Queues: add instructions for converting tests to Calyx (#2364)

What is says on the tin (as discussed on this [slack
thread](https://cucapra.slack.com/archives/C06CV424G94/p1727223025447109))

Due to a new [release](https://releases.rs/docs/1.83.0/) for rust, CI
catches a few errors (unrelated to this PR). For now, we simply pin to
an older version:
- remove toolchain argument for `setup-rust-toolchain@v1` in `rust.yml`
- add `rust-toolchain.toml`

.github/workflows/rust.yml

@@ -20,8 +20,6 @@ jobs:
         uses: actions/checkout@v4
       - name: Install Rust stable
         uses: actions-rust-lang/setup-rust-toolchain@v1
-        with:
-            toolchain: stable
       - name: Build calyx dev
         run: cargo build
       - name: Check calyx build

frontends/queues/README.md

@@ -1,12 +1,35 @@
 # Queues Library
 
-See the [docs](https://docs.calyxir.org/frontends/queues.html) for more details.
+See the [docs][docs] for more details.
 
 ## Installation
 To use our queues:
-1. Install [flit](https://flit.readthedocs.io/en/latest/#install)
+1. Install [flit][flit]
 2. Install the `queues` package:
 ```
     $ cd frontends/queues/
     $ flit install --symlink
+``` 
+
+## Converting Tests to Calyx
+
+To convert any of our [randomized tests][testing-harness] to a single Calyx file and their associated data and expect files:
+
+0. Follow the [installation instructions](#installation)
+1. Choose a test by picking a `.py` file in [`tests/`][tests-dir]
+2. Convert the test to Calyx:
+```
+python3 <queue_name>_test.py 20000 --keepgoing > <queue_name>_test.futil
 ```
+3. Run the script [`gen_test_data.sh`][gen_test_data.sh] to generate data and expect files:
+```
+./gen_test_data.sh
+```
+
+The files `<queue_name>_test.py`, `<queue_name>_test.data`, and `<queue_name>_test.expect` contain the Calyx program, input data, and expected outputs for the test.
+
+[docs]: https://docs.calyxir.org/frontends/queues.html
+[flit]: https://flit.readthedocs.io/en/latest/#install
+[testing-harness]: https://docs.calyxir.org/frontends/queues.html#shared-testing-harness
+[tests-dir]: ./tests/
+[gen_test_data.sh]: ./test_data_gen/gen_test_data.sh

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "1.82.0"