Lines of src/utils.rs from check-in 85fa6bddaa that are changed by the sequence of edits moving toward check-in 3c858ed7c4:

                         1: use crate::Cursor;
                         2: 
                         3: use std::borrow::Cow;
                         4: 
                         5: use html_escape::encode_text;
                         6: use lazy_static::lazy_static;
                         7: use regex::Regex;
                         8: use stacked_errors::{
                         9: 	bail,
                        10: 	Result,
                        11: };
                        12: 
                        13: lazy_static! {
85fa6bddaa 2026-01-18   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])?)*$").unwrap();
85fa6bddaa 2026-01-18   15: 	pub static ref RE_CLOSING: Regex = Regex::new(r"</[ \t]*(pre|code)[ \t]*>").unwrap();
                        16: }
                        17: 
85fa6bddaa 2026-01-18   18: /// `Attachment` object to store number attachment data and corresponding file name
                        19: #[derive(Debug)]
                        20: pub struct Attachment {
                        21: 	pub data: Cursor<Vec<u8>>,
                        22: 	pub name: String,
                        23: }
                        24: 
                        25: /// Pass any text here to be validated as not breaking from Telegram preformatted blocks
                        26: /// escape all HTML chars afterwards
85fa6bddaa 2026-01-18   27: pub fn validate (text: &str) -> Result<Cow<'_, str>> {
                        28: 	if RE_CLOSING.is_match(text) {
                        29: 		bail!("Telegram closing tag found.");
                        30: 	} else {
                        31: 		Ok(encode_text(text))
                        32: 	}
                        33: }