Class: Dhall::TypeChecker::Merge::AnnotatedMerge

Inherits:
Object
  • Object
show all
Defined in:
lib/dhall/typecheck.rb

Instance Method Summary collapse

Constructor Details

#initialize(merge:, record:, input:) ⇒ AnnotatedMerge

Returns a new instance of AnnotatedMerge.



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# File 'lib/dhall/typecheck.rb', line 807

def initialize(merge:, record:, input:)
  @merge = merge.with(record: record, input: input)
  @handlers = Handlers.new(record)
  @record = record
  @union = input

  TypeChecker.assert @union.type, Dhall::UnionType,
                     "Merge expected Union got: #{@union.type}"

  assert_union_and_handlers_match
end

Instance Method Details

#annotation ⇒ Object 



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# File 'lib/dhall/typecheck.rb', line 819

def annotation
  Dhall::TypeAnnotation.new(
    value: @merge,
    type:  type
  )
end

#assert_kind(context) ⇒ Object 



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# File 'lib/dhall/typecheck.rb', line 830

def assert_kind(context)
  kind = TypeChecker.for(type).annotate(context).type

  TypeChecker.assert(
    kind,
    Builtins[:Type],
    "Merge must have kind Type"
  )

  kind
end

#assert_union_and_handlers_match ⇒ Object 



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# File 'lib/dhall/typecheck.rb', line 842

def assert_union_and_handlers_match
  extras = @handlers.keys ^ @union.type.alternatives.keys
  TypeChecker.assert extras.to_a, [],
                     "Merge handlers unknown alternatives: #{extras}"

  @union.type.alternatives.each do |k, atype|
    atype.nil? || TypeChecker.assert(
      @handlers.fetch_input_type(k),
      atype,
      "Handler argument does not match alternative type: #{atype}"
    )
  end
end

#type ⇒ Object 



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# File 'lib/dhall/typecheck.rb', line 826

def type
  @type ||= @handlers.output_type(@merge.type)
end