Mercurial > urweb
changeset 233:c466678af854
SELECTing arbitrary expressions
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Thu, 28 Aug 2008 11:17:14 -0400 |
| parents | a338da9d82f3 |
| children | 82409ef72019 |
| files | lib/basis.lig src/elaborate.sml src/lacweb.grm tests/selexp.lac |
| diffstat | 4 files changed, 63 insertions(+), 41 deletions(-) [+] |
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--- a/lib/basis.lig Thu Aug 21 16:03:45 2008 -0400 +++ b/lib/basis.lig Thu Aug 28 11:17:14 2008 -0400 @@ -13,8 +13,8 @@ (*** Queries *) -con sql_query :: {{Type}} -> Type -con sql_query1 :: {{Type}} -> {{Type}} -> Type +con sql_query :: {{Type}} -> {Type} -> Type +con sql_query1 :: {{Type}} -> {{Type}} -> {Type} -> Type con sql_exp :: {{Type}} -> {{Type}} -> Type -> Type con sql_subset :: {{Type}} -> {{Type}} -> Type @@ -31,14 +31,17 @@ val sql_query1 : tables ::: {{Type}} -> grouped ::: {{Type}} - -> selected ::: {{Type}} + -> selectedFields ::: {{Type}} + -> selectedExps ::: {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 + SelectFields : sql_subset grouped selectedFields, + SelectExps : $(fold (fn nm => fn t :: Type => fn acc => + [nm] ~ acc => [nm = sql_exp grouped tables t] ++ acc) [] selectedExps) } + -> sql_query1 tables selectedFields selectedExps type sql_relop val sql_union : sql_relop @@ -47,8 +50,11 @@ val sql_relop : sql_relop -> tables1 ::: {{Type}} -> tables2 ::: {{Type}} - -> selected ::: {{Type}} - -> sql_query1 tables1 selected -> sql_query1 tables2 selected -> sql_query1 selected selected + -> selectedFields ::: {{Type}} + -> selectedExps ::: {Type} + -> sql_query1 tables1 selectedFields selectedExps + -> sql_query1 tables2 selectedFields selectedExps + -> sql_query1 selectedFields selectedFields selectedExps type sql_direction val sql_asc : sql_direction @@ -69,12 +75,13 @@ val sql_offset : int -> sql_offset val sql_query : tables ::: {{Type}} - -> selected ::: {{Type}} - -> {Rows : sql_query1 tables selected, + -> selectedFields ::: {{Type}} + -> selectedExps ::: {Type} + -> {Rows : sql_query1 tables selectedFields selectedExps, OrderBy : sql_order_by tables, Limit : sql_limit, Offset : sql_offset} - -> sql_query selected + -> sql_query selectedFields selectedExps val sql_field : otherTabs ::: {{Type}} -> otherFields ::: {Type} -> fieldType ::: Type -> agg ::: {{Type}} -> tab :: Name -> field :: Name
--- a/src/elaborate.sml Thu Aug 21 16:03:45 2008 -0400 +++ b/src/elaborate.sml Thu Aug 28 11:17:14 2008 -0400 @@ -1520,7 +1520,8 @@ let val r = ref NONE in - ((L'.EUnif r, loc), ran, [TypeClass (env, dom, r, loc)]) + ((L'.EApp (e1', (L'.EUnif r, loc)), loc), + ran, [TypeClass (env, dom, r, loc)]) end | SOME pf => ((L'.EApp (e1', pf), loc), ran, gs1 @ gs2 @ enD gs3 @ enD gs4) end
--- a/src/lacweb.grm Thu Aug 21 16:03:45 2008 -0400 +++ b/src/lacweb.grm Thu Aug 28 11:17:14 2008 -0400 @@ -42,6 +42,7 @@ datatype select_item = Field of con * con + | Exp of con * exp datatype select = Star @@ -56,25 +57,27 @@ | (CName x1, CName x2) => x1 = x2 | _ => false -fun amend_select loc (si, tabs) = - let - val (tx, c) = case si of - Field (tx, fx) => (tx, (CRecord ([(fx, (CWild (KType, loc), loc))]), loc)) +fun amend_select loc (si, (tabs, exps)) = + case si of + Field (tx, fx) => + let + val c = (CRecord ([(fx, (CWild (KType, loc), loc))]), loc) - val (tabs, found) = ListUtil.foldlMap (fn ((tx', c'), found) => - if eqTnames (tx, tx') then - ((tx', (CConcat (c, c'), loc)), true) - else - ((tx', c'), found)) - false tabs - in - if found then - () - else - ErrorMsg.errorAt loc "Select of field from unbound table"; - - tabs - end + val (tabs, found) = ListUtil.foldlMap (fn ((tx', c'), found) => + if eqTnames (tx, tx') then + ((tx', (CConcat (c, c'), loc)), true) + else + ((tx', c'), found)) + false tabs + in + if found then + () + else + ErrorMsg.errorAt loc "Select of field from unbound table"; + + (tabs, exps) + end + | Exp (c, e) => (tabs, (c, e) :: exps) fun amend_group loc (gi, tabs) = let @@ -681,22 +684,24 @@ (let val loc = s (SELECTleft, tablesright) - val sel = + val (sel, exps) = case select of - Star => map (fn (nm, _) => - (nm, (CTuple [(CWild (KRecord (KType, loc), loc), - loc), - (CRecord [], loc)], - loc))) tables + Star => (map (fn (nm, _) => + (nm, (CTuple [(CWild (KRecord (KType, loc), loc), + loc), + (CRecord [], loc)], + loc))) tables, + []) | Items sis => let val tabs = map (fn (nm, _) => (nm, (CRecord [], loc))) tables - val tabs = foldl (amend_select loc) tabs sis + val (tabs, exps) = foldl (amend_select loc) (tabs, []) sis in - map (fn (nm, c) => (nm, - (CTuple [c, - (CWild (KRecord (KType, loc), loc), - loc)], loc))) tabs + (map (fn (nm, c) => (nm, + (CTuple [c, + (CWild (KRecord (KType, loc), loc), + loc)], loc))) tabs, + exps) end val sel = (CRecord sel, loc) @@ -733,7 +738,9 @@ hopt), ((CName "SelectFields", loc), (ECApp ((EVar (["Basis"], "sql_subset"), loc), - sel), loc))], loc) + sel), loc)), + ((CName "SelectExps", loc), + (ERecord exps, loc))], loc) val e = (EApp (e, re), loc) in @@ -762,6 +769,7 @@ | LBRACE cexp RBRACE (cexp) seli : tident DOT fident (Field (tident, fident)) + | sqlexp AS fident (Exp (fident, sqlexp)) selis : seli ([seli]) | seli COMMA selis (seli :: selis)
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/tests/selexp.lac Thu Aug 28 11:17:14 2008 -0400 @@ -0,0 +1,6 @@ +table t1 : {A : int, B : string, C : float} +table t2 : {A : float, D : int} + +val q1 = (SELECT 0 AS Zero FROM t1) +val q2 = (SELECT t1.A < t2.D AS Lt FROM t1, t2) +val q3 = (SELECT t1.A < t2.D AS Lt, t1.A, t2.D, t1.C = t2.A AS Eq FROM t1, t2)