Marc Weber wrote:
My ghc version: Glasgow Haskell Compiler, Version 6.5.20060117, for Haskell 98,
compiled by GHC version 6.5.20060117
load this into ghci
module Main where
class Table t where
tableName :: t -> String
data TableObj = forall f. (Table f) => TableObj { unObj::f }
instance Table TableObj where
tableName (TableObj t) = tableName t
and do :t unObj
result :
marc@(none) ~/projects/haskell/HTTF/Font/TTF $ ghci -fglasgow-exts
___ ___ _
/ _ \ /\ /\/ __(_)
/ /_\// /_/ / / | | GHC Interactive, version 6.5.20060117, for
Haskell 98.
/ /_\\/ __ / /___| | http://www.haskell.org/ghc/
\____/\/ /_/\____/|_| Type :? for help.
Loading package base-1.0 ... linking ... done.
Prelude> :l Table.hs
[1 of 1] Skipping Font.TTF.Table ( Table.hs, Table.o )
Ok, modules loaded: Font.TTF.Table.
Prelude Font.TTF.Table> :t unObj
<interactive>:1:0:
Can't find interface-file declaration for TableObj
Probable cause: bug in .hi-boot file, or inconsistent .hi file
Use -ddump-if-trace to get an idea of which file caused the error
This can't be right. The code you gave above says "module Main", but
GHCi is loading "Font.TTF.Table", and also it says "Skipping" so there
is an .hi file lying around too.
Can you tell us how to reproduce the problem starting in an empty directory?
Cheers,
Simon
| 