From b61ca744e01d74c4fd185e5c1232e04f4840be16 Mon Sep 17 00:00:00 2001
From: "M.V. Hutz" <git@maximhutz.me>
Date: Sat, 7 Feb 2026 00:20:57 -0500
Subject: [PATCH] feat: documentation for cli

---
 internal/cli/cli.go         |  2 ++
 internal/cli/destination.go |  2 ++
 internal/cli/source.go      | 13 ++++++++-----
 3 files changed, 12 insertions(+), 5 deletions(-)
 create mode 100644 internal/cli/cli.go

diff --git a/internal/cli/cli.go b/internal/cli/cli.go
new file mode 100644
index 0000000..a1ec311
--- /dev/null
+++ b/internal/cli/cli.go
@@ -0,0 +1,2 @@
+// Package cli package provides various utilities to the 'lambda' program.
+package cli
diff --git a/internal/cli/destination.go b/internal/cli/destination.go
index 194dbeb..4917a12 100644
--- a/internal/cli/destination.go
+++ b/internal/cli/destination.go
@@ -14,6 +14,7 @@ type Destination interface {
 // An StdoutDestination writes to stdout.
 type StdoutDestination struct{}
 
+// Write outputs to standard output.
 func (d StdoutDestination) Write(data string) error {
 	fmt.Println(data)
 	return nil
@@ -22,6 +23,7 @@ func (d StdoutDestination) Write(data string) error {
 // A FileDestination writes to a file.
 type FileDestination struct{ Path string }
 
+// Write outputs to a file.
 func (d FileDestination) Write(data string) error {
 	return os.WriteFile(d.Path, []byte(data+"\n"), 0644)
 }
diff --git a/internal/cli/source.go b/internal/cli/source.go
index 0850258..70f72b0 100644
--- a/internal/cli/source.go
+++ b/internal/cli/source.go
@@ -5,20 +5,22 @@ import (
 	"os"
 )
 
-// A method of extracting input from the user.
+// A Source is a method of extracting input from the user.
 type Source interface {
-	// Fetch data from this source.
+	// Extract fetches data from this source.
 	Extract() (string, error)
 }
 
-// A source defined by a string.
+// A StringSource is defined by a string.
 type StringSource struct{ Data string }
 
+// Extract pulls input data from the internal string.
 func (s StringSource) Extract() (string, error) { return s.Data, nil }
 
-// A source pulling from standard input.
+// A StdinSource pulls from standard input.
 type StdinSource struct{}
 
+// Extract pulls input data from standard input.
 func (s StdinSource) Extract() (string, error) {
 	data, err := io.ReadAll(os.Stdin)
 	if err != nil {
@@ -28,9 +30,10 @@ func (s StdinSource) Extract() (string, error) {
 	return string(data), nil
 }
 
-// A source reading from a file.
+// A FileSource reads from a file.
 type FileSource struct{ Path string }
 
+// Extract pulls input data from the file source.
 func (s FileSource) Extract() (string, error) {
 	data, err := os.ReadFile(s.Path)
 	if err != nil {