Class: SyntaxTree::Formatter

Inherits:
PrettierPrint
  • Object
show all
Defined in:
lib/syntax_tree/formatter.rb

Overview

A slightly enhanced PP that knows how to format recursively including comments.

Constant Summary collapse

OPTIONS =

We want to minimize as much as possible the number of options that are available in syntax tree. For the most part, if users want non-default formatting, they should override the format methods on the specific nodes themselves. However, because of some history with prettier and the fact that folks have become entrenched in their ways, we decided to provide a small amount of configurability.

Note that we’re keeping this in a global-ish hash instead of just overriding methods on classes so that other plugins can reference this if necessary. For example, the RBS plugin references the quote style.

{
  quote: "\"",
  trailing_comma: false,
  target_ruby_version: Gem::Version.new(RUBY_VERSION)
}
COMMENT_PRIORITY = 
1
HEREDOC_PRIORITY = 
2

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source, *args, quote: OPTIONS[:quote], trailing_comma: OPTIONS[:trailing_comma], target_ruby_version: OPTIONS[:target_ruby_version]) ⇒ Formatter

Returns a new instance of Formatter.



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# File 'lib/syntax_tree/formatter.rb', line 33

def initialize(
  source,
  *args,
  quote: OPTIONS[:quote],
  trailing_comma: OPTIONS[:trailing_comma],
  target_ruby_version: OPTIONS[:target_ruby_version]
)
  super(*args)

  @source = source
  @stack = []

  # Memoizing these values per formatter to make access faster.
  @quote = quote
  @trailing_comma = trailing_comma
  @target_ruby_version = target_ruby_version
end

Instance Attribute Details

#quote ⇒ Object (readonly)

These options are overridden in plugins to we need to make sure they are available here.



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# File 'lib/syntax_tree/formatter.rb', line 30

def quote
  @quote
end

#source ⇒ Object (readonly)

Returns the value of attribute source.



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# File 'lib/syntax_tree/formatter.rb', line 26

def source
  @source
end

#stack ⇒ Object (readonly)

Returns the value of attribute stack.



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# File 'lib/syntax_tree/formatter.rb', line 26

def stack
  @stack
end

#target_ruby_version ⇒ Object (readonly)

These options are overridden in plugins to we need to make sure they are available here.



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# File 'lib/syntax_tree/formatter.rb', line 30

def target_ruby_version
  @target_ruby_version
end

#trailing_comma ⇒ Object (readonly) Also known as: trailing_comma?

These options are overridden in plugins to we need to make sure they are available here.



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# File 'lib/syntax_tree/formatter.rb', line 30

def trailing_comma
  @trailing_comma
end

Class Method Details

.format(source, node) ⇒ Object 



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# File 'lib/syntax_tree/formatter.rb', line 51

def self.format(source, node)
  q = new(source, [])
  q.format(node)
  q.flush
  q.output.join
end

Instance Method Details

#format(node, stackable: true) ⇒ Object 



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# File 'lib/syntax_tree/formatter.rb', line 58

def format(node, stackable: true)
  stack << node if stackable
  doc = nil

  # If there are comments, then we're going to format them around the node
  # so that they get printed properly.
  if node.comments.any?
    trailing = []
    last_leading = nil

    # First, we're going to print all of the comments that were found before
    # the node. We'll also gather up any trailing comments that we find.
    node.comments.each do |comment|
      if comment.leading?
        comment.format(self)
        breakable(force: true)
        last_leading = comment
      else
        trailing << comment
      end
    end

    # If the node has a stree-ignore comment right before it, then we're
    # going to just print out the node as it was seen in the source.
    doc =
      if last_leading&.ignore?
        range = source[node.location.start_char...node.location.end_char]
        first = true

        range.each_line(chomp: true) do |line|
          if first
            first = false
          else
            breakable_return
          end

          text(line)
        end

        breakable_return if range.end_with?("\n")
      else
        node.format(self)
      end

    # Print all comments that were found after the node.
    trailing.each do |comment|
      line_suffix(priority: COMMENT_PRIORITY) do
        comment.inline? ? text(" ") : breakable
        comment.format(self)
        break_parent
      end
    end
  else
    doc = node.format(self)
  end

  stack.pop if stackable
  doc
end

#format_each(nodes) ⇒ Object 



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# File 'lib/syntax_tree/formatter.rb', line 118

def format_each(nodes)
  nodes.each { |node| format(node) }
end

#grandparent ⇒ Object 



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# File 'lib/syntax_tree/formatter.rb', line 122

def grandparent
  stack[-3]
end

#group ⇒ Object

This is a simplified version of prettyprint’s group. It doesn’t provide any of the more advanced options because we don’t need them and they take up expensive computation time.



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# File 'lib/syntax_tree/formatter.rb', line 137

def group
  contents = []
  doc = Group.new(0, contents: contents)

  groups << doc
  target << doc

  with_target(contents) { yield }
  groups.pop
  doc
end

#parent ⇒ Object 



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# File 'lib/syntax_tree/formatter.rb', line 126

def parent
  stack[-2]
end

#parents ⇒ Object 



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# File 'lib/syntax_tree/formatter.rb', line 130

def parents
  stack[0...-1].reverse_each
end

#seplist(list, sep = nil, iter_method = :each) ⇒ Object

A similar version to the super, except that it calls back into the separator proc with the instance of ‘self`.



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# File 'lib/syntax_tree/formatter.rb', line 151

def seplist(list, sep = nil, iter_method = :each)
  first = true
  list.__send__(iter_method) do |*v|
    if first
      first = false
    elsif sep
      sep.call(self)
    else
      comma_breakable
    end
    yield(*v)
  end
end

#text(string) ⇒ Object

This is a much simplified version of prettyprint’s text. It avoids calculating width by pushing the string directly onto the target.



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# File 'lib/syntax_tree/formatter.rb', line 167

def text(string)
  target << string
end