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Add sample Ur/Web files
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Taken from tokenrove/parsur so I don't have to worry about license
hassles.  (You may relicense these samples as necessary.)

It would be nice to have an example of the embedded SQL syntax in a
sample.
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tokenrove committed Oct 3, 2015
1 parent 88cc73f commit 538f479
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79 changes: 79 additions & 0 deletions samples/UrWeb/iso8601.ur
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open Parse.String

val digit = satisfy isdigit

val decimal_of_len n =
ds <- count n digit;
return (List.foldl (fn d acc => 10*acc + ((ord d)-(ord #"0"))) 0 ds)

val date =
y <- decimal_of_len 4;
char' #"-";
m <- decimal_of_len 2;
char' #"-";
d <- decimal_of_len 2;
if m > 0 && m <= 12 then
return {Year=y, Month=(Datetime.intToMonth (m-1)), Day=d}
else
fail

(* We parse fractions of a second, but ignore them since Datetime
doesn't permit representing them. *)
val time =
h <- decimal_of_len 2;
char' #":";
m <- decimal_of_len 2;
s <- maybe (char' #":";
s <- decimal_of_len 2;
maybe' (char' #"."; skipWhile isdigit);
return s);
return {Hour=h, Minute=m, Second=Option.get 0 s}

val timezone_offset =
let val zulu = char' #"Z"; return 0
val digits = decimal_of_len 2
val sign = or (char' #"+"; return 1)
(char' #"-"; return (-1))
in
zulu `or` (s <- sign;
h <- digits;
m <- (maybe' (char' #":"); or digits (return 0));
return (s*(h*60+m)))
end

val datetime_with_tz =
d <- date; char' #"T"; t <- time;
tz <- timezone_offset;
return (d ++ t ++ {TZOffsetMinutes=tz})

val datetime =
d <- datetime_with_tz;
return (d -- #TZOffsetMinutes)

fun process v =
case parse (d <- datetime_with_tz; eof; return d) v of
Some r =>
let
val {Year=year,Month=month,Day=day,
Hour=hour,Minute=minute,Second=second} =
Datetime.addMinutes (r.TZOffsetMinutes) (r -- #TZOffsetMinutes)
fun pad x =
if x < 10 then "0" `strcat` show x else show x
in
<xml>{[pad hour]}:{[pad minute]}:{[pad second]} {[month]} {[day]}, {[year]}</xml>
end
| None => <xml>none</xml>

fun main () : transaction page =
input <- source "2012-01-01T01:10:42Z";
return <xml>
<body>
<label>
Enter an
<a href="https://en.wikipedia.org/wiki/ISO_8601">ISO 8601</a>
datetime here:
<ctextbox source={input} />
</label>
<ul><dyn signal={v <- signal input; return (process v)} /></ul>
</body>
</xml>
85 changes: 85 additions & 0 deletions samples/UrWeb/parse.urs
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functor Make(Stream : sig type t end) : sig
con t :: Type -> Type

val mreturn : a ::: Type -> a -> t a
val mbind : a ::: Type -> b ::: Type ->
(t a) -> (a -> t b) -> (t b)
val monad_parse : monad t

val parse : a ::: Type -> t a -> Stream.t -> option a

(** Combinators *)
val fail : a ::: Type -> t a
val or : a ::: Type -> t a -> t a -> t a
val maybe : a ::: Type -> t a -> t (option a)
val maybe' : a ::: Type -> t a -> t unit
val many : a ::: Type -> t a -> t (list a)
val count : a ::: Type -> int -> t a -> t (list a)
val skipMany : a ::: Type -> t a -> t unit
val sepBy : a ::: Type -> s ::: Type -> t a -> t s -> t (list a)
end

structure String : sig
con t :: Type -> Type
val monad_parse : monad t

val parse : a ::: Type -> t a -> string -> option a

(** Combinators *)
val fail : a ::: Type -> t a
val or : a ::: Type -> t a -> t a -> t a
val maybe : a ::: Type -> t a -> t (option a)
val maybe' : a ::: Type -> t a -> t unit
val many : a ::: Type -> t a -> t (list a)
val count : a ::: Type -> int -> t a -> t (list a)
val skipMany : a ::: Type -> t a -> t unit
val sepBy : a ::: Type -> s ::: Type -> t a -> t s -> t (list a)

val eof : t unit
(* We provide alternative versions of some of these predicates
* that return t unit as a monadic syntactical convenience. *)
val string : string -> t string
val string' : string -> t unit
val stringCI : string -> t string
val stringCI' : string -> t unit
val char : char -> t char
val char' : char -> t unit
val take : int -> t (string*int)
val drop : int -> t unit
val satisfy : (char -> bool) -> t char
val skip : (char -> bool) -> t unit
val skipWhile : (char -> bool) -> t unit
val takeWhile : (char -> bool) -> t (string*int)
val takeWhile' : (char -> bool) -> t string (* conses *)
(* Well, "till" is the correct form; but "til" is in common enough
* usage that I'll prefer it for terseness. *)
val takeTil : (char -> bool) -> t (string*int)
val takeTil' : (char -> bool) -> t string (* conses *)
val takeRest : t string

(** Convenience functions *)
val skipSpace : t unit
val endOfLine : t unit
val unsigned_int_of_radix : int -> t int
(*
* val signed_int_of_radix : int -> t int
* val double : t float
*)
end

structure Blob : sig
con t :: Type -> Type
val monad_parse : monad t

val parse : a ::: Type -> t a -> blob -> option a

(** Combinators *)
val fail : a ::: Type -> t a
val or : a ::: Type -> t a -> t a -> t a
val maybe : a ::: Type -> t a -> t (option a)
val maybe' : a ::: Type -> t a -> t unit
val many : a ::: Type -> t a -> t (list a)
val count : a ::: Type -> int -> t a -> t (list a)
val skipMany : a ::: Type -> t a -> t unit
val sepBy : a ::: Type -> s ::: Type -> t a -> t s -> t (list a)
end

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