Mercurial > urweb

annotate lib/ur/top.ur @ 1401:af501150678a

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Error message when FOREIGN KEY listts have different lengths
author Adam Chlipala <adam@chlipala.net>
date Sun, 16 Jan 2011 14:16:09 -0500
parents d328983dc5a6
children 8631e9ed0ee8
rev   line source
adamc@623 1 (** Row folding *)
adamc@623 2
adamc@623 3 con folder = K ==> fn r :: {K} =>
adamc@623 4 tf :: ({K} -> Type)
adamc@653 5 -> (nm :: Name -> v :: K -> r :: {K} -> [[nm] ~ r] =>
adamc@653 6 tf r -> tf ([nm = v] ++ r))
adamc@623 7 -> tf [] -> tf r
adamc@623 8
adamc@822 9 fun fold [K] [tf :: {K} -> Type]
adamc@653 10 (f : (nm :: Name -> v :: K -> r :: {K} -> [[nm] ~ r] =>
adamc@653 11 tf r -> tf ([nm = v] ++ r)))
adamc@1093 12 (i : tf []) [r ::: {K}] (fl : folder r) = fl [tf] f i
adamc@653 13
adamc@627 14 structure Folder = struct
adamc@822 15 fun nil [K] [tf :: {K} -> Type]
adamc@653 16 (f : nm :: Name -> v :: K -> r :: {K} -> [[nm] ~ r] =>
adamc@653 17 tf r -> tf ([nm = v] ++ r))
adamc@627 18 (i : tf []) = i
adamc@627 19
adamc@822 20 fun cons [K] [r ::: {K}] [nm :: Name] [v :: K] [[nm] ~ r] (fold : folder r)
adamc@822 21 [tf :: {K} -> Type]
adamc@653 22 (f : nm :: Name -> v :: K -> r :: {K} -> [[nm] ~ r] =>
adamc@653 23 tf r -> tf ([nm = v] ++ r))
adamc@653 24 (i : tf []) = f [nm] [v] [r] ! (fold [tf] f i)
adamc@628 25
adamc@822 26 fun concat [K] [r1 ::: {K}] [r2 ::: {K}] [r1 ~ r2]
adamc@628 27 (f1 : folder r1) (f2 : folder r2)
adamc@822 28 [tf :: {K} -> Type]
adamc@653 29 (f : nm :: Name -> v :: K -> r :: {K} -> [[nm] ~ r] =>
adamc@653 30 tf r -> tf ([nm = v] ++ r))
adamc@628 31 (i : tf []) =
adamc@629 32 f1 [fn r1' => [r1' ~ r2] => tf (r1' ++ r2)]
adamc@822 33 (fn [nm :: Name] [v :: K] [r1' :: {K}] [[nm] ~ r1']
adamc@653 34 (acc : [r1' ~ r2] => tf (r1' ++ r2))
adamc@653 35 [[nm = v] ++ r1' ~ r2] =>
adamc@653 36 f [nm] [v] [r1' ++ r2] ! acc)
adamc@629 37 (fn [[] ~ r2] => f2 [tf] f i) !
adamc@630 38
adamc@822 39 fun mp [K1] [K2] [f ::: K1 -> K2] [r ::: {K1}]
adamc@630 40 (fold : folder r)
adamc@822 41 [tf :: {K2} -> Type]
adamc@653 42 (f : nm :: Name -> v :: K2 -> r :: {K2} -> [[nm] ~ r] =>
adamc@653 43 tf r -> tf ([nm = v] ++ r))
adamc@630 44 (i : tf []) =
adamc@630 45 fold [fn r => tf (map f r)]
adamc@822 46 (fn [nm :: Name] [v :: K1] [rest :: {K1}] [[nm] ~ rest] (acc : tf (map f rest)) =>
adamc@653 47 f [nm] [f v] [map f rest] ! acc)
adamc@630 48 i
adamc@627 49 end
adamc@627 50
adamc@623 51
adamc@422 52 fun not b = if b then False else True
adamc@422 53
adamc@898 54 con id = K ==> fn t :: K => t
adamc@356 55 con record (t :: {Type}) = $t
adamc@637 56 con fst = K1 ==> K2 ==> fn t :: (K1 * K2) => t.1
adamc@637 57 con snd = K1 ==> K2 ==> fn t :: (K1 * K2) => t.2
adamc@637 58 con fst3 = K1 ==> K2 ==> K3 ==> fn t :: (K1 * K2 * K3) => t.1
adamc@637 59 con snd3 = K1 ==> K2 ==> K3 ==> fn t :: (K1 * K2 * K3) => t.2
adamc@637 60 con thd3 = K1 ==> K2 ==> K3 ==> fn t :: (K1 * K2 * K3) => t.3
adamc@329 61
adamc@643 62 con mapU = K ==> fn f :: K => map (fn _ :: Unit => f)
adamc@445 63
adamc@339 64 con ex = fn tf :: (Type -> Type) =>
adamc@356 65 res ::: Type -> (choice :: Type -> tf choice -> res) -> res
adamc@339 66
adamc@822 67 fun ex [tf :: (Type -> Type)] [choice :: Type] (body : tf choice) : ex tf =
adamc@822 68 fn [res] (f : choice :: Type -> tf choice -> res) =>
adamc@356 69 f [choice] body
adamc@339 70
adamc@822 71 fun compose [t1 ::: Type] [t2 ::: Type] [t3 ::: Type]
adamc@356 72 (f1 : t2 -> t3) (f2 : t1 -> t2) (x : t1) = f1 (f2 x)
adamc@325 73
adamc@822 74 fun show_option [t ::: Type] (_ : show t) =
adamc@777 75 mkShow (fn opt : option t =>
adamc@777 76 case opt of
adamc@777 77 None => ""
adamc@777 78 | Some x => show x)
adamc@777 79
adamc@822 80 fun read_option [t ::: Type] (_ : read t) =
adamc@777 81 mkRead (fn s =>
adamc@777 82 case s of
adamc@777 83 "" => None
adamc@777 84 | _ => Some (readError s : t))
adamc@777 85 (fn s =>
adamc@777 86 case s of
adamc@777 87 "" => Some None
adamc@777 88 | _ => case read s of
adamc@777 89 None => None
adamc@777 90 | v => Some v)
adamc@777 91
adam@1360 92 fun txt [t] [ctx ::: {Unit}] [use ::: {Type}] (_ : show t) (v : t) : xml ctx use [] =
adamc@564 93 cdata (show v)
adamc@328 94
adamc@1093 95 fun map0 [K] [tf :: K -> Type] (f : t :: K -> tf t) [r ::: {K}] (fl : folder r) =
adamc@993 96 fl [fn r :: {K} => $(map tf r)]
adamc@993 97 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] acc =>
adamc@993 98 acc ++ {nm = f [t]})
adamc@993 99 {}
adamc@993 100
adamc@1093 101 fun mp [K] [tf1 :: K -> Type] [tf2 :: K -> Type] (f : t ::: K -> tf1 t -> tf2 t) [r ::: {K}] (fl : folder r) =
adamc@898 102 fl [fn r :: {K} => $(map tf1 r) -> $(map tf2 r)]
adamc@898 103 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] acc r =>
adamc@898 104 acc (r -- nm) ++ {nm = f r.nm})
adamc@898 105 (fn _ => {})
adamc@898 106
adamc@905 107 fun map2 [K] [tf1 :: K -> Type] [tf2 :: K -> Type] [tf3 :: K -> Type]
adamc@1093 108 (f : t ::: K -> tf1 t -> tf2 t -> tf3 t) [r ::: {K}] (fl : folder r) =
adamc@905 109 fl [fn r :: {K} => $(map tf1 r) -> $(map tf2 r) -> $(map tf3 r)]
adamc@905 110 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] acc r1 r2 =>
adamc@905 111 acc (r1 -- nm) (r2 -- nm) ++ {nm = f r1.nm r2.nm})
adamc@905 112 (fn _ _ => {})
adamc@898 113
adamc@937 114 fun map3 [K] [tf1 :: K -> Type] [tf2 :: K -> Type] [tf3 :: K -> Type] [tf :: K -> Type]
adamc@1093 115 (f : t ::: K -> tf1 t -> tf2 t -> tf3 t -> tf t) [r ::: {K}] (fl : folder r) =
adamc@937 116 fl [fn r :: {K} => $(map tf1 r) -> $(map tf2 r) -> $(map tf3 r) -> $(map tf r)]
adamc@937 117 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] acc r1 r2 r3 =>
adamc@937 118 acc (r1 -- nm) (r2 -- nm) (r3 -- nm) ++ {nm = f r1.nm r2.nm r3.nm})
adamc@937 119 (fn _ _ _ => {})
adamc@937 120
adamc@822 121 fun foldUR [tf :: Type] [tr :: {Unit} -> Type]
adamc@411 122 (f : nm :: Name -> rest :: {Unit}
adamc@629 123 -> [[nm] ~ rest] =>
adamc@411 124 tf -> tr rest -> tr ([nm] ++ rest))
adamc@1093 125 (i : tr []) [r ::: {Unit}] (fl : folder r) =
adamc@653 126 fl [fn r :: {Unit} => $(mapU tf r) -> tr r]
adamc@822 127 (fn [nm :: Name] [t :: Unit] [rest :: {Unit}] [[nm] ~ rest] acc r =>
adamc@653 128 f [nm] [rest] ! r.nm (acc (r -- nm)))
adamc@653 129 (fn _ => i)
adamc@411 130
adamc@822 131 fun foldUR2 [tf1 :: Type] [tf2 :: Type] [tr :: {Unit} -> Type]
adamc@418 132 (f : nm :: Name -> rest :: {Unit}
adamc@629 133 -> [[nm] ~ rest] =>
adamc@418 134 tf1 -> tf2 -> tr rest -> tr ([nm] ++ rest))
adamc@1093 135 (i : tr []) [r ::: {Unit}] (fl : folder r) =
adamc@653 136 fl [fn r :: {Unit} => $(mapU tf1 r) -> $(mapU tf2 r) -> tr r]
adamc@822 137 (fn [nm :: Name] [t :: Unit] [rest :: {Unit}] [[nm] ~ rest] acc r1 r2 =>
adamc@653 138 f [nm] [rest] ! r1.nm r2.nm (acc (r1 -- nm) (r2 -- nm)))
adamc@653 139 (fn _ _ => i)
adamc@418 140
adamc@822 141 fun foldR [K] [tf :: K -> Type] [tr :: {K} -> Type]
adamc@623 142 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@629 143 -> [[nm] ~ rest] =>
adamc@356 144 tf t -> tr rest -> tr ([nm = t] ++ rest))
adamc@1093 145 (i : tr []) [r ::: {K}] (fl : folder r) =
adamc@653 146 fl [fn r :: {K} => $(map tf r) -> tr r]
adamc@822 147 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] (acc : _ -> tr rest) r =>
adamc@653 148 f [nm] [t] [rest] ! r.nm (acc (r -- nm)))
adamc@653 149 (fn _ => i)
adamc@336 150
adamc@822 151 fun foldR2 [K] [tf1 :: K -> Type] [tf2 :: K -> Type] [tr :: {K} -> Type]
adamc@623 152 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@629 153 -> [[nm] ~ rest] =>
adamc@367 154 tf1 t -> tf2 t -> tr rest -> tr ([nm = t] ++ rest))
adamc@1093 155 (i : tr []) [r ::: {K}] (fl : folder r) =
adamc@653 156 fl [fn r :: {K} => $(map tf1 r) -> $(map tf2 r) -> tr r]
adamc@822 157 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest]
adamc@653 158 (acc : _ -> _ -> tr rest) r1 r2 =>
adamc@653 159 f [nm] [t] [rest] ! r1.nm r2.nm (acc (r1 -- nm) (r2 -- nm)))
adamc@653 160 (fn _ _ => i)
adamc@332 161
adamc@910 162 fun foldR3 [K] [tf1 :: K -> Type] [tf2 :: K -> Type] [tf3 :: K -> Type] [tr :: {K} -> Type]
adamc@910 163 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@910 164 -> [[nm] ~ rest] =>
adamc@910 165 tf1 t -> tf2 t -> tf3 t -> tr rest -> tr ([nm = t] ++ rest))
adamc@1093 166 (i : tr []) [r ::: {K}] (fl : folder r) =
adamc@910 167 fl [fn r :: {K} => $(map tf1 r) -> $(map tf2 r) -> $(map tf3 r) -> tr r]
adamc@910 168 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest]
adamc@910 169 (acc : _ -> _ -> _ -> tr rest) r1 r2 r3 =>
adamc@910 170 f [nm] [t] [rest] ! r1.nm r2.nm r3.nm (acc (r1 -- nm) (r2 -- nm) (r3 -- nm)))
adamc@910 171 (fn _ _ _ => i)
adamc@910 172
adamc@1172 173 fun mapUX [tf :: Type] [ctx :: {Unit}]
adamc@1172 174 (f : nm :: Name -> rest :: {Unit} -> [[nm] ~ rest] => tf -> xml ctx [] []) =
adamc@1172 175 @@foldR [fn _ => tf] [fn _ => xml ctx [] []]
adamc@1172 176 (fn [nm :: Name] [u :: Unit] [rest :: {Unit}] [[nm] ~ rest] r acc =>
adamc@1172 177 <xml>{f [nm] [rest] ! r}{acc}</xml>)
adamc@1172 178 <xml/>
adamc@1172 179
adamc@1172 180 fun mapX [K] [tf :: K -> Type] [ctx :: {Unit}]
adamc@623 181 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@629 182 -> [[nm] ~ rest] =>
adamc@720 183 tf t -> xml ctx [] []) =
adamc@1093 184 @@foldR [tf] [fn _ => xml ctx [] []]
adamc@1093 185 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] r acc =>
adamc@1093 186 <xml>{f [nm] [t] [rest] ! r}{acc}</xml>)
adamc@1093 187 <xml/>
adamc@336 188
adamc@1173 189 fun mapUX2 [tf1 :: Type] [tf2 :: Type] [ctx :: {Unit}]
adamc@1173 190 (f : nm :: Name -> rest :: {Unit}
adamc@1173 191 -> [[nm] ~ rest] =>
adamc@1173 192 tf1 -> tf2 -> xml ctx [] []) =
adamc@1173 193 @@foldUR2 [tf1] [tf2] [fn _ => xml ctx [] []]
adamc@1173 194 (fn [nm :: Name] [rest :: {Unit}] [[nm] ~ rest] v1 v2 acc =>
adamc@1173 195 <xml>{f [nm] [rest] ! v1 v2}{acc}</xml>)
adamc@1173 196 <xml/>
adamc@1173 197
adamc@1172 198 fun mapX2 [K] [tf1 :: K -> Type] [tf2 :: K -> Type] [ctx :: {Unit}]
adamc@623 199 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@629 200 -> [[nm] ~ rest] =>
adamc@720 201 tf1 t -> tf2 t -> xml ctx [] []) =
adamc@1093 202 @@foldR2 [tf1] [tf2] [fn _ => xml ctx [] []]
adamc@1093 203 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest]
adamc@1093 204 r1 r2 acc =>
adamc@1093 205 <xml>{f [nm] [t] [rest] ! r1 r2}{acc}</xml>)
adamc@1093 206 <xml/>
adamc@445 207
adamc@1172 208 fun mapX3 [K] [tf1 :: K -> Type] [tf2 :: K -> Type] [tf3 :: K -> Type] [ctx :: {Unit}]
adamc@910 209 (f : nm :: Name -> t :: K -> rest :: {K}
adamc@910 210 -> [[nm] ~ rest] =>
adamc@910 211 tf1 t -> tf2 t -> tf3 t -> xml ctx [] []) =
adamc@1093 212 @@foldR3 [tf1] [tf2] [tf3] [fn _ => xml ctx [] []]
adamc@1093 213 (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest]
adamc@1093 214 r1 r2 r3 acc =>
adamc@1093 215 <xml>{f [nm] [t] [rest] ! r1 r2 r3}{acc}</xml>)
adamc@1093 216 <xml/>
adamc@910 217
adam@1394 218 fun query1 [t ::: Name] [fs ::: {Type}] [state ::: Type] (q : sql_query [] [] [t = fs] [])
adamc@1177 219 (f : $fs -> state -> transaction state) (i : state) =
adamc@1177 220 query q (fn r => f r.t) i
adamc@1177 221
adam@1394 222 fun query1' [t ::: Name] [fs ::: {Type}] [state ::: Type] (q : sql_query [] [] [t = fs] [])
adamc@1177 223 (f : $fs -> state -> state) (i : state) =
adamc@1177 224 query q (fn r s => return (f r.t s)) i
adamc@1177 225
adam@1394 226 fun queryL [tables] [exps] [tables ~ exps] (q : sql_query [] [] tables exps) =
adamc@1081 227 query q
adamc@1081 228 (fn r ls => return (r :: ls))
adamc@1081 229 []
adamc@1081 230
adam@1394 231 fun queryL1 [t ::: Name] [fs ::: {Type}] (q : sql_query [] [] [t = fs] []) =
adam@1321 232 query q
adam@1321 233 (fn r ls => return (r.t :: ls))
adam@1321 234 []
adam@1321 235
adamc@822 236 fun queryI [tables ::: {{Type}}] [exps ::: {Type}]
adam@1394 237 [tables ~ exps] (q : sql_query [] [] tables exps)
adamc@682 238 (f : $(exps ++ map (fn fields :: {Type} => $fields) tables)
adamc@682 239 -> transaction unit) =
adamc@682 240 query q
adamc@682 241 (fn fs _ => f fs)
adamc@682 242 ()
adamc@682 243
adam@1394 244 fun queryI1 [nm ::: Name] [fs ::: {Type}] (q : sql_query [] [] [nm = fs] [])
adam@1363 245 (f : $fs -> transaction unit) =
adam@1363 246 query q
adam@1363 247 (fn fs _ => f fs.nm)
adam@1363 248 ()
adam@1363 249
adamc@1004 250 fun queryX [tables ::: {{Type}}] [exps ::: {Type}] [ctx ::: {Unit}] [inp ::: {Type}]
adam@1394 251 [tables ~ exps] (q : sql_query [] [] tables exps)
adamc@621 252 (f : $(exps ++ map (fn fields :: {Type} => $fields) tables)
adamc@1004 253 -> xml ctx inp []) =
adamc@356 254 query q
adamc@356 255 (fn fs acc => return <xml>{acc}{f fs}</xml>)
adamc@360 256 <xml/>
adamc@341 257
adamc@1076 258 fun queryX1 [nm ::: Name] [fs ::: {Type}] [ctx ::: {Unit}] [inp ::: {Type}]
adam@1394 259 (q : sql_query [] [] [nm = fs] [])
adamc@1076 260 (f : $fs -> xml ctx inp []) =
adamc@1076 261 query q
adamc@1076 262 (fn fs acc => return <xml>{acc}{f fs.nm}</xml>)
adamc@1076 263 <xml/>
adamc@1076 264
adamc@1032 265 fun queryX' [tables ::: {{Type}}] [exps ::: {Type}] [ctx ::: {Unit}] [inp ::: {Type}]
adam@1394 266 [tables ~ exps] (q : sql_query [] [] tables exps)
adamc@621 267 (f : $(exps ++ map (fn fields :: {Type} => $fields) tables)
adamc@1032 268 -> transaction (xml ctx inp [])) =
adamc@469 269 query q
adamc@469 270 (fn fs acc =>
adamc@469 271 r <- f fs;
adamc@469 272 return <xml>{acc}{r}</xml>)
adamc@469 273 <xml/>
adamc@469 274
adamc@1110 275 fun queryX1' [nm ::: Name] [fs ::: {Type}] [ctx ::: {Unit}] [inp ::: {Type}]
adam@1394 276 (q : sql_query [] [] [nm = fs] [])
adamc@1110 277 (f : $fs -> transaction (xml ctx inp [])) =
adamc@1110 278 query q
adamc@1110 279 (fn fs acc =>
adamc@1110 280 r <- f fs.nm;
adamc@1110 281 return <xml>{acc}{r}</xml>)
adamc@1110 282 <xml/>
adamc@1110 283
adamc@1110 284 fun queryXE' [exps ::: {Type}] [ctx ::: {Unit}] [inp ::: {Type}]
adam@1394 285 (q : sql_query [] [] [] exps)
adamc@1110 286 (f : $exps -> transaction (xml ctx inp [])) =
adamc@1110 287 query q
adamc@1110 288 (fn fs acc =>
adamc@1110 289 r <- f fs;
adamc@1110 290 return <xml>{acc}{r}</xml>)
adamc@1110 291 <xml/>
adamc@1110 292
adamc@1072 293 fun hasRows [tables ::: {{Type}}] [exps ::: {Type}]
adamc@1072 294 [tables ~ exps]
adam@1394 295 (q : sql_query [] [] tables exps) =
adamc@1072 296 query q
adamc@1072 297 (fn _ _ => return True)
adamc@1072 298 False
adamc@1072 299
adamc@822 300 fun oneOrNoRows [tables ::: {{Type}}] [exps ::: {Type}]
adamc@629 301 [tables ~ exps]
adam@1394 302 (q : sql_query [] [] tables exps) =
adamc@356 303 query q
adamc@356 304 (fn fs _ => return (Some fs))
adamc@356 305 None
adamc@440 306
adam@1394 307 fun oneOrNoRows1 [nm ::: Name] [fs ::: {Type}] (q : sql_query [] [] [nm = fs] []) =
adamc@1003 308 query q
adamc@1003 309 (fn fs _ => return (Some fs.nm))
adamc@1003 310 None
adamc@1003 311
adam@1394 312 fun oneOrNoRowsE1 [tabs ::: {Unit}] [nm ::: Name] [t ::: Type] [tabs ~ [nm]] (q : sql_query [] [] (mapU [] tabs) [nm = t]) =
adamc@1006 313 query q
adamc@1006 314 (fn fs _ => return (Some fs.nm))
adamc@1006 315 None
adamc@1006 316
adamc@822 317 fun oneRow [tables ::: {{Type}}] [exps ::: {Type}]
adam@1394 318 [tables ~ exps] (q : sql_query [] [] tables exps) =
adamc@440 319 o <- oneOrNoRows q;
adamc@440 320 return (case o of
adamc@440 321 None => error <xml>Query returned no rows</xml>
adamc@440 322 | Some r => r)
adamc@440 323
adam@1394 324 fun oneRow1 [nm ::: Name] [fs ::: {Type}] (q : sql_query [] [] [nm = fs] []) =
adamc@1076 325 o <- oneOrNoRows q;
adamc@1076 326 return (case o of
adamc@1076 327 None => error <xml>Query returned no rows</xml>
adamc@1076 328 | Some r => r.nm)
adamc@1076 329
adam@1394 330 fun oneRowE1 [tabs ::: {Unit}] [nm ::: Name] [t ::: Type] [tabs ~ [nm]] (q : sql_query [] [] (mapU [] tabs) [nm = t]) =
adamc@1003 331 o <- oneOrNoRows q;
adamc@1003 332 return (case o of
adamc@1003 333 None => error <xml>Query returned no rows</xml>
adamc@1003 334 | Some r => r.nm)
adamc@1003 335
adamc@1074 336 fun nonempty [fs] [us] (t : sql_table fs us) =
adamc@1074 337 oneRowE1 (SELECT COUNT( * ) > 0 AS B FROM t)
adamc@1074 338
adamc@822 339 fun eqNullable [tables ::: {{Type}}] [agg ::: {{Type}}] [exps ::: {Type}]
adamc@822 340 [t ::: Type] (_ : sql_injectable (option t))
adamc@470 341 (e1 : sql_exp tables agg exps (option t))
adamc@470 342 (e2 : sql_exp tables agg exps (option t)) =
adamc@471 343 (SQL ({e1} IS NULL AND {e2} IS NULL) OR {e1} = {e2})
adamc@470 344
adamc@822 345 fun eqNullable' [tables ::: {{Type}}] [agg ::: {{Type}}] [exps ::: {Type}]
adamc@822 346 [t ::: Type] (_ : sql_injectable (option t))
adamc@470 347 (e1 : sql_exp tables agg exps (option t))
adamc@470 348 (e2 : option t) =
adamc@470 349 case e2 of
adamc@471 350 None => (SQL {e1} IS NULL)
adamc@564 351 | Some _ => sql_binary sql_eq e1 (sql_inject e2)
adam@1360 352
adam@1360 353 fun mkRead' [t ::: Type] (f : string -> option t) (name : string) : read t =
adam@1360 354 mkRead (fn s => case f s of
adam@1360 355 None => error <xml>Invalid {txt name}: {txt s}</xml>
adam@1360 356 | Some v => v) f