Benjamin Woodruff 88ac18872c Add a reentrant (incremental) codegen API ... **Context:** This is an experimental performance optimization that we're hoping to use for our internal linter at Instagram. I added some documentation, but it's unsupported, and isn't very user-friendly. This adds `ExperimentalReentrantCodegenProvider`, which tracks the codegen's internal state (indentation level, character offsets, encoding, etc.) and for each statement, it stores a `CodegenPartial` object. The `CodegenPartial` object has enough information about the previous codegen pass to run the codegen on part of a tree and patch the result back into the original module's string. In cases where we need to generate a bunch of small independent patches for the same file (and we can't just generate a new tree with each patch applied), this *should* be a faster alternative. I don't have any performance numbers because I still need to test this end-to-end with our internal codebase, but I'd be shocked if it was slower than what we're doing. This could theoretically live outside of LibCST, but it depends on a whole bunch of LibCST internals, so there's some value in making sure that this is in sync with the rest of LibCST.		2019-10-28 17:23:26 -07:00
..
source	Add a reentrant (incremental) codegen API	2019-10-28 17:23:26 -07:00