Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibHTML/Parser/CSSParser.cpp

@@ -0,0 +1,151 @@
+#include <LibHTML/CSS/StyleSheet.h>
+#include <LibHTML/Parser/CSSParser.h>
+#include <ctype.h>
+#include <stdio.h>
+
+NonnullRefPtr<StyleValue> parse_css_value(const StringView& view)
+{
+    String string(view);
+    bool ok;
+    int as_int = string.to_int(ok);
+    if (ok)
+        return LengthStyleValue::create(Length(as_int, Length::Type::Absolute));
+    unsigned as_uint = string.to_uint(ok);
+    if (ok)
+        return LengthStyleValue::create(Length(as_uint, Length::Type::Absolute));
+    if (string == "auto")
+        return LengthStyleValue::create(Length());
+    return StringStyleValue::create(string);
+}
+
+NonnullRefPtr<StyleSheet> parse_css(const String& css)
+{
+    NonnullRefPtrVector<StyleRule> rules;
+
+    enum class State {
+        Free,
+        InSelectorComponent,
+        InPropertyName,
+        InPropertyValue,
+    };
+
+    struct CurrentRule {
+        Vector<Selector> selectors;
+        NonnullRefPtrVector<StyleDeclaration> declarations;
+    };
+
+    CurrentRule current_rule;
+    Vector<char> buffer;
+
+    int index = 0;
+
+    auto peek = [&]() -> char {
+        if (index < css.length())
+            return css[index];
+        return 0;
+    };
+
+    auto consume_specific = [&](char ch) {
+        ASSERT(peek() == ch);
+        ++index;
+        return ch;
+    };
+
+    auto consume_one = [&]() -> char {
+        return css[index++];
+    };
+
+    auto consume_whitespace = [&] {
+        while (isspace(peek()))
+            ++index;
+    };
+
+    auto is_valid_selector_char = [](char ch) {
+        return isalnum(ch) || ch == '-' || ch == '_';
+    };
+
+    auto parse_selector = [&] {
+        consume_whitespace();
+        Selector::Component::Type type;
+        if (peek() == '.')
+            type = Selector::Component::Type::Class;
+        else if (peek() == '#')
+            type = Selector::Component::Type::Id;
+        else
+            type = Selector::Component::Type::TagName;
+
+        while (is_valid_selector_char(peek()))
+            buffer.append(consume_one());
+
+        ASSERT(!buffer.is_null());
+
+        auto component_string = String::copy(buffer);
+
+        Vector<Selector::Component> components;
+        components.append({ type, component_string });
+        buffer.clear();
+        current_rule.selectors.append(Selector(move(components)));
+    };
+
+    auto parse_selector_list = [&] {
+        for (;;) {
+            parse_selector();
+            consume_whitespace();
+            if (peek() == ',') {
+                consume_one();
+                continue;
+            }
+            if (peek() == '{')
+                break;
+        }
+    };
+
+    auto is_valid_property_name_char = [](char ch) {
+        return !isspace(ch) && ch != ':';
+    };
+
+    auto is_valid_property_value_char = [](char ch) {
+        return !isspace(ch) && ch != ';';
+    };
+
+    auto parse_declaration = [&] {
+        consume_whitespace();
+        buffer.clear();
+        while (is_valid_property_name_char(peek()))
+            buffer.append(consume_one());
+        auto property_name = String::copy(buffer);
+        buffer.clear();
+        consume_whitespace();
+        consume_specific(':');
+        consume_whitespace();
+        while (is_valid_property_value_char(peek()))
+            buffer.append(consume_one());
+        auto property_value = String::copy(buffer);
+        buffer.clear();
+        consume_specific(';');
+        current_rule.declarations.append(StyleDeclaration::create(property_name, parse_css_value(property_value)));
+    };
+
+    auto parse_declarations = [&] {
+        for (;;) {
+            parse_declaration();
+            consume_whitespace();
+            if (peek() == '}')
+                break;
+        }
+    };
+
+    auto parse_rule = [&] {
+        parse_selector_list();
+        consume_specific('{');
+        parse_declarations();
+        consume_specific('}');
+        rules.append(StyleRule::create(move(current_rule.selectors), move(current_rule.declarations)));
+    };
+
+    while (index < css.length()) {
+        parse_rule();
+    }
+
+    return StyleSheet::create(move(rules));
+}