I have a function that uses an array of strings, and before it works it needs to put the strings into canonocal form. Now, I only want to do that the first time I use that array, by "correcting" the elements in-place.

So, how can I tell if I've seen that array (passed by reference to the function) before? If I store a flag in a hash indexed by the ref's string, is that string always the same? That is, could I memo-ize it based on the ref's stringification? The other idea is to bless it, and then test to see if that's been done. But I wonder if there are other ways to "mark" something. Attributes currently work on variables, not values, right?

—John

In reply to Marking an array as already seen by John M. Dlugosz

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