42 lines
1.5 KiB
Haskell
42 lines
1.5 KiB
Haskell
-- (C) Copyright Collin Doering 2011
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--
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-- This program is free software: you can redistribute it and/or modify
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-- it under the terms of the GNU General Public License as published by
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-- the Free Software Foundation, either version 3 of the License, or
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-- (at your option) any later version.
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--
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-- This program is distributed in the hope that it will be useful,
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-- but WITHOUT ANY WARRANTY; without even the implied warranty of
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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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-- GNU General Public License for more details.
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--
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-- You should have received a copy of the GNU General Public License
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-- along with this program. If not, see <http://www.gnu.org/licenses/>.
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-- File: Expressions.hs
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-- Author: Collin J. Doering <rekahsoft@gmail.com>
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-- Date: Nov 11, 2011
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type Symbol = Char
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data Expr a = Const a
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| Add (Expr a) (Expr a)
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| Mult (Expr a) (Expr a)
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| Pow (Expr a) (Expr a)
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| Var Symbol
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deriving (Show)
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-- this has to be done with a parser..
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-- simplifyExpr :: Num a => Expr a -> Expr a
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-- simplifyExpr (Const a) = Const a
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-- simplifyExpr (Add x y) = addExpr x y
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-- simplifyExpr (Mult x y) = multExpr x y
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-- simplifyExpr (Pow x y) = powExpr x y
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-- simplifyExpr (Var x) = Var x
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-- where addExpr (Const x) (Const y) = Const (x + y)
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-- addExpr x y = Add (simplifyExpr x) (simplifyExpr y)
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-- multExpr (Const x) (Const y) = Const (x * y)
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-- multExpr (Const x) (Var y) = ..
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-- dead end..stuck..don't know how to do this :(
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