#12452: TemplateHaskell - variables in top level splices and loading modules. -------------------------------------+------------------------------------- Reporter: mkloczko | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Linux TemplateHaskell | Architecture: x86_64 | Type of failure: GHC rejects (amd64) | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following code fails when loading Main module: {{{#!hs {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE ScopedTypeVariables #-} module TH where import Language.Haskell.TH import Language.Haskell.TH.Syntax import Data.Typeable usingType :: a -> Q [Dec] usingType _ = do let name = "The name!" -- theF = "The name!" return [FunD (mkName "theF") [Clause [] (NormalB $ LitE $ StringL name ) []]] }}} {{{#!hs {-# LANGUAGE TemplateHaskell #-} module Main where import TH data A = A Int -- Runs with `usingType (undefined :: A)` instead $(usingType (A 3) ) main = putStrLn $ theF }}} The error: {{{ $ ghc --make Main.hs [1 of 2] Compiling TH ( TH.hs, TH.o ) [2 of 2] Compiling Main ( Main.hs, Main.o ) attempting to use module ‘Main’ (Main.hs) which is not loaded }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12452 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler