Name extendedGlob() anonymous functions

Moves inline function definitions out of the function.
Helps with code readability.

Signed-off-by: Sebastian Soto <ssoto@redhat.com>

copier/copier.go

@@ -51,7 +51,20 @@ func init() {
 // will be concatenated.
 // The matched paths are returned in lexical order, which makes the output deterministic.
 func extendedGlob(pattern string) (matches []string, err error) {
-	subdirs := func(dir string) []string {
+	patterns := expandPatterns(pattern)
+	for _, pattern := range patterns {
+		theseMatches, err := filepath.Glob(pattern)
+		if err != nil {
+			return nil, err
+		}
+		matches = append(matches, theseMatches...)
+	}
+	sort.Strings(matches)
+	return matches, nil
+}
+
+// subDirs returns a recursive search of all directories under the given dir
+func subDirs(dir string) []string {
 	var subdirectories []string
 	if err := filepath.WalkDir(dir, func(path string, d fs.DirEntry, err error) error {
 		if err != nil {
@@ -68,7 +81,9 @@ func extendedGlob(pattern string) (matches []string, err error) {
 	}
 	return subdirectories
 }
-	expandPatterns := func(pattern string) []string {
+
+// expandPatterns fans out a glob pattern so that "**" is expanded to all possible subdirectory paths at that location.
+func expandPatterns(pattern string) []string {
 	components := []string{}
 	dir := pattern
 	file := ""
@@ -84,7 +99,7 @@ func extendedGlob(pattern string) (matches []string, err error) {
 		var nextPatterns []string
 		if components[i] == "**" {
 			for _, parent := range patterns {
-					nextSubdirs := subdirs(parent)
+				nextSubdirs := subDirs(parent)
 				for _, nextSubdir := range nextSubdirs {
 					nextPatterns = append(nextPatterns, filepath.Join(parent, nextSubdir))
 				}
@@ -107,17 +122,6 @@ func extendedGlob(pattern string) (matches []string, err error) {
 	}
 	return patterns
 }
-	patterns := expandPatterns(pattern)
-	for _, pattern := range patterns {
-		theseMatches, err := filepath.Glob(pattern)
-		if err != nil {
-			return nil, err
-		}
-		matches = append(matches, theseMatches...)
-	}
-	sort.Strings(matches)
-	return matches, nil
-}
 
 // isArchivePath returns true if the specified path can be read like a (possibly
 // compressed) tarball.