LibJS: Start implementing Temporal.PlainDate

This commit adds the PlainDate object itself, its constructor and
prototype (currently empty), and several required abstract operations.

1 files changed, 24 insertions, 0 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.h b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.h
index 8471958743..fde86d4bd3 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.h
@@ -10,6 +10,30 @@
 
 namespace JS::Temporal {
 
+class PlainDate final : public Object {
+    JS_OBJECT(PlainDate, Object);
+
+public:
+    explicit PlainDate(i32 iso_year, i32 iso_month, i32 iso_day, Object& calendar, Object& prototype);
+    virtual ~PlainDate() override = default;
+
+    [[nodiscard]] i32 iso_year() const { return m_iso_year; }
+    [[nodiscard]] i32 iso_month() const { return m_iso_month; }
+    [[nodiscard]] i32 iso_day() const { return m_iso_day; }
+    [[nodiscard]] Object const& calendar() const { return m_calendar; }
+    [[nodiscard]] Object& calendar() { return m_calendar; }
+
+private:
+    virtual void visit_edges(Visitor&) override;
+
+    // 3.4 Properties of Temporal.PlainDate Instances, https://tc39.es/proposal-temporal/#sec-properties-of-temporal-plaindate-instances
+    i32 m_iso_year { 0 };  // [[ISOYear]]
+    i32 m_iso_month { 1 }; // [[ISOMonth]]
+    i32 m_iso_day { 1 };   // [[ISODay]]
+    Object& m_calendar;    // [[Calendar]]
+};
+
+PlainDate* create_temporal_date(GlobalObject&, i32 iso_year, i32 iso_month, i32 iso_day, Object& calendar, FunctionObject* new_target);
 bool is_valid_iso_date(i32 year, i32 month, i32 day);
 
 }