module Reduce.Reduce_Interface where

import System.Directory

import System.Exit

import System.IO

import System.Process

import Text.ParserCombinators.Parsec

import Text.ParserCombinators.Parsec.Expr

import Text.ParserCombinators.Parsec.Token

import Text.ParserCombinators.Parsec.Language

import Reduce.AS_BASIC_Reduce

type Session = (Handle,Handle)

-- | connects to the CAS, prepares the streams and sets initial options

connectCAS :: IO (Handle, Handle, Handle, ProcessHandle)

connectCAS = do

putStr "Connecting CAS.."

(inp,out,err,pid) <-runInteractiveCommand "/home/dodi/import/reduce/reduce-algebra/trunk/bin/redcsl -w"

hSetBuffering out NoBuffering

hSetBuffering inp LineBuffering

hPutStrLn inp "off nat;"

hGetLine out

hGetLine out

hGetLine out

putStrLn "done"

return (inp,out,err,pid)

-- | closes the connection to the CAS

disconnectCAS :: (Handle,Handle)->IO()

disconnectCAS (inp,out) = do

hPutStrLn inp "quit;"

return ()

-- | reads characters from the specified output until the next result is complete,

-- | indicated by $ when using the maxima mode off nat;

getNextResultOutput :: Handle->IO String

getNextResultOutput out = do

b <- hIsEOF out

if b then return [] else do

c <- hGetChar out

if c=='$' then return [] else do

r <- getNextResultOutput out

return (c:r)

procSimpleCmd :: (Handle,Handle)-> String -> IO String

casfactorExp (inp,out) s = do

hPutStrLn inp s

getNextResultOutput out

-- | factors a given expression over the reals

casfactorExp :: (Handle,Handle) -> EXPRESSION -> IO String

casfactorExp (inp,out) exp = procSimpleCmd (inp,out) "factorize(a*a+b*b+2*a*b);"

-- | solves a single equation over the reals

cassolve :: (Handle,Handle)-> String -> IO String

casfactorExp (inp,out) exp = procSimpleCmd (inp,out) "factorize(a*a+b*b+2*a*b);"

-- | solves a list of equations

-- solven

-- | simplifies a given expression over the reals

cassimplify :: (Handle,Handle)-> String -> IO String

cassimplify (inp,out) exp = procSimpleCmd (inp,out) "factorize(a*a+b*b+2*a*b);"

-- | computes the remainder of a division

casremainder :: (Handle,Handle)-> String -> IO String

casremainder (inp,out) exp = procSimpleCmd (inp,out) "remainder((x+y)*(x+2*y),x+3*y);"

-- | computes the gcd of a division

casgcd :: (Handle,Handle)-> String -> IO String

casgcd (inp,out) exp = procSimpleCmd (inp,out) "gcd(f(x)+g(x)-l1-l2,f(x)-l1);"

-- | integrates the given expression

casint :: (Handle,Handle)-> String -> IO String

casint (inp,out) exp = procSimpleCmd (inp,out) "int(log(x),x);"

-- | performs quantifier elimination of a given expression

casqelim :: (Handle,Handle)-> String -> IO String

casqelim (inp,out) exp = procSimpleCmd (inp,out) "qelim(all(x, ex(y, x2+xy+b>0 and x+ay2+b<=0)))"