Add Output Bytecode For A Ruby Program as a Ruby TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1510 TILs and counting..._
+_1511 TILs and counting..._
 
 ---
 
@@ -1249,6 +1249,7 @@ _1510 TILs and counting..._
 - [Navigate Back In The Browser With Capybara](ruby/navigate-back-in-the-browser-with-capybara.md)
 - [Next And Previous Floats](ruby/next-and-previous-floats.md)
 - [Or Operator Precedence](ruby/or-operator-precedence.md)
+- [Output Bytecode For A Ruby Program](ruby/output-bytecode-for-a-ruby-program.md)
 - [Override The Initial Sequence Value](ruby/override-the-initial-sequence-value.md)
 - [Parallel Bundle Install](ruby/parallel-bundle-install.md)
 - [Parse JSON Into An OpenStruct](ruby/parse-json-into-an-open-struct.md)

ruby/output-bytecode-for-a-ruby-program.md

@@ -0,0 +1,42 @@
+# Output Bytecode For A Ruby Program
+
+The `ruby` CLI comes with a flag to dump the disassembled YARV bytecode for the
+given Ruby program. This can be a fun way to explore how a Ruby program is
+interpreted under the hood.
+
+Aaron Patterson demoed this behavior during his RubyConf 2024 talk.
+
+Pass the `--dump` flag with `insns` along with either the path to your file or
+an inline bit of Ruby.
+
+Here is a really basic example:
+
+```bash
+❯ ruby --dump=insns -e '2 + 3'
+== disasm: #<ISeq:<main>@-e:1 (1,0)-(1,5)> (catch: false)
+0000 putobject                              2                         (   1)[Li]
+0002 putobject                              3
+0004 opt_plus                               <calldata!mid:+, argc:1, ARGS_SIMPLE>[CcCr]
+0006 leave
+```
+
+And another quite basic example, but with local variables this time:
+
+```bash
+❯ ruby --dump=insns -e 'x = 2; y = 3; x + y'
+== disasm: #<ISeq:<main>@-e:1 (1,0)-(1,19)> (catch: false)
+local table (size: 2, argc: 0 [opts: 0, rest: -1, post: 0, block: -1, kw: -1@-1, kwrest: -1])
+[ 2] x@0        [ 1] y@1
+0000 putobject                              2                         (   1)[Li]
+0002 setlocal_WC_0                          x@0
+0004 putobject                              3
+0006 setlocal_WC_0                          y@1
+0008 getlocal_WC_0                          x@0
+0010 getlocal_WC_0                          y@1
+0012 opt_plus                               <calldata!mid:+, argc:1, ARGS_SIMPLE>[CcCr]
+0014 leave
+```
+
+If you want to dig in to how to read everything that is going on in these
+outputs, I'd recommend checking out this [Advent of YARV
+series](https://kddnewton.com/2022/11/30/advent-of-yarv-part-0.html)