class SyntaxSuggest::Visitor

Walks the Prism AST to extract structural info that cannot be reliably determined from tokens alone.

Such as the location of lines that must be logically joined so the search algorithm will treat them as one. Example:

source = <<~RUBY
  User                        # 1
    .where(name: "Earlopain") # 2
    .first                    # 3
RUBY
ast, _tokens = Prism.parse_lex(source).value
visitor = Visitor.new
visitor.visit(ast)
visitor.consecutive_lines # => Set[2, 1]

This output means that line 1 and line 2 need to be joined with their next line.

And determining the location of “endless” method definitions. For example:

source = <<~RUBY
  def cube(x)
    x * x * x
  end
  def square(x) = x * x # 1
RUBY

ast, _tokens = Prism.parse_lex(source).value
visitor = Visitor.new
visitor.visit(ast)
visitor.endless_def_keyword_offsets # => Set[28]

Attributes

consecutive_lines [R]

endless_def_keyword_offsets [R]

Public Class Methods

new ()

Source

# File lib/syntax_suggest/visitor.rb, line 38
def initialize
  @endless_def_keyword_offsets = Set.new
  @consecutive_lines = Set.new
end

Public Instance Methods

visit_call_node (node)

Source

# File lib/syntax_suggest/visitor.rb, line 45
def visit_call_node(node)
  receiver_loc = node.receiver&.location
  call_operator_loc = node.call_operator_loc
  message_loc = node.message_loc
  if receiver_loc && call_operator_loc && message_loc
    # dot-leading (dot on the next line)
    #   foo        # line 1 - consecutive
    #     .bar     # line 2
    if receiver_loc.end_line != call_operator_loc.start_line && call_operator_loc.start_line == message_loc.start_line
      (receiver_loc.end_line..call_operator_loc.start_line - 1).each do |line|
        @consecutive_lines << line
      end
    end

    # dot-trailing (dot on the same line as the receiver)
    #   foo.       # line 1 - consecutive
    #     bar      # line 2
    if receiver_loc.end_line == call_operator_loc.start_line && call_operator_loc.start_line != message_loc.start_line
      (call_operator_loc.start_line..message_loc.start_line - 1).each do |line|
        @consecutive_lines << line
      end
    end
  end
  super
end

Called by Prism::Visitor for every method-call node in the AST (e.g. foo.bar, foo.bar.baz).

Calls superclass method Prism::Visitor#visit_call_node

visit_def_node (node)

Source

# File lib/syntax_suggest/visitor.rb, line 75
def visit_def_node(node)
  @endless_def_keyword_offsets << node.def_keyword_loc.start_offset if node.equal_loc
  super
end

Called by Prism::Visitor for every def node in the AST. Records the keyword start location for endless method definitions like ‘def foo = 123`. These are valid without a matching end, so Token must exclude them when deciding if a line is a keyword.

Calls superclass method Prism::Visitor#visit_def_node