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add partial support for parens at the query expression level

This commit is contained in:
Jake Wheat 2024-10-07 10:49:50 +01:00
parent f1ff143457
commit fc002dc549
4 changed files with 70 additions and 4 deletions
Language/SQL/SimpleSQL

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@ -651,7 +651,11 @@ scalar expression parens, row ctor and scalar subquery
parensExpr :: Parser ScalarExpr
parensExpr = parens $ choice
[SubQueryExpr SqSq <$> queryExpr
-- no parens here used for nested parens expressions
-- this could be fixed to be general with some refactoring, but at
-- the moment, you can't use additional redundant parens in a
-- subqueryexpr
[SubQueryExpr SqSq <$> queryExprNoParens
,ctor <$> commaSep1 scalarExpr]
where
ctor [a] = Parens a
@ -1443,7 +1447,9 @@ from = label "from" (keyword_ "from" *> commaSep1 tref)
nonJoinTref =
label "table ref" $ choice
[hidden $ parens $ choice
[TRQueryExpr <$> queryExpr
-- will be tricky to figure out how to support mixes of nested
-- query expr parens and table ref parens
[TRQueryExpr <$> queryExprNoParens
,TRParens <$> tref]
,TRLateral <$> (hidden (keyword_ "lateral") *> nonJoinTref)
,do
@ -1586,9 +1592,18 @@ and union, etc..
-}
queryExpr :: Parser QueryExpr
queryExpr = label "query expr" $ E.makeExprParser qeterm qeOpTable
queryExpr = queryExpr' True
queryExprNoParens :: Parser QueryExpr
queryExprNoParens = queryExpr' False
queryExpr' :: Bool -> Parser QueryExpr
queryExpr' allowParens = label "query expr" $ E.makeExprParser qeterm qeOpTable
where
qeterm = label "query expr" (with <|> select <|> table <|> values)
qeterm
| allowParens =
label "query expr" (with <|> select <|> table <|> values <|> qeParens)
| otherwise =
label "query expr" (with <|> select <|> table <|> values)
select = keyword_ "select" >>
mkSelect
@ -1602,6 +1617,7 @@ queryExpr = label "query expr" $ E.makeExprParser qeterm qeOpTable
values = keyword_ "values"
>> Values <$> commaSep (parens (commaSep scalarExpr))
table = keyword_ "table" >> Table <$> names "table name"
qeParens = QueryExprParens <$> parens queryExpr
qeOpTable =
[[E.InfixL $ setOp Intersect "intersect"]