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, Tree

Constant Summary collapse

Point =

Alias Point to the base class for compatibility

TreeHaver::Base::Point

Class Method Summary collapse

Class Method Details

.available? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tree_haver/backends/psych.rb', line 30

def available?
  return @loaded if @load_attempted # rubocop:disable ThreadSafety/ClassInstanceVariable
  @load_attempted = true # rubocop:disable ThreadSafety/ClassInstanceVariable
  begin
    require "psych"
    @loaded = true # rubocop:disable ThreadSafety/ClassInstanceVariable
  rescue LoadError
    @loaded = false # rubocop:disable ThreadSafety/ClassInstanceVariable
  rescue StandardError
    # :nocov: defensive code - StandardError during require is extremely rare
    @loaded = false # rubocop:disable ThreadSafety/ClassInstanceVariable
    # :nocov:
  end
  @loaded # rubocop:disable ThreadSafety/ClassInstanceVariable
end

.capabilities ⇒ Hash{Symbol => Object}

Get capabilities supported by this backend

Returns:

  • (Hash{Symbol => Object}) —

    capability map



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# File 'lib/tree_haver/backends/psych.rb', line 58

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)



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# File 'lib/tree_haver/backends/psych.rb', line 50

def reset!
  @load_attempted = false # rubocop:disable ThreadSafety/ClassInstanceVariable
  @loaded = false # rubocop:disable ThreadSafety/ClassInstanceVariable
end