class Prism::ParseResult::Newlines

The :line tracepoint event gets fired whenever the Ruby VM encounters an expression on a new line. The types of expressions that can trigger this event are:

if statements
unless statements
nodes that are children of statements lists

In order to keep track of the newlines, we have a list of offsets that come back from the parser. We assign these offsets to the first nodes that we find in the tree that are on those lines.

Note that the logic in this file should be kept in sync with the Java MarkNewlinesVisitor, since that visitor is responsible for marking the newlines for JRuby/TruffleRuby.

This file is autoloaded only when mark_newlines! is called, so the re-opening of the various nodes in this file will only be performed in that case. We do that to avoid storing the extra @newline instance variable on every node if we don’t need it.

Public Class Methods

new(lines) click to toggle source

Create a new Newlines visitor with the given newline offsets.

# File lib/prism/parse_result/newlines.rb, line 27
def initialize(lines)
  # @type var lines: Integer
  @lines = Array.new(1 + lines, false)
end

Public Instance Methods

visit_block_node(node) click to toggle source

Permit block/lambda nodes to mark newlines within themselves.

Calls superclass method

# File lib/prism/parse_result/newlines.rb, line 33
def visit_block_node(node)
  old_lines = @lines
  @lines = Array.new(old_lines.size, false)

  begin
    super(node)
  ensure
    @lines = old_lines
  end
end

Also aliased as: visit_lambda_node

visit_if_node(node) click to toggle source

Mark if/unless nodes as newlines.

Calls superclass method

# File lib/prism/parse_result/newlines.rb, line 47
def visit_if_node(node)
  node.newline_flag!(@lines)
  super(node)
end

Also aliased as: visit_unless_node

visit_lambda_node(node)

Alias for: visit_block_node

visit_statements_node(node) click to toggle source

Permit statements lists to mark newlines within themselves.

Calls superclass method

# File lib/prism/parse_result/newlines.rb, line 55
def visit_statements_node(node)
  node.body.each do |child|
    child.newline_flag!(@lines)
  end
  super(node)
end

visit_unless_node(node)

Alias for: visit_if_node