10-implementation

name: 10-implementation description: Implements the feature per the architecture doc using nhcore-first, NeoHaskell style. kind: leaf executor: sonnet model: claude-sonnet-4-6

Implementation

Replaces the phase 9 stubs with a real implementation that follows the architecture doc exactly.

Inputs

• docs/architecture/<adr-number>-<slug>.md — architecture doc.
• docs/architecture/<adr-number>-<slug>-tests.md — test spec (read-only reference).
• The stub module created in phase 9.

Plan

1. Read the architecture doc and identify the stub module → verify: stubs exist.
2. Plan implementation per architecture decisions → verify: every public function in the doc has a planned body.
3. Implement using nhcore primitives first; fall back to Hackage only with a Ghc prefix as last resort → verify: imports list is auditable.
4. Confirm compilation → verify: nix develop --command cabal build all succeeds.

Assumptions:

• NeoHaskell style is strict: pipes (|>) over nesting, do+let over let..in/where, case...of over guards in arg lists, qualified imports, [fmt|...|] for strings, Task/Result not IO/Either, no $, no point-free.
• nhcore has Strict enabled globally — never add ! annotations.
• Test files are immutable in this phase — never edit them.
• Boy scout rule applies. Any file this phase opens for writing is fair game for fixing pre-existing style debt (unqualified imports, point-free top-levels, wildcard params, raw String/IO/Either, $, let..in/where, <>/++). The rule does not apply to test bodies/assertions (still immutable) but it does apply to helpers, imports, and fixtures the phase legitimately touches. See ../references/nhcore-context.md#boy-scout-rule.

If any assumption fails, refuse — do not guess.

Steps

1. Load the architecture doc.
2. For each public function, replace the stub body with the real implementation.
3. Reach into nhcore (Text, Array, Result, Task, EventStore, etc.) before any external package.
4. If an external package is unavoidable, alias it with a Ghc prefix (e.g. import qualified Data.Map.Strict as GhcMap).
5. Run nix develop --command cabal build all to confirm compilation.
6. Do not run tests here — that is phase 11.
7. Verify no test files changed: git diff --name-only HEAD -- 'core/test/' 'testbed/tests/' (and any other test directories the architecture doc names) must return empty. Refuse if any match — tests are immutable in phase 10.
8. Run python3 .claude/skills/feature-pipeline-preview/scripts/pipeline.py complete 10.

Output

Stubs replaced with real implementations; nix develop --command cabal build all green; phase 10 marked complete.

Refusals

• Architecture doc missing → refuse: "no architecture doc; run phase 07 first".
• Build fails → refuse and surface the error.
• Any test file changed → refuse: "tests are immutable in this phase".
• Any import of Control.Concurrent.Async, Data.Either, Data.IORef, Data.Map, Data.Map.Strict, Data.Vector (or any other Control.*/Data.* module) WITHOUT a Ghc prefix alias → refuse: "import must be aliased with Ghc prefix per nhcore convention (e.g. import qualified Data.Map.Strict as GhcMap)".
• The Task.fromIO (… Task.runResult …) round-trip pattern (or its inverse) detected anywhere → refuse: "stop escaping Task to use an IO library — add the missing primitive to nhcore (e.g. AsyncTask.race, Task.timeout) and use it instead. Document the new primitive in core/concurrency/AsyncTask.hs or core/core/Task.hs with a unit test before consuming it here."

Static checks for both patterns above live at ../../scripts/lint-imports.py. The phase 10 leaf MUST invoke it against every source module it edits. If the script exits non-zero, the leaf MUST refuse and NOT call pipeline.py complete 10 — surface the findings and stop.