DCdcreager·Dec 4, 2020
Hi there! I manage the GitHub team responsible for the Code Nav part of this. Re 30-80% coverage, can you elaborate on the biggest missing piece for you? Is it the number of languages that are covered, or too many false positives in the results we show? (Or something else?)
For the latter, it's a known limitation in that we're only doing "fuzzy" or "c-tags-like" Code Nav — defs and refs are only matched by their textual unqualified symbol names. For some languages that's not a big deal, because symbol names tend to be unique. But for a language like Go, you might have dozens (or hundreds!) of methods named "Parse", and we don't currently distinguish those in our Jump to Def UI.
That's something we're actively working on, though! One benefit to the current fuzzy approach is that it's incremental (we only have to analyze changed files in a
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commit), and does not depend on tapping into a build or CI process. That makes it much faster — we have a long-running indexer service live and hot, and typically have new commits indexed and live in the UI within 1-5 seconds of receiving a push. And it requires no configuration on the part of the repo owner — no need to tell us how to build your project, or to configure an Actions workflow to generate the data. That makes it easier for us to support entire ecosystems when we roll out support for a new language. We've also tried to make it fairly easy for external communities to add support for their languages — this is all driven by the open-source tree-sitter parsing framework. This file, for instance, is where the symbol extraction rules for Go are defined: https://github.com/tree-sitter/tree-sitter-go/blob/master/qu...
We've been working on a new approach to generate more precise symbol data, while keeping those incremental and zero-config properties. It's not ready for public launch, yet, but it's close!
For those who want to learn more, I gave a talk at FOSDEM 2020 (back in the Before Times) going into more detail on some of these constraints and design decisions. (Though please note that this talk references a legacy way of defining symbol extraction rules, which relied on writing code in our open-source Semantic project.) https://dcreager.net/talks/2020-fosdem/