esqueleto 3.5.8.2 → 3.5.9.0

raw patch · 3 files changed

+53/−6 lines, 3 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• changelog.md +6/−5
• esqueleto.cabal +1/−1
• src/Database/Esqueleto/Internal/Internal.hs +46/−0

@@ -1,15 +1,16 @@ 3.5.9.0-========+======= - @9999years-    - #350+    - [#350](https://github.com/bitemyapp/esqueleto/pull/350)       - Add `GetFirstTable`, `getTable`, `getTableMaybe` helpers for selecting         tables from `:&` chains - @josephsumabat     - [#339](https://github.com/bitemyapp/esqueleto/pull/333)       - Add `forUpdateOf`, `forShareOf` locking kinds for postgres--3.5.8.2-=======+- @parsonsmatt+    - [#342](https://github.com/bitemyapp/esqueleto/pull/342)+        - Create a `TypeError` instance for `Functor SqlExpr`, adding+          documentation and work arounds for the need. - @9999years     - [#327](https://github.com/bitemyapp/esqueleto/pull/327)         - Fixed a Haddock typo causing documentation to render incorrectly

@@ -2,7 +2,7 @@  name:           esqueleto -version:        3.5.8.2+version:        3.5.9.0 synopsis:       Type-safe EDSL for SQL queries on persistent backends. description:    @esqueleto@ is a bare bones, type-safe EDSL for SQL queries that works with unmodified @persistent@ SQL backends.  Its language closely resembles SQL, so you don't have to learn new concepts, just new syntax, and it's fairly easy to predict the generated SQL and optimize it for your backend. Most kinds of errors committed when writing SQL are caught as compile-time errors---although it is possible to write type-checked @esqueleto@ queries that fail at runtime.                 .

@@ -1,4 +1,9 @@ {-# LANGUAGE CPP #-}+{-# LANGUAGE DataKinds #-}+{-# LANGUAGE TypeOperators #-}+{-# LANGUAGE TypeApplications #-}+{-# language DerivingStrategies, GeneralizedNewtypeDeriving #-}+ {-# LANGUAGE ConstraintKinds #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE DerivingStrategies #-}@@ -75,6 +80,7 @@        ) import Database.Persist.SqlBackend import GHC.Records+import GHC.TypeLits import Text.Blaze.Html (Html)  -- | (Internal) Start a 'from' query with an entity. 'from'@@ -2212,6 +2218,46 @@ -- string ('TLB.Builder') and a list of values to be -- interpolated by the SQL backend. data SqlExpr a = ERaw SqlExprMeta (NeedParens -> IdentInfo -> (TLB.Builder, [PersistValue]))++-- | Folks often want the ability to promote a Haskell function into the+-- 'SqlExpr' expression language - and naturally reach for 'fmap'.+-- Unfortunately, this is impossible. We cannot send *functions* to the+-- database, which is what we would need to do in order for this to make sense.+-- Let's consider the type of 'fmap' for 'SqlExpr':+--+-- @+-- fmap :: (a -> b) -> 'SqlExpr' a -> 'SqlExpr' b+-- @+--+-- This type signature is making a pretty strong claim: "Give me a Haskell+-- function from @a -> b@. I will then transform a SQL expression representing+-- a Haskell value of type @a@ and turn it into a SQL expression representing+-- a Haskell value of type @b@."+--+-- Let's suppose we *could* do this - @fmap (+1)@ would have to somehow inspect+-- the function expression means "add one", and then translate that to the+-- appropriate SQL.+--+-- This is why @esqueleto@ defines a bunch of operators: @x '+.' ('val' 1)@ can+-- be used instead of @'fmap' (+1) x@.+--+-- If you do have a SQL function, then you can provide a safe type and introduce+-- it with 'unsafeSqlFunction' or 'unsafeSqlBinOp'.+--+-- @since 3.5.8.2+instance TypeError SqlExprFunctorMessage => Functor SqlExpr where+    fmap = error "impossible"++-- | The type error message given when you try to do 'fmap' on a 'SqlExpr'. This+-- is intended to guide folks towards the docs, which should guide them towards+-- alternative implementations.+--+-- @since 3.5.8.2+type SqlExprFunctorMessage =+    'Text "You're trying to treat `SqlExpr` like a `Functor`, but it cannot be one."+    ':$$: 'Text "We would need to send arbitrary functions to the database for interpretation to support that instance."+    ':$$: 'Text "See the docs for the fake instance of `Functor SqlExpr` for more information."+    ':$$: 'Text "Consider using a SQL function with `unsafeSqlFunction` and a good type signature."  -- |  This instance allows you to use @record.field@ notation with GHC 9.2's -- @OverloadedRecordDot@ extension.