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.
# File tmp/rubies/ruby-master/lib/prism/parse_result/newlines.rb, line 27
def initialize(lines)
# @type var lines: Integer
@lines = Array.new(1 + lines, false)
end
Create a new Newlines visitor with the given newline offsets.
# File tmp/rubies/ruby-master/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
Permit block/lambda nodes to mark newlines within themselves.
# File tmp/rubies/ruby-master/lib/prism/parse_result/newlines.rb, line 47
def visit_if_node(node)
node.newline_flag!(@lines)
super(node)
end
Mark if/unless nodes as newlines.
# File tmp/rubies/ruby-master/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
Permit statements lists to mark newlines within themselves.