chore: replace cspell with typos-cli, bump MSRV to 1.94.0

Spell checking:
- Replace cspell (Node.js) with typos-cli (Rust) for spell checking
- Add typos.toml with domain-specific allowlist (author names, math terms)
- Delete cspell.json (107 lines of word dictionary no longer needed)
- Update justfile spell-check recipe to use typos on modified files
- Add _ensure-typos helper and typos-cli to setup-tools install/verify
- Update CI to install typos-cli via taiki-e/install-action instead of
  npm cspell

Toolchain:
- Bump rust-version to 1.94 (Cargo.toml) and channel to 1.94.0
  (rust-toolchain.toml)

Author: acgetchell

.github/workflows/ci.yml

@@ -1,5 +1,4 @@
 name: CI
-# cspell:ignore rhysd binstall mktemp sha256sum sha256sums shasum
 permissions:
   contents: read
 concurrency:
@@ -24,8 +23,8 @@ env:
   RUST_BACKTRACE: 1
   ACTIONLINT_VERSION: "1.7.10"
   MARKDOWNLINT_VERSION: "0.47.0"
-  CSPELL_VERSION: "9.6.2"
   SHFMT_VERSION: "3.12.0"
+  TYPOS_VERSION: "1.43.4"
   UV_VERSION: "0.9.28"
 
 jobs:
@@ -68,7 +67,7 @@ jobs:
         with:
           version: ${{ env.UV_VERSION }}
 
-      - name: Install Node.js (for markdownlint and cspell)
+      - name: Install Node.js (for markdownlint)
         if: matrix.os != 'windows-latest'
         uses: actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238 # v6.2.0
         with:
@@ -77,7 +76,13 @@ jobs:
       - name: Install Node.js packages
         if: matrix.os != 'windows-latest'
         run: |
-          npm install -g markdownlint-cli@${{ env.MARKDOWNLINT_VERSION }} cspell@${{ env.CSPELL_VERSION }}
+          npm install -g markdownlint-cli@${{ env.MARKDOWNLINT_VERSION }}
+
+      - name: Install typos-cli
+        if: matrix.os != 'windows-latest'
+        uses: taiki-e/install-action@f92912fad184299a31e22ad070a5059fd07d4f59 # v2.68.7
+        with:
+          tool: typos-cli@${{ env.TYPOS_VERSION }}
 
       - name: Install taplo (for TOML formatting and linting)
         if: matrix.os != 'windows-latest'

AGENTS.md

@@ -29,7 +29,7 @@ When making changes in this repo, prioritize (in order):
 - Python tests: `just test-python`
 - Run a single test (by name filter): `cargo test solve_2x2_basic` (or the full path: `cargo test lu::tests::solve_2x2_basic`)
 - Run examples: `just examples` (or `cargo run --example det_5x5` / `cargo run --example solve_5x5`)
-- Spell check: `just spell-check` (uses `cspell.json` at repo root; keep the `words` list sorted lexicographically)
+- Spell check: `just spell-check` (uses `typos.toml` at repo root; add false positives to `[default.extend-words]`)
 
 ## Code structure (big picture)
 

Cargo.toml

@@ -2,7 +2,7 @@
 name = "la-stack"
 version = "0.1.3"
 edition = "2024"
-rust-version = "1.93"
+rust-version = "1.94"
 license = "BSD-3-Clause"
 description = "Small, stack-allocated linear algebra for fixed dimensions"
 readme = "README.md"

cspell.json

@@ -49,6 +49,12 @@ _ensure-taplo:
     set -euo pipefail
     command -v taplo >/dev/null || { echo "❌ 'taplo' not found. See 'just setup' or install: brew install taplo (or: cargo install taplo-cli)"; exit 1; }
 
+# Internal helper: ensure typos-cli is installed
+_ensure-typos:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    command -v typos >/dev/null || { echo "❌ 'typos' not found. See 'just setup-tools' or install: cargo install typos-cli"; exit 1; }
+
 _ensure-uv:
     #!/usr/bin/env bash
     set -euo pipefail
@@ -379,6 +385,13 @@ setup-tools:
         echo "  ✓ samply"
     fi
 
+    if ! have typos; then
+        echo "  ⏳ Installing typos-cli (cargo)..."
+        cargo install --locked typos-cli
+    else
+        echo "  ✓ typos"
+    fi
+
     if ! have cargo-tarpaulin; then
         if [[ "$os" == "Linux" ]]; then
             echo "  ⏳ Installing cargo-tarpaulin (cargo)..."
@@ -393,7 +406,7 @@ setup-tools:
     echo ""
     echo "Verifying required commands are available..."
     missing=0
-    for cmd in uv jq taplo yamllint shfmt shellcheck actionlint node npx; do
+    for cmd in uv jq taplo yamllint shfmt shellcheck actionlint node npx typos; do
         if have "$cmd"; then
             echo "  ✓ $cmd"
         else
@@ -442,22 +455,42 @@ shell-fmt: _ensure-shfmt
 
 shell-lint: shell-check
 
-# Spell check (cspell)
-#
-# Requires either:
-# - `cspell` on PATH (recommended: `npm i -g cspell`), or
-# - `npx` (will run cspell without a global install)
-spell-check:
+# Spell check (typos)
+spell-check: _ensure-typos
     #!/usr/bin/env bash
     set -euo pipefail
-    if command -v cspell >/dev/null; then
-        cspell lint --config cspell.json --no-progress --gitignore --cache --dot --exclude cspell.json .
-    elif command -v npx >/dev/null; then
-        npx cspell lint --config cspell.json --no-progress --gitignore --cache --dot --exclude cspell.json .
+    files=()
+    # Use -z for NUL-delimited output to handle filenames with spaces.
+    #
+    # Note: For renames/copies, `git status --porcelain -z` emits *two* NUL-separated paths.
+    # The ordering can differ depending on the porcelain output, so we read both and
+    # spell-check whichever one exists on disk.
+    while IFS= read -r -d '' status_line; do
+        status="${status_line:0:2}"
+        filename="${status_line:3}"
+
+        # For renames/copies, consume the second path token to keep parsing in sync.
+        # Prefer the path that exists on disk to avoid passing stale paths to typos.
+        if [[ "$status" == *"R"* || "$status" == *"C"* ]]; then
+            if IFS= read -r -d '' other_path; then
+                if [ ! -e "$filename" ] && [ -e "$other_path" ]; then
+                    filename="$other_path"
+                fi
+            fi
+        fi
+
+        # Skip deletions (file may no longer exist).
+        if [[ "$status" == *"D"* ]]; then
+            continue
+        fi
+
+        files+=("$filename")
+    done < <(git status --porcelain -z --ignored=no)
+    if [ "${#files[@]}" -gt 0 ]; then
+        # Exclude typos.toml itself: it intentionally contains allowlisted fragments.
+        printf '%s\0' "${files[@]}" | xargs -0 -n100 typos --config typos.toml --force-exclude --exclude typos.toml --
     else
-        echo "❌ cspell not found. Install via npm (recommended): npm i -g cspell"
-        echo "   Or ensure npx is available (Node.js)."
-        exit 1
+        echo "No modified files to spell-check."
     fi
 
 # Testing

justfile

@@ -1,6 +1,6 @@
 [toolchain]
 # Pin to MSRV as specified in Cargo.toml
-channel = "1.93.0"
+channel = "1.94.0"
 
 # Essential components for development
 components = [

rust-toolchain.toml

@@ -79,7 +79,7 @@ impl<const D: usize> Vector<D> {
     /// ```
     #[inline]
     #[must_use]
-    pub fn dot(self, other: Self) -> f64 {
+    pub const fn dot(self, other: Self) -> f64 {
         let mut acc = 0.0;
         let mut i = 0;
         while i < D {
@@ -100,7 +100,7 @@ impl<const D: usize> Vector<D> {
     /// ```
     #[inline]
     #[must_use]
-    pub fn norm2_sq(self) -> f64 {
+    pub const fn norm2_sq(self) -> f64 {
         self.dot(self)
     }
 }

src/vector.rs

@@ -0,0 +1,31 @@
+# Configuration for typos-cli (https://github.com/crate-ci/typos)
+
+[files]
+# Avoid scanning generated/third-party directories and auto-generated files.
+extend-exclude = [
+    ".git/**",
+    "target/**",
+    "coverage/**",
+    "node_modules/**",
+    "venv/**",
+    ".venv/**",
+    ".mypy_cache/**",
+    ".ruff_cache/**",
+    ".pytest_cache/**",
+]
+
+[default.extend-words]
+# Domain terms that typos suggests "fixing" but are correct in this repo.
+# Author / person names
+Brezinski = "Brezinski"
+Businger = "Businger"
+Getchell = "Getchell"
+Higham = "Higham"
+Parlett = "Parlett"
+Schreiber = "Schreiber"
+Tikhomirov = "Tikhomirov"
+Trefethen = "Trefethen"
+# Math / crate terms
+faer = "faer"
+frhs = "frhs"
+nrhs = "nrhs"