Class: YARD::Parser::Ruby::AstNode

Inherits:
Array
  • Object
show all
Defined in:
lib/yard/parser/ruby/ast_node.rb

Overview

An AST node is characterized by a type and a list of children. It is most easily represented by the s-expression #s such as:

# AST for "if true; 5 end":
s(s(:if, s(:var_ref, s(:kw, "true")), s(s(:int, "5")), nil))

The node type is not considered part of the list, only its children. So +ast+ does not refer to the type, but rather the first child (or object). Items that are not AstNode objects can be part of the list, like Strings or Symbols representing names. To return only the AstNode children of the node, use #children.

Constant Summary

KEYWORDS =

List of all known keywords

{:class => true, :alias => true, :lambda => true, :do_block => true,
:def => true, :defs => true, :begin => true, :rescue => true, :rescue_mod => true,
:if => true, :if_mod => true, :else => true, :elsif => true, :case => true,
:when => true, :next => true, :break => true, :retry => true, :redo => true,
:return => true, :throw => true, :catch => true, :until => true, :until_mod => true,
:while => true, :while_mod => true, :yield => true, :yield0 => true, :zsuper => true,
:unless => true, :unless_mod => true, :for => true, :super => true, :return0 => true}

Instance Attribute Summary collapse

Creating an AstNode collapse

Traversing a Node collapse

Node Meta Types collapse

Getting Line Information collapse

Printing a Node collapse

Managing node state collapse

Instance Method Summary collapse

Constructor Details

#initialize(type, arr, opts = {}) ⇒ AstNode

Creates a new AST node

Options Hash (opts):

  • :line (Fixnum) — default: nil

    the line the node starts on in source

  • :char (String) — default: nil

    the character number the node starts on in source

  • :listline (Fixnum) — default: nil

    a special key like :line but for list nodes

  • :listchar (Fixnum) — default: nil

    a special key like :char but for list nodes

  • :token (Boolean) — default: nil

    whether the node represents a token



153
154
155
156
157
158
159
160
161
162
# File 'lib/yard/parser/ruby/ast_node.rb', line 153

def initialize(type, arr, opts = {})
  super(arr)
  self.type = type
  self.line_range = opts[:line]
  self.source_range = opts[:char]
  @fallback_line = opts[:listline]
  @fallback_source = opts[:listchar]
  @token = true if opts[:token]
  @docstring = nil
end

Instance Attribute Details

#docstringObject Also known as: comments

Returns the value of attribute docstring



43
44
45
# File 'lib/yard/parser/ruby/ast_node.rb', line 43

def docstring
  @docstring
end

#docstring_hash_flagObject Also known as: comments_hash_flag

Returns the value of attribute docstring_hash_flag



42
43
44
# File 'lib/yard/parser/ruby/ast_node.rb', line 42

def docstring_hash_flag
  @docstring_hash_flag
end

#docstring_rangeObject Also known as: comments_range

Returns the value of attribute docstring_range



43
44
45
# File 'lib/yard/parser/ruby/ast_node.rb', line 43

def docstring_range
  @docstring_range
end

#fileString



76
77
78
79
# File 'lib/yard/parser/ruby/ast_node.rb', line 76

def file
  return parent.file if parent
  @file
end

#full_sourceString



82
83
84
85
86
# File 'lib/yard/parser/ruby/ast_node.rb', line 82

def full_source
  return parent.full_source if parent
  return @full_source if @full_source
  return IO.read(@file) if file && File.exist?(file)
end

#groupObject

Deprecated.

Groups are now defined by directives



47
48
49
# File 'lib/yard/parser/ruby/ast_node.rb', line 47

def group
  @group
end

#line_rangeRange



70
71
72
73
# File 'lib/yard/parser/ruby/ast_node.rb', line 70

def line_range
  reset_line_info unless @line_range
  @line_range
end

#parentAstNode?



59
60
61
# File 'lib/yard/parser/ruby/ast_node.rb', line 59

def parent
  @parent
end

#sourceString



89
90
91
# File 'lib/yard/parser/ruby/ast_node.rb', line 89

def source
  @source
end

#source_rangeRange



63
64
65
66
# File 'lib/yard/parser/ruby/ast_node.rb', line 63

def source_range
  reset_line_info unless @source_range
  @source_range
end

#typeSymbol



56
57
58
# File 'lib/yard/parser/ruby/ast_node.rb', line 56

def type
  @type
end

Class Method Details

.node_class_for(type) ⇒ Class

Finds the node subclass that should be instantiated for a specific node type



111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
# File 'lib/yard/parser/ruby/ast_node.rb', line 111

def self.node_class_for(type)
  case type
  when :params
    ParameterNode
  when :call, :fcall, :vcall, :command, :command_call
    MethodCallNode
  when :if, :elsif, :if_mod, :unless, :unless_mod
    ConditionalNode
  when :for, :while, :while_mod, :until, :until_mod
    LoopNode
  when :def, :defs
    MethodDefinitionNode
  when :class, :sclass
    ClassNode
  when :module
    ModuleNode
  else
    if type.to_s =~ /_ref\Z/
      ReferenceNode
    elsif type.to_s =~ /_literal\Z/
      LiteralNode
    elsif KEYWORDS.key?(type)
      KeywordNode
    else
      AstNode
    end
  end
end

Instance Method Details

#block?Boolean



260
261
262
# File 'lib/yard/parser/ruby/ast_node.rb', line 260

def block?
  respond_to?(:block) || condition?
end

#call?Boolean



240
241
242
# File 'lib/yard/parser/ruby/ast_node.rb', line 240

def call?
  false
end

#childrenArray<AstNode>



199
200
201
# File 'lib/yard/parser/ruby/ast_node.rb', line 199

def children
  @children ||= select {|e| AstNode === e }
end

#condition?Boolean



250
251
252
# File 'lib/yard/parser/ruby/ast_node.rb', line 250

def condition?
  false
end

#def?Boolean



245
246
247
# File 'lib/yard/parser/ruby/ast_node.rb', line 245

def def?
  false
end

#first_lineString



277
278
279
# File 'lib/yard/parser/ruby/ast_node.rb', line 277

def first_line
  full_source.split(/\r?\n/)[line - 1].strip
end

#has_line?Boolean



267
268
269
# File 'lib/yard/parser/ruby/ast_node.rb', line 267

def has_line?
  @line_range ? true : false
end

#inspectString



322
323
324
325
# File 'lib/yard/parser/ruby/ast_node.rb', line 322

def inspect
  typeinfo = type && type != :list ? ':' + type.to_s + ', ' : ''
  's(' + typeinfo + map(&:inspect).join(", ") + ')'
end

#jump(*node_types) ⇒ AstNode, self

Searches through the node and all descendants and returns the first node with a type matching any of node_types, otherwise returns the original node (self).

Examples:

Returns the first method definition in a block of code

ast = YARD.parse_string("if true; def x; end end").ast
ast.jump(:def)
# => s(:def, s(:ident, "x"), s(:params, nil, nil, nil, nil,
#      nil), s(s(:void_stmt, )))

Returns first 'def' or 'class' statement

ast = YARD.parse_string("class X; def y; end end")
ast.jump(:def, :class).first
# =>

If the node types are not present in the AST

ast = YARD.parse("def x; end")
ast.jump(:def)


193
194
195
196
# File 'lib/yard/parser/ruby/ast_node.rb', line 193

def jump(*node_types)
  traverse {|child| return(child) if node_types.include?(child.type) }
  self
end

#kw?Boolean



235
236
237
# File 'lib/yard/parser/ruby/ast_node.rb', line 235

def kw?
  false
end

#lineFixnum



272
273
274
# File 'lib/yard/parser/ruby/ast_node.rb', line 272

def line
  line_range && line_range.first
end

#literal?Boolean



230
231
232
# File 'lib/yard/parser/ruby/ast_node.rb', line 230

def literal?
  false
end

#loop?Boolean



255
256
257
# File 'lib/yard/parser/ruby/ast_node.rb', line 255

def loop?
  false
end

#pretty_print(q) ⇒ nil



289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
# File 'lib/yard/parser/ruby/ast_node.rb', line 289

def pretty_print(q)
  objs = dup + [:__last__]
  objs.unshift(type) if type && type != :list

  options = []
  options << ['docstring', docstring] if @docstring
  if @source_range || @line_range
    options << ['line', line_range]
    options << ['source', source_range]
  end
  objs.pop if options.empty?

  q.group(3, 's(', ')') do
    q.seplist(objs, nil, :each) do |v|
      if v == :__last__
        q.seplist(options, nil, :each) do |arr|
          k, v2 = *arr
          q.group(3) do
            q.text k
            q.group(3) do
              q.text ': '
              q.pp v2
            end
          end
        end
      else
        q.pp v
      end
    end
  end
end

#ref?Boolean



225
226
227
# File 'lib/yard/parser/ruby/ast_node.rb', line 225

def ref?
  false
end

#showString



284
285
286
# File 'lib/yard/parser/ruby/ast_node.rb', line 284

def show
  "\t#{line}: #{first_line}"
end

#to_sObject

Returns the value of attribute source



53
54
55
# File 'lib/yard/parser/ruby/ast_node.rb', line 53

def source
  @source
end

#token?Boolean



219
220
221
# File 'lib/yard/parser/ruby/ast_node.rb', line 219

def token?
  @token
end

#traverse {|self,| ... } ⇒ void

This method returns an undefined value.

Traverses the object and yields each node (including descendants) in order.

Yields:

  • each descendant node in order

Yield Parameters:

  • self, (AstNode)

    or a child/descendant node



208
209
210
211
212
213
214
# File 'lib/yard/parser/ruby/ast_node.rb', line 208

def traverse
  nodes = [self]
  nodes.each.with_index do |node, index|
    yield node
    nodes.insert index + 1, *node.children
  end
end

#unfreezeObject

Resets node state in tree



330
331
332
# File 'lib/yard/parser/ruby/ast_node.rb', line 330

def unfreeze
  @children = nil
end