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Class: Prism::ParseResult::Newlines

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, Visitor
Instance Chain:
self, Visitor
Inherits: Visitor
  • ::Object
Defined in: lib/prism/parse_result/newlines.rb

Overview

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.

Class Method Summary

Instance Method Summary

Constructor Details

.new(lines) ⇒ Newlines

Create a new Newlines visitor with the given newline offsets.

[ GitHub ]

  
# File 'lib/prism/parse_result/newlines.rb', line 36

def initialize(lines)
  @lines = Array.new(1 + lines, false)
end

Instance Method Details

#visit_block_node(node)

Permit block nodes to mark newlines within themselves.

[ GitHub ]

  
# File 'lib/prism/parse_result/newlines.rb', line 43

def visit_block_node(node)
  old_lines = @lines
  @lines = Array.new(old_lines.size, false)

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

#visit_if_node(node)

Mark if nodes as newlines.

[ GitHub ]

  
# File 'lib/prism/parse_result/newlines.rb', line 71

def visit_if_node(node)
  node.newline_flag!(@lines)
  super(node)
end

#visit_lambda_node(node)

Permit lambda nodes to mark newlines within themselves.

[ GitHub ]

  
# File 'lib/prism/parse_result/newlines.rb', line 57

def visit_lambda_node(node)
  old_lines = @lines
  @lines = Array.new(old_lines.size, false)

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

#visit_statements_node(node)

Permit statements lists to mark newlines within themselves.

[ GitHub ]

  
# File 'lib/prism/parse_result/newlines.rb', line 87

def visit_statements_node(node)
  node.body.each do |child|
    child.newline_flag!(@lines)
  end
  super(node)
end

#visit_unless_node(node)

Mark unless nodes as newlines.

[ GitHub ]

  
# File 'lib/prism/parse_result/newlines.rb', line 79

def visit_unless_node(node)
  node.newline_flag!(@lines)
  super(node)
end