feat: better structured internal

internal/cli/arguments.go

@@ -5,18 +5,24 @@ import (
 	"fmt"
 )
 
+// Arguments given to program.
 type CLIOptions struct {
-	Input       string
-	Verbose     bool
+	// The source code given to the program.
+	Input string
+	// Whether or not to print debug logs.
+	Verbose bool
+	// Whether or not to print an explanation of the reduction.
 	Explanation bool
 }
 
-func ParseOptions(args []string) (*CLIOptions, error) {
-	// Parse flags and arguments.
+// Extract the program configuration from the command-line arguments.
+func ParseOptions() (*CLIOptions, error) {
+	// Parse flags.
 	verbose := flag.Bool("v", false, "Verbosity. If set, the program will print logs.")
 	explanation := flag.Bool("x", false, "Explanation. Whether or not to show all reduction steps.")
 	flag.Parse()
 
+	// Parse non-flag arguments.
 	if flag.NArg() == 0 {
 		return nil, fmt.Errorf("No input given.")
 	} else if flag.NArg() > 1 {

internal/cli/exit.go

@@ -5,6 +5,8 @@ import (
 	"os"
 )
 
+// A helper function to handle errors in the program. If it is given an error,
+// the program will exist, and print the error.
 func HandleError(err error) {
 	if err == nil {
 		return
@@ -12,4 +14,4 @@ func HandleError(err error) {
 
 	fmt.Fprintln(os.Stderr, err)
 	os.Exit(1)
-}
+}

internal/cli/logger.go

@@ -1,21 +0,0 @@
-package cli
-
-import (
-	"log/slog"
-	"os"
-)
-
-func GetLogger(o CLIOptions) *slog.Logger {
-	var level slog.Level
-	if o.Verbose {
-		level = slog.LevelInfo
-	} else {
-		level = slog.LevelError
-	}
-
-	return slog.New(
-		slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
-			Level: level,
-		}),
-	)
-}

internal/cli/read.go

@@ -1,15 +0,0 @@
-package cli
-
-import (
-	"io"
-	"os"
-)
-
-func ReadInput() (string, error) {
-	data, err := io.ReadAll(os.Stdin)
-	if err != nil {
-		return "", err
-	}
-
-	return string(data), nil
-}