Support more ruby types

AGENTS.md

@@ -12,7 +12,20 @@ To run the test suite, execute:
 just test
 ```
 
-The tester executes a number of sample programs in `test/programs` and compares their outputs to the fixtures in `test/fixtures`.
+The test suite executes a number of sample programs in `test/programs` under
+the two separate recorders/tracers:
+
+* One based on a Ruby native extension in `gems/native-tracer`
+* Another based on pure Ruby code in `gems/pure-ruby-tracer`
+
+Their outputs are compared structurally to known good outputs stored
+in `test/fixtures`.
+
+When `just test` fails, I suggest running the two tracers directly and
+analyzing where their outputs differs.
+
+Please note that only the pure-ruby-tracer formats the output json for
+human readability. Thus, you must use `jq -S` when comparing the outputs.
 
 To run the benchmark, execute:
 

examples/selective_tracing.rb

@@ -1,6 +1,11 @@
 #!/usr/bin/env ruby
-ext_base = File.expand_path('../gems/native-tracer/ext/native_tracer/target/release/libcodetracer_ruby_recorder', __dir__)
-require ext_base
+
+# Load the native extension only if RubyRecorder is not already available
+# (e.g., when running directly without the codetracer wrapper)
+unless defined?(RubyRecorder)
+  ext_base = File.expand_path('../gems/native-tracer/ext/native_tracer/target/release/libcodetracer_ruby_recorder', __dir__)
+  require ext_base
+end
 
 recorder = RubyRecorder.new