Module: TreeHaver::Backends::Prism

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

Overview

Note:

This backend only parses Ruby source code

Prism backend using Ruby's built-in Prism parser

This backend wraps Prism, Ruby's official parser (stdlib in Ruby 3.4+, available as a gem for 3.2+). Unlike tree-sitter backends which are language-agnostic runtime parsers, Prism is specifically designed for parsing Ruby source code.

Prism provides excellent error recovery, detailed location information, and is the future of Ruby parsing (used by CRuby, JRuby, TruffleRuby).

Examples:

Basic usage

parser = TreeHaver::Parser.new
parser.language = TreeHaver::Backends::Prism::Language.ruby
tree = parser.parse(ruby_source)
root = tree.root_node
puts root.type  # => "program_node"

See Also:

Defined Under Namespace

Classes: Comment, Language, Node, Parser, Tree

Class Method Summary collapse

Class Method Details

.available? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tree_haver/backends/prism.rb', line 39

def available?
  return @loaded if @load_attempted

  @load_attempted = true
  begin
    require 'prism'
    @loaded = true
  rescue LoadError
    @loaded = false
  rescue StandardError
    # simplecov:disable defensive code - StandardError during require is extremely rare
    @loaded = false
    # simplecov:enable
  end
  @loaded
end

.capabilities ⇒ Hash{Symbol => Object}

Get capabilities supported by this backend

Examples:

TreeHaver::Backends::Prism.capabilities
# => { backend: :prism, query: false, bytes_field: true, incremental: false, ruby_only: true, comment_support: :partial }

Returns:

  • (Hash{Symbol => Object}) —

    capability map



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# File 'lib/tree_haver/backends/prism.rb', line 71

def capabilities
  return {} unless available?

  {
    backend: :prism,
    query: false,           # Prism doesn't have tree-sitter-style queries (has pattern matching)
    bytes_field: true,      # Prism provides byte offsets via Location
    incremental: false,     # Prism doesn't support incremental parsing (yet)
    pure_ruby: false,       # Prism has native C extension (but also pure Ruby mode)
    ruby_only: true,        # Prism only parses Ruby source code
    error_tolerant: true,   # Prism has excellent error recovery
    comment_support: :partial,
    comment_attachment_hints: true
  }
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/prism.rb', line 60

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