A Frames test

> module Frames
> where 

Define frame slots:

> type FirstName = String     -- first name
> type LastName    = String   -- last name
> type Organization = String
> type Email = String
> type WorkPhone = String
> type CellPhone = String
> type TelephoneNumber = String

Define slots for a contact

> data ContactProperty = FN FirstName
>           | LN LastName
>           | OR Organization
>           | EM Email
>           | WP TelephoneNumber
>           | MP TelephoneNumber
>     deriving (Show, Eq)

> data Contact = Contact [ContactProperty]
>     deriving (Show, Eq)

> type Contacts = [ Contact]

Now I need a way to extract properties from the frame. Start by testing pattern matching
without using parameters. Then I need to find out how to pass a constructor as a parameter.

> getProperty:: [ContactProperty] -> FirstName
> getProperty ((FN fn):_) = fn
> getProperty     (_:xs)  = getProperty xs
> getProperty          [] = "unknown"

> firstName:: Contact -> FirstName
> firstName (Contact cpl) = getProperty cpl


Define Contacts

> c1::Contacts
> c1 =
>  [ ( Contact  [(FN "Ralph"),(LN "Hodgson"),(OR "TopQuadrant"),(EM "rhodgson@topquadrant.com")]),
>    ( Contact  [(FN "Mills"),(LN "Davis"),(EM "mdavis@project10x.com")])]

Tests

> t1=firstName $ head c1 -- should be "Ralph"
> t2=firstName $ last c1 -- should be "Mills"
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