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_exp :: {{Type}} -> Type -> Type

val sql_query : tables :: {({Type} * {Type})}
        -> {From : $(fold (fn nm => fn selected_unselected :: ({Type} * {Type}) => fn acc =>
                [nm] ~ acc => selected_unselected.1 ~ selected_unselected.2 =>
                [nm = sql_table (selected_unselected.1 ++ selected_unselected.2)] ++ acc) [] tables),
            Where : sql_exp (fold (fn nm => fn selected_unselected :: ({Type} * {Type}) => fn acc =>
                [nm] ~ acc => selected_unselected.1 ~ selected_unselected.2 =>
                [nm = selected_unselected.1 ++ selected_unselected.2] ++ acc) [] tables) bool}
        -> sql_query (fold (fn nm => fn selected_unselected :: ({Type} * {Type}) => fn acc => [nm] ~ acc =>
                [nm = selected_unselected.1] ++ acc) [] tables)

class sql_type
val sql_bool : sql_type bool
val sql_int : sql_type int
val sql_float : sql_type float
val sql_string : sql_type string

val sql_inject : tables ::: {{Type}} -> t ::: Type -> t -> sql_type t -> sql_exp tables t

con sql_unary :: Type -> Type -> Type
val sql_not : sql_unary bool bool
val sql_unary : tables ::: {{Type}} -> arg ::: Type -> res ::: Type
        -> sql_unary arg res -> sql_exp tables arg -> sql_exp tables 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}} -> arg1 ::: Type -> arg2 ::: Type -> res ::: Type
        -> sql_binary arg1 arg2 res -> sql_exp tables arg1 -> sql_exp tables arg2 -> sql_exp tables 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}} -> t ::: Type -> sql_exp tables t -> sql_exp tables t
        -> sql_type t -> sql_exp tables 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 []