On Wednesday 05 April 2006 20:32, Pedro Miguel Duarte wrote:
I am writing a Java program with a call to a Haskell module M.hs, in order to evaluate some expression expr.
A very simple idea, which I got somewhere in the net, is to create a Process object p which executes a GHC command-line instruction:
Process p = Runtime.getRuntime(); p.exec( " ghc M.hs -e \"expr\" " );
This would be very simple, if it worked...
My problem is that expressions i want to evaluate involve strings, and GHC command-line 'ghc' misinterprets some special symbols when it parses double quoted strings.
For instance, ghc -e " reverse \"2<3\" " gives an error!
Hmm. On my Linux machine (running zsh): ben@sarun: .../play/ghc-e > ghc -e " reverse \"2<3\" " "3<2" But now I see that you run 'p.exec' in Java which probably translates (more or less) to a 'exec' system call. 'exec' is not a shell, it cannot translate complex quotings and unquotings. I would try p.exec( "/bin/sh ghc M.hs -e \"expr\" " ); or something similar. Ben