# frozen_string_literal: true
module Prism
class ParseResult
# 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.
class Newlines < Visitor
# Create a new Newlines visitor with the given newline offsets.
def initialize(newline_marked)
@newline_marked = newline_marked
end
# Permit block/lambda nodes to mark newlines within themselves.
def visit_block_node(node)
old_newline_marked = @newline_marked
@newline_marked = Array.new(old_newline_marked.size, false)
begin
super(node)
ensure
@newline_marked = old_newline_marked
end
end
alias_method :visit_lambda_node, :visit_block_node
# Mark if/unless nodes as newlines.
def visit_if_node(node)
node.set_newline_flag(@newline_marked)
super(node)
end
alias_method :visit_unless_node, :visit_if_node
# Permit statements lists to mark newlines within themselves.
def visit_statements_node(node)
node.body.each do |child|
child.set_newline_flag(@newline_marked)
end
super(node)
end
end
private_constant :Newlines
# Walk the tree and mark nodes that are on a new line.
def mark_newlines!
value.accept(Newlines.new(Array.new(1 + source.offsets.size, false)))
end
end
end
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