Class: Expressir::Express::Visitor

Inherits:
Object
  • Object
show all
Defined in:
lib/expressir/express/visitor.rb

Defined Under Namespace

Classes: Ctx, SimpleCtx

Instance Method Summary collapse

Constructor Details

#initialize(source, include_source: nil) ⇒ Visitor

Returns a new instance of Visitor.

Parameters:

  • Rice-wrapped (::ExpressParser::TokenVector) —

    std::vector<TokenProxy>

  • include_source (Boolean) (defaults to: nil) —

    attach original source code to model elements



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# File 'lib/expressir/express/visitor.rb', line 83

def initialize(source, include_source: nil)
  @source = source
  @include_source = include_source

  @attached_remark_tokens = Set.new

  @visit_methods = private_methods.grep(/^visit_/).to_h do |name|
    rulename = name.to_s.sub(/^visit_/, "").gsub(/_([a-z])/) do
      $1.upcase
    end
    [rulename.to_sym, name.to_sym]
  end
end

Instance Method Details

#get_source(ctx) ⇒ Object 



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# File 'lib/expressir/express/visitor.rb', line 154

def get_source(ctx)
  a, b = get_source_pos ctx
  @source[a..(b - 1)].strip
end

#get_source_pos(ctx) ⇒ Object 



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# File 'lib/expressir/express/visitor.rb', line 133

def get_source_pos(ctx)
  ranges = case ctx
           when Ctx
             ctx.source_pos and return ctx.source_pos # cache
             ctx.values.map { |item| get_source_pos(item) }
           when SimpleCtx
             return nil unless ctx.data.respond_to? :offset

             [[ctx.data.offset, ctx.data.offset + ctx.data.length]]
           when Array
             ctx.map { |item| get_source_pos(item) }
           else
             raise Error::VisitorInvalidInputError.new("unknown type in Ctx tree: #{ctx}")
           end
  source_pos = ranges.compact.reduce do |item, acc|
    [[item[0], acc[0]].min, [item[1], acc[1]].max]
  end
  Ctx === ctx and ctx.source_pos = source_pos
  source_pos
end

#to_ctx(ast, name = :unnamed) ⇒ Object 



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# File 'lib/expressir/express/visitor.rb', line 97

def to_ctx(ast, name = :unnamed)
  case ast
  when Hash
    nodes = ast.to_h do |k, v|
      if k =~ /^listOf_(.*)$/
        itemkey = $1.to_sym
        ary = Array === v ? v : [v]
        [itemkey, to_ctx(ary.select do |v|
          v[itemkey]
        end.map { |v| v.slice(itemkey) })]
      else
        [k, to_ctx(v, k)]
      end
    end
    Ctx.new nodes, name
  when Array
    ast.map do |element|
      # Each array element should have exactly one key-value pair
      unless element.length == 1
        raise Error::VisitorInvalidInputError.new("Invalid array element: expected single key-value pair, got #{element.keys}")
      end

      # Extract the single key and value
      key = element.keys[0]
      value = element.values[0]

      # Create context with the value and name it after the key
      to_ctx(value, key)
    end
  when nil
    nil
  else
    SimpleCtx.new ast, name
  end
end

#visit(ctx) ⇒ Object 



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# File 'lib/expressir/express/visitor.rb', line 165

def visit(ctx)
  if Array === ctx
    return ctx.map { |el| visit el }
  end

  node = ctx
  if @visit_methods[ctx.name]
    node = send(@visit_methods[ctx.name], ctx)
    if @include_source && node.respond_to?(:source)
      node.source = get_source ctx
    end
  end

  attach_remarks(ctx, node)
  node
end

#visit_ast(ast, name) ⇒ Object 



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# File 'lib/expressir/express/visitor.rb', line 159

def visit_ast(ast, name)
  ctx = to_ctx(ast, name)

  visit ctx
end