add enable

[t61j]

Add enable. http://expressjs.com/en/4x/api.html#app.enable

[srghma]

I think it's better if we wont allow to use these methods: enable, disable, get without callback, set

but instead, make safe wrappers for the settings table variables http://expressjs.com/en/4x/api.html#app.settings.table

[srghma]

something like

BuiltinTable.Properties

case_sensitive_routing = "case sensitive routing"
env                    = "env"
etag                   = "etag"
jsonp_callback_name    = "jsonp callback name"
json_escape            = "json escape"
json_replacer          = "json replacer"
json_spaces            = "json spaces"
query_parser           = "query parser"
strict_routing         = "strict routing"
subdomain_offset       = "subdomain offset"
trust_proxy            = "trust proxy"
views                  = "views"
view_cache             = "view cache"
view_engine            = "view engine"
x_powered_by           = "x-powered-by"


BuiltinTable.Unsafe

foreign import _get :: Fn2 Application String (Effect Foreign)
foreign import _set :: Fn2 Application String Foreign (Effect Unit)
foreign import _enable :: Fn2 Application String (Effect Unit)
-- Boolean because https://github.com/expressjs/express/blob/508936853a6e311099c9985d4c11a4b1b8f6af07/lib/application.js#L421
foreign import _enabled :: Fn2 Application String (Effect Boolean)
foreign import _disable :: Fn2 Application String (Effect Unit)
foreign import _disabled :: Fn2 Application String (Effect Boolean)

BuiltinTable.Safe

set__case_sensitive_routing :: Boolean -> AppM Unit
get__case_sensitive_routing :: AppM Boolean

get__env :: AppM String
set__env :: ...

data Etag = Disabled | Enabled | Strong | Weak | Dynamic
get__etag ::

get__jsonp_callback_name :: AppM String
get__json_escape :: AppM Boolean
# set__json_replacer :: AppM
# get__json_spaces :: AppM ???
# get__query_parser :: AppM
# get__strict_routing :: AppM
# get__subdomain_offset :: AppM
# get__trust_proxy :: AppM
# get__views :: AppM
# get__view_cache :: AppM
# get__view_engine :: AppM
# get__x_powered_by :: AppM