This class works in conjunction with Psych::Parser
to build an in-memory parse tree that represents a YAML document.
parser = Psych::Parser.new Psych::TreeBuilder.new parser.parse('--- foo') tree = parser.handler.root
See Psych::Handler
for documentation on the event methods used in this class.
Create a new TreeBuilder
instance
# File psych/lib/psych/tree_builder.rb, line 22 def initialize @stack = [] @last = nil @root = nil @start_line = nil @start_column = nil @end_line = nil @end_column = nil end
# File psych/lib/psych/tree_builder.rb, line 103 def alias anchor a = Nodes::Alias.new(anchor) set_location(a) @last.children << a a end
Handles end_document
events with version
, tag_directives
, and implicit
styling.
See Psych::Handler#start_document
# File psych/lib/psych/tree_builder.rb, line 77 def end_document implicit_end = !streaming? @last.implicit_end = implicit_end n = pop set_end_location(n) n end
# File psych/lib/psych/tree_builder.rb, line 90 def end_stream n = pop set_end_location(n) n end
# File psych/lib/psych/tree_builder.rb, line 33 def event_location(start_line, start_column, end_line, end_column) @start_line = start_line @start_column = start_column @end_line = end_line @end_column = end_column end
# File psych/lib/psych/tree_builder.rb, line 96 def scalar value, anchor, tag, plain, quoted, style s = Nodes::Scalar.new(value,anchor,tag,plain,quoted,style) set_location(s) @last.children << s s end
Handles start_document
events with version
, tag_directives
, and implicit
styling.
See Psych::Handler#start_document
# File psych/lib/psych/tree_builder.rb, line 65 def start_document version, tag_directives, implicit n = Nodes::Document.new version, tag_directives, implicit set_start_location(n) @last.children << n push n end