SwiftGrep

sg is a ripgrep-compatible recursive search tool for macOS, written in Swift and tuned for APFS. Its frontend is rg compatible, but is much faster than rg on macOS.

This requires macOS 27 Golden Gate and thus Apple Silicon. A binary is provided in the releases section.

This is made with AI, and although I guided it, I still need to review it and work out its findings. It seems to be that limiting the number of threads and avoiding open calls is important. There's also some caching to avoid needless open calls based on some comtinatoin of inode and timestamps.

I want to learn more from ghostty and see if there isn't still performance to find, but it's a good start.

Here's a test on the nixpkgs repo:

-c fetchFromGitHub on nixpkgs	wall time	system time	peak footprint
rg (default)	2.74 s	32 s	23 MB
rg -j4 (rg's best)	0.67 s	2.4 s	21 MB
sg --no-cache	0.57 s	2.7 s	21 MB
sg	0.32 s	1.4 s	21 MB

And some more based on different query types (this on the Linux kernel source code):

query	rg (s)	sg (s)	speedup
literal	2.74	0.32	8.6x
literal, -i	2.81	0.32	8.8x
\w+@\w+\.\w+ (no literal)	2.71	0.32	8.5x
[[:upper:]]{5,}	2.69	0.34	8.0x
-w -i the	2.77	0.35	8.0x
alternation	2.66	0.34	7.8x
-v e	2.67	0.34	7.8x
-n lib (46k lines of output)	2.71	0.32	8.4x
--files	0.76	0.04	18x

Memory safety

The package marks all targets as .strictMemorySafety(), but there is a collection of unsafe functions in Sources/SwiftGrepKit/OS.swift, which I'll be checking. It's been security reviewed by AI a few times, but human review is coming too.

When possible, Span, RawSpan and UniqueArray are used instead.

Building and testing

swift build -c release          # binary: $(swift build -c release --show-bin-path)/sg
swift test                      # unit, consistency and end-to-end tests
Scripts/compare.py [corpus]     # output parity with rg (default: ~/Developer/nixpkgs)
Scripts/bench.py [corpus]       # timing against rg with hyperfine (the linux
                                # suite is picked for a directory named linux)
Scripts/compare_cli.py [corpus] # flag-by-flag behavior vs rg, piped and on a
                                # terminal (default: ~/Developer/linux)
Scripts/missing_flags.py        # rg flags sg doesn't recognize
swiftformat . --lint && swiftlint lint   # style (or: nix run nixpkgs#swiftlint -- lint)
Scripts/generate_unicode_tables.py DIR   # UnicodeTables.swift from regex-syntax's unicode_tables
Scripts/generate_encodings.py DIR        # EncodingTables.swift from encoding_rs's src

Nix

There's a nix flake in the repository as well, which should let you build the project without the exact toolchain I used.