Class: TreeHaver::Backends::Citrus::Language

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/tree_haver/backends/citrus.rb

Overview

Citrus grammar wrapper

Unlike tree-sitter which loads compiled .so files, Citrus uses Ruby modules that define grammars. This class wraps a Citrus grammar module.

Examples:

# For TOML, use toml-rb's grammar
language = TreeHaver::Backends::Citrus::Language.new(TomlRB::Document)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(grammar_module) ⇒ Language

Returns a new instance of Language.

Parameters:

  • grammar_module (Module) —

    A Citrus grammar module with a parse method



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# File 'lib/tree_haver/backends/citrus.rb', line 100

def initialize(grammar_module)
  unless grammar_module.respond_to?(:parse)
    raise TreeHaver::NotAvailable,
      "Grammar module must respond to :parse. " \
        "Expected a Citrus grammar module (e.g., TomlRB::Document)."
  end
  @grammar_module = grammar_module
  @backend = :citrus
end

Instance Attribute Details

#backend ⇒ Symbol (readonly)

The backend this language is for

Returns:

  • (Symbol) 


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# File 'lib/tree_haver/backends/citrus.rb', line 97

def backend
  @backend
end

#grammar_module ⇒ Module (readonly)

The Citrus grammar module

Returns:

  • (Module) —

    Citrus grammar module (e.g., TomlRB::Document)



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# File 'lib/tree_haver/backends/citrus.rb', line 93

def grammar_module
  @grammar_module
end

Class Method Details

.from_library(path, symbol: nil, name: nil) ⇒ Object Also known as: from_path

Raises:



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# File 'lib/tree_haver/backends/citrus.rb', line 141

def from_library(path, symbol: nil, name: nil)
  raise TreeHaver::NotAvailable,
    "Citrus backend doesn't use shared libraries. " \
      "Use Citrus::Language.new(GrammarModule) instead."
end

Instance Method Details

#<=>(other) ⇒ Integer?

Compare languages for equality

Citrus languages are equal if they have the same backend and grammar_module. Grammar module uniquely identifies a Citrus language.

Parameters:

  • other (Object) —

    object to compare with

Returns:

  • (Integer, nil) —

    -1, 0, 1, or nil if not comparable



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# File 'lib/tree_haver/backends/citrus.rb', line 117

def <=>(other)
  return unless other.is_a?(Language)
  return unless other.backend == @backend

  # Compare by grammar_module name (modules are compared by object_id by default)
  @grammar_module.name <=> other.grammar_module.name
end

#hash ⇒ Integer

Hash value for this language (for use in Sets/Hashes)

Returns:

  • (Integer) 


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# File 'lib/tree_haver/backends/citrus.rb', line 127

def hash
  [@backend, @grammar_module.name].hash
end