Add native repeat object

compiler+runtime/CMakeLists.txt

@@ -196,6 +196,7 @@ add_library(
   src/cpp/jank/runtime/obj/persistent_string_sequence.cpp
   src/cpp/jank/runtime/obj/cons.cpp
   src/cpp/jank/runtime/obj/range.cpp
+  src/cpp/jank/runtime/obj/repeat.cpp
   src/cpp/jank/runtime/obj/iterator.cpp
   src/cpp/jank/runtime/obj/lazy_sequence.cpp
   src/cpp/jank/runtime/obj/chunk_buffer.cpp

compiler+runtime/include/cpp/jank/runtime/erasure.hpp

@@ -30,6 +30,7 @@
 #include <jank/runtime/obj/array_chunk.hpp>
 #include <jank/runtime/obj/chunked_cons.hpp>
 #include <jank/runtime/obj/range.hpp>
+#include <jank/runtime/obj/repeat.hpp>
 #include <jank/runtime/obj/jit_function.hpp>
 #include <jank/runtime/obj/multi_function.hpp>
 #include <jank/runtime/obj/native_function_wrapper.hpp>
@@ -286,6 +287,11 @@ namespace jank::runtime
           return fn(expect_object<obj::range>(erased), std::forward<Args>(args)...);
         }
         break;
+      case object_type::repeat:
+        {
+          return fn(expect_object<obj::repeat>(erased), std::forward<Args>(args)...);
+        }
+        break;
       case object_type::native_array_sequence:
         {
           return fn(expect_object<obj::native_array_sequence>(erased), std::forward<Args>(args)...);
@@ -522,6 +528,11 @@ namespace jank::runtime
           return fn(expect_object<obj::range>(erased), std::forward<Args>(args)...);
         }
         break;
+      case object_type::repeat:
+        {
+          return fn(expect_object<obj::repeat>(erased), std::forward<Args>(args)...);
+        }
+        break;
       case object_type::native_array_sequence:
         {
           return fn(expect_object<obj::native_array_sequence>(erased), std::forward<Args>(args)...);

compiler+runtime/include/cpp/jank/runtime/obj/repeat.hpp

@@ -0,0 +1,56 @@
+#pragma once
+
+#include <jank/runtime/behavior/seqable.hpp>
+
+namespace jank::runtime
+{
+  template <>
+  struct static_object<object_type::repeat> : gc
+  {
+    static constexpr native_bool pointer_free{ false };
+    static constexpr native_integer INFINITE{ -1 };
+    using bounds_check_t = native_bool (*)(object_ptr);
+
+    static_object() = default;
+    static_object(object_ptr value);
+    static_object(object_ptr count, object_ptr value);
+
+    static object_ptr create(object_ptr value);
+    static object_ptr create(object_ptr count, object_ptr value);
+
+    /* behavior::object_like */
+    native_bool equal(object const &) const;
+    native_persistent_string to_string();
+    void to_string(fmt::memory_buffer &buff);
+    native_persistent_string to_code_string();
+    native_hash to_hash() const;
+
+    /* behavior::seqable */
+    native_box<static_object> seq();
+    native_box<static_object> fresh_seq() const;
+
+    /* behavior::sequenceable */
+    object_ptr first() const;
+    native_box<static_object> next() const;
+
+    /* behavior::sequenceable_in_place */
+    native_box<static_object> next_in_place();
+
+    /* behavior::conjable */
+    obj::cons_ptr conj(object_ptr head) const;
+
+    /* behavior::metadatable */
+    native_box<static_object> with_meta(object_ptr m) const;
+
+    object base{ object_type::repeat };
+    object_ptr value{};
+    object_ptr count{};
+    option<object_ptr> meta{};
+  };
+
+  namespace obj
+  {
+    using repeat = static_object<object_type::repeat>;
+    using repeat_ptr = native_box<repeat>;
+  }
+}

compiler+runtime/include/cpp/jank/runtime/object.hpp

@@ -52,6 +52,7 @@ namespace jank::runtime
     cons,
     lazy_sequence,
     range,
+    repeat,
     iterator,
     native_array_sequence,
     native_vector_sequence,

compiler+runtime/src/cpp/jank/runtime/obj/repeat.cpp

@@ -0,0 +1,134 @@
+#include <jank/runtime/obj/repeat.hpp>
+
+namespace jank::runtime
+{
+
+  obj::repeat::static_object(object_ptr const value)
+    : value{ value }
+    , count{ make_box(INFINITE) }
+  {
+  }
+
+  obj::repeat::static_object(object_ptr const count, object_ptr const value)
+    : value{ value }
+    , count{ count }
+  {
+  }
+
+  object_ptr obj::repeat::create(object_ptr const value)
+  {
+    return make_box<obj::repeat>(value);
+  }
+
+  object_ptr obj::repeat::create(object_ptr const count, object_ptr const value)
+  {
+    if(lte(count, make_box(0)))
+    {
+      return obj::persistent_list::empty();
+    }
+    return make_box<obj::repeat>(count, value);
+  }
+
+  obj::repeat_ptr obj::repeat::seq()
+  {
+    return this;
+  }
+
+  obj::repeat_ptr obj::repeat::fresh_seq() const
+  {
+    return make_box<obj::repeat>(count, value);
+  }
+
+  object_ptr obj::repeat::first() const
+  {
+    return value;
+  }
+
+  obj::repeat_ptr obj::repeat::next() const
+  {
+    if(runtime::equal(count, make_box(INFINITE)))
+    {
+      return this;
+    }
+    if(lt(count, make_box(1)))
+    {
+      return nullptr;
+    }
+    return make_box<obj::repeat>(make_box(add(count, make_box(-1))), value);
+  }
+
+  obj::repeat_ptr obj::repeat::next_in_place()
+  {
+    if(runtime::equal(count, make_box(INFINITE)))
+    {
+      return this;
+    }
+    if(lte(count, make_box(1)))
+    {
+      return nullptr;
+    }
+    count = add(count, make_box(-1));
+    return this;
+  }
+
+  obj::cons_ptr obj::repeat::conj(object_ptr const head) const
+  {
+    return make_box<obj::cons>(head, this);
+  }
+
+  native_bool obj::repeat::equal(object const &o) const
+  {
+    return visit_object(
+      [this](auto const typed_o) {
+        using T = typename decltype(typed_o)::value_type;
+
+        if constexpr(!behavior::seqable<T>)
+        {
+          return false;
+        }
+        else
+        {
+          auto seq(typed_o->fresh_seq());
+          /* TODO: This is common code; can it be shared? */
+          for(auto it(fresh_seq()); it != nullptr;
+              it = runtime::next_in_place(it), seq = runtime::next_in_place(seq))
+          {
+            if(seq == nullptr || !runtime::equal(it, seq->first()))
+            {
+              return false;
+            }
+          }
+          return true;
+        }
+      },
+      &o);
+  }
+
+  void obj::repeat::to_string(fmt::memory_buffer &buff)
+  {
+    runtime::to_string(seq(), buff);
+  }
+
+  native_persistent_string obj::repeat::to_string()
+  {
+    return runtime::to_string(seq());
+  }
+
+  native_persistent_string obj::repeat::to_code_string()
+  {
+    return runtime::to_code_string(seq());
+  }
+
+  native_hash obj::repeat::to_hash() const
+  {
+    return hash::ordered(&base);
+  }
+
+  obj::repeat_ptr obj::repeat::with_meta(object_ptr const m) const
+  {
+    auto const meta(behavior::detail::validate_meta(m));
+    auto ret(fresh_seq());
+    ret->meta = meta;
+    return ret;
+  }
+}

compiler+runtime/src/jank/clojure/core.jank

@@ -2236,13 +2236,12 @@
   ; TODO: Custom cycle object
   (lazy-seq (concat coll (cycle coll))))
 
-; Returns a lazy (infinite!, or length n if supplied) sequence of xs.
+; Returns a lazy (infinite!, or length n if supplied) sequence of val.
 (defn repeat
-  ; TODO: Custom repeat object
-  ([x]
-   (lazy-seq (cons x (repeat x))))
-  ([n x]
-   (take n (repeat x))))
+  ([val]
+   (native/raw "__value = obj::repeat::create(~{ val });"))
+  ([count val]
+   (native/raw "__value = obj::repeat::create(~{ count }, ~{ val });")))
 
 ; Returns a vector of [(take n coll) (drop n coll)]
 (defn split-at [n coll]

compiler+runtime/test/cpp/jank/read/parse.cpp

@@ -1182,4 +1182,4 @@ namespace jank::read::parse
       }
     }
   }
-}
+}