class RBS::TypeAliasDependency

Attributes

dependencies[R]

A hash which stores the transitive closure of the directed graph

direct_dependencies[R]

Direct dependencies corresponds to a directed graph with vertices as types and directions based on assignment of types

env[R]

Public Class Methods

new(env:) click to toggle source

# File rbs-1.4.0/lib/rbs/type_alias_dependency.rb, line 12
def initialize(env:)
  @env = env
end

Public Instance Methods

build_dependencies() click to toggle source

# File rbs-1.4.0/lib/rbs/type_alias_dependency.rb, line 25
def build_dependencies
  return if @direct_dependencies

  # Initialize hash(a directed graph)
  @direct_dependencies = {}
  # Initialize dependencies as an empty hash
  @dependencies = {}
  # Iterate over alias declarations inserted into environment
  env.alias_decls.each do |name, entry|
    # Construct a directed graph by recursively extracting type aliases
    @direct_dependencies[name] = direct_dependency(entry.decl.type)
    # Initialize dependencies with an empty hash
    @dependencies[name] = {}
  end
end

circular_definition?(alias_name) click to toggle source

Check if an alias type definition is circular & prohibited

# File rbs-1.4.0/lib/rbs/type_alias_dependency.rb, line 17
def circular_definition?(alias_name)
  # Construct transitive closure, if not constructed already
  transitive_closure() unless @dependencies

  # Check for recursive type alias
  @dependencies[alias_name][alias_name]
end

transitive_closure() click to toggle source

# File rbs-1.4.0/lib/rbs/type_alias_dependency.rb, line 41
def transitive_closure
  # Construct a graph of direct dependencies
  build_dependencies()
  # Construct transitive closure by using DFS(recursive technique)
  @direct_dependencies.each_key do |name|
    dependency(name, name)
  end
end

Private Instance Methods

dependency(start, vertex, nested = nil) click to toggle source

Recursive function to construct transitive closure

# File rbs-1.4.0/lib/rbs/type_alias_dependency.rb, line 69
def dependency(start, vertex, nested = nil)
  if (start == vertex)
    if (@direct_dependencies[start].include?(vertex) || nested)
      # Mark a vertex as connected to itself
      # if it is connected as an edge || a path(traverse multiple edges)
      @dependencies[start][vertex] = true
    end
  else
    # Mark a pair of vertices as connected while recursively performing DFS
    @dependencies[start][vertex] = true
  end

  # Iterate over the direct dependencies of the vertex
  @direct_dependencies[vertex]&.each do |type_name|
    # Invoke the function unless it is already checked
    dependency(start, type_name, start == type_name) unless @dependencies[start][type_name]
  end
end

direct_dependency(type, result = Set[]) click to toggle source

Constructs directed graph recursively

# File rbs-1.4.0/lib/rbs/type_alias_dependency.rb, line 53
def direct_dependency(type, result = Set[])
  case type
  when RBS::Types::Union, RBS::Types::Intersection, RBS::Types::Optional
    # Iterate over nested types & extract type aliases recursively
    type.each_type do |nested_type|
      direct_dependency(nested_type, result)
    end
  when RBS::Types::Alias
    # Append type name if the type is an alias
    result << type.name
  end

  result
end