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|
structure Sql :> SQL = struct
open Mono
val debug = ref false
type lvar = int
datatype func =
DtCon0 of string
| DtCon1 of string
| UnCon of string
| Other of string
datatype exp =
Const of Prim.t
| Var of int
| Lvar of lvar
| Func of func * exp list
| Recd of (string * exp) list
| Proj of exp * string
datatype cmp =
Eq
| Ne
| Lt
| Le
| Gt
| Ge
datatype reln =
Known
| Sql of string
| PCon0 of string
| PCon1 of string
| Cmp of cmp
datatype lop =
And
| Or
datatype prop =
True
| False
| Unknown
| Lop of lop * prop * prop
| Reln of reln * exp list
| Cond of exp * prop
datatype chunk =
String of string
| Exp of Mono.exp
fun chunkify e =
case #1 e of
EPrim (Prim.String (_, s)) => [String s]
| EStrcat (e1, e2) =>
let
val chs1 = chunkify e1
val chs2 = chunkify e2
in
case chs2 of
String s2 :: chs2' =>
(case List.last chs1 of
String s1 => List.take (chs1, length chs1 - 1) @ String (s1 ^ s2) :: chs2'
| _ => chs1 @ chs2)
| _ => chs1 @ chs2
end
| _ => [Exp e]
type 'a parser = chunk list -> ('a * chunk list) option
fun always v chs = SOME (v, chs)
fun parse p s =
case p (chunkify s) of
SOME (v, []) => SOME v
| _ => NONE
fun const s chs =
case chs of
String s' :: chs => if String.isPrefix s s' then
SOME ((), if size s = size s' then
chs
else
String (String.extract (s', size s, NONE)) :: chs)
else
NONE
| _ => NONE
fun follow p1 p2 chs =
case p1 chs of
NONE => NONE
| SOME (v1, chs) =>
case p2 chs of
NONE => NONE
| SOME (v2, chs) => SOME ((v1, v2), chs)
fun wrap p f chs =
case p chs of
NONE => NONE
| SOME (v, chs) => SOME (f v, chs)
fun wrapP p f chs =
case p chs of
NONE => NONE
| SOME (v, chs) =>
case f v of
NONE => NONE
| SOME r => SOME (r, chs)
fun alt p1 p2 chs =
case p1 chs of
NONE => p2 chs
| v => v
fun altL ps =
case rev ps of
[] => (fn _ => NONE)
| p :: ps =>
foldl (fn (p1, p2) => alt p1 p2) p ps
fun opt p chs =
case p chs of
NONE => SOME (NONE, chs)
| SOME (v, chs) => SOME (SOME v, chs)
fun skip cp chs =
case chs of
String "" :: chs => skip cp chs
| String s :: chs' => if cp (String.sub (s, 0)) then
skip cp (String (String.extract (s, 1, NONE)) :: chs')
else
SOME ((), chs)
| _ => SOME ((), chs)
fun keep cp chs =
case chs of
String "" :: chs => keep cp chs
| String s :: chs' =>
let
val (befor, after) = Substring.splitl cp (Substring.full s)
in
if Substring.isEmpty befor then
NONE
else
SOME (Substring.string befor,
if Substring.isEmpty after then
chs'
else
String (Substring.string after) :: chs')
end
| _ => NONE
(* Used by primSqlcache. *)
fun optConst s chs =
case chs of
String s' :: chs => if String.isPrefix s s' then
SOME (s, if size s = size s' then
chs
else
String (String.extract (s', size s, NONE)) :: chs)
else
SOME ("", String s' :: chs)
| _ => NONE
fun ws p = wrap (follow (skip (fn ch => ch = #" "))
(follow p (skip (fn ch => ch = #" ")))) (#1 o #2)
fun log name p chs =
(if !debug then
(print (name ^ ": ");
app (fn String s => print s
| _ => print "???") chs;
print "\n")
else
();
p chs)
fun list p chs =
altL [wrap (follow p (follow (ws (const ",")) (list p)))
(fn (v, ((), ls)) => v :: ls),
wrap (ws p) (fn v => [v]),
always []] chs
val ident = keep (fn ch => Char.isAlphaNum ch orelse ch = #"_")
val t_ident = wrapP ident (fn s => if String.isPrefix "T_" s then
SOME (String.extract (s, 2, NONE))
else
NONE)
val uw_ident = wrapP ident (fn s => if String.isPrefix "uw_" s andalso size s >= 4 then
SOME (str (Char.toUpper (String.sub (s, 3)))
^ String.extract (s, 4, NONE))
else
SOME s)
val field = wrap (follow (opt (follow t_ident (const ".")))
uw_ident)
(fn (SOME (t, ()), f) => (t, f)
| (NONE, f) => ("T", f)) (* Should probably deal with this MySQL/SQLite case better some day. *)
datatype Rel =
RCmp of cmp
| RLop of lop
datatype sqexp =
SqConst of Prim.t
| SqTrue
| SqFalse
| SqNot of sqexp
| Field of string * string
| Computed of string
| Binop of Rel * sqexp * sqexp
| SqKnown of sqexp
| Inj of Mono.exp
| SqFunc of string * sqexp
| Unmodeled
| Null
fun cmp s r = wrap (const s) (fn () => RCmp r)
val sqbrel = altL [cmp "=" Eq,
cmp "IS NOT DISTINCT FROM" Eq,
cmp "<>" Ne,
cmp "<=" Le,
cmp "<" Lt,
cmp ">=" Ge,
cmp ">" Gt,
wrap (const "AND") (fn () => RLop And),
wrap (const "OR") (fn () => RLop Or)]
datatype ('a, 'b) sum = inl of 'a | inr of 'b
fun string chs =
case chs of
String s :: chs =>
if size s >= 2 andalso String.sub (s, 0) = #"'" then
let
fun loop (cs, acc) =
case cs of
[] => NONE
| c :: cs =>
if c = #"'" then
SOME (String.implode (rev acc), cs)
else if c = #"\\" then
case cs of
c :: cs => loop (cs, c :: acc)
| _ => raise Fail "Iflow.string: Unmatched backslash escape"
else
loop (cs, c :: acc)
in
case loop (String.explode (String.extract (s, 1, NONE)), []) of
NONE => NONE
| SOME (s, []) => SOME (s, chs)
| SOME (s, cs) => SOME (s, String (String.implode cs) :: chs)
end
else
NONE
| _ => NONE
val prim =
altL [wrap (follow (wrapP (follow (keep Char.isDigit) (follow (const ".") (keep Char.isDigit)))
(fn (x, ((), y)) => Option.map Prim.Float (Real64.fromString (x ^ "." ^ y))))
(opt (const "::float8"))) #1,
wrap (follow (wrapP (keep Char.isDigit)
(Option.map Prim.Int o Int64.fromString))
(opt (const "::int8"))) #1,
wrap (follow (opt (const "E")) (follow string (opt (const "::text"))))
((fn s => Prim.String (Prim.Normal, s)) o #1 o #2)]
val primSqlcache =
(* Like [prim], but always uses [Prim.String]s. *)
let
fun wrapS p f = wrap p ((fn s => Prim.String (Prim.Normal, s)) o f)
in
altL [wrapS (follow (wrap (follow (keep Char.isDigit)
(follow (const ".") (keep Char.isDigit)))
(fn (x, ((), y)) => x ^ "." ^ y))
(optConst "::float8"))
op^,
wrapS (follow (keep Char.isDigit)
(optConst "::int8"))
op^,
wrapS (follow (optConst "E") (follow string (optConst "::text")))
(fn (c1, (s, c2)) => c1 ^ s ^ c2)]
end
fun known' chs =
case chs of
Exp (EFfi ("Basis", "sql_known"), _) :: chs => SOME ((), chs)
| _ => NONE
fun sqlify chs =
case chs of
Exp (EFfiApp ("Basis", f, [(e, _)]), _) :: chs =>
if String.isPrefix "sqlify" f then
SOME (e, chs)
else
NONE
| Exp (ECase (e, [((PCon (_, PConFfi {mod = "Basis", con = "True", ...}, NONE), _),
(EPrim (Prim.String (Prim.Normal, "TRUE")), _)),
((PCon (_, PConFfi {mod = "Basis", con = "False", ...}, NONE), _),
(EPrim (Prim.String (Prim.Normal, "FALSE")), _))], _), _) :: chs =>
SOME (e, chs)
| _ => NONE
(* For sqlcache, we only care that we can do string equality on injected Mono
expressions, so accept any expression without modifying it. *)
val sqlifySqlcache =
fn Exp e :: chs => SOME (e, chs)
| _ => NONE
fun constK s = wrap (const s) (fn () => s)
val funcName = altL [constK "COUNT",
constK "MIN",
constK "MAX",
constK "SUM",
constK "AVG"]
fun arithmetic pExp = follow (const "(")
(follow pExp
(follow (altL (map const [" + ", " - ", " * ", " / ", " >> ", " << "]))
(follow pExp (const ")"))))
val unmodeled = altL [const "COUNT(*)",
const "CURRENT_TIMESTAMP"]
val sqlcacheMode = ref false;
fun sqexp chs =
log "sqexp"
(altL [wrap (if !sqlcacheMode then primSqlcache else prim) SqConst,
wrap (const "TRUE") (fn () => SqTrue),
wrap (const "FALSE") (fn () => SqFalse),
wrap (follow (const "NULL::") ident) (fn ((), _) => Null),
wrap (const "NULL") (fn () => Null),
wrap known SqKnown,
wrap func SqFunc,
wrap field Field,
wrap uw_ident Computed,
wrap (arithmetic sqexp) (fn _ => Unmodeled),
wrap unmodeled (fn () => Unmodeled),
wrap (if !sqlcacheMode then sqlifySqlcache else sqlify) Inj,
wrap (follow (const "COALESCE(") (follow sqexp (follow (const ",")
(follow (keep (fn ch => ch <> #")")) (const ")")))))
(fn ((), (e, _)) => e),
wrap (follow (const "(NOT ") (follow sqexp (const ")")))
(fn ((), (e, _)) => SqNot e),
wrap (follow (ws (const "("))
(follow (wrap
(follow sqexp
(alt
(wrap
(follow (ws sqbrel)
(ws sqexp))
inl)
(always (inr ()))))
(fn (e1, sm) =>
case sm of
inl (bo, e2) => Binop (bo, e1, e2)
| inr () => e1))
(const ")")))
(fn ((), (e, ())) => e)])
chs
and known chs = wrap (follow known' (follow (const "(") (follow sqexp (const ")"))))
(fn ((), ((), (e, ()))) => e) chs
and func chs = wrap (follow funcName (follow (const "(") (follow sqexp (const ")"))))
(fn (f, ((), (e, ()))) => (f, e)) chs
datatype sitem =
SqField of string * string
| SqExp of sqexp * string
val sitem = alt (wrap (follow sqexp (follow (const " AS ") uw_ident))
(fn (e, ((), s)) => SqExp (e, s)))
(wrap field SqField)
val select = log "select"
(wrap (follow (const "SELECT ") (list sitem))
(fn ((), ls) => ls))
datatype jtype = Inner | Left | Right | Full
datatype fitem =
Table of string * string (* table AS name *)
| Join of jtype * fitem * fitem * sqexp
| Nested of query * string (* query AS name *)
and query =
Query1 of {Select : sitem list, From : fitem list, Where : sqexp option}
| Union of query * query
val wher = wrap (follow (ws (const "WHERE ")) sqexp)
(fn ((), ls) => ls)
val orderby = log "orderby"
(wrap (follow (ws (const "ORDER BY "))
(list (follow sqexp
(opt (ws (const "DESC"))))))
ignore)
val groupby = log "groupby"
(wrap (follow (ws (const "GROUP BY "))
(list sqexp))
ignore)
val jtype = altL [wrap (const "JOIN") (fn () => Inner),
wrap (const "LEFT JOIN") (fn () => Left),
wrap (const "RIGHT JOIN") (fn () => Right),
wrap (const "FULL JOIN") (fn () => Full)]
fun fitem chs = altL [wrap (follow uw_ident
(follow (const " AS ")
t_ident))
(fn (t, ((), f)) => Table (t, f)),
wrap (follow (const "(")
(follow fitem
(follow (ws jtype)
(follow fitem
(follow (const " ON ")
(follow sqexp
(const ")")))))))
(fn ((), (fi1, (jt, (fi2, ((), (se, ())))))) =>
Join (jt, fi1, fi2, se)),
wrap (follow (const "(")
(follow query
(follow (const ") AS ") t_ident)))
(fn ((), (q, ((), f))) => Nested (q, f))]
chs
and query1 chs = log "query1"
(wrap (follow (follow select from) (opt wher))
(fn ((fs, ts), wher) => {Select = fs, From = ts, Where = wher}))
chs
and from chs = log "from"
(wrap (follow (const "FROM ") (list fitem))
(fn ((), ls) => ls))
chs
and query chs = log "query"
(wrap (follow
(alt (wrap (follow (const "((")
(follow query
(follow (const ") UNION (")
(follow query (const "))")))))
(fn ((), (q1, ((), (q2, ())))) => Union (q1, q2)))
(wrap query1 Query1))
(follow (opt groupby) (opt orderby)))
#1)
chs
datatype dml =
Insert of string * (string * sqexp) list
| Delete of string * sqexp
| Update of string * (string * sqexp) list * sqexp
val insert = log "insert"
(wrapP (follow (const "INSERT INTO ")
(follow uw_ident
(follow (const " (")
(follow (list uw_ident)
(follow (const ") VALUES (")
(follow (list sqexp)
(const ")")))))))
(fn ((), (tab, ((), (fs, ((), (es, ())))))) =>
(SOME (tab, ListPair.zipEq (fs, es)))
handle ListPair.UnequalLengths => NONE))
val delete = log "delete"
(wrap (follow (const "DELETE FROM ")
(follow uw_ident
(follow (opt (const " AS T_T"))
(opt (follow (const " WHERE ") sqexp)))))
(fn ((), (tab, (_, wher))) => (tab, case wher of
SOME (_, es) => es
| NONE => SqTrue)))
val setting = log "setting"
(wrap (follow uw_ident (follow (const " = ") sqexp))
(fn (f, ((), e)) => (f, e)))
val update = log "update"
(wrap (follow (const "UPDATE ")
(follow uw_ident
(follow (follow (opt (const " AS T_T")) (const " SET "))
(follow (list setting)
(follow (ws (const "WHERE "))
sqexp)))))
(fn ((), (tab, (_, (fs, ((), e))))) =>
(tab, fs, e)))
val dml = log "dml"
(altL [wrap insert Insert,
wrap delete Delete,
wrap update Update])
datatype querydml =
Query of query
| Dml of dml
val querydml = log "querydml" (altL [wrap dml Dml, wrap query Query])
end
|
