{"id":"push-pull-coupling-tradeoff-is-fundamental-composition-design-decision","text":"The push/pull data-flow tension — eagerly providing all data (simpler but coupling) versus letting the receiver pull what it needs (flexible but requiring back-reference) — recurs identically across Observer's notification models and Strategy's data-passing approaches, establishing it as a fundamental design decision inherent to composition-based behavioral patterns rather than a pattern-specific concern.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["push-pull-coupling-tradeoff-recurs-across-patterns","composition-paradigm-convergent-and-scalable-with-bounded-exception"],"outlist":[],"label":"Push/pull tradeoff recurring across patterns combined with composition's validated default status elevates it to a fundamental composition design decision"}],"dependents":[],"metadata":{"source_type":"derived","review_result":"unnecessary"},"created_at":"2026-06-18T04:50:15+00:00","updated_at":"2026-06-18T06:15:08+00:00","reviewed_at":"2026-06-18T06:15:08+00:00","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"push-pull-coupling-tradeoff-is-fundamental-composition-design-decision","truth_value":"IN","reason":"SL justification valid","antecedents":["push-pull-coupling-tradeoff-recurs-across-patterns","composition-paradigm-convergent-and-scalable-with-bounded-exception"],"label":"Push/pull tradeoff recurring across patterns combined with composition's validated default status elevates it to a fundamental composition design decision"},{"node":"push-pull-coupling-tradeoff-recurs-across-patterns","truth_value":"IN","reason":"SL justification valid","antecedents":["gof-observer-push-vs-pull-models","gof-strategy-data-passing-two-approaches"],"label":"Two independently documented push/pull tradeoffs in different patterns converge on a single recurring coupling-reusability decision axis"},{"node":"gof-observer-push-vs-pull-models","truth_value":"IN","reason":"premise"},{"node":"gof-strategy-data-passing-two-approaches","truth_value":"IN","reason":"premise"},{"node":"composition-paradigm-convergent-and-scalable-with-bounded-exception","truth_value":"IN","reason":"SL justification valid","antecedents":["composition-convergence-scalably-grounded","template-method-inheritance-bounded-by-composition"],"label":"Composition as validated default + Template Method as precisely bounded exception = complete reuse decision framework"},{"node":"composition-convergence-scalably-grounded","truth_value":"IN","reason":"SL justification valid","antecedents":["convergent-evolution-toward-composition","composition-scalability-doubly-grounded"],"label":"Convergent evolution says composition is right; doubly-grounded scalability says it works at scale"},{"node":"convergent-evolution-toward-composition","truth_value":"IN","reason":"SL justification valid","antecedents":["creational-evolution-inheritance-to-composition","ocp-evolution-validates-composition-shift"],"label":"Two independent evolutionary trajectories converging on composition is stronger than either alone"},{"node":"creational-evolution-inheritance-to-composition","truth_value":"IN","reason":"SL justification valid","antecedents":["factory-method-uses-inheritance-abstract-factory-uses-composition","creational-pattern-evolution-trajectory"],"label":"Creational pattern evolution mirrors the broader GoF shift from inheritance to composition"},{"node":"factory-method-uses-inheritance-abstract-factory-uses-composition","truth_value":"IN","reason":"premise"},{"node":"creational-pattern-evolution-trajectory","truth_value":"IN","reason":"premise"},{"node":"ocp-evolution-validates-composition-shift","truth_value":"IN","reason":"SL justification valid","antecedents":["ocp-evolved-from-inheritance-to-abstraction","composition-superiority-for-reuse"],"label":"OCP's own history recapitulates the broader paradigm shift — convergent validation from principle and practice"},{"node":"ocp-evolved-from-inheritance-to-abstraction","truth_value":"IN","reason":"SL justification valid","antecedents":["ocp-coined-by-meyer-1988","ocp-meyer-vs-polymorphic-interpretation","ocp-polymorphic-version-is-dominant-modern-interpretation"],"label":"OCP's evolution from concrete inheritance to abstract polymorphism parallels and foreshadows the GoF's composition-over-inheritance principle"},{"node":"ocp-coined-by-meyer-1988","truth_value":"IN","reason":"premise"},{"node":"ocp-meyer-vs-polymorphic-interpretation","truth_value":"IN","reason":"premise"},{"node":"ocp-polymorphic-version-is-dominant-modern-interpretation","truth_value":"IN","reason":"premise"},{"node":"composition-superiority-for-reuse","truth_value":"IN","reason":"SL justification valid","antecedents":["favor-composition-over-inheritance","inheritance-breaks-encapsulation","inheritance-compile-time-composition-run-time","delegation-composition-as-powerful-as-inheritance"],"label":"Four independent arguments converge on composition's superiority over inheritance"},{"node":"favor-composition-over-inheritance","truth_value":"IN","reason":"premise"},{"node":"inheritance-breaks-encapsulation","truth_value":"IN","reason":"premise"},{"node":"inheritance-compile-time-composition-run-time","truth_value":"IN","reason":"premise"},{"node":"delegation-composition-as-powerful-as-inheritance","truth_value":"IN","reason":"premise"},{"node":"composition-scalability-doubly-grounded","truth_value":"IN","reason":"SL justification valid","antecedents":["composition-quadruply-evidenced","sharing-infrastructure-enables-scalable-composition"],"label":"Four independent theoretical proofs + practical sharing infrastructure = doubly grounded scalability"},{"node":"composition-quadruply-evidenced","truth_value":"IN","reason":"SL justification valid","antecedents":["composition-paradigm-doubly-validated","dual-proof-composition-prevents-explosion"],"label":"Two independent double-evidence chains (theoretical+practical and structural+structural) merge into four-point convergence for composition superiority"},{"node":"composition-paradigm-doubly-validated","truth_value":"IN","reason":"SL justification valid","antecedents":["ocp-evolution-validates-composition-shift","decorator-proves-composition-scalability"],"label":"Independent theoretical (principle evolution) and empirical (quantitative measurement) convergence on composition"},{"node":"decorator-proves-composition-scalability","truth_value":"IN","reason":"SL justification valid","antecedents":["decorator-avoids-inheritance-explosion","composition-superiority-for-reuse"],"label":"Decorator's avoidance of class explosion quantifies composition's advantage as exponential, not just qualitative"},{"node":"decorator-avoids-inheritance-explosion","truth_value":"IN","reason":"premise"},{"node":"dual-proof-composition-prevents-explosion","truth_value":"IN","reason":"SL justification valid","antecedents":["decorator-proves-composition-scalability","bridge-eliminates-class-explosion"],"label":"Two independent quantitative proofs of composition's advantage across different GoF categories"},{"node":"bridge-eliminates-class-explosion","truth_value":"IN","reason":"premise"},{"node":"sharing-infrastructure-enables-scalable-composition","truth_value":"IN","reason":"SL justification valid","antecedents":["creational-enables-cross-category-sharing","composite-flyweight-scalable-trees"],"label":"Controlled-sharing infrastructure (Singleton registries + Flyweight factories) is the efficiency substrate that makes large-scale composition viable"},{"node":"creational-enables-cross-category-sharing","truth_value":"IN","reason":"SL justification valid","antecedents":["controlled-sharing-meta-pattern","creational-patterns-enable-composition-reuse"],"label":"Depth-3 — controlled-sharing (depth-1) + creational-enable-composition (depth-2) reveal creational patterns as cross-category infrastructure, not just lifecycle management"},{"node":"controlled-sharing-meta-pattern","truth_value":"IN","reason":"SL justification valid","antecedents":["gof-state-subclasses-often-singletons","flyweight-factory-ensures-sharing"],"label":"Depth-1 — two independent base observations (State-as-Singleton and Flyweight-via-Factory) converge on a cross-category meta-pattern where creational mechanisms serve as sharing infrastructure for behavioral and structural patterns"},{"node":"gof-state-subclasses-often-singletons","truth_value":"IN","reason":"premise"},{"node":"flyweight-factory-ensures-sharing","truth_value":"IN","reason":"premise"},{"node":"creational-patterns-enable-composition-reuse","truth_value":"IN","reason":"SL justification valid","antecedents":["factory-method-as-foundational-creational","composition-superiority-for-reuse"],"label":"Composition cannot be flexible without creational abstraction; Factory Method provides that abstraction"},{"node":"factory-method-as-foundational-creational","truth_value":"IN","reason":"SL justification valid","antecedents":["abstract-factory-often-uses-factory-methods","factory-method-called-within-template-methods","iterator-factory-method-creates-appropriate-iterator"],"label":"Factory Method appears as a building block inside three other patterns"},{"node":"abstract-factory-often-uses-factory-methods","truth_value":"IN","reason":"premise"},{"node":"factory-method-called-within-template-methods","truth_value":"IN","reason":"premise"},{"node":"iterator-factory-method-creates-appropriate-iterator","truth_value":"IN","reason":"premise"},{"node":"composite-flyweight-scalable-trees","truth_value":"IN","reason":"SL justification valid","antecedents":["composite-as-universal-recursive-structure","flyweight-solves-composite-sharing"],"label":"Two depth-1 conclusions about Composite's structure and Flyweight's optimization combine into a single scalable-tree design"},{"node":"composite-as-universal-recursive-structure","truth_value":"IN","reason":"SL justification valid","antecedents":["composite-uniform-leaf-composite-treatment","interpreter-abstract-syntax-tree-is-composite","macrocommand-is-composite-of-commands"],"label":"Three distinct patterns reuse Composite's recursive composition structure"},{"node":"composite-uniform-leaf-composite-treatment","truth_value":"IN","reason":"premise"},{"node":"interpreter-abstract-syntax-tree-is-composite","truth_value":"IN","reason":"premise"},{"node":"macrocommand-is-composite-of-commands","truth_value":"IN","reason":"premise"},{"node":"flyweight-solves-composite-sharing","truth_value":"IN","reason":"SL justification valid","antecedents":["flyweight-solves-composite-sharing","flyweight-intrinsic-vs-extrinsic-state","flyweight-doc-editor-180k-chars-480-objects"],"label":"Flyweight's state-splitting mechanism directly solves Composite's sharing problem"},{"node":"flyweight-solves-composite-sharing","truth_value":"IN","reason":"circular dependency"},{"node":"flyweight-intrinsic-vs-extrinsic-state","truth_value":"IN","reason":"premise"},{"node":"flyweight-doc-editor-180k-chars-480-objects","truth_value":"IN","reason":"premise"},{"node":"template-method-inheritance-bounded-by-composition","truth_value":"IN","reason":"SL justification valid","antecedents":["template-method-principled-inheritance-counterexample","decorator-proves-composition-scalability"],"label":"Template Method defines when inheritance works; Decorator proves composition works everywhere else"},{"node":"template-method-principled-inheritance-counterexample","truth_value":"IN","reason":"SL justification valid","antecedents":["template-method-fine-grained-override-control","composition-superiority-for-reuse"],"label":"Template Method is the exception that proves the composition rule by showing when inheritance works"},{"node":"template-method-fine-grained-override-control","truth_value":"IN","reason":"SL justification valid","antecedents":["gof-template-method-five-operation-kinds","hook-operations-overridable-defaults","gof-cpp-template-method-nonvirtual"],"label":"Five operation kinds plus non-virtual skeleton produce the most controlled inheritance in the GoF"},{"node":"gof-template-method-five-operation-kinds","truth_value":"IN","reason":"premise"},{"node":"hook-operations-overridable-defaults","truth_value":"IN","reason":"premise"},{"node":"gof-cpp-template-method-nonvirtual","truth_value":"IN","reason":"premise"}]}}