Anonymous types are used a lot in relation to LINQ. See the LINQ example below. In the first LINQ statement an anonymous class is created
The following example shows a couple of LINQ Queries in X#
//references:
//System.dll
//System.Core.dll
//System.Linq.dll
USING System.Collections.Generic
USING System.Linq
USING STATIC System.Console
FUNCTION Start AS VOID
VAR oDev := GetDevelopers()
VAR oC := GetCountries()
VAR oAll := FROM D IN oDev ;
JOIN C IN oC ON D:Country EQUALS C:Name ;
ORDERBY D:LastName ;
SELECT CLASS {D:Name, D:Country, C:Region} // Anonymous class !
// The type of oAll is IOrderedEnumerable<<>f__AnonymousType0<Developer,Country>>
// We prefer the VAR keyword!
VAR oGreek := FROM Developer IN oDev ;
WHERE Developer:Country == "Greece" ;
ORDERBY Developer:LastName DESCENDING ;
SELECT Developer
// The type of oGreek is IOrderedEnumerable<Developer>
// We prefer the VAR keyword!
VAR oCount := FROM Developer IN oDev ;
GROUP Developer BY Developer:Country INTO NewGroup ;
ORDERBY NewGroup:Key SELECT NewGroup
// The type of oCount is IOrderedEnumerable<<IGrouping<string,Developer>>
// We prefer the VAR keyword!
WriteLine(e"X# does LINQ!\n")
WriteLine(e"All X# developers (country+lastname order)\n")
FOREACH VAR oDeveloper IN oAll
WriteLine("{0} in {1}, {2}",oDeveloper:Name, oDeveloper:Country, oDeveloper:Region)
NEXT
WriteLine(e"\nGreek X# Developers (descending lastname)\n")
FOREACH oDeveloper AS Developer IN oGreek
WriteLine(oDeveloper:Name)
NEXT
WriteLine(e"\nDevelopers grouped per country\n")
FOREACH VAR country IN oCount
WriteLine(i"{country.Key}, {country.Count()} developer(s)")
FOREACH VAR oDeveloper IN country
WriteLine(" " + oDeveloper:Name)
NEXT
NEXT
WriteLine("Enter to continue")
ReadLine()
RETURN
FUNCTION GetDevelopers AS IList<Developer>
// This function uses a collection initializer for the List of Developers
// and Object initializers for the Developer Objects
VAR oList := List<Developer>{} { ;
Developer{}{ FirstName := "Chris", LastName := "Pyrgas", Country := "Greece"},;
Developer{}{ FirstName := "Robert", LastName := "van der Hulst", Country := "The Netherlands"},;
Developer{}{ FirstName := "Fabrice", LastName := "Foray", Country := "France"},;
Developer{}{ FirstName := "Nikos", LastName := "Kokkalis", Country := "Greece"} ;
}
RETURN oList
FUNCTION GetCountries AS IList<Country>
// This function uses a collection initializer for the List of Counties
// and Object initializers for the Country Objects
VAR oList := List<Country>{}{ ;
Country{} {Name := "Greece", Region := "South East Europe"},;
Country{} {Name := "France", Region := "West Europe"},;
Country{} {Name := "The Netherlands", Region := "North West Europe"} ;
}
RETURN oList
CLASS Developer
PROPERTY Name AS STRING GET FirstName + " " + LastName
PROPERTY FirstName AS STRING AUTO
PROPERTY LastName AS STRING AUTO
PROPERTY Country AS STRING AUTO
END CLASS
CLASS Country
PROPERTY Name AS STRING AUTO
PROPERTY Region AS STRING AUTO
END CLASS
