Re: Field record relation indicators

[Mark Lazarus <mlazarus@xxxxxxxx>]

Hans,

At 10:31 AM 4/1/98 -0500, you wrote:
>Mark wrote:
>>>If you need some sort of lookahead on sequential reads to an externally
>>>described file, you could probably manage nicely using externally
>>>described data structures and READ into DS.
>>
>> Wouldn't you still have to define the from and to positions in the
>>look-ahead area?
>
>No.  The technique I described works like this:  You define 2 externally
>described data structures
>(called, say, CURREC and LOOKREC) from the file you want to read from, using
>PREFIX to rename
>all the fields in one of them.  Keep the current record in CURREC and the
>lookahead record in
>LOOKREC.   To start reading, do:
>
>       C                          READ        FILE              CURREC
>       C                          READ        FILE              LOOKREC
>
>To read the next record, do:
>
>       C                          EVAL        CURREC = LOOKREC
>       C                          READ        FILE              LOOKREC

 This method doesn't stack up well when using level breaks.

 -mark

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