From 0fe17392bbfeee4a0e12d824493fbcd1442170b8 Mon Sep 17 00:00:00 2001
From: Stevan Freeborn <65925598+StevanFreeborn@users.noreply.github.com>
Date: Fri, 16 Jan 2026 14:53:35 -0600
Subject: [PATCH] talk: finish pres and yt script

---
 .../functional_options_pattern_in_go/index.md | 216 ++++++++++++++++++
 .../script.md                                 | 148 ++++++++++++
 2 files changed, 364 insertions(+)
 create mode 100644 slides/functional_options_pattern_in_go/index.md
 create mode 100644 slides/functional_options_pattern_in_go/script.md

diff --git a/slides/functional_options_pattern_in_go/index.md b/slides/functional_options_pattern_in_go/index.md
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+---
+theme: default
+layout: center
+class: text-center
+fonts:
+  sans: "CaskaydiaCove Nerd Font Mono"
+---
+
+# A Trick for Designing<br>Friendly APIs in Go
+
+---
+layout: center
+---
+
+# The Optional Configuration Problem
+
+```go
+// No defaults?
+// What is sensible?
+// What does 'true' do?
+// What is '30'?
+srv := NewServer("localhost", 8080, 30, true)
+```
+
+---
+layout: center 
+---
+
+# "We need to add a TLS parameter."
+
+```go
+func NewServer(host string, port int, timeout int) *Server {
+    // ...
+}
+```
+
+---
+layout: center 
+---
+
+# "Just use a struct"
+
+```go
+srv := NewServer(Config{
+    Host: "localhost",
+    Port: 0, 
+})
+```
+
+---
+layout: center 
+class: text-center
+---
+
+# "Nah bro, use functional options."
+
+---
+layout: center
+---
+
+# 1. Define the option
+
+```go
+type Server struct {
+    host string
+    port int
+}
+
+// Option is a function that modifies the Server
+type Option func(*Server)
+```
+
+---
+layout: center
+---
+
+# 2. Create closures
+
+```go
+// WithPort captures the 'port' value
+func WithPort(port int) Option {
+    // It returns a closure
+    return func(s *Server) {
+        s.port = port
+    }
+}
+
+func WithHost(h string) Option {
+    return func(s *Server) {
+        s.host = h
+    }
+}
+```
+
+---
+layout: center 
+class: text-center
+---
+
+# 3. Get variadic
+
+<div class="grid grid-cols-2 gap-10 text-left mt-10">
+<div>
+```go
+func NewServer(host string, port int) *Server {
+    return &Server{
+        host: host,
+        port: port,
+    }
+}
+```
+</div>
+<div>
+<v-click>
+```go
+func NewServer(opts ...Option) *Server {
+    
+    s := &Server{
+        host: "localhost", 
+        port: 80,
+    }
+
+    for _, opt := range opts {
+        opt(s)
+    }
+
+    return s
+}
+```
+</v-click>
+</div>
+</div>
+
+---
+layout: center 
+---
+
+# Almost as good as C#
+
+```go
+srv := NewServer(
+    WithHost("api.google.com"),
+    WithPort(9090),
+    WithTimeout(30 * time.Second),
+)
+```
+
+---
+layout: center
+class: text-center
+---
+
+# Extensibility? We got you.
+
+<div class="grid grid-cols-2 gap-10 text-left mt-10">
+<div>
+<v-click>
+Support TLS...
+```go
+func WithTLS(cert, key string) Option {
+    return func(s *Server) {
+        s.tls = true
+        s.cert = cert
+        s.key = key
+    }
+}
+```
+</v-click>
+</div>
+<div>
+<v-click>
+Breaks nothing.
+```go
+srv := NewServer(WithPort(8080))
+
+srv2 := NewServer(
+    WithPort(8080),
+    WithTLS("cert.pem", "key.pem"),
+)
+```
+</v-click>
+</div>
+</div>
+
+---
+layout: center 
+class: text-center
+---
+
+# So why use this pattern?
+
+<div class="text-left mx-auto w-max text-xl leading-10 flex flex-col">
+    <div>
+        <v-click>
+            <carbon:checkmark-filled class="text-green-500 mr-2"/> Defaults are easy (just call New)
+        </v-click>
+    </div>
+    <div>
+        <v-click>
+            <carbon:checkmark-filled class="text-green-500 mr-2"/> Usage is self-documenting
+        </v-click>
+    </div>
+    <div>
+        <v-click>
+            <carbon:checkmark-filled class="text-green-500 mr-2"/> New options don't break old code
+        </v-click>
+    </div>
+</div>
+
+---
+layout: center
+class: text-center
+---
+
+# <span class="text-[#00ADD8]">Go</span> forth and build friendly APIs!
+
diff --git a/slides/functional_options_pattern_in_go/script.md b/slides/functional_options_pattern_in_go/script.md
new file mode 100644
index 0000000..6808eb0
--- /dev/null
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+# Script: A Trick for Designing Friendly APIs in Go
+
+---
+
+### The Hook (The Pain)
+
+**[VISUAL: Face Camera]**
+
+"There is nothing worse than opening a codebase, finding a constructor, and seeing a list of magic numbers and boolean flags."
+
+"You know the ones. `NewServer(true, 30, false)`."
+
+"What is true? What is 30? Is false good or bad? You have to go read the definition just to understand the call site. It’s a bad developer experience."
+
+---
+
+### The Problem
+
+**[VISUAL: Slide 2 - The Optional Configuration Problem]**
+
+"This is the problem we are trying to solve. The 'Optional Configuration' problem."
+
+"Go doesn't support method overloading like C# or Java. So when you write a constructor like `NewServer`, you’re stuck with that signature."
+
+"If you have optional parameters—like a timeout or a verbose flag—you end up forcing the user to pass `0` or `nil` or `true` just to satisfy the compiler."
+
+---
+
+### The Breaking Change
+
+**[VISUAL: Slide 3 - "We need to add a TLS parameter"]**
+
+"And it gets worse when requirements change. Let's say six months later, you need to add TLS support."
+
+"If you just add a parameter to the function, you have now broken every single place in your application where `NewServer` was called. You have to go refactor the entire world just to add one optional setting."
+
+---
+
+### The "Okay" Alternative
+
+**[VISUAL: Slide 4 - "Just use a struct"]**
+
+"Now, the common response is: 'Just use a config struct.'"
+
+"And honestly? This is fine. It's better than magic numbers. But it has a flaw: Ambiguity around zero values."
+
+"If I pass `Port: 0` in that config... do I mean 'Please bind to a random available port'? Or do I mean 'I forgot to set this, please use the default port 80'?"
+
+"Distinguishing between 'default' and 'intentionally zero' is annoying with structs."
+
+---
+
+### The Solution
+
+**[VISUAL: Slide 5 - "Nah bro, functional options"]**
+
+"So, the Go community settled on a better pattern. Functional Options."
+
+"It looks a little scary at first because it uses closures, but once you get it, you’ll never go back."
+
+---
+
+### Step 1: The Type
+
+**[VISUAL: Slide 6 - 1. Define the option]**
+
+"Step one: We define our Server struct, but we keep the fields unexported."
+
+"Then, we define a type—let's call it `Option`. An `Option` is just a function that takes a pointer to your Server and modifies it. It returns nothing."
+
+---
+
+### Step 2: The Closures
+
+**[VISUAL: Slide 7 - 2. Create closures]**
+
+"Step two: We create 'Constructor' functions that return that `Option` type."
+
+"This is where the magic happens. Look at `WithPort`. It takes an integer, and it returns a closure that *captures* that integer."
+
+"When that inner function eventually runs, it will apply that specific port to the server."
+
+---
+
+### 2:45 - Step 3: The Variadic Constructor
+
+**[VISUAL: Slide 8 - 3. Get variadic]**
+
+"Step three: The Constructor."
+
+"Instead of taking a fixed list of arguments, we take a variadic slice of our `Option` type."
+
+**[CLICK to reveal the implementation]**
+
+"Inside the constructor, we do three things:"
+1.  "We initialize the server with sensible **defaults**. (Host is localhost, Port is 80)."
+2.  "We loop through the provided options and execute them. This overwrites the defaults with whatever the user provided."
+3.  "We return the server."
+
+---
+
+### The Result
+
+**[VISUAL: Slide 9 - Almost as good as C#]**
+
+"The result is a beautiful API usage."
+
+"For my C# friends out there, this feels a lot like Named Parameters. It reads like a sentence: `NewServer, WithHost, WithPort`."
+
+"I don't need to know what the default timeout is. I don't need to pass `nil` for things I don't care about. I just declare what I want to change."
+
+---
+
+### Extensibility
+
+**[VISUAL: Slide 10 - Extensibility? We got you.]**
+
+"But the killer feature is extensibility."
+
+**[CLICK to reveal WithTLS]**
+
+"Let's go back to that TLS requirement. I can add a `WithTLS` option function..."
+
+**[CLICK to reveal usage]**
+
+"...and I don't break a single existing line of code. `srv` (the first one) still compiles perfectly. `srv2` uses the new feature. Backward compatibility is preserved."
+
+---
+
+### Summary
+
+**[VISUAL: Slide 11 - So why use this pattern?]**
+
+"To recap, why should you use this?"
+
+**[CLICK]** "1. Defaults are easy. You define them once in the constructor, and the user never has to think about them."
+**[CLICK]** "2. It's self-documenting. No more `true, false, 30`."
+**[CLICK]** "3. It's future-proof. You can add new options forever without breaking your consumers."
+
+---
+
+### Outro
+
+**[VISUAL: Slide 12 - Go forth...]**
+
+"This is the standard for a reason. If you're building a library or a package in Go, treat your users nicely. Use Functional Options."
+
+"I'll see you in the next one."