1 files changed, 45 insertions, 0 deletions
diff --git a/src/parser/expr.hs b/src/parser/expr.hs
new file mode 100644
index 0000000..b84362d
--- /dev/null
+++ b/src/parser/expr.hs
@@ -0,0 +1,45 @@
+module Parser.Expr where
+
+import Control.Applicative
+
+import Parser.Core
+import Atom
+import Expr
+
+
+imaginaryP :: Parser Atom
+imaginaryP = AImaginary <$> (floatP <* char 'i')
+
+rationalP :: Parser Atom
+rationalP = ARational <$> floatP
+
+termOpP :: Parser (Expr -> Expr -> Expr)
+termOpP = infixOp "+" Add <|> infixOp "-" Sub
+
+factorOpP :: Parser (Expr -> Expr -> Expr)
+factorOpP = infixOp "*" Mul <|> infixOp "/" Div <|> infixOp "%" Mod
+
+expOpP :: Parser (Expr -> Expr -> Expr)
+expOpP = infixOp "^" Exp
+
+exprP :: Parser Expr
+exprP = termP `chainl1` termOpP
+
+termP :: Parser Expr
+termP =  factorP `chainl1` factorOpP
+
+variableP :: Parser Expr
+variableP = Variable <$> alphaStringP
+
+functionP :: Parser Expr
+functionP = Function <$> alphaStringP <*> parenthesisExprP
+
+factorP :: Parser Expr
+factorP =  endpointP `chainl1` expOpP
+    where endpointP = parenthesisExprP <|> (EAtom <$> atomP) <|> functionP <|> variableP
+
+parenthesisExprP :: Parser Expr
+parenthesisExprP = parenthesize exprP
+
+atomP :: Parser Atom
+atomP = imaginaryP <|> rationalP