Module: TreeHaver::Backends::Psych

Defined in:
lib/tree_haver/backends/psych.rb

Overview

Note:

This backend only parses YAML source code

Psych backend using Ruby’s built-in YAML parser

This backend wraps Psych, Ruby’s standard library YAML parser. Psych provides AST access via Psych.parse_stream which returns Psych::Nodes::* objects (Stream, Document, Mapping, Sequence, Scalar, Alias).

Examples:

Basic usage

parser = TreeHaver::Parser.new
parser.language = TreeHaver::Backends::Psych::Language.yaml
tree = parser.parse(yaml_source)
root = tree.root_node
puts root.type  # => "stream"

See Also:

Defined Under Namespace

Classes: Language, Node, Parser, Point, Tree

Class Method Summary collapse

Class Method Details

.available? ⇒ Boolean

Returns:

  • (Boolean) 


30
31
32
33
34
35
36
37
38
39
40
 
# File 'lib/tree_haver/backends/psych.rb', line 30

def available?
  return @loaded if @load_attempted
  @load_attempted = true
  begin
    require "psych"
    @loaded = true
  rescue LoadError
    @loaded = false
  end
  @loaded
end

.capabilities ⇒ Hash{Symbol => Object}

Get capabilities supported by this backend

Returns:

  • (Hash{Symbol => Object}) —

    capability map



54
55
56
57
58
59
60
61
62
63
64
65
 
# File 'lib/tree_haver/backends/psych.rb', line 54

def capabilities
  return {} unless available?
  {
    backend: :psych,
    query: false,           # Psych doesn't have tree-sitter-style queries
    bytes_field: false,     # Psych uses line/column, not byte offsets
    incremental: false,     # Psych doesn't support incremental parsing
    pure_ruby: false,       # Psych has native libyaml C extension
    yaml_only: true,        # Psych only parses YAML
    error_tolerant: false,  # Psych raises on syntax errors
  }
end

.reset! ⇒ void

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

This method returns an undefined value.

Reset the load state (primarily for testing)



46
47
48
49
 
# File 'lib/tree_haver/backends/psych.rb', line 46

def reset!
  @load_attempted = false
  @loaded = false
end