Lines of src/utils.rs from check-in 3c858ed7c4 that are changed by the sequence of edits moving toward check-in bf99298edf:

                         1: use crate::Cursor;
                         2: 
                         3: use std::borrow::Cow;
                         4: 
                         5: use html_escape::encode_text;
                         6: use lazy_static::lazy_static;
3c858ed7c4 2026-07-31    7: use regex::Regex;
                         8: use stacked_errors::{
                         9: 	bail,
                        10: 	Result,
                        11: };
                        12: 
                        13: lazy_static! {
                        14: 	pub static ref RE_DOMAIN: Regex = Regex::new(r"^[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$").expect("Invalid domain regex");
3c858ed7c4 2026-07-31   15: 	pub static ref RE_CLOSING: Regex = Regex::new(r"</[ \t]*(pre|code)[ \t]*>").expect("Invalid cloding tag regex");
                        16: }
                        17: 
                        18: /// Stores binary attachment data and metadata for Telegram messages.
                        19: /// The data is wrapped in a `Cursor<Vec<u8>>` for efficient streaming,
                        20: /// while `name` holds the filename or display name of the attachment.
                        21: #[derive(Debug)]
                        22: pub struct Attachment {
                        23: 	pub data: Cursor<Vec<u8>>,
                        24: 	pub name: String,
                        25: }
                        26: 
                        27: /// Pass any text here to be validated as not breaking from Telegram preformatted blocks
                        28: /// escape all HTML chars afterwards
                        29: pub fn validate <'a>(text: &'a str) -> Result<Cow<'a, str>> {
                        30: 	if RE_CLOSING.is_match(text) {
                        31: 		bail!("Telegram closing tag found.");
                        32: 	} else {
                        33: 		Ok(encode_text(text))
                        34: 	}
                        35: }