4673: roll back AtVoid

[R0bari]

#4673

In this PR I rolled back Attr, AtVoid and created a missed test for AtVoid

Summary by CodeRabbit

• New Features

  • Introduced Attr interface and AtVoid class for improved attribute lifecycle management with single-assignment semantics.
  • Added copy(Phi self) method to support enhanced object copying with explicit self-reference.

• Bug Fixes

  • Improved RHO and void attribute handling in object delegation patterns.

• Refactor

  • Streamlined internal wrapper architecture by removing unused abstraction layers.
  • Transitioned from lazy-composition to single-evaluation semantics for improved predictability.
  • Reorganized attribute access and mutation validation flows.

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[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

This PR refactors the EO runtime's attribute and caching infrastructure by introducing a new Attr interface, replacing the composition-based wrapping (PhComposite) with expression-based lazy evaluation (PhOnce), removing several wrapper classes (PhCached, PhComposite, PhRho, PhWithRho), and substantially refactoring PhDefault, PhVoid, and related classes to support writable-once semantics and improved attribute lifecycle management. The XSL template also switches to PhOnce for code generation.

Changes

Cohort / File(s)	Change Summary
New abstraction layer eo-runtime/src/main/java/org/eolang/Attr.java, eo-runtime/src/main/java/org/eolang/AtVoid.java	Introduces Attr interface defining copy(Phi self), get(), put(Phi) contract with three string constants (LAMBDA, PHI, RHO). Implements AtVoid as a writable-once attribute wrapper with lifecycle methods (set(), isSet(), validation).
Removed wrapper classes eo-runtime/src/main/java/org/eolang/PhCached.java, eo-runtime/src/main/java/org/eolang/PhComposite.java, eo-runtime/src/main/java/org/eolang/PhRho.java, eo-runtime/src/main/java/org/eolang/PhWithRho.java	Deletes caching and composition wrapper infrastructure; functionality integrated into remaining classes.
PhOnce refactoring eo-runtime/src/main/java/org/eolang/PhOnce.java	Replaces Supplier-based storage with Function<Phi, Phi> expression evaluation; adds new constructor PhOnce(Phi obj, Function<Phi, Phi> func) and copy(Phi self) method; evaluates expression lazily via expr.apply(arg) for all Phi operations.
PhVoid lifecycle & delegation eo-runtime/src/main/java/org/eolang/PhVoid.java	Adds validation (validate(), isSet(), set() methods); updates copy(Phi self) to delegate inner copy; adds take(String) and put(String, Phi) delegation to inner object; modifies delta(), hasRho(), locator() to support new semantics.
PhDefault attribute handling eo-runtime/src/main/java/org/eolang/PhDefault.java	Adds copy(Phi self) overload; refactors take(String) to support RHO copying without wrapper; updates put(int/String) with validation and ExUnset/ExReadOnly errors; replaces RHO initialization from PhRho to PhVoid; updates delta() logic.
Phi interface & logging eo-runtime/src/main/java/org/eolang/Phi.java, eo-runtime/src/main/java/org/eolang/PhLogged.java	Adds copy(Phi self) method to Phi interface; introduces copy(Phi self) override in PhLogged with logging and delta() method delegation.
Code generation XSL eo-maven-plugin/src/main/resources/org/eolang/maven/transpile/to-java.xsl	Replaces inner wrapping type from PhComposite to PhOnce in atom, abstract, and bound paths for PhCached-wrapped functions.
Test suite updates eo-runtime/src/test/java/org/eolang/AtVoidTest.java, eo-runtime/src/test/java/org/eolang/PhDefaultTest.java, eo-runtime/src/test/java/org/eolang/PhMethodTest.java, eo-runtime/src/test/java/org/eolang/PhSimple.java, eo-runtime/src/test/java/org/eolang/PhWithTest.java, eo-runtime/src/test/java/EOorg/EOeolang/...	Adds AtVoidTest suite (5 tests for writable-once semantics); replaces PhComposite with PhOnce across multiple test files (EOerrorTest, EOmallocTest, EOtryTest, HeapsTest, PhDefaultTest, PhMethodTest, PhSimple, PhWithTest); removes PhCompositeTest.

Sequence Diagram(s)

sequenceDiagram
    participant Old as Old Flow (PhComposite)
    participant New as New Flow (PhOnce)
    participant Caller as Caller
    
    Caller->>Old: take(name) / put(pos) call
    Old->>Old: re-evaluate expression each time
    Old-->>Caller: result (recomputed)
    
    Caller->>New: take(name) / put(pos) call
    New->>New: expr.apply(arg) once, cache in AtomicRef
    New->>New: compareAndSet checks cache
    New-->>Caller: cached result

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sequenceDiagram
    participant PhDefault as PhDefault
    participant PhVoid as PhVoid (Attr impl)
    participant Inner as Inner Phi
    
    rect rgb(220, 240, 255)
    Note over PhDefault,Inner: Writable-Once Lifecycle
    end
    
    PhDefault->>PhDefault: add(name, PhVoid)
    PhVoid->>PhVoid: initialize with name, null object
    
    Caller->>PhVoid: put(value)
    PhVoid->>PhVoid: validate() check
    PhVoid->>PhVoid: set(value) if not already set
    PhVoid-->>Caller: success or throw ExReadOnly
    
    Caller->>PhVoid: get()
    PhVoid->>PhVoid: validate() or throw ExUnset
    PhVoid-->>Caller: inner Phi object

Loading

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~75 minutes

• PhOnce refactoring: The fundamental shift from Supplier to Function<Phi, Phi> with expression-based lazy evaluation affects all Phi method delegates; requires careful review of expression caching semantics and interaction with the new arg parameter.
• PhDefault attribute handling: Multiple interacting changes to take(String), put(int/String), and RHO initialization; the transition from PhRho/PhWithRho wrappers to inline PhVoid requires understanding the new single-assignment semantics.
• PhVoid lifecycle management: New validation, state-checking, and delegation patterns require verification that the writable-once contract is enforced correctly across all paths.
• Cascading effects across tests: Eight test files update from PhComposite to PhOnce; each needs verification that the new lazy-evaluation semantics maintain intended behavior.
• Removal of four classes: Need to verify all usages are correctly replaced and no orphaned dependencies remain.

Areas requiring extra attention:

• PhOnce.copy(Phi self) semantics and interaction with expr.apply(arg) vs. direct argument passing
• PhDefault.take(String) and RHO handling without PhWithRho wrapper
• PhVoid.set(Phi) enforcement of single-assignment for Phi.RHO specifically
• PhDefault.put(String/int) validation logic and ExUnset vs. ExReadOnly error path correctness
• Test changes to EOmallocTest, EOtryTest, and HeapsTest for semantic correctness

Possibly related PRs

• objectionary/eo#4333: Modifies PhDefault attribute-access logic and take(String) control flow; overlaps in the same class/method area.
• objectionary/eo#4223: Modifies the EO attribute/caching layer including PhComposite, PhOnce, PhCached, AtVoid, and PhVoid classes.
• objectionary/eo#4389: Modifies PhCompositeTest (changes visibility, removes constants); related through test file changes.

Suggested labels

core, refactoring

Suggested reviewers

• h1alexbel
• yegor256
• maxonfjvipon

Poem

🐰 Whiskers twitching with glee

Old Composite hops away,
PhOnce takes the stage today—
Single-shot, cache-true, hooray!
RHO finds its void, so bright,
Attributes locked—once, just right! 🔐✨

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between bd32543 and 26644ff.

📒 Files selected for processing (22)

• eo-maven-plugin/src/main/resources/org/eolang/maven/transpile/to-java.xsl (3 hunks)
• eo-runtime/src/main/java/org/eolang/AtVoid.java (1 hunks)
• eo-runtime/src/main/java/org/eolang/Attr.java (1 hunks)
• eo-runtime/src/main/java/org/eolang/PhCached.java (0 hunks)
• eo-runtime/src/main/java/org/eolang/PhComposite.java (0 hunks)
• eo-runtime/src/main/java/org/eolang/PhDefault.java (10 hunks)
• eo-runtime/src/main/java/org/eolang/PhLogged.java (2 hunks)
• eo-runtime/src/main/java/org/eolang/PhOnce.java (1 hunks)
• eo-runtime/src/main/java/org/eolang/PhRho.java (0 hunks)
• eo-runtime/src/main/java/org/eolang/PhVoid.java (2 hunks)
• eo-runtime/src/main/java/org/eolang/PhWithRho.java (0 hunks)
• eo-runtime/src/main/java/org/eolang/Phi.java (2 hunks)
• eo-runtime/src/test/java/EOorg/EOeolang/EOerrorTest.java (1 hunks)
• eo-runtime/src/test/java/EOorg/EOeolang/EOmallocTest.java (2 hunks)
• eo-runtime/src/test/java/EOorg/EOeolang/EOtryTest.java (4 hunks)
• eo-runtime/src/test/java/EOorg/EOeolang/HeapsTest.java (1 hunks)
• eo-runtime/src/test/java/org/eolang/AtVoidTest.java (1 hunks)
• eo-runtime/src/test/java/org/eolang/PhCompositeTest.java (0 hunks)
• eo-runtime/src/test/java/org/eolang/PhDefaultTest.java (6 hunks)
• eo-runtime/src/test/java/org/eolang/PhMethodTest.java (1 hunks)
• eo-runtime/src/test/java/org/eolang/PhSimple.java (1 hunks)
• eo-runtime/src/test/java/org/eolang/PhWithTest.java (1 hunks)

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🚀 Performance Analysis

All benchmarks are within the acceptable range. No critical degradation detected (threshold is 100%). Please refer to the detailed report for more information.

Click to see the detailed report

Test	Base Score	PR Score	Change	% Change	Unit	Mode
benchmarks.XmirBench.xmirToEO	182.705	189.368	6.663	3.65%	ms/op	Average Time

⚠️ Performance loss: benchmarks.XmirBench.xmirToEO is slower by 6.663 ms/op (3.65%)