为什么在尝试"读取"此值时出现错误？

Question

.hs代码:

data Person = Person { firstName :: String  
                     , lastName :: String  
                     , age :: Int  
                     } deriving (Eq, Show, Read)

编译:

*Main> :load "/home/optimight/baby.hs"  
[1 of 1] Compiling Main             ( /home/optimight/baby.hs, interpreted )  
Ok, modules loaded: Main.  

在编译后立即测试:

*Main> read "Person {firstName = \"Michael\", lastName \"Diamond\", age = 43}" :: Person  
*** Exception: Prelude.read: no parse

请指导.为什么会出现此错误以及如何避免此类错误？

Answer 1

lastName \"Diamond\"

缺少一个等号.

read "Person {firstName = \"Michael\", lastName = \"Diamond\", age = 43}" :: Person