Re: compound operators

[John W. Eaton]

On  8-May-2008, Jaroslav Hajek wrote:

| I hope not. The tree_compound_binary_expression class has a slightly
| different philosophy:
| it does not "own" the stripped operands, just stores pointers to them
| (note that it has no destructor). The orginal operands is still owned
| by the parent tree_binary_expression object.

OK, I see now.

| I thought this would be the best design - the compound operator needs
| not be visible to printing code (we want the code to print normally
| like `A'*B') or breakpoints, so tree-print-code and tree-breakpoint
| need not care. The original expression is retained, because it may
| still be useful. For example, we may later want to implement a
| simplification that
| trace (A*B) evaluates as sum((A.*B)(:)) (this is probably not of much
| use, but demonstrates the matter). With my approach, trace (A'*B) will
| be properly simplified, because the A'*B expression can still be
| identified as a multiplication.

Will this always work as we want, or could there be problems if we
perform additional transformations on the parse tree?

jwe