diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,5 @@ +# Revision history for quotet + +## 0.0.0.0 -- 2021-07-08 + +* First version. Released on an unsuspecting world. diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,121 @@ +Creative Commons Legal Code + +CC0 1.0 Universal + + CREATIVE COMMONS CORPORATION IS NOT A LAW FIRM AND DOES NOT PROVIDE + LEGAL SERVICES. DISTRIBUTION OF THIS DOCUMENT DOES NOT CREATE AN + ATTORNEY-CLIENT RELATIONSHIP. CREATIVE COMMONS PROVIDES THIS + INFORMATION ON AN "AS-IS" BASIS. CREATIVE COMMONS MAKES NO WARRANTIES + REGARDING THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS + PROVIDED HEREUNDER, AND DISCLAIMS LIABILITY FOR DAMAGES RESULTING FROM + THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS PROVIDED + HEREUNDER. + +Statement of Purpose + +The laws of most jurisdictions throughout the world automatically confer +exclusive Copyright and Related Rights (defined below) upon the creator +and subsequent owner(s) (each and all, an "owner") of an original work of +authorship and/or a database (each, a "Work"). + +Certain owners wish to permanently relinquish those rights to a Work for +the purpose of contributing to a commons of creative, cultural and +scientific works ("Commons") that the public can reliably and without fear +of later claims of infringement build upon, modify, incorporate in other +works, reuse and redistribute as freely as possible in any form whatsoever +and for any purposes, including without limitation commercial purposes. +These owners may contribute to the Commons to promote the ideal of a free +culture and the further production of creative, cultural and scientific +works, or to gain reputation or greater distribution for their Work in +part through the use and efforts of others. + +For these and/or other purposes and motivations, and without any +expectation of additional consideration or compensation, the person +associating CC0 with a Work (the "Affirmer"), to the extent that he or she +is an owner of Copyright and Related Rights in the Work, voluntarily +elects to apply CC0 to the Work and publicly distribute the Work under its +terms, with knowledge of his or her Copyright and Related Rights in the +Work and the meaning and intended legal effect of CC0 on those rights. + +1. Copyright and Related Rights. A Work made available under CC0 may be +protected by copyright and related or neighboring rights ("Copyright and +Related Rights"). Copyright and Related Rights include, but are not +limited to, the following: + + i. the right to reproduce, adapt, distribute, perform, display, + communicate, and translate a Work; + ii. moral rights retained by the original author(s) and/or performer(s); +iii. publicity and privacy rights pertaining to a person's image or + likeness depicted in a Work; + iv. rights protecting against unfair competition in regards to a Work, + subject to the limitations in paragraph 4(a), below; + v. rights protecting the extraction, dissemination, use and reuse of data + in a Work; + vi. database rights (such as those arising under Directive 96/9/EC of the + European Parliament and of the Council of 11 March 1996 on the legal + protection of databases, and under any national implementation + thereof, including any amended or successor version of such + directive); and +vii. other similar, equivalent or corresponding rights throughout the + world based on applicable law or treaty, and any national + implementations thereof. + +2. Waiver. To the greatest extent permitted by, but not in contravention +of, applicable law, Affirmer hereby overtly, fully, permanently, +irrevocably and unconditionally waives, abandons, and surrenders all of +Affirmer's Copyright and Related Rights and associated claims and causes +of action, whether now known or unknown (including existing as well as +future claims and causes of action), in the Work (i) in all territories +worldwide, (ii) for the maximum duration provided by applicable law or +treaty (including future time extensions), (iii) in any current or future +medium and for any number of copies, and (iv) for any purpose whatsoever, +including without limitation commercial, advertising or promotional +purposes (the "Waiver"). Affirmer makes the Waiver for the benefit of each +member of the public at large and to the detriment of Affirmer's heirs and +successors, fully intending that such Waiver shall not be subject to +revocation, rescission, cancellation, termination, or any other legal or +equitable action to disrupt the quiet enjoyment of the Work by the public +as contemplated by Affirmer's express Statement of Purpose. + +3. Public License Fallback. Should any part of the Waiver for any reason +be judged legally invalid or ineffective under applicable law, then the +Waiver shall be preserved to the maximum extent permitted taking into +account Affirmer's express Statement of Purpose. In addition, to the +extent the Waiver is so judged Affirmer hereby grants to each affected +person a royalty-free, non transferable, non sublicensable, non exclusive, +irrevocable and unconditional license to exercise Affirmer's Copyright and +Related Rights in the Work (i) in all territories worldwide, (ii) for the +maximum duration provided by applicable law or treaty (including future +time extensions), (iii) in any current or future medium and for any number +of copies, and (iv) for any purpose whatsoever, including without +limitation commercial, advertising or promotional purposes (the +"License"). The License shall be deemed effective as of the date CC0 was +applied by Affirmer to the Work. Should any part of the License for any +reason be judged legally invalid or ineffective under applicable law, such +partial invalidity or ineffectiveness shall not invalidate the remainder +of the License, and in such case Affirmer hereby affirms that he or she +will not (i) exercise any of his or her remaining Copyright and Related +Rights in the Work or (ii) assert any associated claims and causes of +action with respect to the Work, in either case contrary to Affirmer's +express Statement of Purpose. + +4. Limitations and Disclaimers. + + a. No trademark or patent rights held by Affirmer are waived, abandoned, + surrendered, licensed or otherwise affected by this document. + b. Affirmer offers the Work as-is and makes no representations or + warranties of any kind concerning the Work, express, implied, + statutory or otherwise, including without limitation warranties of + title, merchantability, fitness for a particular purpose, non + infringement, or the absence of latent or other defects, accuracy, or + the present or absence of errors, whether or not discoverable, all to + the greatest extent permissible under applicable law. + c. Affirmer disclaims responsibility for clearing rights of other persons + that may apply to the Work or any use thereof, including without + limitation any person's Copyright and Related Rights in the Work. + Further, Affirmer disclaims responsibility for obtaining any necessary + consents, permissions or other rights required for any use of the + Work. + d. Affirmer understands and acknowledges that Creative Commons is not a + party to this document and has no duty or obligation with respect to + this CC0 or use of the Work. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,7 @@ +# quotet +[![CI](https://github.com/amesgen/quotet/workflows/CI/badge.svg)](https://github.com/amesgen/quotet/actions) +[![Hackage](https://img.shields.io/hackage/v/quotet)](https://hackage.haskell.org/package/quotet) + +A monad transformer for the [`Quote`](https://hackage.haskell.org/package/template-haskell/docs/Language-Haskell-TH.html#t:Quote) type class from template-haskell, in spirit of the ["Overloaded Quotations" proposal](https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0246-overloaded-bracket.rst) implemented in GHC 9.0. + +See [the haddocks](https://hackage.haskell.org/package/quotet/docs/Control/Monad/Quote.html) for documentation. diff --git a/quotet.cabal b/quotet.cabal new file mode 100644 --- /dev/null +++ b/quotet.cabal @@ -0,0 +1,60 @@ +cabal-version: 2.4 +name: quotet +version: 0.0.0.0 + +synopsis: Monad transformer for Quote from template-haskell +description: + A monad transformer for the @Quote@ type class from template-haskell, in spirit of the ["Overloaded Quotations" proposal](https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0246-overloaded-bracket.rst) proposal implemented in GHC 9.0. +category: String, Text, QuasiQuotes + +homepage: https://github.com/amesgen/quotet +bug-reports: https://github.com/amesgen/quotet/issues +license: CC0-1.0 +license-file: LICENSE +extra-source-files: README.md +author: amesgen +maintainer: amesgen@amesgen.de +extra-source-files: CHANGELOG.md + +source-repository head + location: https://github.com/amesgen/quotet + type: git + +flag exceptions + description: Support instances from exceptions + default: True + manual: True + +flag semigroupoids + description: Support instances from semigroupoids + default: False + manual: True + +flag monad-control + description: Support instances from monad-control + default: False + manual: True + +common commons + default-language: Haskell2010 + ghc-options: -Wall -Wincomplete-record-updates -Wincomplete-uni-patterns -Wredundant-constraints -fno-warn-name-shadowing -fhide-source-paths -Wunused-packages + default-extensions: DerivingStrategies FlexibleInstances GeneralizedNewtypeDeriving MultiParamTypeClasses StandaloneDeriving UndecidableInstances + +library + import: commons + ghc-options: -Wmissing-export-lists + hs-source-dirs: src + exposed-modules: + Control.Monad.Quote + Control.Monad.Quote.Internal + build-depends: + base >= 4.14 && < 5 + , template-haskell >= 2.16 && < 2.18 + , th-compat >= 0.1.2 + , mtl ^>= 2.2 + if flag(exceptions) + build-depends: exceptions ^>= 0.10 + if flag(semigroupoids) + build-depends: semigroupoids ^>= 5.3 + if flag(monad-control) + build-depends: transformers-base ^>= 0.4, monad-control ^>= 1.0 diff --git a/src/Control/Monad/Quote.hs b/src/Control/Monad/Quote.hs new file mode 100644 --- /dev/null +++ b/src/Control/Monad/Quote.hs @@ -0,0 +1,48 @@ +-- | A monad transformer for the 'Quote' type class from template-haskell. +-- +-- The ["Overloaded Quotations" proposal](https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0246-overloaded-bracket.rst) +-- has been implemented in GHC 9.0, and generalizes the type of quotation brackets from +-- +-- @[| \x -> x + 1 |] :: 'Language.Haskell.TH.Q' 'Language.Haskell.TH.Exp'@ +-- +-- to +-- +-- @[| \x -> x + 1 |] :: 'Quote' m => m 'Language.Haskell.TH.Exp'@ +-- +-- where the 'Quote' type class only has a single function, 'newName', in order to generate +-- fresh 'Language.Haskell.TH.Name's. +-- +-- By default, template-haskell provides 'Quote' instances for 'Language.Haskell.TH.Q' and 'IO'. +-- This library provides pure versions, 'PureQ' and its transformer variant 'QuoteT', in order to +-- e.g. extract an 'Language.Haskell.TH.Exp' from the bracket above in a pure context. +-- See 'runPureQ' and 'runQuoteT' for concrete examples. +module Control.Monad.Quote + ( -- * The @Quote@ class + Quote (..), + + -- * The @PureQ@ monad + PureQ, + runPureQ, + + -- * The @QuoteT@ monad transformer + QuoteT, + runQuoteT, + ) +where + +import Control.Monad.Quote.Internal +import Data.Functor.Identity + +-- | A pure variant of the 'QuoteT' monad transformer. +-- +-- Useful to get an 'Language.Haskell.TH.Exp' out of a @'Quote' m => m 'Language.Haskell.TH.Exp'@ via 'runPureQ'. +type PureQ = QuoteT Identity + +-- | Extract @a@ from @'PureQ' a@, where 'PureQ' is an instance of 'Quote'. +-- +-- On GHC 9.0+, you can use this to extract an 'Language.Haskell.TH.Exp' out of a quotation bracket: +-- +-- >>> runPureQ [| \x -> x + 5 |] +-- LamE [VarP x_0] (InfixE (Just (VarE x_0)) (VarE GHC.Num.+) (Just (LitE (IntegerL 5)))) +runPureQ :: PureQ a -> a +runPureQ = runIdentity . runQuoteT diff --git a/src/Control/Monad/Quote/Internal.hs b/src/Control/Monad/Quote/Internal.hs new file mode 100644 --- /dev/null +++ b/src/Control/Monad/Quote/Internal.hs @@ -0,0 +1,99 @@ +{-# LANGUAGE CPP #-} + +-- | Internal module, no stability guarantees +module Control.Monad.Quote.Internal + ( Quote (..), + QuoteT (..), + runQuoteT, + ) +where + +import Control.Applicative +import Control.Monad.Cont.Class +import Control.Monad.Error.Class +import Control.Monad.RWS.Class +import Control.Monad.State.Strict +import Language.Haskell.TH.Syntax (Uniq, mkNameU) +import Language.Haskell.TH.Syntax.Compat (Quote (..)) + +#ifdef MIN_VERSION_exceptions +import Control.Monad.Catch +#endif + +#ifdef MIN_VERSION_semigroupoids +import Data.Functor.Apply (Apply (..)) +import Data.Functor.Bind (Bind (..)) +#endif + +#ifdef MIN_VERSION_monad_control +import Control.Monad.Base +import Control.Monad.Trans.Control +#endif + +-- $setup +-- >>> import Language.Haskell.TH (Exp) +-- >>> import Control.Monad.Reader + +-- | The 'QuoteT' monad transformer. Also see 'runQuoteT'. +-- +-- Useful to add a 'Quote' instance to any monad transformer stack. +-- +-- Internally, this is a newtype of @'StateT' 'Uniq'@. +newtype QuoteT m a = QuoteT {unQuoteT :: StateT Uniq m a} + deriving newtype + ( Functor, + Applicative, + Monad, + MonadFail, + MonadIO, + Alternative, + MonadPlus, + MonadFix, + MonadTrans, + MonadReader r, + MonadWriter w, + MonadRWS r w s, + MonadCont, + MonadError e + ) + +#ifdef MIN_VERSION_exceptions + deriving newtype (MonadThrow, MonadCatch, MonadMask) +#endif + +#ifdef MIN_VERSION_semigroupoids + deriving newtype (Apply) +#endif + +#ifdef MIN_VERSION_monad_control + deriving newtype (MonadBase b, MonadBaseControl b, MonadTransControl) +#endif + +instance MonadState s m => MonadState s (QuoteT m) where + get = lift get + put = lift . put + state = lift . state + +instance Monad m => Quote (QuoteT m) where + newName s = QuoteT . state $ \i -> (mkNameU s i, i + 1) + +#ifdef MIN_VERSION_semigroupoids +instance Bind m => Bind (QuoteT m) where + QuoteT sma >>- f = QuoteT $ sma >>- unQuoteT . f +#endif + +-- | Extract @m a@ from @'QuoteT' m a@, where @'QuoteT' m@ is always an instance of 'Quote'. +-- +-- On GHC 9.0+, you can use this to extract an 'Language.Haskell.TH.Exp' out of a quotation bracket: +-- +-- >>> import qualified Language.Haskell.TH.Lib as TH +-- >>> :{ +-- let mExp :: (Quote m, MonadReader String m) => m Exp +-- mExp = [| \a -> a <> $(TH.stringE =<< ask) |] +-- exp :: Exp +-- exp = flip runReader " world" . runQuoteT $ mExp +-- in exp +-- :} +-- LamE [VarP a_0] (InfixE (Just (VarE a_0)) (VarE GHC.Base.<>) (Just (LitE (StringL " world")))) +runQuoteT :: Monad m => QuoteT m a -> m a +runQuoteT = flip evalStateT 0 . unQuoteT