Question

我需要能够动态加载Haskell模块，并在动态加载模块的上下文中计算表达式。

Hint做到了;问题是，它至少在Windows上不适用于GHCi。

cygwin-bash> ghci HintTest.hs
GHCi, version 7.6.3: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Ok, modules loaded: Main.
Prelude Main>
Prelude Main> main
[... lots of "Loading package" messages snipped]

GHCi runtime linker: fatal error: I found a duplicate definition for symbol
   _debugLn
whilst processing object file
   C:\PROGRAM FILES (X86)\HASKELL PLATFORM\2013.2.0.0\lib\ghc-prim-0.3.0.0\HSghc-prim-0.3.0.0.o
This could be caused by:
   * Loading two different object files which export the same symbol
   * Specifying the same object file twice on the GHCi command line
   * An incorrect `package.conf' entry, causing some object to be
     loaded twice.
GHCi cannot safely continue in this situation.  Exiting now.  Sorry.

直接使用GHC模块时出现同样的错误，如GHC/As a library所示。

作为已编译的程序，HintTest运行得很好。

有什么可以做的吗？

我不需要独立运行我的程序;总是使用GHCi就足够了。如果程序可以使用GHCi本身作为解释器而不是它自己的GHC副本，那也是很好的。也就是说，我希望能够做到这样的事情：

do
  context <- loadToGhci "MyModule.hs"
  inContext context "MyModule.myFunction 2 5"

当我返回REPL时，MyModule被神奇地加载到它。 context是一种带有GHCi状态的monad。

更新相同的代码适用于Linux。也许这是GHC中特定于Windows的错误。可以解决吗？

更新2 这是完整的日志

Prelude Main> main
Loading package array-0.4.0.1 ... linking ... done.
Loading package deepseq-1.3.0.1 ... linking ... done.
Loading package bytestring-0.10.0.2 ... linking ... done.
Loading package Win32-2.3.0.0 ... linking ... done.
Loading package transformers-0.3.0.0 ... linking ... done.
Loading package old-locale-1.0.0.5 ... linking ... done.
Loading package time-1.4.0.1 ... linking ... done.
Loading package syb-0.4.0 ... linking ... done.
Loading package random-1.0.1.1 ... linking ... done.
Loading package filepath-1.3.0.1 ... linking ... done.
Loading package directory-1.2.0.1 ... linking ... done.
Loading package process-1.1.0.2 ... linking ... done.
Loading package pretty-1.1.1.0 ... linking ... done.
Loading package mtl-2.1.2 ... linking ... done.
Loading package containers-0.5.0.0 ... linking ... done.
Loading package hpc-0.6.0.0 ... linking ... done.
Loading package hoopl-3.9.0.0 ... linking ... done.
Loading package haskell-src-1.0.1.5 ... linking ... done.
Loading package old-time-1.1.0.1 ... linking ... done.
Loading package Cabal-1.16.0 ... linking ... done.
Loading package binary-0.5.1.1 ... linking ... done.
Loading package bin-package-db-0.0.0.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
Loading package ghc-7.6.3 ... linking ... done.
Loading package extensible-exceptions-0.1.1.4 ... linking ... done.
Loading package MonadCatchIO-mtl-0.3.0.5 ... linking ... done.
Loading package ghc-mtl-1.0.1.2 ... linking ... done.
Loading package ghc-paths-0.1.0.9 ... linking ... done.
Loading package utf8-string-0.3.7 ... linking ... done.
Loading package hint-0.3.3.7 ... linking ... done.


GHCi runtime linker: fatal error: I found a duplicate definition for symbol
   _debugLn
whilst processing object file
   C:\PROGRAM FILES (X86)\HASKELL PLATFORM\2013.2.0.0\lib\ghc-prim-0.3.0.0\HSghc-prim-0.3.0.0.o
This could be caused by:
   * Loading two different object files which export the same symbol
   * Specifying the same object file twice on the GHCi command line
   * An incorrect `package.conf' entry, causing some object to be
     loaded twice.
GHCi cannot safely continue in this situation.  Exiting now.  Sorry.

Answer 1

您尝试将字节码解释器和运行时动态加载到字节码解释器和运行时。这是否有效取决于底层C库如何在您的系统上链接 - 这是非常依赖于平台的。

特别是，C链符号将被复制，除非在链接时特别小心，当您第二次加载各种RTS模块时，这将导致链接器错误。

GHCi下的动态加载

1 个答案: