RDoc::CrossReference is a reusable way to create cross references for names.

Methods
N
R
Constants
CLASS_REGEXP_STR = '\\\\?((?:\:{2})?[A-Z]\w*(?:\:\:\w+)*)'
 

Regular expression to match class references

  1. There can be a '\' in front of text to suppress the cross-reference

  2. There can be a '::' in front of class names to reference from the top-level namespace.

  3. The method can be followed by parenthesis (not recommended)
METHOD_REGEXP_STR = '([a-z]\w*[!?=]?)(?:\([\w.+*/=<>-]*\))?'
 

Regular expression to match method references.

See CLASS_REGEXP_STR
CROSSREF_REGEXP = /( # A::B::C.meth #{CLASS_REGEXP_STR}(?:[.#]|::)#{METHOD_REGEXP_STR} # Stand-alone method (preceded by a #) | \\?\##{METHOD_REGEXP_STR} # Stand-alone method (preceded by ::) | ::#{METHOD_REGEXP_STR} # A::B::C # The stuff after CLASS_REGEXP_STR is a # nasty hack. CLASS_REGEXP_STR unfortunately matches # words like dog and cat (these are legal "class" # names in Fortran 95). When a word is flagged as a # potential cross-reference, limitations in the markup # engine suppress other processing, such as typesetting. # This is particularly noticeable for contractions. # In order that words like "can't" not # be flagged as potential cross-references, only # flag potential class cross-references if the character # after the cross-reference is a space, sentence # punctuation, tag start character, or attribute # marker. | #{CLASS_REGEXP_STR}(?=[\s\)\.\?\!\,\;<\000]|\z) # Things that look like filenames # The key thing is that there must be at least # one special character (period, slash, or # underscore). | (?:\.\.\/)*[-\/\w]+[_\/\.][-\w\/\.]+ # Things that have markup suppressed # Don't process things like '\<' in \<tt>, though. # TODO: including < is a hack, not very satisfying. | \\[^\s<] )/x
 

Regular expressions matching text that should potentially have cross-reference links generated are passed to add_special. Note that these expressions are meant to pick up text for which cross-references have been suppressed, since the suppression characters are removed by the code that is triggered.
ALL_CROSSREF_REGEXP = /( # A::B::C.meth #{CLASS_REGEXP_STR}(?:[.#]|::)#{METHOD_REGEXP_STR} # Stand-alone method | \\?#{METHOD_REGEXP_STR} # A::B::C | #{CLASS_REGEXP_STR}(?=[\s\)\.\?\!\,\;<\000]|\z) # Things that look like filenames | (?:\.\.\/)*[-\/\w]+[_\/\.][-\w\/\.]+ # Things that have markup suppressed | \\[^\s<] )/x
 

Version of CROSSREF_REGEXP used when --hyperlink-all is specified.
Attributes
[RW] seen
Class Public methods
new(context)

Allows cross-references to be created based on the given context (RDoc::Context).

Source: show | on GitHub 

# File ../ruby/lib/rdoc/cross_reference.rb, line 94
def initialize context
  @context = context

  @seen = {}
end
Instance Public methods
resolve(name, text)

Returns a reference to name.

If the reference is found and name is not documented text will be returned. If name is escaped name is returned. If name is not found text is returned.

Source: show | on GitHub 

# File ../ruby/lib/rdoc/cross_reference.rb, line 107
def resolve name, text
  return @seen[name] if @seen.include? name

  # Find class, module, or method in class or module.
  #
  # Do not, however, use an if/elsif/else chain to do so.  Instead, test
  # each possible pattern until one matches.  The reason for this is that a
  # string like "YAML.txt" could be the txt() class method of class YAML (in
  # which case it would match the first pattern, which splits the string
  # into container and method components and looks up both) or a filename
  # (in which case it would match the last pattern, which just checks
  # whether the string as a whole is a known symbol).

  if /#{CLASS_REGEXP_STR}([.#]|::)#{METHOD_REGEXP_STR}/o =~ name then
    type = $2
    type = '' if type == '.'  # will find either #method or ::method
    method = "#{type}#{$3}"
    container = @context.find_symbol_module($1)
  elsif /^([.#]|::)#{METHOD_REGEXP_STR}/o =~ name then
    type = $1
    type = '' if type == '.'
    method = "#{type}#{$2}"
    container = @context
  else
    container = nil
  end

  if container then
    ref = container.find_local_symbol method

    unless ref || RDoc::TopLevel === container then
      ref = container.find_ancestor_local_symbol method
    end
  end

  ref = case name
        when /^\(#{CLASS_REGEXP_STR})$/o then
          ref = @context.find_symbol $1
        else
          ref = @context.find_symbol name
        end unless ref

  ref = nil if RDoc::Alias === ref # external alias: can't link to it

  out = if name == '\' then
          name
        elsif name =~ /^\/ then
          # we remove the \ only in front of what we know:
          # other backslashes are treated later, only outside of <tt>
          ref ? $' : name
        elsif ref then
          if ref.display? then
            ref
          else
            text
          end
        else
          text
        end

  @seen[name] = out

  out
end