Update docs

docs/src/03-response-anatomy.md

@@ -195,6 +195,23 @@ setStatus :: IsResp a => Status -> a -> a
 Although we rarely need this function as `ok` sets the right status 
 for successful response and all functions that need the status take it as argument.
 
+Also we have functions to set cookies that are form url-encoded:
+
+```haskell
+setCookie :: (ToForm val, IsResp a) => SetCookie val -> a -> a
+
+-- sets cookie params
+data SetCookie 
+
+-- | Cookie setter with default params (only value)
+defCookie :: val -> SetCookie val
+defCookie = ...
+```
+
+For great explanation on how cookies work in HTTP you can read [an article](https://web.archive.org/web/20170122122852/https://www.nczonline.net/blog/2009/05/05/http-cookies-explained/).
+Under the hood it is just a http-header with name `SetCookie`.
+To read the cookie value use input request `newtype`-wrapper `Cookie`.
+
 ### How it works with server definition
 
 How can we use both of the types as responses: `Resp` and `RespOr`?

docs/src/09-reference.md

@@ -138,6 +138,21 @@ class IsResp a where
 
 setHeader :: (IsResp a, ToHttpApiData h) => HeaderName -> h -> a -> a
 
+-- | Set cookie as http header from form url encoded value
+setCookie :: (ToForm cookie, IsResp resp) => SetCookie cookie -> resp -> resp
+
+data SetCookie a = SetCookie
+  { cookie :: a
+  , expires :: Maybe UTCTime
+  , domain :: Maybe Text
+  , path :: Maybe Text
+  , secure :: Bool
+  , httpOnly :: Bool
+  }
+
+-- | Default cookie which sets only the cookie itself.
+defCookie :: a -> SetCookie a
+
 -- | Bad request. The @bad@ response with 400 status.
 badReq :: (IsResp a) => RespError a -> a