1 files changed, 156 insertions, 0 deletions
diff --git a/Userland/Libraries/LibMarkdown/List.cpp b/Userland/Libraries/LibMarkdown/List.cpp
new file mode 100644
index 0000000000..d9484cb098
--- /dev/null
+++ b/Userland/Libraries/LibMarkdown/List.cpp
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/StringBuilder.h>
+#include <LibMarkdown/List.h>
+
+namespace Markdown {
+
+String List::render_to_html() const
+{
+    StringBuilder builder;
+
+    const char* tag = m_is_ordered ? "ol" : "ul";
+    builder.appendf("<%s>", tag);
+
+    for (auto& item : m_items) {
+        builder.append("<li>");
+        builder.append(item.render_to_html());
+        builder.append("</li>\n");
+    }
+
+    builder.appendf("</%s>\n", tag);
+
+    return builder.build();
+}
+
+String List::render_for_terminal(size_t) const
+{
+    StringBuilder builder;
+
+    int i = 0;
+    for (auto& item : m_items) {
+        builder.append("  ");
+        if (m_is_ordered)
+            builder.appendf("%d. ", ++i);
+        else
+            builder.append("* ");
+        builder.append(item.render_for_terminal());
+        builder.append("\n");
+    }
+    builder.append("\n");
+
+    return builder.build();
+}
+
+OwnPtr<List> List::parse(Vector<StringView>::ConstIterator& lines)
+{
+    Vector<Text> items;
+    bool is_ordered = false;
+
+    bool first = true;
+    size_t offset = 0;
+    StringBuilder item_builder;
+    auto flush_item_if_needed = [&] {
+        if (first)
+            return true;
+
+        auto text = Text::parse(item_builder.string_view());
+        if (!text.has_value())
+            return false;
+
+        items.append(move(text.value()));
+
+        item_builder.clear();
+        return true;
+    };
+
+    while (true) {
+        if (lines.is_end())
+            break;
+        const StringView& line = *lines;
+        if (line.is_empty())
+            break;
+
+        bool appears_unordered = false;
+        if (line.length() > 2) {
+            if (line[1] == ' ' && (line[0] == '*' || line[0] == '-')) {
+                appears_unordered = true;
+                offset = 2;
+            }
+        }
+
+        bool appears_ordered = false;
+        for (size_t i = 0; i < 10 && i < line.length(); i++) {
+            char ch = line[i];
+            if ('0' <= ch && ch <= '9')
+                continue;
+            if (ch == '.' || ch == ')')
+                if (i + 1 < line.length() && line[i + 1] == ' ') {
+                    appears_ordered = true;
+                    offset = i + 1;
+                }
+            break;
+        }
+
+        ASSERT(!(appears_unordered && appears_ordered));
+
+        if (appears_unordered || appears_ordered) {
+            if (first)
+                is_ordered = appears_ordered;
+            else if (is_ordered != appears_ordered)
+                return {};
+
+            if (!flush_item_if_needed())
+                return {};
+
+            while (offset + 1 < line.length() && line[offset + 1] == ' ')
+                offset++;
+
+        } else {
+            if (first)
+                return {};
+            for (size_t i = 0; i < offset; i++) {
+                if (line[i] != ' ')
+                    return {};
+            }
+        }
+
+        first = false;
+        if (!item_builder.is_empty())
+            item_builder.append(' ');
+        ASSERT(offset <= line.length());
+        item_builder.append(line.substring_view(offset, line.length() - offset));
+        ++lines;
+        offset = 0;
+    }
+
+    if (!flush_item_if_needed() || first)
+        return {};
+    return make<List>(move(items), is_ordered);
+}
+
+}