Ruby

Enhance keep_tokens option for RubyVM::AbstractSyntaxTree parsing methods

Implementation for Language Server Protocol (LSP) sometimes needs token information.
For example both m(1) and m(1, ) has same AST structure other than node locations
then it's impossible to check the existence of , from AST. However in later case,
it might be better to suggest variables list for the second argument.
Token information is important for such case.

This commit adds these methods.

• Add keep_tokens option for RubyVM::AbstractSyntaxTree.parse, .parse_file and .of
• Add RubyVM::AbstractSyntaxTree::Node#tokens which returns tokens for the node including tokens for descendants nodes.
• Add RubyVM::AbstractSyntaxTree::Node#all_tokens which returns all tokens for the input script regardless the receiver node.

[Feature #19070]

Impacts on memory usage and performance are below:

Memory usage:

$ cat test.rb root = RubyVM::AbstractSyntaxTree.parse_file(File.expand_path('../test/ruby/test_keyword.rb', __FILE__), keep_tokens: true) $ /usr/bin/time -f %Mkb /usr/local/bin/ruby -v ruby 3.2.0dev (2022-11-19T09:41:54Z 19070-keep_tokens d3af1b8057) [x86_64-linux] 11408kb # keep_tokens :false $ /usr/bin/time -f %Mkb /usr/local/bin/ruby test.rb 17508kb # keep_tokens :true $ /usr/bin/time -f %Mkb /usr/local/bin/ruby test.rb 30960kb 

Performance:

$ cat ../ast_keep_tokens.yml prelude: | src = <<~SRC module M class C def m1(a, b) 1 + a + b end end end SRC benchmark: without_keep_tokens: | RubyVM::AbstractSyntaxTree.parse(src, keep_tokens: false) with_keep_tokens: | RubyVM::AbstractSyntaxTree.parse(src, keep_tokens: true) $ make benchmark COMPARE_RUBY="./ruby" ARGS=../ast_keep_tokens.yml /home/kaneko.y/.rbenv/shims/ruby --disable=gems -rrubygems -I../benchmark/lib ../benchmark/benchmark-driver/exe/benchmark-driver \ --executables="compare-ruby::./ruby -I.ext/common --disable-gem" \ --executables="built-ruby::./miniruby -I../lib -I. -I.ext/common ../tool/runruby.rb --extout=.ext -- --disable-gems --disable-gem" \ --output=markdown --output-compare -v ../ast_keep_tokens.yml compare-ruby: ruby 3.2.0dev (2022-11-19T09:41:54Z 19070-keep_tokens d3af1b8057) [x86_64-linux] built-ruby: ruby 3.2.0dev (2022-11-19T09:41:54Z 19070-keep_tokens d3af1b8057) [x86_64-linux] warming up.. | |compare-ruby|built-ruby| |:--------------------|-----------:|---------:| |without_keep_tokens | 21.659k| 21.303k| | | 1.02x| -| |with_keep_tokens | 6.220k| 5.691k| | | 1.09x| -|