| name | systems-languages-core |
| description | Shared reference for the systems-languages cluster: the language-axis decision (Go · C++ · Perl), the write → prove → harden lifecycle each spoke plugs into, and the per-language idiom / error-model / tooling matrix. USE WHEN choosing conventions, picking a test or coverage command, or deciding how strict to be about input safety across Go, C++, or Perl. |
| cluster | systems-languages |
| version | 1.0.0 |
Systems Languages Core
Shared model for the systems-languages cluster. The patterns, testing, and security spokes for
Go, C++, and Perl all plug into the same lifecycle — keep the decisions and toolchain consistent
here so no spoke contradicts another.
1. The decision the cluster turns on: language axis → lifecycle
There is no cross-language framework choice here — each spoke is a single language. The one
decision is which language you are in, which then fixes the idiom, the error model, and the
toolchain. From there every task walks the same three-stage lifecycle:
Language (Go · C++ · Perl) ──> write ──> prove ──> harden
│ │ │
patterns / standards │ (Perl) security
testing spoke
- write — the language's conventions spoke (
golang-patterns, cpp-coding-standards, perl-patterns).
- prove — the matching testing spoke (
golang-testing, cpp-testing, perl-testing), TDD red→green→refactor.
- harden — only Perl ships a dedicated security spoke (
perl-security), because untrusted input + the shell + DBI is Perl's defining hazard. Go and C++ fold safety into their write stage (validate inputs, RAII, explicit errors).
Rule: pick one language and stay in its lane — don't carry Go's error returns into C++
exceptions or Perl's dynamic looseness into Go. Resolve the language first; the rest cascades.
2. Shared conventions (every spoke)
- Tests first. All three testing spokes are TDD-first: write a failing test, make it pass, refactor. Test behavior through the public surface, not internals.
- Errors are explicit, not swallowed. Go: wrap with
fmt.Errorf("...: %w", err), never _-ignore. C++: custom exception types, throw by value / catch by reference, RAII so nothing leaks. Perl: checked syscalls, Try::Tiny or native try/catch (5.40+), never bare eval without a check.
- Immutability / least privilege by default. C++
const/constexpr unless mutation is intended; Go's useful zero values and small interfaces; Perl use constant/Moo defaults over mutable globals.
- Validate every external input. Allowlist over blocklist. In Perl this is enforced (taint mode + untaint regex); in Go/C++ it is a discipline the patterns spokes describe.
- No
sleep-based synchronization in tests. Use conditions/latches/channels; keep tests deterministic and isolated; clean up temp dirs.
- Coverage target ≈ 80%+ on business logic; 100% on critical paths. All three testing spokes converge on this.
3. Per-language idiom · error model · tooling matrix
| Language | Idiom anchor | Error model | Test framework | Runner / build | Coverage | Lint / format | Patterns spoke | Testing spoke |
|---|
| Go | accept interfaces, return structs; useful zero value; context first arg | error values + %w wrap; errors.Is/As | stdlib testing (table-driven), fuzzing 1.18+ | go test ./... (-race) | go test -cover / go tool cover | gofmt, goimports, go vet, golangci-lint | golang-patterns | golang-testing |
| C++ | RAII, Rule of Zero/Five, smart pointers, enum class, concepts (C++17/20/23) | exceptions (custom types, throw-by-value) + noexcept; RAII cleanup | GoogleTest / GoogleMock | CMake + CTest (gtest_discover_tests) | gcov/lcov or llvm-cov; ASan/UBSan/TSan | C++ Core Guidelines; clang-format/clang-tidy | cpp-coding-standards | cpp-testing |
| Perl | use v5.36, signatures, postfix deref, Moo/Corinna OO | Try::Tiny / native try/catch (5.40+); checked syscalls; taint mode | Test2::V0 (or Test::More) | prove -lr (-j parallel) | Devel::Cover (cover -test) | perltidy, perlcritic (+ security theme) | perl-patterns | perl-testing (+ perl-security) |
4. Version / language baselines
- Go — modern modules, Go 1.18+ for generics & fuzzing, 1.22+ recommended for CI examples.
- C++ — C++17/20/23; concepts and ranges assume C++20.
- Perl — target 5.36+ (
use v5.36 enables strict/warnings/signatures); native try/catch is 5.40+, the class keyword (Corinna) is 5.38+. Pin CPAN deps in cpanfile.
5. Shared guardrails
- One language per task; don't mix idioms or toolchains across spokes.
- TDD-first: a failing test before the fix; deterministic, isolated tests; no
sleep sync.
- Errors are explicit and checked — never silently ignored (Go
_, empty C++ catch, bare Perl eval).
- Validate all external input with allowlists; constrain filesystem and process execution.
- Perl-specific (non-negotiable when input is untrusted): taint mode (
-T) on web/CGI, three-arg open, list-form system/exec, DBI placeholders for every query, context-correct output encoding. State any widening of an input surface explicitly. → perl-security
- Immutability /
const / least privilege by default; pin language and dependency versions.
