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use super::*;
use crate::ParseOptions;
use crate::html::is_dangerous_url;
static EM_CLOSE: [&str; 6] = ["</em>", "</em>", "</strong>", "</del>", "</mark>", "</u>"];
static EM_OPEN: [&str; 6] = ["<em>", "<em>", "<strong>", "<del>", "<mark>", "<u>"];
impl<'a> InlineScanner<'a> {
pub(super) fn render_to_html(&self, out: &mut String, opts: &ParseOptions) {
let mut tag_buf: [u8; 16] = [0; 16];
let mut tag_len: usize = 0;
let mut i = 0;
while i < self.items.len() {
match &self.items[i] {
InlineItem::TextRange(start, end) => {
escape_html_into(out, &self.input[*start..*end]);
}
InlineItem::TextOwned(t) => out.push_str(t),
InlineItem::TextStatic(t) => out.push_str(t),
InlineItem::TextInline { buf, len } => {
// SAFETY: `buf` is constructed from UTF-8 bytes and `len` tracks initialized prefix length.
out.push_str(unsafe { std::str::from_utf8_unchecked(&buf[..*len as usize]) });
}
InlineItem::RawHtml(start, end) => {
if opts.disable_raw_html {
escape_html_into(out, &self.input[*start..*end]);
} else {
out.push_str(&self.input[*start..*end]);
}
}
InlineItem::Autolink(start, end, is_email) => {
let content = &self.input[*start as usize..*end as usize];
out.push_str("<a href=\"");
if *is_email {
out.push_str("mailto:");
}
crate::html::encode_url_escaped_into(out, content);
out.push_str("\">");
escape_html_into(out, content);
out.push_str("</a>");
}
InlineItem::Code(c) => {
out.push_str("<code>");
escape_html_into(out, c);
out.push_str("</code>");
}
InlineItem::CodeRange(s, e) => {
out.push_str("<code>");
escape_html_into(out, &self.input[*s as usize..*e as usize]);
out.push_str("</code>");
}
InlineItem::HardBreak => out.push_str("<br />\n"),
InlineItem::SoftBreak => {
if opts.hard_breaks {
out.push_str("<br />\n");
} else {
out.push('\n');
}
}
InlineItem::DelimRun {
kind,
count,
open_em,
close_em,
..
} => {
for &size in close_em.as_slice() {
if tag_len > 0 && tag_buf[tag_len - 1] == size {
tag_len -= 1;
out.push_str(EM_CLOSE[size as usize]);
}
}
if *count > 0 {
for _ in 0..*count {
out.push(*kind as char);
}
}
for &size in open_em.as_slice().iter().rev() {
if tag_len < 16 {
tag_buf[tag_len] = size;
tag_len += 1;
}
out.push_str(EM_OPEN[size as usize]);
}
}
InlineItem::BracketOpen { is_image, .. } => {
if *is_image {
out.push_str("![");
} else {
out.push('[');
}
}
InlineItem::LinkStart(link_idx) => {
let LinkInfo {
dest,
title,
is_image,
} = &self.links[*link_idx as usize];
let safe = !is_dangerous_link_dest(dest, self.input);
if *is_image {
let alt_start = i + 1;
let mut alt_end = alt_start;
let mut depth = 1;
while alt_end < self.items.len() {
match &self.items[alt_end] {
InlineItem::LinkStart(..) => depth += 1,
InlineItem::LinkEnd => {
depth -= 1;
if depth == 0 {
break;
}
}
_ => {}
}
alt_end += 1;
}
let alt = self.collect_alt_text(alt_start, alt_end);
out.push_str("<img src=\"");
if safe {
write_link_dest(out, dest, self.input);
}
out.push_str("\" alt=\"");
out.push_str(&alt);
out.push('"');
if let Some(t) = title {
out.push_str(" title=\"");
escape_html_into(out, t);
out.push('"');
}
out.push_str(" />");
i = alt_end;
} else {
out.push_str("<a href=\"");
if safe {
write_link_dest(out, dest, self.input);
}
out.push('"');
if let Some(t) = title {
out.push_str(" title=\"");
escape_html_into(out, t);
out.push('"');
}
out.push('>');
if tag_len < 16 {
tag_buf[tag_len] = 0;
tag_len += 1;
}
}
}
InlineItem::LinkEnd => {
if tag_len > 0 && tag_buf[tag_len - 1] == 0 {
tag_len -= 1;
out.push_str("</a>");
}
}
}
i += 1;
}
}
pub(super) fn collect_alt_text(&self, start: usize, end: usize) -> String {
let mut s = String::new();
for idx in start..end {
match &self.items[idx] {
InlineItem::TextRange(a, b) => s.push_str(&self.input[*a..*b]),
InlineItem::CodeRange(a, b) => s.push_str(&self.input[*a as usize..*b as usize]),
InlineItem::TextOwned(t) | InlineItem::Code(t) => s.push_str(t),
InlineItem::TextStatic(t) => s.push_str(t),
InlineItem::TextInline { buf, len } => {
// SAFETY: `buf` is constructed from UTF-8 bytes and `len` tracks initialized prefix length.
s.push_str(unsafe { std::str::from_utf8_unchecked(&buf[..*len as usize]) });
}
InlineItem::DelimRun { kind, count, .. } => {
for _ in 0..*count {
s.push(*kind as char);
}
}
InlineItem::BracketOpen { is_image: true, .. } => s.push_str("!["),
InlineItem::BracketOpen { .. } => s.push('['),
_ => {}
}
}
s
}
}
/// Check if a LinkDest points to a dangerous URL without allocating.
#[inline]
fn is_dangerous_link_dest(dest: &LinkDest, input: &str) -> bool {
match dest {
LinkDest::Range(s, e) => {
let s = *s as usize;
let e = *e as usize;
if s < e {
is_dangerous_url(&input[s..e])
} else {
false
}
}
LinkDest::Owned(d) => is_dangerous_url(d),
}
}
#[inline]
pub(super) fn write_link_dest(out: &mut String, dest: &LinkDest, input: &str) {
match dest {
LinkDest::Range(s, e) => {
let s = *s as usize;
let e = *e as usize;
if s < e {
crate::html::encode_url_escaped_into(out, &input[s..e]);
}
}
LinkDest::Owned(d) => {
crate::html::encode_url_escaped_into(out, d);
}
}
}