amazing-print/amazing_print

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lib/amazing_print/formatters/base_formatter.rb

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# frozen_string_literal: true

require_relative '../colorize'

module AmazingPrint
  module Formatters
    class BaseFormatter
      include Colorize

      DEFAULT_LIMIT_SIZE = 7

      # To support limited output, for example:
      #
      # ap ('a'..'z').to_a, :limit => 3
      # [
      #     [ 0] "a",
      #     [ 1] .. [24],
      #     [25] "z"
      # ]
      #
      # ap (1..100).to_a, :limit => true # Default limit is 7.
      # [
      #     [ 0] 1,
      #     [ 1] 2,
      #     [ 2] 3,
      #     [ 3] .. [96],
      #     [97] 98,
      #     [98] 99,
      #     [99] 100
      # ]
      #------------------------------------------------------------------------------
      def should_be_limited?
        options[:limit] || (options[:limit].is_a?(Integer) && options[:limit].positive?)
      end

      def get_limit_size
        case options[:limit]
        when true
          DEFAULT_LIMIT_SIZE
        else
          options[:limit]
        end
      end

      def limited(data, width, is_hash: false)
        limit = get_limit_size
        if data.length <= limit
          data
        else
          # Calculate how many elements to be displayed above and below the separator.
          head = limit / 2
          tail = head - ((limit - 1) % 2)

          # Add the proper elements to the temp array and format the separator.
          temp = data[0, head] + [nil] + data[-tail, tail]

          temp[head] = if is_hash
                         "#{indent}#{data[head].strip} .. #{data[data.length - tail - 1].strip}"
                       else
                         "#{indent}[#{head.to_s.rjust(width)}] .. [#{data.length - tail - 1}]"
                       end

          temp
        end
      end

      def method_tuple(method)
        # See http://readruby.chengguangnan.com/methods#method-objects-parameters
        # (mirror: http://archive.is/XguCA#selection-3381.1-3381.11)
        args = method.parameters.inject([]) do |arr, (type, name)|
          name ||= (type == :block ? 'block' : "arg#{arr.size + 1}")
          arr << case type
                 when :req        then name.to_s
                 when :keyreq     then "#{name}:"
                 when :key        then "*#{name}:"
                 when :opt, :rest then "*#{name}"
                 when :block      then "&#{name}"
                 else '?'
                 end
        end

        # method.to_s formats to handle:
        #
        # #<Method: Fixnum#zero?>
        # #<Method: Fixnum(Integer)#years>
        # #<Method: User(#<Module:0x00000103207c00>)#_username>
        # #<Method: User(id: integer, username: string).table_name>
        # #<Method: User(id: integer, username: string)(ActiveRecord::Base).current>
        # #<Method: #<Class:0x100c567f>(ActiveRecord::Querying)#first>
        # #<UnboundMethod: Hello#world>
        # #<UnboundMethod: Hello#world() /home/hs/code/amazing_print/spec/methods_spec.rb:68>
        #
        if method.to_s =~ %r{(Unbound)*Method: ((#<)?[^/#]*)[#.]}
          unbound = Regexp.last_match(1) && '(unbound)'
          klass = Regexp.last_match(2)
          if klass && klass =~ /(\(\w+:\s.*?\))/ # Is this ActiveRecord-style class?
            klass.sub!(Regexp.last_match(1), '') # Yes, strip the fields leaving class name only.
          end

          owner = "#{klass}#{unbound}".gsub('(', ' (')
        end

        [method.name.to_s, "(#{args.join(', ')})", owner.to_s]
      end

      #
      # Indentation related methods
      #-----------------------------------------
      def indentation
        inspector.current_indentation
      end

      def indented(&blk)
        inspector.increase_indentation(&blk)
      end

      # precompute common indentations
      INDENT_CACHE = (0..100).map { |i| ' ' * i }.map(&:freeze).freeze

      def indent(n = indentation)
        INDENT_CACHE[n] || (' ' * n)
      end

      def outdent
        i = indentation - options[:indent].abs

        INDENT_CACHE[i] || (' ' * i)
      end

      def align(value, width)
        if options[:multiline]
          indent_option = options[:indent]
          effective_width = width + value.size - colorless_size(value)
          if indent_option.positive?
            value.rjust(effective_width)
          elsif indent_option.zero?
            "#{indent}#{value.ljust(effective_width)}"
          else
            "#{indent(indentation + indent_option)}#{value.ljust(effective_width)}"
          end
        else
          value
        end
      end

      def colorless_size(string)
        string.gsub(/\e\[[\d;]+m/, '').size
      end
    end
  end
end