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@ -543,8 +543,8 @@ case (1,2,3) of
##### Ability patterns
An _ability pattern_ only appears in an _ability handler_ and has one of two forms (see [Abilities and ability handlers](#abilities-and-ability-handlers) for details):
1. `{C p1 p2 ... pn -> k}` where `C` is the name of an ability constructor in scope, and `p1` through `pn` are patterns such that `n` is the arity of `C`. Note that `n` may be zero. This pattern matches if the scrutinee reduces to a fully applied invocation of the ability constructor `C` and the patterns `p1` through `pn` match the arguments to the constructor. The scrutinee must be of type `Effect A T` for some ability `{A}` and type `T`. The variable `k` will be bound to the continuation of the program. If the scrutinee has type `Effect A T` and `C` has type `X ->{A} Y`, then `k` has type `Y -> {A} T`.
2. `{p}` where `p` is a pattern. This matches the case where the computation is _pure_ (the value of type `Effect A T` calls none of the constructors of the ability `{A}`). A pattern match on an `Effect` is not complete unless this case is handled.
1. `{C p1 p2 ... pn -> k}` where `C` is the name of an ability constructor in scope, and `p1` through `pn` are patterns such that `n` is the arity of `C`. Note that `n` may be zero. This pattern matches if the scrutinee reduces to a fully applied invocation of the ability constructor `C` and the patterns `p1` through `pn` match the arguments to the constructor. The scrutinee must be of type `Request A T` for some ability `{A}` and type `T`. The variable `k` will be bound to the continuation of the program. If the scrutinee has type `Request A T` and `C` has type `X ->{A} Y`, then `k` has type `Y -> {A} T`.
2. `{p}` where `p` is a pattern. This matches the case where the computation is _pure_ (the value of type `Request A T` calls none of the constructors of the ability `{A}`). A pattern match on an `Request` is not complete unless this case is handled.
See the section on [abilities and ability handlers](#abilities-and-ability-handlers) for examples of ability patterns.
@ -729,7 +729,7 @@ ability Abort where
aborting : ()
-- Returns `a` immediately if the program `e` calls `abort`
abortHandler : a -> Effect Abort a -> a
abortHandler : a -> Request Abort a -> a
abortHandler a e = case e of
{ Abort.aborting -> _ } -> a
{ x } -> x
@ -748,13 +748,13 @@ The pattern `{ x }` matches the case where the computation is pure (makes no fur
When a handler calls the continuation, it needs describe how the ability is provided in the rest of the program, usually with a recursive call, like this:
``` haskell
use .base Effect
use .base Request
ability Stored v where
get : v
put : v -> ()
storeHandler : v -> Effect (Stored v) a -> a
storeHandler : v -> Request (Stored v) a -> a
storeHandler storedValue s = case s of
{Stored.get -> k} ->
handle storeHandler storedValue in k storedValue