Class: Steep::TypeInference::Logic

Inherits:
Object
  • Object
show all
Defined in:
lib/steep/type_inference/logic.rb

Defined Under Namespace

Classes: Result

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(subtyping:) ⇒ Logic

Returns a new instance of Logic.



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# File 'lib/steep/type_inference/logic.rb', line 35

def initialize(subtyping:)
  @subtyping = subtyping
end

Instance Attribute Details

#subtyping ⇒ Object (readonly)

Returns the value of attribute subtyping.



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# File 'lib/steep/type_inference/logic.rb', line 33

def subtyping
  @subtyping
end

Instance Method Details

#environments(truthy_vars:, falsey_vars:, lvar_env:) ⇒ Object 



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# File 'lib/steep/type_inference/logic.rb', line 83

def environments(truthy_vars:, falsey_vars:, lvar_env:)
  truthy_hash = lvar_env.assigned_types.dup
  falsey_hash = lvar_env.assigned_types.dup

  (truthy_vars + falsey_vars).each do |var|
    type = lvar_env[var]
    truthy_type, falsey_type = partition_union(type)

    if truthy_vars.include?(var)
      truthy_hash[var] = LocalVariableTypeEnv::Entry.new(type: truthy_type)
    end

    if falsey_vars.include?(var)
      falsey_hash[var] = LocalVariableTypeEnv::Entry.new(type: falsey_type)
    end
  end

  [
    lvar_env.except(truthy_vars).update(assigned_types: truthy_hash),
    lvar_env.except(falsey_vars).update(assigned_types: falsey_hash)
  ]
end

#nodes(node:) ⇒ Object 



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# File 'lib/steep/type_inference/logic.rb', line 39

def nodes(node:)
  case node.type
  when :lvasgn
    rhs = node.children[1]
    t, f = nodes(node: rhs)

    [
      t.merge([node]),
      f.merge([node])
    ]

  when :and
    lhs, rhs = node.children

    lt, _ = nodes(node: lhs)
    rt, _ = nodes(node: rhs)

    [
      Result.new([node]) + lt + rt,
      Result.new([node])
    ]

  when :or
    lhs, rhs = node.children

    _, lf = nodes(node: lhs)
    _, rf = nodes(node: rhs)

    [
      Result.new([node]),
      Result.new([node]) + lf + rf
    ]

  when :begin
    nodes(node: node.children.last)

  else
    [
      Result.new([node]),
      Result.new([node])
    ]
  end
end

#partition_union(type) ⇒ Object 



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# File 'lib/steep/type_inference/logic.rb', line 106

def partition_union(type)
  case type
  when AST::Types::Union
    falsey_types, truthy_types = type.types.partition do |type|
      case type
      when AST::Types::Nil
        true
      when AST::Types::Literal
        type.value == false
      end
    end

    [
      truthy_types.empty? ? AST::Types::Bot.new : AST::Types::Union.build(types: truthy_types),
      falsey_types.empty? ? AST::Types::Bot.new : AST::Types::Union.build(types: falsey_types)
    ]
  when AST::Types::Any, AST::Types::Top, AST::Types::Boolean, AST::Types::Void
    [type, type]
  else
    [type, AST::Types::Bot.new]
  end
end