type int
type float
type string

type unit = {}

datatype bool = False | True


(** SQL *)

con sql_table :: {Type} -> Type

(*** Queries *)

con sql_query :: {{Type}} -> Type
con sql_query1 :: {{Type}} -> {{Type}} -> Type
con sql_exp :: {{Type}} -> {{Type}} -> Type -> Type

con sql_subset :: {{Type}} -> {{Type}} -> Type
val sql_subset : keep_drop :: {({Type} * {Type})}
        -> sql_subset
                (fold (fn nm => fn fields :: ({Type} * {Type}) => fn acc =>
                        [nm] ~ acc => fields.1 ~ fields.2 =>
                        [nm = fields.1 ++ fields.2] ++ acc) [] keep_drop)
                (fold (fn nm => fn fields :: ({Type} * {Type}) => fn acc =>
                        [nm] ~ acc =>
                        [nm = fields.1] ++ acc) [] keep_drop)
val sql_subset_all : tables :: {{Type}}
        -> sql_subset tables tables

val sql_query1 : tables ::: {{Type}}
        -> grouped ::: {{Type}}
        -> selected ::: {{Type}}
        -> {From : $(fold (fn nm => fn fields :: {Type} => fn acc =>
                [nm] ~ acc => [nm = sql_table fields] ++ acc) [] tables),
            Where : sql_exp tables [] bool,
            GroupBy : sql_subset tables grouped,
            Having : sql_exp grouped tables bool,
            SelectFields : sql_subset grouped selected}
        -> sql_query1 tables selected

type sql_relop 
val sql_union : sql_relop
val sql_intersect : sql_relop
val sql_except : sql_relop
val sql_relop : sql_relop
        -> tables1 ::: {{Type}}
        -> tables2 ::: {{Type}}
        -> selected ::: {{Type}}
        -> sql_query1 tables1 selected -> sql_query1 tables2 selected -> sql_query1 selected selected

type sql_direction
val sql_asc : sql_direction
val sql_desc : sql_direction

con sql_order_by :: {{Type}} -> Type
val sql_order_by_Nil : tables :: {{Type}} -> sql_order_by tables
val sql_order_by_Cons : tables ::: {{Type}} -> t ::: Type
        -> sql_exp tables [] t -> sql_order_by tables
        -> sql_order_by tables

type sql_limit
val sql_no_limit : sql_limit
val sql_limit : int -> sql_limit

val sql_query : tables ::: {{Type}}
        -> selected ::: {{Type}}
        -> {Rows : sql_query1 tables selected,
            OrderBy : sql_order_by tables,
            Limit : sql_limit}
        -> sql_query selected

val sql_field : otherTabs ::: {{Type}} -> otherFields ::: {Type} -> fieldType ::: Type -> agg ::: {{Type}}
        -> tab :: Name -> field :: Name
        -> sql_exp ([tab = [field = fieldType] ++ otherFields] ++ otherTabs) agg fieldType

class sql_injectable
val sql_bool : sql_injectable bool
val sql_int : sql_injectable int
val sql_float : sql_injectable float
val sql_string : sql_injectable string
val sql_inject : tables ::: {{Type}} -> agg ::: {{Type}} -> t ::: Type -> t -> sql_injectable t -> sql_exp tables agg t

con sql_unary :: Type -> Type -> Type
val sql_not : sql_unary bool bool
val sql_unary : tables ::: {{Type}} -> agg ::: {{Type}} -> arg ::: Type -> res ::: Type
        -> sql_unary arg res -> sql_exp tables agg arg -> sql_exp tables agg res

con sql_binary :: Type -> Type -> Type -> Type
val sql_and : sql_binary bool bool bool
val sql_or : sql_binary bool bool bool
val sql_binary : tables ::: {{Type}} -> agg ::: {{Type}} -> arg1 ::: Type -> arg2 ::: Type -> res ::: Type
        -> sql_binary arg1 arg2 res -> sql_exp tables agg arg1 -> sql_exp tables agg arg2 -> sql_exp tables agg res

type sql_comparison
val sql_eq : sql_comparison
val sql_ne : sql_comparison
val sql_lt : sql_comparison
val sql_le : sql_comparison
val sql_gt : sql_comparison
val sql_ge : sql_comparison
val sql_comparison : sql_comparison
        -> tables ::: {{Type}} -> agg ::: {{Type}} -> t ::: Type -> sql_exp tables agg t -> sql_exp tables agg t
        -> sql_injectable t -> sql_exp tables agg bool

(** XML *)

con tag :: {Type} -> {Unit} -> {Unit} -> {Type} -> {Type} -> Type


con xml :: {Unit} -> {Type} -> {Type} -> Type
val cdata : ctx ::: {Unit} -> use ::: {Type} -> string -> xml ctx use []
val tag : attrsGiven ::: {Type} -> attrsAbsent ::: {Type} -> attrsGiven ~ attrsAbsent
        -> ctxOuter ::: {Unit} -> ctxInner ::: {Unit}
        -> useOuter ::: {Type} -> useInner ::: {Type} -> useOuter ~ useInner
        -> bindOuter ::: {Type} -> bindInner ::: {Type} -> bindOuter ~ bindInner
        -> $attrsGiven
        -> tag (attrsGiven ++ attrsAbsent) ctxOuter ctxInner useOuter bindOuter
        -> xml ctxInner useInner bindInner
        -> xml ctxOuter (useOuter ++ useInner) (bindOuter ++ bindInner)
val join : ctx ::: {Unit} 
        -> use1 ::: {Type} -> bind1 ::: {Type} -> bind2 ::: {Type}
        -> use1 ~ bind1 -> bind1 ~ bind2
        -> xml ctx use1 bind1
        -> xml ctx (use1 ++ bind1) bind2
        -> xml ctx use1 (bind1 ++ bind2)
val useMore : ctx ::: {Unit} -> use1 ::: {Type} -> use2 ::: {Type} -> bind ::: {Type}
        -> use1 ~ use2
        -> xml ctx use1 bind
        -> xml ctx (use1 ++ use2) bind

con xhtml = xml [Html]
con page = xhtml [] []

(*** HTML details *)

con html = [Html]
con head = [Head]
con body = [Body]
con lform = [Body, LForm]

val head : unit -> tag [] html head [] []
val title : unit -> tag [] head [] [] []

val body : unit -> tag [] html body [] []
con bodyTag = fn attrs :: {Type} => ctx ::: {Unit} -> [Body] ~ ctx -> unit
        -> tag attrs ([Body] ++ ctx) ([Body] ++ ctx) [] []
con bodyTagStandalone = fn attrs :: {Type} => ctx ::: {Unit} -> [Body] ~ ctx -> unit
        -> tag attrs ([Body] ++ ctx) [] [] []

val br : bodyTagStandalone []

val p : bodyTag []
val b : bodyTag []
val i : bodyTag []
val font : bodyTag [Size = int, Face = string]

val h1 : bodyTag []
val li : bodyTag []

val a : bodyTag [Link = page]

val lform : ctx ::: {Unit} -> [Body] ~ ctx -> bind ::: {Type}
        -> xml lform [] bind
        -> xml ([Body] ++ ctx) [] []
con lformTag = fn ty :: Type => fn inner :: {Unit} => fn attrs :: {Type} =>
        ctx ::: {Unit} -> [LForm] ~ ctx
        -> nm :: Name -> unit
        -> tag attrs ([LForm] ++ ctx) inner [] [nm = ty]
val textbox : lformTag string [] []
val password : lformTag string [] []
val ltextarea : lformTag string [] []

val checkbox : lformTag bool [] []

con radio = [Body, Radio]
val radio : lformTag string radio []
val radioOption : unit -> tag [Value = string] radio [] [] []

con select = [Select]
val lselect : lformTag string select []
val loption : unit -> tag [Value = string] select [] [] []

val submit : ctx ::: {Unit} -> [LForm] ~ ctx
        -> use ::: {Type} -> unit
        -> tag [Action = $use -> page] ([LForm] ++ ctx) ([LForm] ++ ctx) use []