Class: Antlr4Native::VisitorGenerator

Inherits:
Object
  • Object
show all
Includes:
StringHelpers
Defined in:
lib/antlr4-native/visitor_generator.rb

Constant Summary collapse

VISITOR_METHOD_BLACKLIST = 
%w(visit visitChildren).freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from StringHelpers

#capitalize, #dasherize, #underscore

Constructor Details

#initialize(visitor_methods, antlr_ns, parser_ns) ⇒ VisitorGenerator

Returns a new instance of VisitorGenerator.



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# File 'lib/antlr4-native/visitor_generator.rb', line 9

def initialize(visitor_methods, antlr_ns, parser_ns)
  @visitor_methods = visitor_methods
  @antlr_ns = antlr_ns
  @parser_ns = parser_ns
end

Instance Attribute Details

#antlr_ns ⇒ Object (readonly)

Returns the value of attribute antlr_ns.



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# File 'lib/antlr4-native/visitor_generator.rb', line 7

def antlr_ns
  @antlr_ns
end

#parser_ns ⇒ Object (readonly)

Returns the value of attribute parser_ns.



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# File 'lib/antlr4-native/visitor_generator.rb', line 7

def parser_ns
  @parser_ns
end

#visitor_methods ⇒ Object (readonly)

Returns the value of attribute visitor_methods.



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# File 'lib/antlr4-native/visitor_generator.rb', line 7

def visitor_methods
  @visitor_methods
end

Instance Method Details

#class_name ⇒ Object 



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# File 'lib/antlr4-native/visitor_generator.rb', line 15

def class_name
  @class_name ||= 'Visitor'
end

#cpp_class_name ⇒ Object 



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# File 'lib/antlr4-native/visitor_generator.rb', line 19

def cpp_class_name
  @cpp_class_name ||= 'VisitorProxy'
end

#each_visitor_method ⇒ Object 



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# File 'lib/antlr4-native/visitor_generator.rb', line 23

def each_visitor_method
  return to_enum(__method__) unless block_given?

  visitor_methods.each do |visitor_method|
    yield visitor_method unless VISITOR_METHOD_BLACKLIST.include?(visitor_method)
  end
end

#visitor_proxy ⇒ Object 



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# File 'lib/antlr4-native/visitor_generator.rb', line 31

def visitor_proxy
  vms = each_visitor_method.flat_map do |visitor_method|
    context = "#{capitalize(visitor_method.sub(/\Avisit/, ''))}Context"

    [
      "  virtual antlrcpp::Any #{visitor_method}(#{parser_ns}::#{context} *ctx) override {",
      "    #{context}Proxy proxy(ctx);",
      "    return getSelf().call(\"#{underscore(visitor_method)}\", &proxy);",
      "  }\n"
    ]
  end

  <<~END
    class #{cpp_class_name} : public #{antlr_ns}BaseVisitor, public Director {
    public:
      #{cpp_class_name}(Object self) : Director(self) { }

      Object ruby_visit(ContextProxy* proxy) {
        auto result = visit(proxy -> getOriginal());
        try {
          return std::any_cast<Object>(result);
        } catch(std::bad_cast) {
          return Qnil;
        }
      }

      Object ruby_visitChildren(ContextProxy* proxy) {
        auto result = visitChildren(proxy -> getOriginal());
        try {
          return std::any_cast<Object>(result);
        } catch(std::bad_cast) {
          return Qnil;
        }
      }

    #{vms.join("\n")}
    };
  END
end

#visitor_proxy_methods(indent) ⇒ Object 



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# File 'lib/antlr4-native/visitor_generator.rb', line 71

def visitor_proxy_methods(indent)
  @visitor_proxy_methods ||= each_visitor_method.map do |visitor_method|
    "#{indent}.define_method(\"#{underscore(visitor_method)}\", &#{cpp_class_name}::ruby_visitChildren)"
  end
end