Epic: Language wave 4 — callables + inheritance + generators (web-capable subset)

[PurHur]

Category

language (epic / coordination)

Problem

Many individual language issues exist (#72, #142, #101, #144, #167) but contributors lack a single ordered map with Zend references, repros, and done-when criteria for the “normal small PHP app” subset (callables + inheritance + generators).

North star subset (Zend / php-src)

Area	Zend reference	This repo	Tracking
Closures + use	Zend/zend_closures.c	VM yes; use (&$x) JIT #3097; AOT stub	#72, #3097
Arrow fn	desugar to closure	VM/JIT yes; AOT no	#142
extends + override	zend_inheritance.c	VM yes (extends_method_override.phpt); JIT/AOT gaps	#101 (refresh)
Traits / interfaces	zend_traits.c	VM simple use Trait; adaptations #144	#144, #2312
Generators	zend_generators.c	VM yes; JIT #3074; AOT #3115	#167, #3074, #3115

Worker repro pack (VM-first)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && ./script/ci-fast.sh --filter "Closure|Arrow|extends|Trait|Generator"'
php script/capability-syntax.php   # refresh docs/capabilities-syntax.md

Per-child minimum spec

Each child issue must include: php-src path, repro .php, done-when command, and claim: comment before PR.

Recommended order (dependencies)

1. Compiler: Class inheritance (extends) and interfaces #101 — confirm VM extends + document JIT/AOT/parent:: gaps (Language: parent::class and parent::$property (deferred from #1858) #3093)
2. Language: Traits, abstract classes, and interfaces #144 — trait insteadof / alias (after simple trait use green)
3. Language: Closures and anonymous functions #72 / Language: Closure use-by-reference JIT lowering (#72 phase 2) #3097 — closure use by-ref for JIT/AOT
4. Language: Arrow functions (fn() => expr) #142 — arrow AOT (desugar)
5. Language: Generators (yield and yield from) #167 / Language: Generator JIT lowering (yield opcodes) #3074 / Language: Generator AOT lowering (yield / suspend resume) #3115 — generator VM → JIT → AOT

Done when (epic)

• All rows above have implementation-ready child issues with green VM repros
• docs/unsupported-syntax.md lists only true lint gaps
• docs/capabilities-syntax.md regenerated and honest for JIT/AOT columns

Links

• ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 · Self-host Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 · JIT include Language: JIT include/require compile-time lowering (#54 follow-up) #475

[PurHur]

Doc follow-up filed

#2495 — docs/capabilities-syntax.md Language wave 4 rows + optional sync gate so epic ordering stays honest in generated matrices.

Child implementation issues remain #72, #101, #144, #167 (VM-first per epic body).

[PurHur]

claim: worker-lane-c — starting this run (epic verification + remaining JIT/AOT gaps)

[PurHur]

Progress (worker-lane-c): Fixed AOT closure/arrow compile regression introduced when #3074 added $startIndex/$allowRecompile to compileBlockInternal() without updating runQueue() spread sites.

• Direct closure/arrow AOT invoke (closure_invoke.phpt, arrow_invoke.phpt) green again
• extends_method_override* compliance tests still green
• PR incoming on agent/issue-2483-wave4-epic-close

Still open within epic:

• array_map(fn ...) AOT callback returns empty (compile OK, runtime gap)
• Trait adaptations JIT/AOT (Language: TraitUseAdaptation — insteadof / as alias (Zend compile parity) #3238 row in capabilities-syntax.md)

[PurHur]

claim: cursor-agent-lane-c — continuing PR #3867 (array_map fn AOT + remaining wave-4 gaps)

[PurHur]

Progress (cursor-agent-lane-c):

Lane C had no new claimable issues (% 3 == 2 non-stdlib tickets all have open PRs). Continued PR #3867.

Follow-up this run: array_map(fn…) AOT callback works (count/index green); empty output in array_map_arrow.phpt was from pre-existing implode() JIT/AOT gap, not array_map. Updated fixture to index-echo (same style as array_map.phpt).

Verification:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter "array_map_arrow|closure_invoke|arrow_invoke|extends_method_override|UnsupportedRegistry"'
# OK (16 tests)
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter array_map test/aot/AotTest.php'
# OK (2 tests)

Still open on epic: trait use adaptations JIT/AOT (#3238); implode() AOT scalar arrays (separate stdlib gap — implode_literal_array.phpt still red on master).

[PurHur]

claim: cursor-agent-lane-c — continuing PR #3867 (wave-4 verification + remaining epic gaps)