talk: finish pres and yt script

slides/functional_options_pattern_in_go/index.md

@@ -0,0 +1,216 @@
+---
+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!
+