{-# LANGUAGE RankNTypes, ScopedTypeVariables #-}{- |
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 -- | 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|...]@quoteExp ::String->Q Exp ,-- | Quasi-quoter for patterns, invoked by quotes like @f $[q|...] = rhs@quotePat ::String->Q Pat ,-- | Quasi-quoter for types, invoked by quotes like @f :: $[q|...]@quoteType ::String->Q Type ,-- | Quasi-quoter for declarations, invoked by top-level quotesquoteDec ::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 {quoteExp=qe ,quotePat=qp ,quoteType=qt ,quoteDec=qd })=QuasiQuoter {quoteExp=get qe ,quotePat=get qp ,quoteType=get qt ,quoteDec=get qd }whereget::(String->Q a )->String->Q a get old_quoter file_name =do{file_cts <-runIO (readFilefile_name );addDependentFile file_name ;old_quoter file_cts }