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