Preserve metadata on collection operations

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
  * Fix a bug where symbols and keyword containing `:` characters in the name were rejected by the reader (#1105)
  * Fix a bug where records did not support reducing via `reduce-kv` (#1102)
+ * Fix a bug where collection modifying library functions such as `conj`, `disj`, `assoc`, `dissoc`, and `empty` would not preserve collection metadata (#1103)
 
 ## [v0.3.0]
 ### Added

src/basilisp/contrib/sphinx/autodoc.py

@@ -380,7 +380,7 @@ def get_object_members(self, want_all: bool) -> tuple[bool, list[ObjectMember]]:
         assert isinstance(proto, IPersistentMap)
         proto_methods = cast(
             IPersistentMap[kw.Keyword, Any],
-            proto.val_at(_METHODS_KW, lmap.PersistentMap.empty()),
+            proto.val_at(_METHODS_KW, lmap.EMPTY),
         )
         return False, list(
             map(

src/basilisp/lang/atom.py

@@ -3,8 +3,8 @@
 
 from typing_extensions import Concatenate, ParamSpec
 
+from basilisp.lang import map as lmap
 from basilisp.lang.interfaces import IPersistentMap, RefValidator
-from basilisp.lang.map import PersistentMap
 from basilisp.lang.reference import RefBase
 
 T = TypeVar("T")
@@ -23,7 +23,7 @@ def __init__(
         self._meta: Optional[IPersistentMap] = meta
         self._state = state
         self._lock = threading.RLock()
-        self._watches = PersistentMap.empty()
+        self._watches = lmap.EMPTY
         self._validator = validator
 
         if validator is not None:

src/basilisp/lang/compiler/analyzer.py

@@ -331,7 +331,7 @@ def __init__(
         self._func_ctx: collections.deque[FunctionContext] = collections.deque([])
         self._is_quoted: collections.deque[bool] = collections.deque([])
         self._opts = (
-            Maybe(opts).map(lmap.map).or_else_get(lmap.PersistentMap.empty())  # type: ignore[arg-type, unused-ignore]
+            Maybe(opts).map(lmap.map).or_else_get(lmap.EMPTY)  # type: ignore[arg-type, unused-ignore]
         )
         self._recur_points: collections.deque[RecurPoint] = collections.deque([])
         self._should_macroexpand = should_macroexpand
@@ -808,7 +808,7 @@ def _call_args_ast(
                 kwargs = lmap.map(kw_map)
         else:
             args = vec.vector(map(lambda form: _analyze_form(form, ctx), form))
-            kwargs = lmap.PersistentMap.empty()
+            kwargs = lmap.EMPTY
 
         return args, kwargs
 
@@ -940,7 +940,7 @@ def _def_ast(  # pylint: disable=too-many-locals,too-many-statements
     if nelems == 2:
         init_idx = None
         doc = None
-        children = vec.PersistentVector.empty()
+        children = vec.EMPTY
     elif nelems == 3:
         init_idx = 2
         doc = None
@@ -2823,9 +2823,7 @@ def __letfn_fn_body(form: ISeq, ctx: AnalyzerContext) -> Fn:
     fn_body = _analyze_form(
         fn_rest.cons(
             fn_name.with_meta(
-                (fn_name.meta or lmap.PersistentMap.empty()).assoc(
-                    SYM_NO_WARN_ON_SHADOW_META_KEY, True
-                )
+                (fn_name.meta or lmap.EMPTY).assoc(SYM_NO_WARN_ON_SHADOW_META_KEY, True)
             )
         ).cons(fn_sym),
         ctx,
@@ -3456,7 +3454,7 @@ def _yield_ast(form: ISeq, ctx: AnalyzerContext) -> Yield:
 @_analyze_form.register(ISeq)
 @_with_loc
 def _list_node(form: ISeq, ctx: AnalyzerContext) -> Node:
-    if form == llist.PersistentList.empty():
+    if form == llist.EMPTY:
         with ctx.quoted():
             return _const_node(form, ctx)