* Add caching for printing
For printing the last argument expansion, we need to print the same node a bit differently with a flag. It's not easy to re-print just the node that is different so we end up printing all the sub-tree twice. Since it is often nested, it means that we run into an exponential complexity.
I finally found a simple solution: we can use a Map to store the nodes and their printed values. It is really cheap to do so (I can't notice a time difference with or without on normal code) and allows us to stop going through the two sub-trees in the bad case.
Fixes#1250
* Update printer.js
This is the second part of the fix for the performance regression seen in #1250. In #1217, for correctness reasons, we're now traversing all the conditional groups. This means that we're now in O(n^2). But, in practice, many of those groups are === between each others. So we only need to recurse through one of the instances to know if it's going to break.
This makes the first example go from not terminating to being instant. The second one going from not terminating to taking ~1s. We can also make it instant by tweaking the printing phase, but that's for another PR.
Christopher Chedeau