grex
A command-line tool and Rust library with Python bindings for generating regular expressions from user-provided test cases
Runssource: GitHubhomepageRustApache-2.0commit 99cc34770737
Rust, Apache-2.0 licensed. The project labels itself: cli, command line tool, python, python library, regex, regex pattern, regexp and regular expression.
grex runs. An Argusic agent installed it in 3 minutes and hit 2 errors and fixed every one without help on a clean machine with no GPU, and the whole session was recorded.
grex 1.4.6 builds from source, its CLI prints version 1.4.6 and generates correct regexes from stdin input, all 693 Rust tests and 23 Python tests pass, and the Python extension wheel installs and builds regexes via RegExpBuilder.
What the agent ended up with on a clean machine, in its own words. How this is measured
Measured by Argusic on a fresh machine every time. Every number links to its evidence. Argusic Score 100 of 100 (the mean of this project's run scores).
At a glance
Subject data from GitHub, linked at the top of this page, refreshed . Test data by Argusic (CC BY 4.0); every number links to a run page with the full log, the recording, and their sha256 hashes.
What was measured
From the run that decided this verdict. Every line is a recorded value, not an estimate.
What went wrong, in the agent's own words
The agent's own words, worst first, never rewritten into advice.
- No Rust toolchain present: 'cargo: not found'1 minute
- maturin build failed: 'Cargo metadata failed. Do you have cargo in your PATH?'1 minute
- Install time
- 3 minutes
- Cold machine to finish
- 4 minutes
- Errors hit and fixed
- 2 hit, 2 fixed with no human help
- How the result was proved
- cargo test exited 0: 693 passed, 0 failed (19 lib + 243 cli + 375 lib integration + 45 property + 11 doc); target/debug/grex --version printed 'grex 1.4.6'; pipeline 'printf 'A cat\nA dog\n' | target/debug/grex --no-anchors -' printed 'A (?:cat|dog)'; python -m pytest tests/python exited 0: 23 passed
- Model tokens used
- 87,542
- Exact commit tested
- 99cc34770737
- Container image
- sha256:cdd920bce783
What was not measured
The other half, so you can see exactly how far this evidence goes. A gap is printed as a gap and never filled in.
- Peak GPU memory
- this ran on a CPU machine, so there was no GPU to sample
- Behaviour over a long run
- each attempt uses the smallest documented settings and a fixed time budget, so this measures whether it runs, not how it holds up under load
The end of the recording
The last lines of the terminal session that decided this verdict, exactly as they were recorded.
- `cargo test` → 693 passed, 0 failed (19 lib unit, 243 CLI integration, 375 lib integration, 45 pr… - `target/debug/grex --version` → `grex 1.4.6`; stdin generation works (`A cat / A dog --no-anchors… - Python extension: maturin wheel built/installed, `RegExpBuilder.from_test_cases(['a','b']).build(… - Media decodes cleanly via `ffmpeg -v error -i <file> -f null -` for `demo.gif`, `website.jpg`, `l… tokens used 87,542 All checks complete. Final state verified: - `cargo build` → finished successfully - `cargo test` → 693 passed, 0 failed (19 lib unit, 243 CLI integration, 375 lib integration, 45 pr… - `target/debug/grex --version` → `grex 1.4.6`; stdin generation works (`A cat / A dog --no-anchors… - Python extension: maturin wheel built/installed, `RegExpBuilder.from_test_cases(['a','b']).build(… - Media decodes cleanly via `ffmpeg -v error -i <file> -f null -` for `demo.gif`, `website.jpg`, `l…
Replay the whole session, every command from a clean machine to this point.
How it was tested
One agent, one container, no human help. It installs the project the way its own documentation says to, runs it, and fixes what breaks. Everything below is recorded as it happened: the terminal session, the log and the exact commit. The full method.
Strengths and limits
Measured facts, not opinions. How this is written.
What went well
- Reached a running state on a clean machine, with the session recorded.
- Installed in 3 minutes, faster than the median of the 123 comparable projects Argusic has measured.
- Recovered from all 2 errors without a human stepping in, which says the failures are documented well enough to solve.
- Ran without a GPU, so it does not need one to start.
- Licensed Apache-2.0, as reported by its host.
- Measured 3 times, so the result is not a one-off.
Of the 124 cli projects Argusic has installed and timed, grex was the 45th fastest to reach a running state, and 111 of 124 reached one at all.
What it is a reasonable choice for
- Trying it on a laptop or a small server: it reached a running state without a GPU.
- A quick evaluation: it was running 3 minutes after the clone.
Also tested, in the same area
Every one of these was installed and run by Argusic on a clean machine. Nothing appears here that was not tested.
Run history
Topics (from GitHub)
clicommand-line-toolpythonpython-libraryregexregex-patternregexpregular-expressionregular-expressionsrustrust-clirust-craterust-libraryterminaltool
Embed the badge
Markdown for the project README. It links back here; terms on the terms page.
[](https://argusic.com/subject/grex)Questions
- Does grex run?
- Yes. grex runs. Argusic installed and launched it on a clean machine in 3 minutes, hitting 2 errors on the way, and recorded the session.
- How did Argusic test grex?
- On a fresh, disposable machine, with every command recorded and the repository pinned at commit 99cc34770737. 3 attempts are recorded, and the full method is on the methodology page.
- What did it cost to test grex?
- The run that produced this verdict cost $0.02: real compute and model cost, not a list price per million tokens. It is recorded on that run's page.
- How long does grex take to install?
- 3 minutes in the run that decided this verdict, from a clean machine to a running state. That is one measured attempt, not an average.
- Does grex need a GPU?
- Not to start. Argusic reached a running state on a machine with no GPU.
- What goes wrong when installing grex?
- 2 things broke in the recorded run, and 2 were fixed without human help. Each one, and the time it cost, is listed on this page.
- How does grex compare with the alternatives?
- Of the 124 cli projects Argusic has installed and timed, grex was the 45th fastest to reach a running state, and 111 of 124 reached one at all.
- Where is the evidence for grex?
- All 3 recorded runs are on this page, each linking to its full log and terminal recording, stored with a sha256 fingerprint so it cannot be quietly altered.