Update let for the removal of special forms

Co-authored-by: Allison Casey <allie.jo.casey@gmail.com>

hy/contrib/walk.hy

@@ -13,7 +13,7 @@
         [collections [OrderedDict]]
         [hy.macros [macroexpand :as mexpand]]
         [hy.compiler [HyASTCompiler calling-module]]
-        [hy.extra.reserved [special]])
+        hy.extra.reserved)
 
 (defn walk [inner outer form]
   "``walk`` traverses ``form``, an arbitrary data structure. Applies
@@ -220,13 +220,15 @@
               [(= (get form 0) (hy.models.Symbol "require"))
                (ast-compiler.compile form)
                (return)]
-              [True (traverse (mexpand form ast-compiler.module ast-compiler))])
+              [(in (get form 0) '[except unpack-mapping])
+               (hy.models.Expression [(get form 0) #* (traverse (cut form 1 None))])]
+              [True (traverse (mexpand form ast-compiler.module ast-compiler :result-ok False))])
         (if (coll? form)
             (traverse form)
             form)))
   (expand form))
 
-(setv _mangled-special (frozenset (map hy.mangle (special))))
+(setv _mangled-core-macs (frozenset (map hy.mangle (hy.extra.reserved.macros))))
 
 
 (defn lambda-list [form]
@@ -466,7 +468,7 @@
       [(= head 'match) (self.handle-match)]
       [(= head 'quasiquote) (self.+quote)]
         ;; must be checked last!
-      [(in (hy.mangle head) _mangled-special) (self.handle-special-form)]
+      [(in (hy.mangle head) _mangled-core-macs) (self.handle-special-form)]
         ;; Not a special form. Traverse it like a coll
       [True (self.handle-coll)]))
 

hy/core/language.hy

@@ -309,7 +309,7 @@
   "
   (+ n 1))
 
-(defn macroexpand [form]
+(defn macroexpand [form [result-ok False]]
   "Return the full macro expansion of `form`.
 
   .. versionadded:: 0.10.0
@@ -327,7 +327,7 @@
   "
   (import hy.macros)
   (setv module (calling-module))
-  (hy.macros.macroexpand form module (HyASTCompiler module)))
+  (hy.macros.macroexpand form module (HyASTCompiler module) :result-ok result-ok))
 
 (defn macroexpand-1 [form]
   "Return the single step macro expansion of `form`.

hy/macros.py

@@ -273,7 +273,7 @@ def __exit__(self, exc_type, exc_value, exc_traceback):
             return False
 
 
-def macroexpand(tree, module, compiler=None, once=False):
+def macroexpand(tree, module, compiler=None, once=False, result_ok=True):
     """Expand the toplevel macros for the given Hy AST tree.
 
     Load the macros from the given `module`, then expand the (top-level) macros
@@ -338,7 +338,7 @@ def macroexpand(tree, module, compiler=None, once=False):
             from hy.compiler import Result
             from ast import AST
             if isinstance(obj, (Result, AST)):
-                return obj
+                return obj if result_ok else tree
 
             if isinstance(obj, Expression):
                 obj.module = inspect.getmodule(m)