relational-query-0.11.1.0: src/Database/Relational/TH.hs
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE ExplicitForAll #-}
{-# LANGUAGE ParallelListComp #-}
{-# LANGUAGE CPP #-}
-- |
-- Module : Database.Relational.TH
-- Copyright : 2013-2017 Kei Hibino
-- License : BSD3
--
-- Maintainer : ex8k.hibino@gmail.com
-- Stability : experimental
-- Portability : unknown
--
-- This module defines templates for Haskell record type and type class instances
-- to define column projection on SQL query like Haskell records.
-- Templates are generated by also using functions of "Database.Record.TH" module,
-- so mapping between list of untyped SQL type and Haskell record type will be done too.
module Database.Relational.TH (
-- * All templates about table
defineTable,
-- * Inlining typed 'Query'
unsafeInlineQuery,
inlineQuery,
-- * Column projections and basic 'Relation' for Haskell record
defineTableTypesAndRecord,
-- * Constraint key templates
defineHasPrimaryKeyInstance,
defineHasPrimaryKeyInstanceWithConfig,
defineHasNotNullKeyInstance,
defineHasNotNullKeyInstanceWithConfig,
defineScalarDegree,
-- * Column projections
defineColumnsDefault, defineOverloadedColumnsDefault,
defineColumns, defineOverloadedColumns,
defineTuplePi,
-- * Table metadata type and basic 'Relation'
defineTableTypes, defineTableTypesWithConfig,
-- * Basic SQL templates generate rules
definePrimaryQuery,
definePrimaryUpdate,
-- * Var expression templates
derivationExpDefault,
tableVarExpDefault,
relationVarExp,
-- * Derived SQL templates from table definitions
defineSqlsWithPrimaryKey,
defineSqlsWithPrimaryKeyDefault,
-- * Reify
makeRelationalRecordDefault,
makeRelationalRecordDefault',
reifyRelation,
) where
import Data.Char (toUpper, toLower)
import Data.List (foldl1')
import Data.Array.IArray ((!))
import Data.Functor.ProductIsomorphic.TH
(reifyRecordType, defineProductConstructor)
import Data.Functor.ProductIsomorphic.Unsafe (ProductConstructor (..))
import Language.Haskell.TH
(Name, nameBase, Q, reify, Dec, instanceD, ExpQ, stringE, listE,
TypeQ, Type (AppT, ConT), varT, tupleT, appT, arrowT, classP)
import Language.Haskell.TH.Compat.Reify (unVarI)
import Language.Haskell.TH.Name.CamelCase
(VarName, varName, ConName (ConName), conName,
varCamelcaseName, toVarExp, toTypeCon)
import Language.Haskell.TH.Lib.Extra (simpleValD, maybeD, integralE)
import Database.Record.TH
(columnOffsetsVarNameDefault, recordTypeName, recordTemplate,
defineRecordTypeWithConfig, defineHasColumnConstraintInstance)
import qualified Database.Record.TH as Record
import Database.Relational
(Table, Pi, id', Relation, ShowConstantTermsSQL,
NameConfig (..), SchemaNameMode (..), IdentifierQuotation (..), defaultConfig,
Config (normalizedTableName, disableOverloadedProjection, disableSpecializedProjection,
schemaNameMode, nameConfig, identifierQuotation),
relationalQuerySQL, Query, relationalQuery, KeyUpdate,
Insert, derivedInsert, InsertQuery, derivedInsertQuery,
HasConstraintKey(constraintKey), Primary, NotNull, primary, primaryUpdate)
import Database.Relational.InternalTH.Base (defineTuplePi, defineRecordProjections)
import Database.Relational.Scalar (defineScalarDegree)
import Database.Relational.Constraint (unsafeDefineConstraintKey)
import Database.Relational.Table (TableDerivable (..))
import qualified Database.Relational.Table as Table
import Database.Relational.Relation (derivedRelation)
import Database.Relational.SimpleSql (QuerySuffix)
import Database.Relational.Type (unsafeTypedQuery)
import qualified Database.Relational.Pi.Unsafe as UnsafePi
import qualified Database.Relational.InternalTH.Overloaded as Overloaded
-- | Rule template to infer constraint key.
defineHasConstraintKeyInstance :: TypeQ -- ^ Constraint type
-> TypeQ -- ^ Record type
-> TypeQ -- ^ Key type
-> [Int] -- ^ Indexes specifies key
-> Q [Dec] -- ^ Result 'HasConstraintKey' declaration
defineHasConstraintKeyInstance constraint recType colType indexes = do
-- kc <- defineHasColumnConstraintInstance constraint recType index
ck <- [d| instance HasConstraintKey $constraint $recType $colType where
constraintKey = unsafeDefineConstraintKey $(listE [integralE ix | ix <- indexes])
|]
return ck
-- | Rule template to infer primary key.
defineHasPrimaryKeyInstance :: TypeQ -- ^ Record type
-> TypeQ -- ^ Key type
-> [Int] -- ^ Indexes specifies key
-> Q [Dec] -- ^ Result constraint key declarations
defineHasPrimaryKeyInstance recType colType indexes = do
kc <- Record.defineHasPrimaryKeyInstance recType indexes
ck <- defineHasConstraintKeyInstance [t| Primary |] recType colType indexes
return $ kc ++ ck
-- | Rule template to infer primary key.
defineHasPrimaryKeyInstanceWithConfig :: Config -- ^ configuration parameters
-> String -- ^ Schema name
-> String -- ^ Table name
-> TypeQ -- ^ Column type
-> [Int] -- ^ Primary key index
-> Q [Dec] -- ^ Declarations of primary constraint key
defineHasPrimaryKeyInstanceWithConfig config scm =
defineHasPrimaryKeyInstance . fst . recordTemplate (recordConfig $ nameConfig config) scm
-- | Rule template to infer not-null key.
defineHasNotNullKeyInstance :: TypeQ -- ^ Record type
-> Int -- ^ Column index
-> Q [Dec] -- ^ Result 'ColumnConstraint' declaration
defineHasNotNullKeyInstance =
defineHasColumnConstraintInstance [t| NotNull |]
-- | Rule template to infer not-null key.
defineHasNotNullKeyInstanceWithConfig :: Config -- ^ configuration parameters
-> String -- ^ Schema name
-> String -- ^ Table name
-> Int -- ^ NotNull key index
-> Q [Dec] -- ^ Declaration of not-null constraint key
defineHasNotNullKeyInstanceWithConfig config scm =
defineHasNotNullKeyInstance . fst . recordTemplate (recordConfig $ nameConfig config) scm
projectionTemplate :: ConName -- ^ Record type name
-> VarName -- ^ Column declaration variable name
-> Int -- ^ Column leftest index
-> TypeQ -- ^ Column type
-> Q [Dec] -- ^ Column projection path declaration
projectionTemplate recName var ix colType = do
let offsetsExp = toVarExp . columnOffsetsVarNameDefault $ conName recName
simpleValD (varName var)
[t| Pi $(toTypeCon recName) $colType |]
[| UnsafePi.definePi $ $offsetsExp ! $(integralE ix) |]
-- | Projection path 'Pi' templates.
defineColumns :: ConName -- ^ Record type name
-> [(VarName, TypeQ)] -- ^ Column info list
-> Q [Dec] -- ^ Column projection path declarations
defineColumns recTypeName cols = do
let defC (name, typ) ix = projectionTemplate recTypeName name ix typ
fmap concat . sequence $ zipWith defC cols [0 :: Int ..]
-- | Overloaded projection path 'Pi' templates.
defineOverloadedColumns :: ConName -- ^ Record type name
-> [(String, TypeQ)] -- ^ Column info list
-> Q [Dec] -- ^ Column projection path declarations
defineOverloadedColumns recTypeName cols = do
let defC (name, typ) ix =
Overloaded.monomorphicProjection recTypeName name ix typ
fmap concat . sequence $ zipWith defC cols [0 :: Int ..]
-- | Make projection path templates using default naming rule.
defineColumnsDefault :: ConName -- ^ Record type name
-> [(String, TypeQ)] -- ^ Column info list
-> Q [Dec] -- ^ Column projection path declarations
defineColumnsDefault recTypeName cols =
defineColumns recTypeName [ (varCamelcaseName $ name ++ "'", typ) | (name, typ) <- cols ]
-- | Make overloaded projection path templates using default naming rule.
defineOverloadedColumnsDefault :: ConName -- ^ Record type name
-> [(String, TypeQ)] -- ^ Column info list
-> Q [Dec] -- ^ Column projection path declarations
defineOverloadedColumnsDefault recTypeName cols =
defineOverloadedColumns recTypeName [ (nameBase . varName $ varCamelcaseName name, typ) | (name, typ) <- cols ]
-- | Rule template to infer table derivations.
defineTableDerivableInstance :: TypeQ -> String -> [String] -> Q [Dec]
defineTableDerivableInstance recordType' table columns =
[d| instance TableDerivable $recordType' where
derivedTable = Table.table $(stringE table) $(listE $ map stringE columns)
|]
-- | Template to define inferred entries from table type.
defineTableDerivations :: VarName -- ^ Table declaration variable name
-> VarName -- ^ Relation declaration variable name
-> VarName -- ^ Insert statement declaration variable name
-> VarName -- ^ InsertQuery statement declaration variable name
-> TypeQ -- ^ Record type
-> Q [Dec] -- ^ Table and Relation declaration
defineTableDerivations tableVar' relVar' insVar' insQVar' recordType' = do
let tableVar = varName tableVar'
tableDs <- simpleValD tableVar [t| Table $recordType' |]
[| derivedTable |]
let relVar = varName relVar'
relDs <- simpleValD relVar [t| Relation () $recordType' |]
[| derivedRelation |]
let insVar = varName insVar'
insDs <- simpleValD insVar [t| Insert $recordType' |]
[| derivedInsert id' |]
let insQVar = varName insQVar'
insQDs <- simpleValD insQVar [t| forall p . Relation p $recordType' -> InsertQuery p |]
[| derivedInsertQuery id' |]
return $ concat [tableDs, relDs, insDs, insQDs]
-- | 'Table' and 'Relation' templates.
defineTableTypes :: VarName -- ^ Table declaration variable name
-> VarName -- ^ Relation declaration variable name
-> VarName -- ^ Insert statement declaration variable name
-> VarName -- ^ InsertQuery statement declaration variable name
-> TypeQ -- ^ Record type
-> String -- ^ Table name in SQL ex. FOO_SCHEMA.table0
-> [String] -- ^ Column names
-> Q [Dec] -- ^ Table and Relation declaration
defineTableTypes tableVar' relVar' insVar' insQVar' recordType' table columns = do
iDs <- defineTableDerivableInstance recordType' table columns
dDs <- defineTableDerivations tableVar' relVar' insVar' insQVar' recordType'
return $ iDs ++ dDs
tableSQL :: Bool -> SchemaNameMode -> IdentifierQuotation -> String -> String -> String
tableSQL normalize snm iq schema table = case snm of
SchemaQualified -> (qt normalizeS) ++ '.' : (qt normalizeT)
SchemaNotQualified -> (qt normalizeT)
where
normalizeS
| normalize = map toUpper schema
| otherwise = schema
normalizeT
| normalize = map toLower table
| otherwise = table
qt = quote iq
quote :: IdentifierQuotation -> String -> String
quote NoQuotation s = s
quote (Quotation q) s = q : (escape s) ++ q : []
where escape = (>>= (\c -> if c == q then [q, q] else [c]))
varNameWithPrefix :: String -> String -> VarName
varNameWithPrefix n p = varCamelcaseName $ p ++ "_" ++ n
derivationVarNameDefault :: String -> VarName
derivationVarNameDefault = (`varNameWithPrefix` "derivationFrom")
-- | Make 'TableDerivation' variable expression template from table name using default naming rule.
derivationExpDefault :: String -- ^ Table name string
-> ExpQ -- ^ Result var Exp
derivationExpDefault = toVarExp . derivationVarNameDefault
tableVarNameDefault :: String -> VarName
tableVarNameDefault = (`varNameWithPrefix` "tableOf")
-- | Make 'Table' variable expression template from table name using default naming rule.
tableVarExpDefault :: String -- ^ Table name string
-> ExpQ -- ^ Result var Exp
tableVarExpDefault = toVarExp . tableVarNameDefault
-- | Make 'Relation' variable expression template from table name using specified naming rule.
relationVarExp :: Config -- ^ Configuration which has naming rules of templates
-> String -- ^ Schema name string
-> String -- ^ Table name string
-> ExpQ -- ^ Result var Exp
relationVarExp config scm = toVarExp . relationVarName (nameConfig config) scm
-- | Make template for record 'ProductConstructor' instance using specified naming rule.
defineProductConstructorInstanceWithConfig :: Config -> String -> String -> [Q Type] -> Q [Dec]
defineProductConstructorInstanceWithConfig config schema table colTypes = do
let (recType, recData) = recordTemplate (recordConfig $ nameConfig config) schema table
[d| instance ProductConstructor $(foldr (appT . (arrowT `appT`)) recType colTypes) where
productConstructor = $(recData)
|]
-- | Make templates about table and column metadatas using specified naming rule.
defineTableTypesWithConfig :: Config -- ^ Configuration to generate query with
-> String -- ^ Schema name
-> String -- ^ Table name
-> [(String, TypeQ)] -- ^ Column names and types and constraint type
-> Q [Dec] -- ^ Result declarations
defineTableTypesWithConfig config schema table columns = do
let nmconfig = nameConfig config
recConfig = recordConfig nmconfig
tableDs <- defineTableTypes
(tableVarNameDefault table)
(relationVarName nmconfig schema table)
(table `varNameWithPrefix` "insert")
(table `varNameWithPrefix` "insertQuery")
(fst $ recordTemplate recConfig schema table)
(tableSQL (normalizedTableName config) (schemaNameMode config) (identifierQuotation config) schema table)
(map ((quote (identifierQuotation config)) . fst) columns)
let typeName = recordTypeName recConfig schema table
colsDs <- if disableSpecializedProjection config
then [d| |]
else defineColumnsDefault typeName columns
pcolsDs <- if disableOverloadedProjection config
then [d| |]
else defineOverloadedColumnsDefault typeName columns
return $ tableDs ++ colsDs ++ pcolsDs
-- | Make templates about table, column and haskell record using specified naming rule.
defineTableTypesAndRecord :: Config -- ^ Configuration to generate query with
-> String -- ^ Schema name
-> String -- ^ Table name
-> [(String, TypeQ)] -- ^ Column names and types
-> [Name] -- ^ Record derivings
-> Q [Dec] -- ^ Result declarations
defineTableTypesAndRecord config schema table columns derives = do
let recConfig = recordConfig $ nameConfig config
recD <- defineRecordTypeWithConfig recConfig schema table columns derives
rconD <- defineProductConstructorInstanceWithConfig config schema table [t | (_, t) <- columns]
ctD <- [d| instance ShowConstantTermsSQL $(fst $ recordTemplate recConfig schema table) |]
tableDs <- defineTableTypesWithConfig config schema table columns
return $ recD ++ rconD ++ ctD ++ tableDs
-- | Template of derived primary 'Query'.
definePrimaryQuery :: VarName -- ^ Variable name of result declaration
-> TypeQ -- ^ Parameter type of 'Query'
-> TypeQ -- ^ Record type of 'Query'
-> ExpQ -- ^ 'Relation' expression
-> Q [Dec] -- ^ Result 'Query' declaration
definePrimaryQuery toDef' paramType recType relE = do
let toDef = varName toDef'
simpleValD toDef
[t| Query $paramType $recType |]
[| relationalQuery (primary $relE) |]
-- | Template of derived primary 'Update'.
definePrimaryUpdate :: VarName -- ^ Variable name of result declaration
-> TypeQ -- ^ Parameter type of 'Update'
-> TypeQ -- ^ Record type of 'Update'
-> ExpQ -- ^ 'Table' expression
-> Q [Dec] -- ^ Result 'Update' declaration
definePrimaryUpdate toDef' paramType recType tableE = do
let toDef = varName toDef'
simpleValD toDef
[t| KeyUpdate $paramType $recType |]
[| primaryUpdate $tableE |]
-- | SQL templates derived from primary key.
defineSqlsWithPrimaryKey :: VarName -- ^ Variable name of select query definition from primary key
-> VarName -- ^ Variable name of update statement definition from primary key
-> TypeQ -- ^ Primary key type
-> TypeQ -- ^ Record type
-> ExpQ -- ^ Relation expression
-> ExpQ -- ^ Table expression
-> Q [Dec] -- ^ Result declarations
defineSqlsWithPrimaryKey sel upd paramType recType relE tableE = do
selD <- definePrimaryQuery sel paramType recType relE
updD <- definePrimaryUpdate upd paramType recType tableE
return $ selD ++ updD
-- | SQL templates derived from primary key using default naming rule.
defineSqlsWithPrimaryKeyDefault :: String -- ^ Table name of Database
-> TypeQ -- ^ Primary key type
-> TypeQ -- ^ Record type
-> ExpQ -- ^ Relation expression
-> ExpQ -- ^ Table expression
-> Q [Dec] -- ^ Result declarations
defineSqlsWithPrimaryKeyDefault table =
defineSqlsWithPrimaryKey sel upd
where
sel = table `varNameWithPrefix` "select"
upd = table `varNameWithPrefix` "update"
-- | All templates about primary key.
defineWithPrimaryKey :: Config
-> String -- ^ Schema name
-> String -- ^ Table name string
-> TypeQ -- ^ Type of primary key
-> [Int] -- ^ Indexes specifies primary key
-> Q [Dec] -- ^ Result declarations
defineWithPrimaryKey config schema table keyType ixs = do
instD <- defineHasPrimaryKeyInstanceWithConfig config schema table keyType ixs
let recType = fst $ recordTemplate (recordConfig $ nameConfig config) schema table
tableE = tableVarExpDefault table
relE = relationVarExp config schema table
sqlsD <- defineSqlsWithPrimaryKeyDefault table keyType recType relE tableE
return $ instD ++ sqlsD
-- | All templates about not-null key.
defineWithNotNullKeyWithConfig :: Config -> String -> String -> Int -> Q [Dec]
defineWithNotNullKeyWithConfig = defineHasNotNullKeyInstanceWithConfig
-- | Generate all templtes about table using specified naming rule.
defineTable :: Config -- ^ Configuration to generate query with
-> String -- ^ Schema name string of Database
-> String -- ^ Table name string of Database
-> [(String, TypeQ)] -- ^ Column names and types
-> [Name] -- ^ derivings for Record type
-> [Int] -- ^ Primary key index
-> Maybe Int -- ^ Not null key index
-> Q [Dec] -- ^ Result declarations
defineTable config schema table columns derives primaryIxs mayNotNullIdx = do
tblD <- defineTableTypesAndRecord config schema table columns derives
let pairT x y = appT (appT (tupleT 2) x) y
keyType = foldl1' pairT . map (snd . (columns !!)) $ primaryIxs
primD <- case primaryIxs of
[] -> return []
ixs -> defineWithPrimaryKey config schema table keyType ixs
nnD <- maybeD (\i -> defineWithNotNullKeyWithConfig config schema table i) mayNotNullIdx
return $ tblD ++ primD ++ nnD
-- | Unsafely inlining SQL string 'Query' in compile type.
unsafeInlineQuery :: TypeQ -- ^ Query parameter type
-> TypeQ -- ^ Query result type
-> String -- ^ SQL string query to inline
-> VarName -- ^ Variable name for inlined query
-> Q [Dec] -- ^ Result declarations
unsafeInlineQuery p r sql qVar' =
simpleValD (varName qVar')
[t| Query $p $r |]
[| unsafeTypedQuery $(stringE sql) |]
-- | Extract param type and result type from defined Relation
reifyRelation :: Name -- ^ Variable name which has Relation type
-> Q (Type, Type) -- ^ Extracted param type and result type from Relation type
reifyRelation relVar = do
relInfo <- reify relVar
case unVarI relInfo of
Just (_, (AppT (AppT (ConT prn) p) r), _)
| prn == ''Relation -> return (p, r)
_ ->
fail $ "expandRelation: Variable must have Relation type: " ++ show relVar
-- | Inlining composed 'Query' in compile type.
inlineQuery :: Name -- ^ Top-level variable name which has 'Relation' type
-> Relation p r -- ^ Object which has 'Relation' type
-> Config -- ^ Configuration to generate SQL
-> QuerySuffix -- ^ suffix SQL words
-> String -- ^ Variable name to define as inlined query
-> Q [Dec] -- ^ Result declarations
inlineQuery relVar rel config sufs qns = do
(p, r) <- reifyRelation relVar
unsafeInlineQuery (return p) (return r)
(relationalQuerySQL config rel sufs)
(varCamelcaseName qns)
-- | Generate all templates against defined record like type constructor
-- other than depending on sql-value type.
makeRelationalRecordDefault' :: Config
-> Name -- ^ Type constructor name
-> Q [Dec] -- ^ Result declaration
makeRelationalRecordDefault' config recTypeName = do
let recTypeConName = ConName recTypeName
(((tyCon, vars), _dataCon), (mayNs, cts)) <- reifyRecordType recTypeName
pw <- Record.definePersistableWidthInstance tyCon vars
cols <- case mayNs of
Nothing -> return []
Just ns -> case vars of
[] -> do {- monomorphic case -}
off <- Record.defineColumnOffsets recTypeConName
let cnames = [ (nameBase n, ct) | n <- ns | ct <- cts ]
cs <- if disableSpecializedProjection config
then [d| |]
else defineColumnsDefault recTypeConName cnames
pcs <- if disableOverloadedProjection config
then [d| |]
else defineOverloadedColumnsDefault recTypeConName cnames
return $ off ++ cs ++ pcs
_:_ -> do {- polymorphic case -}
cols <- if disableSpecializedProjection config
then [d| |]
else defineRecordProjections tyCon vars
[varName $ varCamelcaseName (nameBase n ++ "'") | n <- ns]
cts
ovls <- if disableOverloadedProjection config
then [d| |]
else Overloaded.polymorphicProjections tyCon vars
[nameBase n | n <- ns]
cts
return $ cols ++ ovls
pc <- defineProductConstructor recTypeName
let scPred v = classP ''ShowConstantTermsSQL [varT v]
ct <- instanceD (mapM scPred vars) (appT [t| ShowConstantTermsSQL |] tyCon) []
return $ concat [pw, cols, pc, [ct]]
-- | Generate all templates against defined record like type constructor
-- other than depending on sql-value type.
makeRelationalRecordDefault :: Name -- ^ Type constructor name
-> Q [Dec] -- ^ Result declaration
makeRelationalRecordDefault = makeRelationalRecordDefault' defaultConfig