First-order recursive filters #117
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR adds support for recursively defined filters with filter arguments.
For example:
(Note that you should not actually write
repeatlike this; even jq gives you quadratic runtime with that definition.)Apart from this, this PR mostly rewrites MIR/LIR. Previously, LIR was a behemoth very hard to understand, which prevented further advances, such as tail-call optimisation. Now that road is open.
As a result of rewriting MIR/LIR, the compilation should now run in worst-case quadratic time, whereas before, it was exponential. Consider the following example:
Before the PR, this took 2.5 seconds (on my AMD Ryzen 5 5500U), and for every additional
d(...), the runtime doubled.This was because all arguments were inlined, leading to the exponential blowup.
After the PR, this terminates instantly. The disadvantage of the new approach is that it adds some overhead to function calls, but I hope that future optimisations could deal with this.