Lines of src/utils.rs from check-in bf99298edf that are changed by the sequence of edits moving toward check-in 997fb1cff4:

                         1: use crate::Cursor;
                         2: 
bf99298edf 2026-07-31    3: use std::borrow::Cow;
                         4: 
                         5: use html_escape::encode_text;
bf99298edf 2026-07-31    6: use lazy_static::lazy_static;
                         7: use regex::{
                         8: 	Regex,
                         9: 	RegexBuilder,
                        10: };
                        11: use stacked_errors::{
                        12: 	bail,
                        13: 	Result,
                        14: };
                        15: 
bf99298edf 2026-07-31   16: lazy_static! {
bf99298edf 2026-07-31   17: 	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");
bf99298edf 2026-07-31   18: 	pub static ref RE_CLOSING: Regex = RegexBuilder::new(r"</[ \t]*(pre|code)[ \t]*>")
bf99298edf 2026-07-31   19: 		.case_insensitive(true).build().expect("Invalid closing tag regex");
bf99298edf 2026-07-31   20: }
                        21: 
                        22: /// Stores binary attachment data and metadata for Telegram messages.
                        23: /// The data is wrapped in a `Cursor<Vec<u8>>` for efficient streaming,
                        24: /// while `name` holds the filename or display name of the attachment.
                        25: #[derive(Debug)]
                        26: pub struct Attachment {
                        27: 	pub data: Cursor<Vec<u8>>,
                        28: 	pub name: String,
                        29: }
                        30: 
                        31: /// Pass any text here to be validated as not breaking from Telegram preformatted blocks
                        32: /// escape all HTML chars afterwards
                        33: pub fn validate <'a>(text: &'a str) -> Result<Cow<'a, str>> {
                        34: 	if RE_CLOSING.is_match(text) {
                        35: 		bail!("Telegram closing tag found.");
                        36: 	} else {
                        37: 		Ok(encode_text(text))
                        38: 	}
                        39: }