utility: add new helper functions

examples/doc_utility_check_sheet_name.rs

@@ -7,10 +7,8 @@
 use rust_xlsxwriter::{utility, XlsxError};
 
 fn main() -> Result<(), XlsxError> {
-    // This worksheet name is valid.
-    let result = utility::check_sheet_name("2030-01-01")?;
-
-    assert!(matches!(result, ()));
+    // This worksheet name is valid and doesn't raise an error.
+    utility::check_sheet_name("2030-01-01")?;
 
     // This worksheet name isn't valid due to the forward slashes.
     let result = utility::check_sheet_name("2030/01/01");

examples/doc_utility_quote_sheet_name.rs

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+//
+// Copyright 2022-2025, John McNamara, [email protected]
+
+//! The following example demonstrates quoting worksheet names.
+
+use rust_xlsxwriter::utility;
+
+fn main() {
+    // Doesn't need to be quoted.
+    let result = utility::quote_sheet_name("Sheet1");
+    assert_eq!(result, "Sheet1");
+
+    // Spaces need to be quoted.
+    let result = utility::quote_sheet_name("Sheet 1");
+    assert_eq!(result, "'Sheet 1'");
+
+    // Special characters need to be quoted.
+    let result = utility::quote_sheet_name("Sheet-1");
+    assert_eq!(result, "'Sheet-1'");
+
+    // Single quotes need to be escaped with a quote.
+    let result = utility::quote_sheet_name("Sheet'1");
+    assert_eq!(result, "'Sheet''1'");
+
+    // A1 style cell references don't need to be quoted.
+    let result = utility::quote_sheet_name("A1");
+    assert_eq!(result, "'A1'");
+
+    // R1C1 style cell references need to be quoted.
+    let result = utility::quote_sheet_name("RC1");
+    assert_eq!(result, "'RC1'");
+}

examples/doc_worksheet_serialize_datetime3.rs

@@ -6,9 +6,10 @@
 //! function.
 
 use chrono::NaiveDate;
-use rust_xlsxwriter::utility::serialize_chrono_naive_to_excel;
 use serde::Serialize;
 
+use rust_xlsxwriter::utility::serialize_chrono_naive_to_excel;
+
 fn main() {
     #[derive(Serialize)]
     struct Student {