root/cobra/trunk/HowTo/301-ImplementIEnumerable2.cobra

"""
ImplementIEnumerable2.cobra

This version implements a generic file cabinet: You can give it any type of
object to hold.


See also: ImplementIEnumerable1.cobra
"""


class FileCabinet<of T> implements IEnumerable<of T>

    get records from var = List<of T>()

    get nextSerialNum as int
        return _records.count + 1

    def getEnumerator as IEnumerator<of T>
        return _records.getEnumerator

    def getEnumerator as System.Collections.IEnumerator
        implements System.Collections.IEnumerable
        return .getEnumerator


class Record

    cue init(serialNum as int, name as String)
        base.init
        _serialNum, _name = serialNum, name

    pro serialNum from var as int

    pro name from var as String

    def toString as String is override
        return '[.typeOf.name]([_serialNum], [_name])'


class Program

    def main
        # build a cabinet:
        cabinet = FileCabinet<of Record>()
        cabinet.records.add(Record(cabinet.nextSerialNum, 'Red'))
        cabinet.records.add(Record(cabinet.nextSerialNum, 'Green'))
        cabinet.records.add(Record(cabinet.nextSerialNum, 'Blue'))

        # because cabinet is an IEnumerable, it can be for'ed:
        for r2 in cabinet, print r2

        # and passed to a List initializer:
        records = List<of Record>(cabinet)
        for r3 in records
            assert r3.serialNum > 0