• Simon Peyton Jones's avatar
    Refactor the handling of quasi-quotes · f46360ed
    Simon Peyton Jones authored
    As Trac #10047 points out, a quasi-quotation [n|...blah...|] is supposed
    to behave exactly like $(n "...blah...").  But it doesn't!  This was outright
    wrong: quasiquotes were being run even inside brackets.
    
    Now that TH supports both typed and untyped splices, a quasi-quote is properly
    regarded as a particular syntax for an untyped splice. But apart from that
    they should be treated the same.  So this patch refactors the handling of
    quasiquotes to do just that.
    
    The changes touch quite a lot of files, but mostly in a routine way.
    The biggest changes by far are in RnSplice, and more minor changes in
    TcSplice.  These are the places where there was real work to be done.
    Everything else is routine knock-on changes.
    
    * No more QuasiQuote forms in declarations, expressions, types, etc.
      So we get rid of these data constructors
        * HsBinds.QuasiQuoteD
        * HsExpr.HsSpliceE
        * HsPat.QuasiQuotePat
        * HsType.HsQuasiQuoteTy
    
    * We get rid of the HsQuasiQuote type altogether
    
    * Instead, we augment the HsExpr.HsSplice type to have three
      consructors, for the three types of splice:
        * HsTypedSplice
        * HsUntypedSplice
        * HsQuasiQuote
      There are some related changes in the data types in HsExpr near HsSplice.
      Specifically: PendingRnSplice, PendingTcSplice, UntypedSpliceFlavour.
    
    * In Hooks, we combine rnQuasiQuoteHook and rnRnSpliceHook into one.
      A smaller, clearer interface.
    
    * We have to update the Haddock submodule, to accommodate the hsSyn changes
    f46360ed
TcEnv.hs 36.4 KB