Module: Rigor::Inference::MethodDispatcher

Defined in:
lib/rigor/inference/method_dispatcher.rb,
lib/rigor/inference/method_dispatcher/cgi_folding.rb,
lib/rigor/inference/method_dispatcher/set_folding.rb,
lib/rigor/inference/method_dispatcher/uri_folding.rb,
lib/rigor/inference/method_dispatcher/call_context.rb,
lib/rigor/inference/method_dispatcher/data_folding.rb,
lib/rigor/inference/method_dispatcher/file_folding.rb,
lib/rigor/inference/method_dispatcher/math_folding.rb,
lib/rigor/inference/method_dispatcher/rbs_dispatch.rb,
lib/rigor/inference/method_dispatcher/time_folding.rb,
lib/rigor/inference/method_dispatcher/block_folding.rb,
lib/rigor/inference/method_dispatcher/method_folding.rb,
lib/rigor/inference/method_dispatcher/regexp_folding.rb,
lib/rigor/inference/method_dispatcher/shape_dispatch.rb,
lib/rigor/inference/method_dispatcher/kernel_dispatch.rb,
lib/rigor/inference/method_dispatcher/constant_folding.rb,
lib/rigor/inference/method_dispatcher/iterator_dispatch.rb,
lib/rigor/inference/method_dispatcher/overload_selector.rb,
lib/rigor/inference/method_dispatcher/receiver_affinity.rb,
lib/rigor/inference/method_dispatcher/singleton_folding.rb,
lib/rigor/inference/method_dispatcher/shellwords_folding.rb,
lib/rigor/inference/method_dispatcher/literal_string_folding.rb

Overview

Coordinates method dispatch for the inference engine.

Given ‘(receiver_type, method_name, arg_types, block_type, environment)`, the dispatcher returns the inferred result type or `nil` when no rule matches. `nil` is a deliberately blunt “I don’t know” signal: callers (today only ‘ExpressionTyper`) own the fail-soft fallback and decide whether to record a `FallbackTracer` event.

Tiers (in order):

  1. ConstantFolding: executes the Ruby operation directly when the receiver and argument are ‘Constant` carriers and the method is on the curated whitelist. Slice 2.

  2. ShapeDispatch: returns the precise element/value type for a curated catalogue of ‘Tuple`/`HashShape` element-access methods (`first`, `last`, `[]` with a static integer/key, `fetch`, `dig`, `size`/`length`/`count`). Slice 5 phase 2.

  3. RbsDispatch: looks up the receiver’s class in the RBS environment carried by the scope and translates the method’s return type into a Rigor::Type. Slice 4.

‘ShapeDispatch` deliberately runs above RbsDispatch so the precise per-position/per-key answer wins over the projected `Array#[]`/`Hash#fetch` answer; it falls through (`nil`) when the call cannot be proved against the static shape, in which case the projection answer from RbsDispatch applies.

The dispatcher’s public signature reserves space for ‘block_type:` and ADR-2 plugin extensions (later slices), so call sites added now do not have to be rewritten when those tiers arrive.

Defined Under Namespace

Modules: BlockFolding, CGIFolding, ConstantFolding, DataFolding, FileFolding, IteratorDispatch, KernelDispatch, LiteralStringFolding, MathFolding, MethodFolding, OverloadSelector, RbsDispatch, ReceiverAffinity, RegexpFolding, SetFolding, ShapeDispatch, ShellwordsFolding, SingletonFolding, TimeFolding, URIFolding Classes: CallContext

Class Method Summary collapse

Class Method Details

.array_new_fill(type) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 986

def array_new_fill(type)
  return Type::Combinator.constant_of(nil) if type.nil?

  type
end

.array_new_lift(class_name, arg_types) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 969

def array_new_lift(class_name, arg_types)
  return nil unless class_name == "Array"
  return nil if arg_types.empty? || arg_types.size > 2

  size = array_new_size(arg_types.first)
  return nil if size.nil? || size.negative? || size > ARRAY_NEW_TUPLE_LIMIT

  fill = array_new_fill(arg_types[1])
  Type::Combinator.tuple_of(*Array.new(size, fill))
end

.array_new_size(type) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 980

def array_new_size(type)
  return nil unless type.is_a?(Type::Constant) && type.value.is_a?(Integer)

  type.value
end

.boundary_cross_class_name(receiver_type, environment, rbs_result) ⇒ Object

Composite preflight for #record_boundary_cross_if_applicable. Returns the receiver class name only when every prerequisite for emitting the diagnostic is satisfied (environment carries an index + reporter, receiver is a nominal carrier, RBS-side result is not the trivial ‘Dynamic` envelope). Returns `nil` to short-circuit otherwise.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 616

def boundary_cross_class_name(receiver_type, environment, rbs_result)
  return nil if environment.nil?
  return nil if environment.dependency_source_index.nil?
  return nil if environment.dependency_source_index.empty?
  return nil if environment.boundary_cross_reporter.nil?
  return nil if rbs_result_untyped?(rbs_result)

  dep_source_class_name(receiver_type)
end

.budget_silence_result(class_name, index, _environment) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 636

def budget_silence_result(class_name, index, _environment)
  return nil unless index.budget_overrun_strategy == :dependency_silence

  owning_gem = index.gem_for(class_name)
  return nil if owning_gem.nil?
  return nil unless index.budget_exceeded.include?(owning_gem)

  Type::Combinator.untyped
end

.class_new_lift(class_name, arg_types) ⇒ Object

‘Class.new` and `Class.new(Parent)` create a brand-new anonymous class. Statically that class is representable as the parent’s singleton type — its singleton-method surface is the parent’s (plus whatever the block defines, which we do not statically track here), so ‘Singleton` lets downstream `klass.some_class_method` resolve. No parent →`singleton(Object)`. Anything else (dynamic parent, more than one positional, …) falls back to `Nominal` via the surrounding `meta_new` tail.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 915

def class_new_lift(class_name, arg_types)
  return nil unless class_name == "Class"
  return Type::Combinator.singleton_of("Object") if arg_types.empty?
  return nil unless arg_types.size == 1

  parent = arg_types.first
  return parent if parent.is_a?(Type::Singleton)

  nil
end

.collect_plugin_contributions(registry, call_node, scope, receiver_type) ⇒ Object

Collects every plugin’s flow / dynamic-return contribution for one call site. Two prunings keep this off the hot path on plugin-heavy projects (it was the #1 allocation site and a top CPU cost):

  1. Only the plugins that structurally implement a per-call path are visited — ‘registry.contribution_index.for_method_dispatch` is the registry-ordered subset overriding `flow_contribution_for` or declaring a `dynamic_return` (GitLab: 2 of 11). Iterating the subset in registry order, and gating each path by membership, yields the exact same contributions in the same order as visiting every plugin would (a skipped plugin’s call returns nil/[] anyway). The receiver-class ancestry match still happens per dispatch inside ‘dynamic_return_type`.

  2. Contributions accumulate lazily — allocate only when one actually appears, and share a frozen empty array otherwise. The caller treats the result as read-only (‘.empty?` / `Merger.merge`).



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# File 'lib/rigor/inference/method_dispatcher.rb', line 695

def collect_plugin_contributions(registry, call_node, scope, receiver_type)
  index = registry.contribution_index
  relevant = index.for_method_dispatch
  return EMPTY_CONTRIBUTIONS if relevant.empty?

  result = nil
  relevant.each do |plugin|
    if index.flow?(plugin)
      legacy = plugin.flow_contribution_for(call_node: call_node, scope: scope)
      (result ||= []) << legacy if legacy.is_a?(FlowContribution)
    end
    if index.dynamic?(plugin)
      dynamic = plugin.dynamic_return_type(call_node: call_node, scope: scope, receiver_type: receiver_type)
      (result ||= []) << FlowContribution.new(return_type: dynamic) if dynamic
    end
  rescue StandardError
    next
  end
  result || EMPTY_CONTRIBUTIONS
end

.constant_constructor_lift(class_name, arg_types) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 947

def constant_constructor_lift(class_name, arg_types)
  builder = CONSTANT_CONSTRUCTORS[class_name]
  return nil if builder.nil?
  return nil unless arg_types.size == 1

  arg = arg_types.first
  return nil unless arg.is_a?(Type::Constant) && arg.value.is_a?(String)

  result = builder.call(arg.value)
  Type::Combinator.constant_of(result)
rescue StandardError
  nil
end

.constant_metaclass(value) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 1113

def constant_metaclass(value)
  CONSTANT_METACLASSES.each do |klass, name|
    return Type::Combinator.singleton_of(name) if value.is_a?(klass)
  end
  nil
end

.date_new_lift(class_name, arg_types) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 1091

def date_new_lift(class_name, arg_types)
  return nil unless DATE_NEW_CLASSES.include?(class_name)
  return nil unless arg_types.size.between?(1, 8)
  return nil unless arg_types.all?(Type::Constant)

  values = arg_types.map(&:value)
  return nil unless values.all? { |v| v.is_a?(Integer) || v.is_a?(Rational) || v.is_a?(String) }

  klass = class_name == "Date" ? Date : DateTime
  Type::Combinator.constant_of(klass.new(*values))
rescue StandardError
  nil
end

.dep_source_class_name(receiver_type) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 665

def dep_source_class_name(receiver_type)
  case receiver_type
  when Type::Nominal, Type::Singleton then receiver_type.class_name
  end
end

.dependency_source_return_type(contribution) ⇒ Object

Maps a DependencySourceInference::Walker::CatalogEntry to the Type the dispatcher returns at the call site. When the heuristic recovered a static facet, wrap it in ‘Dynamic` per ADR-10’s gem-boundary contract; otherwise fall back to the pre-heuristic ‘Dynamic`.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 604

def dependency_source_return_type(contribution)
  return Type::Combinator.untyped if contribution.return_type.nil?

  Type::Combinator.dynamic(contribution.return_type)
end

.discovered_method_lookup(receiver_type) ⇒ Object

Resolves the ‘(class_name, kind)` pair scope_indexer keys its `discovered_methods` table on. `Nominal` looks up instance methods on X; `Singleton` looks up singleton methods on X. Other carriers return `[nil, nil]` so the tier declines.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 267

def discovered_method_lookup(receiver_type)
  case receiver_type
  when Type::Nominal then [receiver_type.class_name, :instance]
  when Type::Singleton then [receiver_type.class_name, :singleton]
  else [nil, nil]
  end
end

.dispatch(receiver_type:, method_name:, arg_types:, block_type: nil, environment: nil, call_node: nil, scope: nil) ⇒ Rigor::Type?

Returns inferred result type, or ‘nil` for “no rule”.

Parameters:

  • receiver_type (Rigor::Type, nil) —

    type of the receiver expression, or ‘nil` for an implicit-self call.

  • method_name (Symbol)
  • arg_types (Array<Rigor::Type>) —

    positional argument types.

  • block_type (Rigor::Type, nil) (defaults to: nil) —

    inferred return type of the accompanying ‘do … end` / `{ … }` block (Slice 6 phase C sub-phase 2). When non-nil, the dispatcher prefers an overload that declares a block, and binds the method’s block-return type variable to ‘block_type` so a return type like `Array` resolves to `Array`.

  • environment (Rigor::Environment, nil) (defaults to: nil) —

    required for RBS-backed dispatch; when nil only constant folding can fire.

Returns:

  • (Rigor::Type, nil) —

    inferred result type, or ‘nil` for “no rule”.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 76

def dispatch(receiver_type:, method_name:, arg_types:, # rubocop:disable Metrics/MethodLength, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
             block_type: nil, environment: nil,
             call_node: nil, scope: nil)
  return nil if receiver_type.nil?

  # Build the call context once and thread it — unchanged —
  # through every tier (`_DispatchTier#try_dispatch`). The
  # dispatcher's own private fallback tiers still read the
  # positional locals below; only the tier modules consume the
  # context object.
  context = CallContext.build(
    receiver: receiver_type, method_name: method_name, args: arg_types,
    block_type: block_type, environment: environment,
    call_node: call_node, scope: scope
  )

  bound_method_result = MethodFolding.try_backward(context)
  return bound_method_result if bound_method_result

  precise = dispatch_precise_tiers(context)
  return precise if precise

  # v0.1.1 Track 2 slice 7 — plugin return-type contribution
  # tier. Sits ahead of `RbsDispatch` so a plugin that
  # understands a domain-specific dispatch (e.g. an
  # `ActiveRecord::Base.find` returning `Nominal[<resolved
  # model>]`) wins over the RBS-projected envelope. Only
  # consults the registry when both `call_node` and `scope`
  # are supplied — the dispatcher's own internal callers
  # (per-element block fold, etc.) skip this tier.
  plugin_result = try_plugin_contribution(call_node, scope, receiver_type)
  return plugin_result if plugin_result

  # ADR-20 slice 3 — Rigor-bundled HKT-builtin return-
  # type tier. Sits ABOVE `RbsDispatch.try_dispatch` so
  # the handful of stdlib methods whose upstream RBS
  # signature is `untyped` but whose runtime shape Rigor
  # models via a Lightweight HKT (`json::value`,
  # eventually `dry_monads::result`, …) get the reduced
  # type instead of `Dynamic[Top]`. The table that
  # populates this tier lives in
  # `Rigor::Builtins::HktBuiltins::METHOD_RETURN_OVERRIDES`;
  # plugin-supplied per-method overrides are out of
  # scope for slice 3 and continue to flow through the
  # `try_plugin_contribution` tier above.
  hkt_builtin_result = try_hkt_builtin_return(receiver_type, method_name, arg_types, environment)
  return hkt_builtin_result if hkt_builtin_result

  # Rigor-bundled static refinement tier. Sits between HKT
  # and RBS so stdlib methods whose upstream RBS is broader
  # than the documented behaviour (e.g. `Kernel#__dir__`
  # declared `() -> String?` when the documented return is
  # `non-empty-string | nil`) get the tightened type
  # without modifying the vendored `ruby/rbs` submodule.
  # The override table lives in
  # `Rigor::Builtins::StaticReturnRefinements::OVERRIDES`.
  static_refinement = try_static_refinement(receiver_type, method_name, arg_types)
  return static_refinement if static_refinement

  rbs_result = RbsDispatch.try_dispatch(context)
  if rbs_result
    record_boundary_cross_if_applicable(receiver_type, method_name, rbs_result, environment)
    return rbs_result
  end

  # ADR-16 Tier B / Tier C — synthetic-method tier. Sits
  # BELOW RBS dispatch (per WD13: user-authored RBS overrides
  # substrate synthesis) and ABOVE the dependency-source
  # inference tier so a plugin's declared emit table beats
  # the generic gem-source fallback for the same class. Slice
  # 6a-TierB (origin_module dispatch) lands precise return
  # types for Tier B emissions; Tier C emissions still return
  # `Dynamic[T]` at this tier (slice 6b is the Tier C
  # promotion via ADR-13's resolver chain).
  synthetic_result = try_synthetic_method(
    receiver_type, method_name, arg_types, block_type, environment
  )
  return synthetic_result if synthetic_result

  # ADR-17 slice 2 — project-side patched-method tier.
  # Sits BELOW the substrate / plugin tiers and ABOVE
  # dependency-source inference per ADR-17 § "Inference
  # contract". When the user's `pre_eval:` list named a
  # file that re-opens a class (e.g.,
  # `lib/core_ext/string_extensions.rb` declaring
  # `class String; def to_url; end; end`), the pre-pass
  # populated `ProjectPatchedMethods` with the `(class,
  # method, kind)` triple; this tier surfaces it as
  # `Dynamic[top]` so the patched call resolves
  # cross-file without `call.undefined-method`.
  patched_result = try_project_patched_method(receiver_type, method_name, environment)
  return patched_result if patched_result

  # ADR-10 slice 2b-ii — dependency-source inference tier.
  # Sits BELOW RBS dispatch (RBS / RBS::Inline / generated
  # stubs / plugin contracts always win) and ABOVE the
  # user-class fallback so a method defined in an opt-in
  # gem stops emitting `call.undefined-method` even when
  # no signature contract resolves. Returns
  # `Dynamic[top]` — slice 2b-ii deliberately stops at the
  # dynamic-origin envelope; per-method return-type
  # precision is queued for a later slice.
  dep_source_result = try_dependency_source(receiver_type, method_name, environment)
  return dep_source_result if dep_source_result

  # v0.1.3 — discovered-method dispatch tier. When the
  # receiver class has no RBS BUT scope_indexer recorded
  # `def method_name` for that class (or singleton), the
  # call dispatches to `Dynamic[top]` rather than falling
  # through to the user-class fallback. Sits below RBS /
  # dependency-source so authoritative signatures still win.
  # The scope-indexer-built table records every project-side
  # `def`, `define_method`, and `alias_method`; the
  # `discovered_method?` consult here closes the
  # fail-soft-event hot spot on implicit-self calls
  # (`sibling_private(...)`) inside `lib/rigor/`'s own
  # internals (analyser private helpers don't have RBS).
  discovered_result = try_discovered_method(receiver_type, method_name, scope)
  return discovered_result if discovered_result

  # ADR-5 robustness — synthesized-stub-type tier. When the
  # receiver is a type Rigor invented to make an otherwise-
  # unbuildable project signature resolve (a missing-namespace
  # module, or a stub for a referenced-but-undeclared type like
  # an unavailable `DRb::DRbServer`), the stub carries no methods,
  # so an unresolved call against it would otherwise mis-fire
  # `call.undefined-method`. Resolve it to `Dynamic[Top]` instead
  # — the same no-false-positive contract as the dependency-
  # source tier. Sits below every real resolution tier so a
  # genuine signature always wins.
  stub_result = try_synthesized_stub_type(receiver_type, environment)
  return stub_result if stub_result

  # Slice 7 phase 10 — user-class ancestor fallback. When
  # the receiver is `Nominal[T]` or `Singleton[T]` for a
  # class not in the RBS environment (typically a
  # user-defined class), retry the dispatch against the
  # implicit ancestor: `Nominal[Object]` for instance
  # receivers and `Singleton[Object]` for singleton
  # receivers. This resolves Kernel intrinsics
  # (`require`, `raise`, `puts`, ...) and Module/Class
  # introspection (`attr_reader`, `private`, ...) on
  # user classes without requiring the user to author
  # their own RBS.
  try_user_class_fallback(receiver_type, method_name, arg_types, environment, block_type, call_node)
end

.dispatch_precise_tiers(context) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 746

def dispatch_precise_tiers(context)
  # ADR-48 — Data value folding runs ahead of meta-introspection:
  # `meta_new` intercepts every `Singleton[*].new` (returning
  # `Nominal`), which would mask a `Data` class's precise instance.
  # The tier only fires on Data receivers (a `Data.define`, a
  # `DataClass`/`DataInstance`, or a `Singleton` with a recorded
  # member layout), so it never shadows meta's Array/Set/Range lifts.
  data_result = DataFolding.try_dispatch(context)
  return data_result if data_result

  meta_result = try_meta_introspection(context.receiver, context.method_name, context.args)
  return meta_result if meta_result

  PRECISE_TIERS.each do |tier|
    result = tier.try_dispatch(context)
    return result if result
  end
  nil
end

.expected_block_param_types(receiver_type:, method_name:, arg_types:, environment: nil) ⇒ Array<Rigor::Type>

Returns the positional block parameter types declared by the receiving method’s selected RBS overload, translated into ‘Rigor::Type`. Used by the StatementEvaluator’s CallNode handler to bind block parameter names before evaluating the block body.

The probe is best-effort: it returns an empty array whenever the receiver, environment, method definition, or selected overload does not provide statically declared block parameter types. Callers MUST treat the empty array as “no information”; the binder falls back to ‘Dynamic` for every parameter slot in that case.

Parameters:

Returns:



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# File 'lib/rigor/inference/method_dispatcher.rb', line 1138

def expected_block_param_types(receiver_type:, method_name:, arg_types:, environment: nil)
  return [] if receiver_type.nil?

  context = CallContext.build(
    receiver: receiver_type, method_name: method_name,
    args: arg_types, environment: environment
  )
  iterator_result = IteratorDispatch.block_param_types(context)
  return iterator_result if iterator_result

  RbsDispatch.block_param_types(context)
end

.explicit_non_self_receiver?(call_node) ⇒ Boolean

True when the call node carries an explicit receiver that is not the literal ‘self`. Such a call cannot legally dispatch to a private method, so the user-class fallback must skip private signatures rather than return a confidently-wrong type. Returns false for implicit-self calls and `self.`-receiver calls (both may legally reach a private method in modern Ruby), and false when no `call_node` is supplied (internal dispatcher callers).

Returns:

  • (Boolean) 


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# File 'lib/rigor/inference/method_dispatcher.rb', line 810

def explicit_non_self_receiver?(call_node)
  return false if call_node.nil?
  return false unless call_node.respond_to?(:receiver)

  receiver = call_node.receiver
  return false if receiver.nil?

  !receiver.is_a?(Prism::SelfNode)
end

.meta_class(receiver_type) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 860

def meta_class(receiver_type)
  case receiver_type
  when Type::Nominal then Type::Combinator.singleton_of(receiver_type.class_name)
  when Type::Constant then constant_metaclass(receiver_type.value)
  end
end

.meta_new(receiver_type, arg_types = []) ⇒ Object

‘Singleton.new` returns `Nominal` (a fresh instance), regardless of whether Foo is in RBS. This short-circuits the Class.new generic-`instance` plumbing for user classes, so a discovered-class `ScanAccumulator.new` types as `Nominal` rather than `Class`.

v0.0.7 — for the curated set of immutable scalar-shaped classes that ‘Type::Constant::SCALAR_CLASSES` accepts (today: `Pathname`), `.new(Constant<…>)` lifts to a `Constant<…>` carrier so downstream method calls fold through the standard catalog tier.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 879

def meta_new(receiver_type, arg_types = [])
  return nil unless receiver_type.is_a?(Type::Singleton)

  constant_lift = constant_constructor_lift(receiver_type.class_name, arg_types)
  return constant_lift if constant_lift

  array_lift = array_new_lift(receiver_type.class_name, arg_types)
  return array_lift if array_lift

  range_lift = range_new_lift(receiver_type.class_name, arg_types)
  return range_lift if range_lift

  set_lift = set_new_lift(receiver_type.class_name, arg_types)
  return set_lift if set_lift

  regexp_lift = regexp_new_lift(receiver_type.class_name, arg_types)
  return regexp_lift if regexp_lift

  date_lift = date_new_lift(receiver_type.class_name, arg_types)
  return date_lift if date_lift

  class_new_lift = class_new_lift(receiver_type.class_name, arg_types)
  return class_new_lift if class_new_lift

  Type::Combinator.nominal_of(receiver_type.class_name)
end

.plugin_owns_receiver?(class_name, environment) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rigor/inference/method_dispatcher.rb', line 646

def plugin_owns_receiver?(class_name, environment)
  registry = environment&.plugin_registry
  return false if registry.nil? || registry.empty?

  registry.plugins.any? do |plugin|
    owns = plugin.manifest.owns_receivers # rigor:disable undefined-method
    owns.any? { |owner| receiver_matches_owner?(class_name, owner, environment) }
  end
end

.promote_synthetic_match(matches, method_name, arg_types, block_type, environment) ⇒ Object

First non-nil promotion wins. Tier B (origin_module) and Tier C (return_type nominal lookup) are tried in the same registration-order pass per WD11 first-wins —the slice-3b scanner sets ‘origin_module` for Tier B entries and leaves it absent for Tier C, so the two paths self-route per match.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 453

def promote_synthetic_match(matches, method_name, arg_types, block_type, environment)
  return nil if environment.nil?

  matches.each do |synthetic|
    promoted =
      promote_via_origin_module(synthetic, method_name, arg_types, block_type, environment) ||
      promote_via_return_type(synthetic, environment)
    return promoted if promoted
  end
  nil
end

.promote_via_origin_module(synthetic, method_name, arg_types, block_type, environment) ⇒ Object

Slice 6a-TierB. For Tier B emissions (origin_module recorded in provenance), redispatch the call on the included module’s ‘Nominal` type via `RbsDispatch`. Returns nil when the SyntheticMethod is not a Tier B entry or when the origin_module is not in the RBS env.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 470

def promote_via_origin_module(synthetic, method_name, arg_types, block_type, environment)
  module_name = synthetic.provenance[:origin_module]
  return nil unless module_name

  module_type = Type::Combinator.nominal_of(module_name)
  RbsDispatch.try_dispatch(
    CallContext.build(
      receiver: module_type, method_name: method_name, args: arg_types,
      environment: environment, block_type: block_type
    )
  )
end

.promote_via_return_type(synthetic, environment) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 493

def promote_via_return_type(synthetic, environment)
  return_type = synthetic.return_type
  return nil if return_type.nil? || TIER_C_PLACEHOLDER_RETURNS.include?(return_type)

  environment.nominal_for_name(return_type)
end

.range_new_excl(excl_type) ⇒ Object

Resolves the optional ‘exclude_end` argument for `range_new_lift`. Returns `false` (no arg), `true`/`false` (Constant arg), or `nil` to signal “decline” (wrong type / wrong value class).



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# File 'lib/rigor/inference/method_dispatcher.rb', line 1026

def range_new_excl(excl_type)
  case excl_type
  when nil then false
  when Type::Constant
    excl_type.value if [true, false].include?(excl_type.value)
  end
end

.range_new_lift(class_name, arg_types) ⇒ Object

‘Range.new(b, e)` / `Range.new(b, e, excl)` — folds to `Constant` when both endpoints are `Constant` or both are `Constant`, and the optional third argument is a `Constant`. Nil endpoints (beginless / endless ranges) are not folded because the useful instance methods (`to_a`, `first`, `last`) are not defined for them; the RBS tier answers `Nominal` for those forms.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 999

def range_new_lift(class_name, arg_types)
  return nil unless class_name == "Range"
  return nil if arg_types.size < 2 || arg_types.size > 3

  b_type = arg_types[0]
  e_type = arg_types[1]

  return nil unless b_type.is_a?(Type::Constant) && e_type.is_a?(Type::Constant)

  b_val = b_type.value
  e_val = e_type.value

  # Only fold homogeneous Integer or String endpoint pairs.
  return nil unless b_val.instance_of?(e_val.class)
  return nil unless b_val.is_a?(Integer) || b_val.is_a?(String)

  excl = range_new_excl(arg_types[2])
  return nil if excl.nil?

  Type::Combinator.constant_of(Range.new(b_val, e_val, excl))
rescue StandardError
  nil
end

.rbs_display_for(rbs_result) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 630

def rbs_display_for(rbs_result)
  return "untyped" if rbs_result.nil?

  rbs_result.respond_to?(:describe) ? rbs_result.describe : rbs_result.inspect
end

.rbs_result_untyped?(rbs_result) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rigor/inference/method_dispatcher.rb', line 626

def rbs_result_untyped?(rbs_result)
  rbs_result.is_a?(Type::Dynamic) && rbs_result.static_facet.is_a?(Type::Top)
end

.receiver_matches_owner?(class_name, owner, environment) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rigor/inference/method_dispatcher.rb', line 656

def receiver_matches_owner?(class_name, owner, environment)
  return true if class_name == owner

  ordering = environment.class_ordering(class_name, owner)
  %i[equal subclass].include?(ordering)
rescue StandardError
  false
end

.record_boundary_cross_if_applicable(receiver_type, method_name, rbs_result, environment) ⇒ Object

ADR-10 slice 5c — record a ‘dynamic.dependency-source.boundary-cross` event when RBS dispatch resolves a call AND the receiver class belongs to a `mode: :full` opt-in gem whose Walker also catalogued the same `(class_name, method_name)`. The dispatcher still returns the RBS answer (per ADR-10’s tier order: authoritative-source wins), but the reporter accumulates the crossing for end-of-run audit diagnostics.

Five honest fall-throughs keep the gate narrow:

  • environment / index / reporter missing — slice 5c needs all three.

  • receiver has no nominal class name (Dynamic-only carriers) — nothing to look up.

  • receiver class doesn’t belong to a ‘mode: :full` gem — the user didn’t opt this gem into the distinct dispatch path.

  • the gem-source catalog has no entry for the method —only RBS knows about it; nothing to cross.

  • the RBS-side result is itself ‘Dynamic` — the “agreement” is trivially `untyped ≈ untyped`, no meaningful divergence to flag.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 584

def record_boundary_cross_if_applicable(receiver_type, method_name, rbs_result, environment)
  class_name = boundary_cross_class_name(receiver_type, environment, rbs_result)
  return if class_name.nil?

  index = environment.dependency_source_index
  return unless index.full_mode?(class_name)
  return unless index.contribution_for(class_name: class_name, method_name: method_name)

  environment.boundary_cross_reporter.record(
    class_name: class_name, method_name: method_name,
    gem_name: index.gem_for(class_name),
    rbs_display: rbs_display_for(rbs_result)
  )
end

.regexp_new_lift(class_name, arg_types) ⇒ Object

‘Regexp.new(pattern)` / `Regexp.new(pattern, opts)` — folds to `Constant` when the pattern is a `Constant`. Mirrors `RegexpFolding#fold_new` but lives here so the `:new` path in `try_meta_introspection` can reach it.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 1058

def regexp_new_lift(class_name, arg_types)
  return nil unless class_name == "Regexp"
  return nil if arg_types.empty? || arg_types.size > 2

  pattern_arg = arg_types.first
  return nil unless pattern_arg.is_a?(Type::Constant) && pattern_arg.value.is_a?(String)

  opts = if arg_types.size == 2
           opt_type = arg_types[1]
           return nil unless opt_type.is_a?(Type::Constant)

           opt_type.value
         else
           0
         end

  Type::Combinator.constant_of(Regexp.new(pattern_arg.value, opts))
rescue StandardError
  nil
end

.set_new_lift(class_name, arg_types) ⇒ Object

‘Set.new` / `Set.new(tuple_of_constants)` — folds to `Constant` when zero arguments are given or the single argument is a `Tuple` whose every element is a `Constant`. Mirrors `SetFolding#fold_new` but lives here so the `:new` path in `try_meta_introspection` can reach it before the RBS tier answers `Nominal`.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 1039

def set_new_lift(class_name, arg_types)
  return nil unless class_name == "Set"
  return Type::Combinator.constant_of(::Set.new) if arg_types.empty?
  return nil if arg_types.size > 1

  arg = arg_types.first
  return nil unless arg.is_a?(Type::Tuple)
  return nil unless arg.elements.all?(Type::Constant)

  values = arg.elements.map(&:value)
  Type::Combinator.constant_of(::Set.new(values))
rescue StandardError
  nil
end

.static_refinement_class_for(receiver_type) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 380

def static_refinement_class_for(receiver_type)
  case receiver_type
  when Type::Singleton, Type::Nominal
    receiver_type.class_name
  end
end

.static_refinement_owner_for(receiver_type, candidates) ⇒ Object

Picks the most specific override owner the receiver honours. For Kernel-owned overrides the receiver simply needs to be a real-class Nominal / Singleton (i.e. not BasicObject and not a Dynamic / Constant / shape carrier — those carriers go through their own narrower tiers).



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# File 'lib/rigor/inference/method_dispatcher.rb', line 371

def static_refinement_owner_for(receiver_type, candidates)
  receiver_class = static_refinement_class_for(receiver_type)
  return nil unless receiver_class

  return "Kernel" if candidates.include?("Kernel") && receiver_class != "BasicObject"

  candidates.find { |owner| owner == receiver_class }
end

.synthetic_method_class_name(receiver_type) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 500

def synthetic_method_class_name(receiver_type)
  case receiver_type
  when Type::Nominal, Type::Singleton then receiver_type.class_name
  end
end

.try_dependency_source(receiver_type, method_name, environment) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 530

def try_dependency_source(receiver_type, method_name, environment)
  index = environment&.dependency_source_index
  return nil if index.nil? || index.empty?

  class_name = dep_source_class_name(receiver_type)
  return nil if class_name.nil?

  # ADR-10 5a — per-receiver plugin veto. When a
  # registered plugin declares `manifest(owns_receivers:
  # [<class>])` AND the call's receiver IS that class
  # (or a subclass), decline and let plugins handle the
  # call. Plugins that own a receiver are the
  # authoritative source for that type; gem-source
  # inference must not contribute behind their backs.
  return nil if plugin_owns_receiver?(class_name, environment)

  contribution = index.contribution_for(class_name: class_name, method_name: method_name)
  return dependency_source_return_type(contribution) if contribution

  # ADR-10 5b — β budget semantics. On a catalog miss,
  # if the receiver class belongs to a budget-exceeded
  # gem AND the user opted into `:dependency_silence`,
  # return `Dynamic[top]` rather than falling through to
  # the user-class fallback. The user-class fallback
  # would otherwise emit `call.undefined-method` for
  # methods Rigor's catalog couldn't reach because the
  # walker hit its cap.
  budget_silence_result(class_name, index, environment)
end

.try_discovered_method(receiver_type, method_name, scope) ⇒ Object

v0.1.3 — discovered-method dispatch tier. ‘scope` carries the `discovered_methods` table built once per program by `ScopeIndexer` (a `Hash[String, Hash[Symbol, :instance | :singleton]]`). When the receiver names a discovered class AND the requested method is recorded for that class’s appropriate kind, return ‘Type::Combinator.untyped` — the dispatcher cannot infer a more precise return type from the bare `def` shape, but the call site stops being a fail-soft hot spot.

Returns ‘nil` when scope / receiver class is unavailable, when the method is not in the discovered table, OR when `discovered_def_nodes` carries a re-typable body for the method (so the downstream `ExpressionTyper#try_user_method_inference` tier can re-type the body for a precise return type rather than collapsing to `Dynamic` here).

The tier does NOT gate on ‘rbs_class_known?`. RBS dispatch already had its turn upstream and returned `nil` (otherwise we wouldn’t be here). When RBS knows the class but the particular method is missing from the sig — common for internal helpers and for auto-generated stubs that emit ‘class X` without enumerating every method — falling through to the user-class fallback would mistakenly fire `call.undefined-method`. Honoring the discovered table here keeps the sibling-private call resolution working under partial RBS coverage.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 251

def try_discovered_method(receiver_type, method_name, scope)
  return nil if scope.nil?

  class_name, kind = discovered_method_lookup(receiver_type)
  return nil if class_name.nil?
  return nil unless scope.discovered_method?(class_name, method_name, kind)
  return nil if kind == :instance && scope.user_def_for(class_name, method_name)

  Type::Combinator.untyped
end

.try_hkt_builtin_return(receiver_type, method_name, arg_types, environment) ⇒ Object

ADR-2 § “Flow Contribution Bundle” / v0.1.1 Track 2 slice 7. Walks every loaded plugin’s ‘#flow_contribution_for(call_node:, scope:)` hook, collects the non-nil `FlowContribution` bundles, merges them through `FlowContribution::Merger`, and returns the merged `return_type` slot (or nil when no plugin contributed a return type).

Plugins whose hook raises have their contribution silently dropped for this call so the dispatch chain keeps moving — the run-level diagnostic envelope (per ADR-2 § “Plugin Trust and I/O Policy”) is owned by ‘Analysis::Runner#plugin_emitted_diagnostics`. ADR-20 slice 3 — looks up the receiver / method pair in Builtins::HktBuiltins::METHOD_RETURN_OVERRIDES and returns the reduced HKT type. Only fires when the receiver is a Type::Singleton (the `JSON.parse` shape) and the registry-backed reduction succeeds; returns `nil` otherwise so the dispatcher falls through to RBS.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 320

def try_hkt_builtin_return(receiver_type, method_name, arg_types, environment)
  return nil if environment.nil?
  return nil unless receiver_type.is_a?(Type::Singleton)

  Rigor::Builtins::HktBuiltins.method_return_override(
    class_name: receiver_type.class_name,
    method_name: method_name,
    kind: :singleton,
    arg_types: arg_types,
    hkt_registry: environment.hkt_registry
  )
end

.try_meta_introspection(receiver_type, method_name, arg_types = []) ⇒ Object

Slice 7 phase 8 — meta-introspection shortcuts. The default ‘Object#class` RBS return type is `Class`, but for a receiver of known nominal identity we can do better: `instance_of(Foo).class` is `Singleton` (the class object itself), which downstream dispatch uses to resolve `self.class.some_class_method`. The same logic answers `Foo.class` as `Singleton` (deliberate; calling `.class` on a class object yields `Class`, the metaclass). We also special-case `is_a?`- adjacent calls and the trivial `instance_of?(self)` later as the rule catalogue grows; for now only `class` is handled.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 853

def try_meta_introspection(receiver_type, method_name, arg_types = [])
  case method_name
  when :class then meta_class(receiver_type)
  when :new then meta_new(receiver_type, arg_types)
  end
end

.try_plugin_contribution(call_node, scope, receiver_type) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 387

def try_plugin_contribution(call_node, scope, receiver_type)
  return nil if call_node.nil? || scope.nil?

  registry = scope.environment&.plugin_registry
  return nil if registry.nil? || registry.empty?

  contributions = collect_plugin_contributions(registry, call_node, scope, receiver_type)
  return nil if contributions.empty?

  FlowContribution::Merger.merge(contributions).return_type
end

.try_project_patched_method(receiver_type, method_name, environment) ⇒ Object

ADR-17 slice 2 — project-side patched-method tier. Slice 3a uses the registry’s heuristic-extracted ‘return_type` (populated via the same `Analysis::DependencySourceInference::ReturnTypeHeuristic` the ADR-10 walker uses): a `def to_url; “hello”; end` patched onto `String` now resolves `s.to_url` to `Dynamic[Nominal]` instead of the pre-3a `Dynamic`. Falls back to `Dynamic` when the heuristic declined (non-literal tail expression).



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# File 'lib/rigor/inference/method_dispatcher.rb', line 515

def try_project_patched_method(receiver_type, method_name, environment)
  registry = environment&.project_patched_methods
  return nil if registry.nil? || registry.empty?

  class_name = synthetic_method_class_name(receiver_type)
  return nil if class_name.nil?

  kind = receiver_type.is_a?(Type::Singleton) ? :singleton : :instance
  entry = registry.lookup(class_name: class_name, method_name: method_name, kind: kind)
  return nil if entry.nil?
  return Type::Combinator.untyped if entry.return_type.nil?

  Type::Combinator.dynamic(entry.return_type)
end

.try_static_refinement(receiver_type, method_name, arg_types) ⇒ Object

Consults the Rigor-bundled static refinement table for a (owner-class, method-name, kind) entry. Kernel methods are mixed into every non-BasicObject class, so an implicit-self ‘__dir__` call (receiver_type = Nominal) is matched by looking up Kernel as the owner. Explicit `Kernel.__dir__` (receiver_type = Singleton) and instance-side calls (receiver_type = Nominal) share the `:both` row.

The receiver-side ancestor check is intentionally cheap: any non-BasicObject Nominal / Singleton matches every Kernel-owned override. BasicObject explicitly excludes Kernel and is therefore rejected. The narrow risk of a user-defined ‘def __dir__` shadowing Kernel’s method would also alter the runtime answer; users with that configuration opt out via a ‘signature_paths` overlay declaring their own return type.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 350

def try_static_refinement(receiver_type, method_name, arg_types)
  candidates = Rigor::Builtins::StaticReturnRefinements.owners_for(method_name)
  return nil if candidates.empty?

  owner = static_refinement_owner_for(receiver_type, candidates)
  return nil unless owner

  kind = receiver_type.is_a?(Type::Singleton) ? :singleton : :instance
  Rigor::Builtins::StaticReturnRefinements.lookup(
    owner_class_name: owner,
    method_name: method_name,
    kind: kind,
    arg_types: arg_types
  )
end

.try_synthesized_stub_type(receiver_type, environment) ⇒ Object

ADR-5 robustness — returns ‘Dynamic` when the receiver is an instance or singleton of a type Rigor synthesized (a missing-namespace module or a referenced-type stub). The stub has no methods, so the call would otherwise reach the user-class fallback and surface `call.undefined-method`; the honest answer for a type Rigor invented is “unknown shape”, i.e. `Dynamic`. Returns nil (declines) for any real type.



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# File 'lib/rigor/inference/method_dispatcher.rb', line 282

def try_synthesized_stub_type(receiver_type, environment)
  return nil if environment.nil?

  loader = environment.rbs_loader
  return nil if loader.nil? || !loader.respond_to?(:synthesized_type_names)

  names = loader.synthesized_type_names
  return nil if names.empty?

  class_name =
    case receiver_type
    when Type::Nominal, Type::Singleton then receiver_type.class_name.to_s.sub(/\A::/, "")
    end
  return nil unless class_name && names.include?(class_name)

  Type::Combinator.untyped
end

.try_synthetic_method(receiver_type, method_name, arg_types, block_type, environment) ⇒ Object

ADR-10 slice 2b-ii. Consults the per-run ‘Analysis::DependencySourceInference::Index` carried by the environment for `(class_name, method_name)` observations harvested from opt-in gems’ ‘roots:`. On a hit, returns `Combinator.untyped` so the call site carries the `Dynamic` provenance (per ADR-10’s “Inference contract”: gem-source-inferred shapes never publish as ground-truth ‘T`). Returns `nil` when the environment carries no index, the index has no entry, or the receiver has no nominal class to look up. ADR-16 synthetic-method tier. Slice 2b shipped the floor —a match short-circuits at the right precedence (above dep-source / discovered / user-class-fallback; below RBS) and returns `Dynamic`. Slice 6 (precision promotion):

  • Tier B path (slice 6a, ‘provenance` recorded by the slice-3b scanner): redispatch on `Nominal` via `RbsDispatch` so the module’s authored RBS return type wins. Devise’s ‘valid_password?` returns `bool`, not `Dynamic`.

  • Tier C path (slice 6b, plain ‘return_type:` string from the manifest’s emit table): look up ‘environment.nominal_for_name(return_type)` so `attribute :avatar, Types::String` emits a synthetic reader returning `Nominal` (when the class is in RBS). Unparameterised class names only — parameterised forms (`Array`, `Hash[K, V]`) and plugin-supplied utility-type names (`Pick<T, K>`) require routing through the full ADR-13 `Plugin::TypeNodeResolver` chain, which slice 6 does not yet wire in (the resolver chain is consulted only for `%arigor:v1:…` payloads as of ADR-13 slice 3).



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# File 'lib/rigor/inference/method_dispatcher.rb', line 430

def try_synthetic_method(receiver_type, method_name, arg_types, block_type, environment)
  index = environment&.synthetic_method_index
  return nil if index.nil? || index.empty?

  class_name = synthetic_method_class_name(receiver_type)
  return nil if class_name.nil?

  matches = case receiver_type
            when Type::Singleton then index.lookup_singleton(class_name, method_name)
            else index.lookup_instance(class_name, method_name)
            end
  return nil if matches.empty?

  promoted = promote_synthetic_match(matches, method_name, arg_types, block_type, environment)
  promoted || Type::Combinator.untyped
end

.try_user_class_fallback(receiver_type, method_name, arg_types, environment, block_type, call_node = nil) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 766

def try_user_class_fallback(receiver_type, method_name, arg_types, environment, block_type, call_node = nil)
  return nil if environment.nil?

  fallback_receiver = user_class_fallback_receiver(receiver_type, environment)
  return nil if fallback_receiver.nil?

  # Preserve the ORIGINAL receiver type as the `self`
  # substitution so `Kernel#dup: () -> self` and other
  # `self`-returning methods route through Object's RBS
  # while still returning the caller's type rather than
  # `Object`. Without this, `base = self.dup` inside a
  # `Bundler::URI::Generic` instance method types `base`
  # as `Object` because `Bundler::URI::Generic` is not in
  # RBS and the fallback's `self` resolves to Object.
  #
  # `public_only:` — when the call has an EXPLICIT, non-`self`
  # receiver (`Favourite.select(...)`), suppress the private
  # `Object`/`Kernel`/`Class` methods the fallback would
  # otherwise resolve. Ruby raises `NoMethodError` for a
  # private method called with an explicit receiver, so
  # resolving `Favourite.select` to the private `Kernel#select`
  # (`-> Array[String]`) is a confidently-wrong type. Implicit-
  # self / `self.`-receiver calls (`puts`, `raise`, `require`)
  # keep resolving — those are the fallback's intended targets.
  RbsDispatch.try_dispatch(
    CallContext.build(
      receiver: fallback_receiver,
      method_name: method_name,
      args: arg_types,
      environment: environment,
      block_type: block_type,
      self_type_override: receiver_type,
      public_only: explicit_non_self_receiver?(call_node)
    )
  )
end

.user_class_fallback_receiver(receiver_type, environment) ⇒ Object 



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# File 'lib/rigor/inference/method_dispatcher.rb', line 820

def user_class_fallback_receiver(receiver_type, environment)
  case receiver_type
  when Type::Nominal
    # Modules: even when RBS knows the module, an instance
    # method on a mixin-only module (e.g. `PP::ObjectMixin`)
    # observes Kernel / Object methods through every concrete
    # includer's ancestor chain. Route through the
    # `Nominal[Object]` fallback so `self.inspect` /
    # `self.respond_to?` / `self.class` resolve cleanly when
    # the module itself does not declare them.
    known = Rigor::Reflection.rbs_class_known?(receiver_type.class_name, environment: environment)
    return environment.nominal_for_name("Object") if !known || environment.rbs_module?(receiver_type.class_name)

    nil
  when Type::Singleton
    return nil if Rigor::Reflection.rbs_class_known?(receiver_type.class_name, environment: environment)

    environment.singleton_for_name("Class")
  end
end