Feature request/help: evaluating template haskell at runtime
Hello, I am attempting some genetic programming in Haskell. Rather than defining my own data type for programs and writing my own interpreter, I want to use the template haskell expression data types and evaluate them with the rts's byte code interpreter. This gives me a nice fast interpreter that provides the statistics that I want. I could pretty print the template haskell and then execute the result string using the GHC module or hs-plugins, but I would like to save the pretty printing and parsing as normally the program generation time is important by GP. I have being looking at module TcSplice. I see that I need to run the TH expression through function convertToHsExpr, but after that I am stuck. This produces LHsExpr RdrName and I need to get CoreSyn.CoreExpr. What functions to use? dsLExpr :: LHsExpr Id -> DsM CoreSyn.CoreExpr seems one important step, but I haven't figured out how to get from LHtsExpr RdrName to LHsExpr Id. It would be nice to have standard GHC functionality to have the ability to compile and evaluate template haskell at runtime using the GHC library. Rene.
Perhaps you can just write a client to the GHC library that - constructs a string for your program - asks GHC to evaluate it just as if you'd typed it at the command line You may say that a string is a silly thing -- your GA will construct a tree, so the GHC API should supply a function that takes the parse tree rather than the string. Good point. There should be a Trac feature request on which to accumulate feature requests for the GHC API. But meanwhile, serialising it as a string should be fine, no? Simon | -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] On | Behalf Of Rene de Visser | Sent: 20 May 2007 21:30 | To: glasgow-haskell-users@haskell.org | Subject: Feature request/help: evaluating template haskell at runtime | | Hello, | | I am attempting some genetic programming in Haskell. | | Rather than defining my own data type for programs and writing my own | interpreter, I want to use the template haskell expression data types and | evaluate them with the rts's byte code interpreter. This gives me a nice | fast interpreter that provides the statistics that I want. | | I could pretty print the template haskell and then execute the result string | using the GHC module or hs-plugins, but I would like to save the pretty | printing and parsing as normally the program generation time is important by | GP. | | I have being looking at module TcSplice. | | I see that I need to run the TH expression through function convertToHsExpr, | but after that I am stuck. | | This produces LHsExpr RdrName and I need to get CoreSyn.CoreExpr. | | What functions to use? | | dsLExpr :: LHsExpr Id -> DsM CoreSyn.CoreExpr seems one important step, | but I haven't figured out how to get from LHtsExpr RdrName to LHsExpr Id. | | It would be nice to have standard GHC functionality to have the ability to | compile and evaluate template haskell at runtime using the GHC library. | | Rene. | | | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
participants (2)
-
Rene de Visser -
Simon Peyton-Jones