Class: Tailor::Rulers::IndentationSpacesRuler::IndentationManager

Inherits:
Object
  • Object
show all
Includes:
LexerConstants, Logger::Mixin
Defined in:
lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb

Overview

Used for managing the state of indentation for some file/text. An object of this type has no knowledge of the file/text itself, but rather just manages indentation expectations based on the object’s user’s input, somewhat like a state machine.

For the sake of talking about indentation expectations, the docs here make mention of ‘levels’ of indentation. A level here is simply 1 * (number of spaces to indent); so if you’ve set (number of spaces to indent) to 2, saying something should be indented 1 level, is simply saying that it should be indented 2 spaces.

Constant Summary collapse

ENCLOSERS =

These are event names generated by the Lexer that signify indentation level should/could increase by 1.

Set.new [:on_lbrace, :on_lbracket, :on_lparen]
OPEN_EVENT_FOR =

Look-up table that allows for OPEN_EVENT_FOR[:on_rbrace].

{
  on_kw: :on_kw,
  on_rbrace: :on_lbrace,
  on_rbracket: :on_lbracket,
  on_rparen: :on_lparen
}

Constants included from LexerConstants

LexerConstants::CONTINUATION_KEYWORDS, LexerConstants::KEYWORDS_AND_MODIFIERS, LexerConstants::KEYWORDS_TO_INDENT, LexerConstants::LOOP_KEYWORDS, LexerConstants::MODIFIERS, LexerConstants::MULTILINE_OPERATORS

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Logger::Mixin

included

Constructor Details

#initialize(spaces) ⇒ IndentationManager

Returns a new instance of IndentationManager.

Parameters:

  • spaces (Fixnum) —

    The number of spaces each level of indentation should move in & out.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 47

def initialize(spaces)
  @spaces = spaces
  @proper = { this_line: 0, next_line: 0 }
  @actual_indentation = 0
  @indent_reasons = []

  start
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(meth, *args, &blk) ⇒ Boolean

Overriding to be able to call #multi_line_brackets?, #multi_line_braces?, and #multi_line_parens?, where each takes a single parameter, which is the lineno.

Returns:

  • (Boolean) 


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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 363

def method_missing(meth, *args, &blk)
  if meth.to_s =~ /^multi_line_(.+)\?$/
    token = case $1
    when 'brackets' then '['
    when 'braces' then '{'
    when 'parens' then '('
    else
      super(meth, *args, &blk)
    end

    lineno = args.first

    tokens = @indent_reasons.find_all do |t|
      t[:token] == token
    end

    log "#{meth} called, but no #{$1} were found." if tokens.empty?
    return false if tokens.empty?

    token_on_this_line = tokens.find { |t| t[:lineno] == lineno }
    return true if token_on_this_line.nil?

    false
  else
    super(meth, *args, &blk)
  end
end

Instance Attribute Details

#actual_indentation ⇒ Fixnum (readonly)

Returns The actual number of characters the current line is indented.

Returns:

  • (Fixnum) —

    The actual number of characters the current line is indented.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 38

def actual_indentation
  @actual_indentation
end

#indent_reasons ⇒ Array<Hash> (readonly)

Returns Each element represents a reason why code should be indented. Indent levels are not necessarily 1:1 relationship to these reasons (hence the need for this class).

Returns:

  • (Array<Hash>) —

    Each element represents a reason why code should be indented. Indent levels are not necessarily 1:1 relationship to these reasons (hence the need for this class).



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 43

def indent_reasons
  @indent_reasons
end

Instance Method Details

#add_indent_reason(event_type, token, lineno) ⇒ Object

Adds to the list of reasons to indent the next line, then increases the expectation for the next line by @spaces.

Parameters:

  • event_type (Symbol) —

    The event type that caused the reason for indenting.

  • token (Tailor::Token, String) —

    The token that caused the reason for indenting.

  • lineno (Fixnum) —

    The line number the reason for indenting was discovered on.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 188

def add_indent_reason(event_type, token, lineno)
  @indent_reasons << {
    event_type: event_type,
    token: token,
    lineno: lineno,
    should_be_at: @proper[:this_line]
  }

  @proper[:next_line] = @indent_reasons.last[:should_be_at] + @spaces
  log "Added indent reason; it's now:"
  @indent_reasons.each { |r| log r.to_s }
end

#decrease_this_line ⇒ Object

Decreases the indentation expectation for the current line by 1 level.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 63

def decrease_this_line
  if started?
    @proper[:this_line] -= @spaces

    if @proper[:this_line] < 0
      @proper[:this_line] = 0
    end

    log "@proper[:this_line] = #{@proper[:this_line]}"
    log "@proper[:next_line] = #{@proper[:next_line]}"
  else
    log '#decrease_this_line called, but checking is stopped.'
  end
end

#in_an_enclosure? ⇒ Boolean

Determines if the current spot in the file is enclosed in braces, brackets, or parens.

Returns:

  • (Boolean) 


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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 161

def in_an_enclosure?
  return false if @indent_reasons.empty?

  i_reasons = @indent_reasons.dup
  log "i reasons: #{i_reasons}"

  until ENCLOSERS.include? i_reasons.last[:event_type]
    i_reasons.pop
    break if i_reasons.empty?
  end

  return false if i_reasons.empty?

  i_reasons.last[:event_type] == :on_lbrace ||
    i_reasons.last[:event_type] == :on_lbracket ||
    i_reasons.last[:event_type] == :on_lparen
end

#last_indent_reason_type ⇒ Object 



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 342

def last_indent_reason_type
  return if @indent_reasons.empty?

  @indent_reasons.last[:event_type]
end

#last_opening_event(closing_event_type) ⇒ Object

Returns the last matching opening event that corresponds to the closing_event_type.

Parameters:

  • closing_event_type (Symbol) —

    The closing event for which to find its associated opening event.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 334

def last_opening_event(closing_event_type)
  return nil if @indent_reasons.empty?

  @indent_reasons.reverse.find do |r|
    r[:event_type] == OPEN_EVENT_FOR[closing_event_type]
  end
end

#last_single_token_event ⇒ Object

A “single-token” event is one that that causes indentation expectations to increase. They don’t have have a paired closing reason like opening reasons. Instead, they’re determined to be done with their indenting when an :on_ignored_nl occurs. Single-token events are operators and commas (commas that aren’t used as separators in {, [, ( events).



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 321

def last_single_token_event
  return nil if @indent_reasons.empty?

  @indent_reasons.reverse.find do |r|
    !ENCLOSERS.include?(r[:event_type]) && r[:event_type] != :on_kw
  end
end

#line_ends_with_same_as_last(token_event) ⇒ Boolean

Checks to see if the last token in @single_tokens is the same as the one in token_event.

Parameters:

  • token_event (Array) —

    A single event (probably extracted from a LexedLine).

Returns:

  • (Boolean) 


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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 151

def line_ends_with_same_as_last(token_event)
  return false if @indent_reasons.empty?

  @indent_reasons.last[:event_type] == token_event[1]
end

#line_ends_with_single_token_indenter?(lexed_line) ⇒ Boolean

Checks if the current line ends with an operator, comma, or period.

Parameters:

Returns:

  • (Boolean) 


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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 137

def line_ends_with_single_token_indenter?(lexed_line)
  lexed_line.ends_with_op? ||
    lexed_line.ends_with_comma? ||
    lexed_line.ends_with_period? ||
    lexed_line.ends_with_label? ||
    lexed_line.ends_with_modifier_kw?
end

#remove_appropriate_reason(closing_event_type) ⇒ Object

Removes the last matching opening reason reason of event_type from the list of indent reasons.

Parameters:

  • closing_event_type (Symbol) —

    The closing event for which to find the matching opening event to remove from the list of indent reasons.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 293

def remove_appropriate_reason(closing_event_type)
  if last_opening_event = last_opening_event(closing_event_type)
    r_index = @indent_reasons.reverse.index(last_opening_event)
    index = @indent_reasons.size - r_index - 1
    tmp_reasons = []

    @indent_reasons.each_with_index do |r, i|
      tmp_reasons << r unless i == index
    end

    @indent_reasons.replace(tmp_reasons)
  elsif last_single_token_event
    log "Just popped off reason: #{@indent_reasons.pop}"
  else
    log "Couldn't find a matching opening reason to pop off...'"
    return
  end

  log "Removed indent reason; it's now:"
  @indent_reasons.each { |r| log r.to_s }
end

#remove_continuation_keywords ⇒ Object

Removes all continuation keywords from the list of indentation reasons.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 350

def remove_continuation_keywords
  return if @indent_reasons.empty?

  while CONTINUATION_KEYWORDS.include?(@indent_reasons.last[:token])
    log "Just popped off continuation reason: #{@indent_reasons.pop}"
  end
end

#should_be_at ⇒ Fixnum

Returns The indent level the file should currently be at.

Returns:

  • (Fixnum) —

    The indent level the file should currently be at.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 57

def should_be_at
  @proper[:this_line]
end

#start ⇒ Object

Starts the process of increasing/decreasing line indentation expectations.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 94

def start
  log 'Starting indentation ruling.'
  log "Next check should be at #{should_be_at}"
  @do_measurement = true
end

#started? ⇒ Boolean

Tells if the indentation checking process is on.

Returns:

  • (Boolean) —

    true if it’s started; false if not.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 103

def started?
  @do_measurement
end

#stop ⇒ Object

Stops the process of increasing/decreasing line indentation expectations.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 109

def stop
  if started?
    msg = "Stopping indentation ruling.  Should be: #{should_be_at}; "
    msg << "actual: #{@actual_indentation}"
    log msg
  end

  @do_measurement = false
end

#transition_lines ⇒ Object

Should be called just before moving to the next line. This sets the expectation set in @proper to @proper.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 81

def transition_lines
  if started?
    log 'Resetting change_this to 0.'
    log 'Setting @proper[:this_line] = that of :next_line'
    @proper[:this_line] = @proper[:next_line]
    log "Transitioning @proper[:this_line] to #{@proper[:this_line]}"
  else
    log 'Skipping #transition_lines; checking is stopped.'
  end
end

#update_actual_indentation(lexed_line_output) ⇒ Object

Updates @actual_indentation based on the given lexed_line_output.

Parameters:

  • lexed_line_output (Array) —

    The lexed output for the current line.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 122

def update_actual_indentation(lexed_line_output)
  if lexed_line_output.end_of_multi_line_string?
    log 'Found end of multi-line string.'
    return
  end

  first_non_space_element = lexed_line_output.first_non_space_element
  @actual_indentation = first_non_space_element.first.last
  log "Actual indentation: #{@actual_indentation}"
end

#update_for_closing_reason(event_type, lexed_line) ⇒ Object

A “closing reason” is a reason for indenting that also has an “opening reason”, such as a end, }, ], ).

Parameters:

  • event_type (Symbol) —

    The event type that is the closing reason.

  • lexed_line (Tailor::LexedLine) —

    The line that contains the closing reason.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 265

def update_for_closing_reason(event_type, lexed_line)
  remove_continuation_keywords
  remove_appropriate_reason(event_type)

  @proper[:next_line] = if @indent_reasons.empty?
    0
  else
    @indent_reasons.last[:should_be_at] + @spaces
  end

  log "Updated :next after closing; it's now #{@proper[:next_line]}"

  meth = "only_#{event_type.to_s.sub(/^on_/, '')}?"

  if lexed_line.send(meth.to_sym) || lexed_line.to_s =~ /^\s*end\n?$/
    @proper[:this_line] = [0, @proper[:this_line] - @spaces].max
    msg = 'End multi-line statement. '
    msg < "change_this -= 1 -> #{@proper[:this_line]}."
    log msg
  end
end

#update_for_continuation_reason(token, lexed_line, lineno) ⇒ Object

A “continuation reason” is a reason for indenting & outdenting that’s not an opening or closing reason, such as elsif, rescue, when (in a case statement), etc.

Parameters:

  • token (Symbol)
  • lexed_line (Tailor::LexedLine)
  • lineno (Fixnum) —

    The line number the opening reason was found on.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 233

def update_for_continuation_reason(token, lexed_line, lineno)
  d_tokens = @indent_reasons.dup
  d_tokens.pop
  on_line_token = d_tokens.find { |t| t[:lineno] == lineno }
  log "online token: #{on_line_token}"

  if on_line_token.nil? && lexed_line.to_s =~ /^\s*#{token}/
    @proper[:this_line] -= @spaces unless @proper[:this_line].zero?
    msg = "Continuation keyword: '#{token}'.  "
    msg << "change_this -= 1 -> #{@proper[:this_line]}"
    log msg
  end

  last_reason_line = @indent_reasons.find { |r| r[:lineno] == lineno }

  @proper[:next_line] = if last_reason_line.nil?
    if @indent_reasons.empty?
      @spaces
    else
      @indent_reasons.last[:should_be_at] + @spaces
    end
  else
    @indent_reasons.last[:should_be_at] - @spaces
  end
end

#update_for_opening_reason(event_type, token, lineno) ⇒ Object

An “opening reason” is a reason for indenting that also has a “closing reason”, such as a def, {, [, (.

Parameters:

  • event_type (Symbol) —

    The event type that is the opening reason.

  • token (Tailor::Token, String) —

    The token that is the opening reasons.

  • lineno (Fixnum) —

    The line number the opening reason was found on.



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# File 'lib/tailor/rulers/indentation_spaces_ruler/indentation_manager.rb', line 209

def update_for_opening_reason(event_type, token, lineno)
  if token.modifier_keyword?
    log "Found modifier in line: '#{token}'"
    return
  end

  log "Token '#{token}' not used as a modifier."

  if token.do_is_for_a_loop?
    log "Found keyword loop using optional 'do'"
    return
  end

  add_indent_reason(event_type, token, lineno)
end