{-# LANGUAGE RankNTypes, ScopedTypeVariables, Safe #-}{- |
Module : Language.Haskell.TH.Quote
Description : Quasi-quoting support for Template Haskell
Template Haskell supports quasiquoting, which permits users to construct
program fragments by directly writing concrete syntax. A quasiquoter is
essentially a function with takes a string to a Template Haskell AST.
This module defines the 'QuasiQuoter' datatype, which specifies a
quasiquoter @q@ which can be invoked using the syntax
@[q| ... string to parse ... |]@ when the @QuasiQuotes@ language
extension is enabled, and some utility functions for manipulating
quasiquoters. Nota bene: this package does not define any parsers,
that is up to you.
-}moduleLanguage.Haskell.TH.Quote(QuasiQuoter (..),quoteFile ,-- * For backwards compatibilitydataToQa ,dataToExpQ ,dataToPatQ )whereimportLanguage.Haskell.TH.Syntax importPrelude -- | The 'QuasiQuoter' type, a value @q@ of this type can be used-- in the syntax @[q| ... string to parse ...|]@. In fact, for-- convenience, a 'QuasiQuoter' actually defines multiple quasiquoters-- to be used in different splice contexts; if you are only interested-- in defining a quasiquoter to be used for expressions, you would-- define a 'QuasiQuoter' with only 'quoteExp', and leave the other-- fields stubbed out with errors.dataQuasiQuoter =QuasiQuoter {-- | Quasi-quoter for expressions, invoked by quotes like @lhs = $[q|...]@QuasiQuoter -> String -> Q Exp
quoteExp ::String ->Q Exp ,-- | Quasi-quoter for patterns, invoked by quotes like @f $[q|...] = rhs@QuasiQuoter -> String -> Q Pat
quotePat ::String ->Q Pat ,-- | Quasi-quoter for types, invoked by quotes like @f :: $[q|...]@QuasiQuoter -> String -> Q Type
quoteType ::String ->Q Type ,-- | Quasi-quoter for declarations, invoked by top-level quotesQuasiQuoter -> String -> Q [Dec]
quoteDec ::String ->Q [Dec ]}-- | 'quoteFile' takes a 'QuasiQuoter' and lifts it into one that read-- the data out of a file. For example, suppose @asmq@ is an-- assembly-language quoter, so that you can write [asmq| ld r1, r2 |]-- as an expression. Then if you define @asmq_f = quoteFile asmq@, then-- the quote [asmq_f|foo.s|] will take input from file @"foo.s"@ instead-- of the inline textquoteFile ::QuasiQuoter ->QuasiQuoter quoteFile :: QuasiQuoter -> QuasiQuoter
quoteFile (QuasiQuoter {quoteExp :: QuasiQuoter -> String -> Q Exp
quoteExp =String -> Q Exp
qe ,quotePat :: QuasiQuoter -> String -> Q Pat
quotePat =String -> Q Pat
qp ,quoteType :: QuasiQuoter -> String -> Q Type
quoteType =String -> Q Type
qt ,quoteDec :: QuasiQuoter -> String -> Q [Dec]
quoteDec =String -> Q [Dec]
qd })=QuasiQuoter {quoteExp :: String -> Q Exp
quoteExp =(String -> Q Exp) -> String -> Q Exp
forall a. (String -> Q a) -> String -> Q a
get String -> Q Exp
qe ,quotePat :: String -> Q Pat
quotePat =(String -> Q Pat) -> String -> Q Pat
forall a. (String -> Q a) -> String -> Q a
get String -> Q Pat
qp ,quoteType :: String -> Q Type
quoteType =(String -> Q Type) -> String -> Q Type
forall a. (String -> Q a) -> String -> Q a
get String -> Q Type
qt ,quoteDec :: String -> Q [Dec]
quoteDec =(String -> Q [Dec]) -> String -> Q [Dec]
forall a. (String -> Q a) -> String -> Q a
get String -> Q [Dec]
qd }whereget ::(String ->Q a )->String ->Q a get :: forall a. (String -> Q a) -> String -> Q a
get String -> Q a
old_quoter String
file_name =do{String
file_cts <-IO String -> Q String
forall a. IO a -> Q a
runIO (String -> IO String
readFile String
file_name );String -> Q ()
addDependentFile String
file_name ;String -> Q a
old_quoter String
file_cts }