beginExpr :: Parser Expression
beginExpr = do
  keyWord "begin"
  exprs <- sepBy1 (try expression) semiColon
  keyWord "end"
  return $ BeginExpr exprs
beginExpr :: Parser Expression
beginExpr = do
  keyWord "begin"
  exprs <- sepBy1 (try expression) semiColon
  keyWord "end"
  return $ BeginExpr exprs
beginExpr = do
  keyWord "begin"
  exprs <- sepBy1 (try expression) semiColon
  keyWord "end"
  return $ BeginExpr exprs