Class: Solargraph::Source::Chain

Inherits:
Object
  • Object
show all
Includes:
Equality, Logging
Defined in:
lib/solargraph/source/chain.rb,
lib/solargraph/source/chain/if.rb,
lib/solargraph/source/chain/or.rb,
lib/solargraph/source/chain/call.rb,
lib/solargraph/source/chain/hash.rb,
lib/solargraph/source/chain/head.rb,
lib/solargraph/source/chain/link.rb,
lib/solargraph/source/chain/array.rb,
lib/solargraph/source/chain/q_call.rb,
lib/solargraph/source/chain/literal.rb,
lib/solargraph/source/chain/z_super.rb,
lib/solargraph/source/chain/constant.rb,
lib/solargraph/source/chain/variable.rb,
lib/solargraph/source/chain/block_symbol.rb,
lib/solargraph/source/chain/block_variable.rb,
lib/solargraph/source/chain/class_variable.rb,
lib/solargraph/source/chain/global_variable.rb,
lib/solargraph/source/chain/instance_variable.rb

Overview

Represents an expression as a single call chain at the parse tree level, made up of constants, variables, and method calls, each represented as a Link object.

Computes Pins and/or ComplexTypes representing the interpreted expression.

Defined Under Namespace

Classes: Array, BlockSymbol, BlockVariable, Call, ClassVariable, Constant, GlobalVariable, Hash, Head, If, InstanceVariable, Link, Literal, Or, QCall, Variable, ZSuper

Constant Summary collapse

UNDEFINED_CALL = 
Chain::Call.new('<undefined>', nil)
UNDEFINED_CONSTANT = 
Chain::Constant.new('<undefined>')
@@inference_stack = 
[]
@@inference_depth = 
0
@@inference_invalidation_key = 
nil
@@inference_cache = 
{}

Constants included from Logging

Logging::DEFAULT_LOG_LEVEL, Logging::LOG_LEVELS

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Logging

log_level, logger

Methods included from Equality

#==, #eql?, #freeze, #hash

Constructor Details

#initialize(links, node = nil, splat = false) ⇒ Chain

Returns a new instance of Chain.

Parameters:

  • node (Parser::AST::Node, nil) (defaults to: nil)
  • links (::Array<Chain::Link>)
  • splat (Boolean) (defaults to: false) 


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# File 'lib/solargraph/source/chain.rb', line 54

def initialize links, node = nil, splat = false
  @links = links.clone
  @links.push UNDEFINED_CALL if @links.empty?
  head = true
  @links.map! do |link|
    result = (head ? link.clone_head : link.clone_body)
    head = false
    result
  end
  @node = node
  @splat = splat
end

Instance Attribute Details

Returns:



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# File 'lib/solargraph/source/chain.rb', line 47

def links
  @links
end

#node ⇒ Object (readonly)

Returns the value of attribute node.



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# File 'lib/solargraph/source/chain.rb', line 49

def node
  @node
end

Instance Method Details

#base ⇒ Chain

Returns:



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# File 'lib/solargraph/source/chain.rb', line 68

def base
  # @sg-ignore Need to add nil check here
  @base ||= Chain.new(links[0..-2])
end

#constant? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/solargraph/source/chain.rb', line 194

def constant?
  links.last.is_a?(Chain::Constant)
end

#define(api_map, name_pin, locals) ⇒ ::Array<Pin::Base>

Determine potential Pins returned by this chain of words

Parameters:

  • api_map (ApiMap)
  • name_pin (Pin::Base) —

    A pin representing the closure in which expression is evaluated (e.g., a Method pin, or a Module or Class pin if not run within a method - both in terms of the closure around the chain, as well as the self type used for any method calls in head position.

    Requirements for name_pin:

    * name_pin.context: This should be a type representing the
namespace where we can look up non-local variables.  If
it is a Class<X>, we will look up :class scoped
instance variables.

* name_pin.binder: Used for method call lookups only
(Chain::Call links).  For method calls as the first
element in the chain, 'name_pin.binder' should be the
same as name_pin.context above.  For method calls later
in the chain, it changes.  (e.g., for 'b' in a.b.c, it
should represent the type of 'a').
  • locals (::Array<Pin::LocalVariable>) —

    Any local variables / method parameters etc visible by the statement

Returns:

  • (::Array<Pin::Base>) —

    Pins representing possible return types of this method.



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# File 'lib/solargraph/source/chain.rb', line 102

def define api_map, name_pin, locals
  return [] if undefined?

  # working_pin is the surrounding closure pin for the link
  # being processed, whose #binder method will provide the LHS /
  # 'self type' of the next link (same as the  #return_type method
  # --the type of the result so far).
  #
  # @todo ProxyType uses 'type' for the binder, but '
  working_pin = name_pin
  # @sg-ignore Need to add nil check here
  links[0..-2].each do |link|
    pins = link.resolve(api_map, working_pin, locals)
    type = infer_from_definitions(pins, working_pin, api_map, locals)
    if type.undefined?
      logger.debug do
        "Chain#define(links=#{links.map(&:desc)}, name_pin=#{name_pin.inspect}, locals=#{locals}) => [] - undefined type from #{link.desc}"
      end
      return []
    end
    # We continue to use the context from the head pin, in case
    # we need it to, for instance, provide context for a block
    # evaluation.  However, we use the last link's return type
    # for the binder, as this is chaining off of it, and the
    # binder is now the lhs of the rhs we are evaluating.
    working_pin = Pin::ProxyType.anonymous(name_pin.context, binder: type, closure: name_pin, source: :chain)
    logger.debug do
      "Chain#define(links=#{links.map(&:desc)}, name_pin=#{name_pin.inspect}, locals=#{locals}) - after processing #{link.desc}, new working_pin=#{working_pin} with binder #{working_pin.binder}"
    end
  end
  links.last.last_context = working_pin
  links.last.resolve(api_map, working_pin, locals)
end

#defined? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/solargraph/source/chain.rb', line 189

def defined?
  !undefined?
end

#desc ⇒ String

Returns:

  • (String) 


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# File 'lib/solargraph/source/chain.rb', line 239

def desc
  links.map(&:desc).to_s
end

#infer(api_map, name_pin, locals) ⇒ ComplexType

@sg-ignore

Parameters:

Returns:



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# File 'lib/solargraph/source/chain.rb', line 141

def infer api_map, name_pin, locals
  # includes binder as it is mutable in Pin::Block
  cache_key = [node, node&.location, links, name_pin&.return_type, name_pin&.binder, locals]
  if @@inference_invalidation_key == api_map.hash
    cached = @@inference_cache[cache_key]
    return cached if cached
  else
    @@inference_invalidation_key = api_map.hash
    @@inference_cache = {}
  end
  out = infer_uncached(api_map, name_pin, locals).downcast_to_literal_if_possible
  logger.debug do
    "Chain#infer() - caching result - cache_key_hash=#{cache_key.hash}, links.map(&:hash)=#{links.map(&:hash)}, links=#{links}, cache_key.map(&:hash) = #{cache_key.map(&:hash)}, cache_key=#{cache_key}"
  end
  @@inference_cache[cache_key] = out
end

#infer_uncached(api_map, name_pin, locals) ⇒ ComplexType, ComplexType::UniqueType

Parameters:

Returns:



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# File 'lib/solargraph/source/chain.rb', line 162

def infer_uncached api_map, name_pin, locals
  pins = define(api_map, name_pin, locals)
  if pins.empty?
    logger.debug do
      "Chain#infer_uncached(links=#{links.map(&:desc)}, locals=#{locals.map(&:desc)}) => undefined - no pins"
    end
    return ComplexType::UNDEFINED
  end
  type = infer_from_definitions(pins, links.last.last_context, api_map, locals)
  out = maybe_nil(type, api_map)
  logger.debug do
    "Chain#infer_uncached(links=#{links.map(&:desc)}, locals=#{locals.map(&:desc)}, " \
      "name_pin=#{name_pin}, name_pin.closure=#{name_pin&.closure&.inspect}, " \
      "name_pin.binder=#{name_pin&.binder}) => #{out.rooted_tags.inspect}"
  end
  out
end

#literal? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/solargraph/source/chain.rb', line 181

def literal?
  links.last.is_a?(Chain::Literal)
end

#nullable?(api_map) ⇒ Boolean

Whether this chain's inferred type should have nil added to it because a &. earlier in the chain might have short-circuited evaluation to nil.

A &. only makes the immediate call nil-or-normal-result; a later, non-safe-navigated call in the same chain is still invoked on whatever that produced. If receiver is nil at that point, Ruby calls the method on nil itself instead of skipping it - so nil only continues to flow through subsequent links that NilClass defines as returning self (e.g., #tap, #itself). Any other subsequent call resolves to a concrete, non-nil-including type (e.g. NilClass#== returns Boolean), and nil no longer needs to be tracked past that point (unless a later &. reintroduces it).

Parameters:

Returns:

  • (Boolean) 


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# File 'lib/solargraph/source/chain.rb', line 219

def nullable? api_map
  currently_nullable = false
  links.each do |link|
    if link.nullable?
      currently_nullable = true
      next
    end
    next unless currently_nullable
    next unless link.is_a?(Chain::Call)

    pin = api_map.get_method_stack('NilClass', link.word, scope: :instance).first
    # @sg-ignore Need to add nil check here
    currently_nullable = pin.nil? || pin.return_type.tag == 'self'
  end
  currently_nullable
end

#splat? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/solargraph/source/chain.rb', line 198

def splat?
  @splat
end

#to_s ⇒ Object 



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# File 'lib/solargraph/source/chain.rb', line 243

def to_s
  desc
end

#undefined? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/solargraph/source/chain.rb', line 185

def undefined?
  links.any?(&:undefined?)
end