Wookey wrote

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OK - changing therion this way would be easy - but converting existing data is difficult. I would be very happy if I could remove

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subtypes, but

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it would be quite substantial change...

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It it really that difficult to write some perl conversion that would usually do the right thing?

I think you are right that this was a design error and we should fix it if at all possible. There are not that many datasets now - in the future it will only get harder...

I think we should say that this will change in 0.4 or something. If we can add the new functionality now/soon so that people can create new data in the new style, then that will make it easier to convert (because there will be a version that can cope with old and new data for people to use until they have converted).

I don't want to break my dataset any more than necessary, but if changes are necessary for long-term growth, and we can design a reasonable transition, then it is probably worth doing.

The difference and different ways to get the same thing confused me, I think that although it would break my data, it would be better to change it now so that the program can be developed coherently in the future. Andrew PS On a related topic, how does Therion now fit with survex, I have to say that I am finding data set conversion a little tedious, and I have not tried to for a big cave yet.