key-hash-proc for Set-of

[RobertShiplett]

I have had no success setting key-hash-proc and key-equality-proc for a {Set-of } even when predefining as constants as per the docs for ChartDataSeriesSet

Is there a known issue?

The compiler reports that Applet already defines key-hash-proc or complans that the proc passed is not a compile-time constant.

The docs contain no working example of a set of user-defined instances using declared hash and equal? as described in the {Set of } docs

A reply would be much appreciated as I should be able to use {difference } and {intersection } to handle my sets efficiently.

thanks in advance for any assistance ...

Contrary to the Doc's

QUOTE

This Type is simply a convenient shorthand for:

{Set-of
ChartDataSeries,
key-hash-proc = ChartDataSeries.hash,
key-equality-proc = ChartDataSeries.equal?
}


THAT CODE GIVES ERROR Argument [proc ChartDataSeries.hash] to Set-of is not an immutable value

It is in fact required to use a {define-proc } wrapper as a work-around, is it not ?