Merge 295fe153ad into 527038ca23

README.md

@@ -10,7 +10,11 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1552 TILs and counting..._
+_1555 TILs and counting..._
+
+See some of the other learning resources I work on:
+- [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
+- [Vim Un-Alphabet](https://www.youtube.com/playlist?list=PL46-cKSxMYYCMpzXo6p0Cof8hJInYgohU)
 
 ---
 
@@ -403,9 +407,11 @@ _1552 TILs and counting..._
 
 - [Access Go Docs Offline](go/access-go-docs-offline.md)
 - [Add A Method To A Struct](go/add-a-method-to-a-struct.md)
+- [Basic Delve Debugging Session](go/basic-delve-debugging-session.md)
 - [Build For A Specific OS And Architecture](go/build-for-a-specific-os-and-architecture.md)
 - [Check If Cobra Flag Was Set](go/check-if-cobra-flag-was-set.md)
 - [Combine Two Slices](go/combine-two-slices.md)
+- [Connect To A SQLite Database](go/connect-to-a-sqlite-database.md)
 - [Create A Slice From An Array](go/create-a-slice-from-an-array.md)
 - [Detect If Stdin Comes From A Redirect](go/detect-if-stdin-comes-from-a-redirect.md)
 - [Deterministically Seed A Random Number Generator](go/deterministically-seed-a-random-number-generator.md)
@@ -1269,6 +1275,7 @@ _1552 TILs and counting..._
 - [Iterate With An Offset Index](ruby/iterate-with-an-offset-index.md)
 - [Include Extra Context In A Honeybadger Notify](ruby/include-extra-context-in-a-honeybadger-notify.md)
 - [Ins And Outs Of Pry](ruby/ins-and-outs-of-pry.md)
+- [Install Latest Version Of Ruby With asdf](ruby/install-latest-version-of-ruby-with-asdf.md)
 - [Invoking Rake Tasks Multiple Times](ruby/invoking-rake-tasks-multiple-times.md)
 - [IRB Has Built-In Benchmarking With Ruby 3](ruby/irb-has-built-in-benchmarking-with-ruby-3.md)
 - [Jump Out Of A Nested Context With Throw/Catch](ruby/jump-out-of-a-nested-context-with-throw-catch.md)
@@ -1301,6 +1308,7 @@ _1552 TILs and counting..._
 - [Question Mark Operator](ruby/question-mark-operator.md)
 - [Rake Only Lists Tasks With Descriptions](ruby/rake-only-lists-tasks-with-descriptions.md)
 - [Read The First Line From A File](ruby/read-the-first-line-from-a-file.md)
+- [Refer To Implicit Block Argument With It](ruby/refer-to-implicit-block-argument-with-it.md)
 - [Rendering ERB](ruby/rendering-erb.md)
 - [Replace The Current Process With An External Command](ruby/replace-the-current-process-with-an-external-command.md)
 - [Require Entire Gemfile In Pry Session](ruby/require-entire-gemfile-in-pry-session.md)
@@ -1856,11 +1864,11 @@ I shamelessly stole this idea from
 
 * [Today I Learned by Hashrocket](https://til.hashrocket.com)
 * [jwworth/til](https://github.com/jwworth/til)
-* [thoughtbot/til](https://github.com/thoughtbot/til)
+* [til.simonwillison.net](https://til.simonwillison.net/)
 
 ## License
 
-© 2015-2022 Josh Branchaud
+© 2015-2025 Josh Branchaud
 
 This repository is licensed under the MIT license. See `LICENSE` for
 details.

go/basic-delve-debugging-session.md

@@ -0,0 +1,63 @@
+# Basic Delve Debugging Session
+
+When using [delve](https://github.com/go-delve/delve) to debug a Go program,
+these are the series of things I usually find myself doing.
+
+First, I start running the program with `dlv` including any arguments after a `--` (in my case, the `solve` subcommand and a filename).
+
+```bash
+$ dlv debug . -- solve samples/001.txt
+```
+
+`dlv` starts up and is ready to run my program from the beginning. I'll need to
+set a couple breakpoints before continuing. I do this with the `break` command,
+specifying the filename and line number.
+
+```
+(dlv) break main.go:528
+Breakpoint 1 set at 0x10c1a5bea for main.traversePuzzleIterative() ./main.go:528
+(dlv) break main.go:599
+Breakpoint 2 set at 0x10c1a6dcc for main.traversePuzzleIterative() ./main.go:599 
+```
+
+Now I can continue which will run the program until hitting a breakpoint.
+
+```
+(dlv) continue
+> [Breakpoint 2] main.traversePuzzleIterative() ./main.go:599 (hits goroutine(1):1 total:1) (PC: 0x10c1a6dcc)
+   594:                                 }
+   595:                         }
+   596:
+   597:                         topStackFrame := stack[len(stack)-1]
+   598:                         // if the current stack frame has more values, try the next
+=> 599:                         if len(topStackFrame.PossibleValues) > 0 {
+   600:                                 nextValue := topStackFrame.PossibleValues[0]
+   601:                                 topStackFrame.PossibleValues = topStackFrame.PossibleValues[1:]
+   602:                                 topStackFrame.CurrValue = nextValue
+   603:
+   604:                                 // Undo the last placement and make a new one
+```
+
+I can see the context around the line we've stopped on. From here I can dig
+into the current state of the program by looking at local variables (`locals`)
+or printing out a specific value (`print someVar`). I can continue to step
+through the program line by line with `next` or eventually run `continue` to
+proceed to the next breakpoint.
+
+```
+(dlv) locals
+diagnostics = main.Diagnostics {BacktrackCount: 0, NodeVisitCount: 1, ValidityCheckCount: 2,...+2 more}
+stack = []main.StackData len: 1, cap: 1, [...]
+emptyCellPositions = [][]int len: 3, cap: 4, [...]
+emptyCellIndex = 1
+status = "Invalid"
+topStackFrame = main.StackData {RowIndex: 1, ColumnIndex: 7, PossibleValues: []int len: 8, cap: 8, [...],...+1 more}
+(dlv) print topStackFrame
+main.StackData {
+        RowIndex: 1,
+        ColumnIndex: 7,
+        PossibleValues: []int len: 8, cap: 8, [2,3,4,5,6,7,8,9],
+        CurrValue: 1,}
+(dlv) next
+> main.traversePuzzleIterative() ./main.go:600 (PC: 0x10c1a6dea)
+```

go/connect-to-a-sqlite-database.md

@@ -0,0 +1,50 @@
+# Connect To A SQLite Database
+
+Using the `database/sql` module and the `github.com/mattn/go-sqlite3` package,
+we can connect to a SQLite database and run some queries. In my case, I have a
+SQLite connection string exported to my environment, so I can access that with
+`os.Getenv`. It's a local SQLite file, `./test.db`.
+
+Calling `sql.Open`, I'm able to connect with a SQLite3 driver to the database
+at that connection string. The `setupDatabase` function returns that database
+connection pointer. Things like `Exec` and `QueryRow` can be called on `db`. I
+also need to make sure I close the connection to the database with a `defer`.
+
+Here is a full example of connecting to a local SQLite database and inserting a
+record:
+
+```go
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"os"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func setupDatabase() *sql.DB {
+	databaseString := os.Getenv("GOOSE_DBSTRING")
+	if len(databaseString) == 0 {
+		fmt.Println("Error retrieving `GOOSE_DBSTRING` from env")
+		os.Exit(1)
+	}
+	db, err := sql.Open("sqlite3", databaseString)
+	if err != nil {
+		fmt.Printf("Error opening database: %v\n", err)
+		os.Exit(1)
+	}
+
+	return db
+}
+
+func main() {
+	db := setupDatabase()
+	defer db.Close()
+
+	sql := `insert into users (name) values (?);`
+
+	db.Exec(sql, "Josh")
+}
+```

ruby/install-latest-version-of-ruby-with-asdf.md

@@ -0,0 +1,54 @@
+# Install Latest Version Of Ruby With asdf
+
+When I check the `asdf` Ruby plugin for known versions of Ruby:
+
+```bash
+$ asdf list-all ruby | fzf
+```
+
+I don't find the latest (`3.4`).
+
+I need to update the plugin. A newer version of the plugin will know about
+newer Ruby versions.
+
+```bash
+$ asdf plugin-update ruby
+```
+
+Now, if I run the `list-all` command again, I'll find the version I'm looking
+for — `3.4.1`.
+
+Now that `asdf` and I both know about the version to be installed, I can tell
+`asdf` to install it:
+
+```bash
+$ asdf install ruby 3.4.1
+```
+
+Now, if I check the current Ruby version, I'll see that it is still set to some
+other version.
+
+```bash
+$ ruby --version
+ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-darwin22]
+```
+
+I need to tell `asdf` to start using this newly installed version instead,
+either globally or locally.
+
+```bash
+$ # globally
+$ asdf global ruby 3.4.1
+$ # or locally
+$ asdf local ruby 3.4.1
+```
+
+And now I'm all set:
+
+```bash
+$ asdf current ruby
+ruby            3.4.1           /Users/jbranchaud/.tool-versions
+
+$ ruby --version
+ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [x86_64-darwin22]
+```

ruby/refer-to-implicit-block-argument-with-it.md

@@ -0,0 +1,43 @@
+# Refer To Implicit Block Argument With It
+
+One of the key features of the Ruby 3.4 release is the `it` implicit block
+argument.
+
+The vast majority of inline blocks defined in Ruby code receive a single block
+argument. Typically we name and reference a block argument explictly like so:
+
+```ruby
+items.map { |item| item * item }
+```
+
+Ruby likes to cut away excess syntax when possible. To that end, the implicit
+`it` block argument has been added. This is an identifier we can reference in
+the context of a block and its value is the current
+
+```ruby
+items = [1,2,3,4,5]
+
+squares = items.map { it * it }
+
+pp squares
+#=> [1, 4, 9, 16, 25]
+```
+
+Note: we cannot mix numbered parameters (`_1`, `_2`) with the `it` parameter.
+If we do, we'll get the following error:
+
+```ruby
+def method_using_block(a, b)
+  yield(a, b) if block_given?
+end
+
+puts method_using_block(4,5) { _2 ** _1 } #=> 625
+puts method_using_block(4,5) { _2 ** it }
+# it_block.rb:12: syntax error found (SyntaxError)
+#   10 |
+#   11 | puts method_using_block(4,5) { _2 ** _1 }
+# > 12 | ... it }
+#      |     ^~ `it` is not allowed when a numbered parameter is already used
+```
+
+[source](https://docs.ruby-lang.org/en/3.4/NEWS_md.html)