Lines of src/utils.rs from check-in 997fb1cff4 that are changed by the sequence of edits moving toward check-in 512369f93e:

                         1: use crate::Cursor;
                         2: 
                         3: use std::{
                         4: 	borrow::Cow,
                         5: 	sync::LazyLock,
                         6: };
                         7: 
                         8: use html_escape::encode_text;
                         9: use regex::{
                        10: 	Regex,
                        11: 	RegexBuilder,
                        12: };
                        13: use stacked_errors::{
                        14: 	bail,
                        15: 	Result,
                        16: };
                        17: 
                        18: pub static RE_DOMAIN: LazyLock<Regex> = LazyLock::new(|| {
                        19: 	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")
                        20: });
                        21: pub static RE_CLOSING: LazyLock<Regex> = LazyLock::new(|| {
                        22: 	RegexBuilder::new(r"</[ \t]*(pre|code)[ \t]*>")
                        23: 		.case_insensitive(true).build().expect("Invalid closing tag regex")
                        24: });
                        25: 
                        26: /// Stores binary attachment data and metadata for Telegram messages.
                        27: /// The data is wrapped in a `Cursor<Vec<u8>>` for efficient streaming,
                        28: /// while `name` holds the filename or display name of the attachment.
                        29: #[derive(Debug)]
                        30: pub struct Attachment {
                        31: 	pub data: Cursor<Vec<u8>>,
                        32: 	pub name: String,
                        33: }
                        34: 
997fb1cff4 2026-08-01   35: /// Pass any text here to be validated as not breaking from Telegram preformatted blocks
997fb1cff4 2026-08-01   36: /// escape all HTML chars afterwards
                        37: pub fn validate <'a>(text: &'a str) -> Result<Cow<'a, str>> {
                        38: 	if RE_CLOSING.is_match(text) {
                        39: 		bail!("Telegram closing tag found.");
                        40: 	} else {
                        41: 		Ok(encode_text(text))
                        42: 	}
                        43: }