signature

horizon-dark

main : '{IO, Exception} ()
main = do
  printLine "hello"

atom-one-dark

main : '{IO, Exception} ()
main = do
  printLine "hello"

github-dark

main : '{IO, Exception} ()
main = do
  printLine "hello"

dracula

main : '{IO, Exception} ()
main = do
  printLine "hello"

nord

main : '{IO, Exception} ()
main = do
  printLine "hello"

github

main : '{IO, Exception} ()
main = do
  printLine "hello"

3. Doc literals

the {{ }} doc literal syntax

horizon-dark

## double
{{ Doubles the given number. }}
double : Nat -> Nat
double n = n * 2

atom-one-dark

## double
{{ Doubles the given number. }}
double : Nat -> Nat
double n = n * 2

github-dark

## double
{{ Doubles the given number. }}
double : Nat -> Nat
double n = n * 2

dracula

## double
{{ Doubles the given number. }}
double : Nat -> Nat
double n = n * 2

nord

## double
{{ Doubles the given number. }}
double : Nat -> Nat
double n = n * 2

github

## double
{{ Doubles the given number. }}
double : Nat -> Nat
double n = n * 2