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/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/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, FileFolding, IteratorDispatch, KernelDispatch, LiteralStringFolding, MathFolding, MethodFolding, OverloadSelector, RbsDispatch, ReceiverAffinity, RegexpFolding, SetFolding, ShapeDispatch, ShellwordsFolding, TimeFolding, URIFolding

Class Method Summary collapse

Class Method Details

.array_new_fill(type) ⇒ Object 



871
872
873
874
875
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 871

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

  type
end

.array_new_lift(class_name, arg_types) ⇒ Object 



854
855
856
857
858
859
860
861
862
863
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 854

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 



865
866
867
868
869
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 865

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.



570
571
572
573
574
575
576
577
578
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 570

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 



590
591
592
593
594
595
596
597
598
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 590

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

.collect_plugin_contributions(registry, call_node, scope) ⇒ Object 



625
626
627
628
629
630
631
632
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 625

def collect_plugin_contributions(registry, call_node, scope)
  registry.plugins.filter_map do |plugin|
    contribution = plugin.flow_contribution_for(call_node: call_node, scope: scope)
    contribution.is_a?(FlowContribution) ? contribution : nil
  rescue StandardError
    nil
  end
end

.constant_constructor_lift(class_name, arg_types) ⇒ Object 



832
833
834
835
836
837
838
839
840
841
842
843
844
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 832

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 



998
999
1000
1001
1002
1003
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 998

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 



976
977
978
979
980
981
982
983
984
985
986
987
988
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 976

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 



619
620
621
622
623
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 619

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`.



558
559
560
561
562
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 558

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.



248
249
250
251
252
253
254
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 248

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”.



74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 74

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

  bound_method_result = MethodFolding.try_backward(
    receiver: receiver_type, method_name: method_name, args: arg_types,
    block_type: block_type, environment: environment,
    call_node: call_node, scope: scope
  )
  return bound_method_result if bound_method_result

  precise = dispatch_precise_tiers(receiver_type, method_name, arg_types, block_type)
  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)
  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(
    receiver: receiver_type, method_name: method_name, args: arg_types,
    environment: environment, block_type: block_type
  )
  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

  # 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(receiver_type, method_name, arg_types, block_type = nil) ⇒ Object

Runs the precision tiers (constant fold, shape dispatch, file-path fold, block fold) in order and returns the first non-nil answer. Each tier owns its own receiver/argument shape checks; a tier that does not recognise the receiver returns nil so the next tier can try. The RBS tier sits below this chain and is invoked by the outer ‘dispatch` method.

‘BlockFolding` runs last among the precision tiers because its rules apply only to block-taking calls, so the cheaper arity-based fold tiers above it filter out the common cases first. When `block_type` is nil the tier is a no-op.



646
647
648
649
650
651
652
653
654
655
656
657
658
659
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 646

def dispatch_precise_tiers(receiver_type, method_name, arg_types, block_type = nil)
  meta_result = try_meta_introspection(receiver_type, method_name, arg_types)
  return meta_result if meta_result

  ConstantFolding.try_fold(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    LiteralStringFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    ShapeDispatch.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    dispatch_stdlib_module_tiers(receiver_type, method_name, arg_types) ||
    KernelDispatch.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    MethodFolding.try_forward(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    BlockFolding.try_fold(
      receiver: receiver_type, method_name: method_name, args: arg_types, block_type: block_type
    )
end

.dispatch_stdlib_module_tiers(receiver_type, method_name, arg_types) ⇒ Object

Stdlib module singleton-folding tiers: File, Shellwords, Math, Time, Regexp, CGI, URI, Set. Extracted from ‘dispatch_precise_tiers` to keep the parent method within the cyclomatic-complexity limit.



665
666
667
668
669
670
671
672
673
674
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 665

def dispatch_stdlib_module_tiers(receiver_type, method_name, arg_types)
  FileFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    ShellwordsFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    MathFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    TimeFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    RegexpFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    CGIFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    URIFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types) ||
    SetFolding.try_dispatch(receiver: receiver_type, method_name: method_name, args: arg_types)
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:



1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 1023

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

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

  RbsDispatch.block_param_types(
    receiver: receiver_type,
    method_name: method_name,
    args: arg_types,
    environment: environment
  )
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) 


718
719
720
721
722
723
724
725
726
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 718

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 



768
769
770
771
772
773
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 768

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.



787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 787

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

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

.plugin_owns_receiver?(class_name, environment) ⇒ Boolean

Returns:

  • (Boolean) 


600
601
602
603
604
605
606
607
608
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 600

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.



409
410
411
412
413
414
415
416
417
418
419
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 409

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.



426
427
428
429
430
431
432
433
434
435
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 426

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(
    receiver: module_type, method_name: method_name, args: arg_types,
    environment: environment, block_type: block_type
  )
end

.promote_via_return_type(synthetic, environment) ⇒ Object 



447
448
449
450
451
452
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 447

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).



911
912
913
914
915
916
917
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 911

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.



884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 884

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 



584
585
586
587
588
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 584

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) 


580
581
582
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 580

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) 


610
611
612
613
614
615
616
617
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 610

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.



538
539
540
541
542
543
544
545
546
547
548
549
550
551
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 538

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.



943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 943

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`.



924
925
926
927
928
929
930
931
932
933
934
935
936
937
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 924

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 



336
337
338
339
340
341
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 336

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).



327
328
329
330
331
332
333
334
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 327

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 



454
455
456
457
458
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 454

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 



484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 484

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.



232
233
234
235
236
237
238
239
240
241
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 232

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.



276
277
278
279
280
281
282
283
284
285
286
287
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 276

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.



761
762
763
764
765
766
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 761

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) ⇒ Object 



343
344
345
346
347
348
349
350
351
352
353
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 343

def try_plugin_contribution(call_node, scope)
  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)
  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).



469
470
471
472
473
474
475
476
477
478
479
480
481
482
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 469

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.



306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 306

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_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).



386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 386

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 



676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 676

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(
    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 



728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
 
# File 'lib/rigor/inference/method_dispatcher.rb', line 728

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