Libraries: Add LibMarkdown

Libraries/LibMarkdown/MDCodeBlock.cpp

@@ -0,0 +1,137 @@
+#include <AK/StringBuilder.h>
+#include <LibMarkdown/MDCodeBlock.h>
+
+MDText::Style MDCodeBlock::style() const
+{
+    if (m_style_spec.spans().is_empty())
+        return {};
+    return m_style_spec.spans()[0].style;
+}
+
+String MDCodeBlock::style_language() const
+{
+    if (m_style_spec.spans().is_empty())
+        return {};
+    return m_style_spec.spans()[0].text;
+}
+
+String MDCodeBlock::render_to_html() const
+{
+    StringBuilder builder;
+
+    String style_language = this->style_language();
+    MDText::Style style = this->style();
+
+    if (style.strong)
+        builder.append("<b>");
+    if (style.emph)
+        builder.append("<i>");
+
+    builder.append("<pre>");
+
+    if (style_language.is_null())
+        builder.append("<code>");
+    else
+        builder.appendf("<code class=\"%s\">", style_language.characters());
+
+    // TODO: This should also be done in other places.
+    for (int i = 0; i < m_code.length(); i++)
+        if (m_code[i] == '<')
+            builder.append("&lt;");
+        else if (m_code[i] == '>')
+            builder.append("&gt;");
+        else if (m_code[i] == '&')
+            builder.append("&amp;");
+        else
+            builder.append(m_code[i]);
+
+    builder.append("</code></pre>");
+
+    if (style.emph)
+        builder.append("</i>");
+    if (style.strong)
+        builder.append("</b>");
+
+    builder.append('\n');
+
+    return builder.build();
+}
+
+String MDCodeBlock::render_for_terminal() const
+{
+    StringBuilder builder;
+
+    MDText::Style style = this->style();
+    bool needs_styling = style.strong || style.emph;
+    if (needs_styling) {
+        builder.append("\033[");
+        bool first = true;
+        if (style.strong) {
+            builder.append('1');
+            first = false;
+        }
+        if (style.emph) {
+            if (!first)
+                builder.append(';');
+            builder.append('4');
+        }
+        builder.append('m');
+    }
+
+    builder.append(m_code);
+
+    if (needs_styling)
+        builder.append("\033[0m");
+
+    builder.append("\n\n");
+
+    return builder.build();
+}
+
+bool MDCodeBlock::parse(Vector<StringView>::ConstIterator& lines)
+{
+    if (lines.is_end())
+        return false;
+
+    constexpr auto tick_tick_tick = "```";
+
+    StringView line = *lines;
+    if (!line.starts_with(tick_tick_tick))
+        return false;
+
+    // Our Markdown extension: we allow
+    // specifying a style and a language
+    // for a code block, like so:
+    //
+    // ```**sh**
+    // $ echo hello friends!
+    // ````
+    //
+    // The code block will be made bold,
+    // and if possible syntax-highlighted
+    // as appropriate for a shell script.
+    StringView style_spec = line.substring_view(3, line.length() - 3);
+    bool success = m_style_spec.parse(style_spec);
+    ASSERT(success);
+
+    ++lines;
+
+    bool first = true;
+    StringBuilder builder;
+
+    while (true) {
+        if (lines.is_end())
+            break;
+        line = *lines;
+        ++lines;
+        if (line == tick_tick_tick)
+            break;
+        if (!first)
+            builder.append('\n');
+        builder.append(line);
+        first = false;
+    }
+
+    m_code = builder.build();
+    return true;
+}