Merge pull request #107 from Kodiologist/rm-walk

Remove `walk` and overhaul `macroexpand-all`

NEWS.rst

@@ -3,10 +3,16 @@
 Unreleased
 ======================================================
 
+Removals
+------------------------------
+* `walk`, `prewalk`, and `postwalk` have been removed. Use `map-model` and
+  `map-hyseq` instead.
+
 Breaking Changes
 ------------------------------
 * `recur` is now a real object that must be imported from Hyrule when
   using `loop`.
+* `macroexpand-all` now uses the same parameters as `hy.macroexpand`.
 
 New Features
 ------------------------------
@@ -19,6 +25,8 @@ Bug Fixes
 * `map-model` now calls `as-model` only once (before its own recursion),
   and it does so unconditionally.
 * `loop` now works when nested.
+* `macroexpand-all` no longer crashes on stub macros.
+* `macroexpand-all` now recognizes macro names properly.
 
 0.7.0 (released 2024-09-22; uses Hy ≥ 1)
 ======================================================

docs/index.rst

@@ -47,10 +47,7 @@ Reference
 
 .. hy:autofunction:: assoc
 .. hy:automacro:: ncut
-.. hy:autofunction:: postwalk
-.. hy:autofunction:: prewalk
 .. hy:autotag:: s
-.. hy:autofunction:: walk
 
 ``control`` — Control structures
 ----------------------------------------------------------------------

hyrule/collections.hy

@@ -113,168 +113,6 @@
         sym))
 
 
-(defn postwalk [f form]
-  "Performs depth-first, post-order traversal of ``form``. Calls ``f`` on
-  each sub-form, uses ``f`` 's return value in place of the original.
-
-  Examples:
-    ::
-
-       => (import hyrule.contrib.walk [postwalk])
-       => (setv trail '([1 2 3] [4 [5 6 [7]]]))
-       => (defn walking [x]
-       ...   (print \"Walking\" x :sep \"\\n\")
-       ...   x)
-       => (postwalk walking trail)
-       Walking
-       1
-       Walking
-       2
-       Walking
-       3
-       Walking
-       hy.models.Expression([
-         hy.models.Integer(1),
-         hy.models.Integer(2),
-         hy.models.Integer(3)])
-       Walking
-       4
-       Walking
-       5
-       Walking
-       6
-       Walking
-       7
-       Walking
-       hy.models.Expression([
-         hy.models.Integer(7)])
-       Walking
-       hy.models.Expression([
-         hy.models.Integer(5),
-         hy.models.Integer(6),
-         hy.models.List([
-           hy.models.Integer(7)])])
-       Walking
-       hy.models.Expression([
-         hy.models.Integer(4),
-         hy.models.List([
-           hy.models.Integer(5),
-           hy.models.Integer(6),
-           hy.models.List([
-             hy.models.Integer(7)])])])
-       Walking
-       hy.models.Expression([
-         hy.models.List([
-           hy.models.Integer(1),
-           hy.models.Integer(2),
-           hy.models.Integer(3)]),
-         hy.models.List([
-           hy.models.Integer(4),
-           hy.models.List([
-             hy.models.Integer(5),
-             hy.models.Integer(6),
-             hy.models.List([
-               hy.models.Integer(7)])])])])
-       '([1 2 3] [4 [5 6 [7]]]))
-  "
-  (walk (partial postwalk f) f form))
-
-
-(defn prewalk [f form]
-  "Performs depth-first, pre-order traversal of ``form``. Calls ``f`` on
-  each sub-form, uses ``f`` 's return value in place of the original.
-
-  Examples:
-    ::
-
-       => (import hyrule.contrib.walk [prewalk])
-       => (setv trail '([1 2 3] [4 [5 6 [7]]]))
-       => (defn walking [x]
-       ...  (print \"Walking\" x :sep \"\\n\")
-       ...  x)
-       => (prewalk walking trail)
-       Walking
-       hy.models.Expression([
-         hy.models.List([
-           hy.models.Integer(1),
-           hy.models.Integer(2),
-           hy.models.Integer(3)]),
-         hy.models.List([
-           hy.models.Integer(4),
-           hy.models.List([
-             hy.models.Integer(5),
-             hy.models.Integer(6),
-             hy.models.List([
-               hy.models.Integer(7)])])])])
-       Walking
-       hy.models.List([
-         hy.models.Integer(1),
-         hy.models.Integer(2),
-         hy.models.Integer(3)])
-       Walking
-       1
-       Walking
-       2
-       Walking
-       3
-       Walking
-       hy.models.List([
-         hy.models.Integer(4),
-         hy.models.List([
-           hy.models.Integer(5),
-           hy.models.Integer(6),
-           hy.models.List([
-             hy.models.Integer(7)])])])
-       Walking
-       4
-       Walking
-       hy.models.List([
-         hy.models.Integer(5),
-         hy.models.Integer(6),
-         hy.models.List([
-           hy.models.Integer(7)])])
-       Walking
-       5
-       Walking
-       6
-       Walking
-       hy.models.List([
-         hy.models.Integer(7)])
-       Walking
-       7
-       '([1 2 3] [4 [5 6 [7]]])
-  "
-  (walk (partial prewalk f) (fn [x] x) (f form)))
-
-
-(defn walk [inner outer form]
-  "``walk`` traverses ``form``, an arbitrary data structure. Applies
-  ``inner`` to each element of form, building up a data structure of the
-  same type.  Applies ``outer`` to the result.
-
-  Examples:
-    ::
-
-       => (import hyrule.contrib.walk [walk])
-       => (setv a '(a b c d e f))
-       => (walk ord (fn [x] x)  a)
-       '(97 98 99 100 101 102)
-
-    ::
-
-       => (walk ord (fn [x] (get x 0)) a)
-       97
-  "
-  (cond
-    (isinstance form hy.models.Expression)
-      (outer (hy.models.Expression (map inner form)))
-    (or (isinstance form #(hy.models.Sequence list)))
-      ((type form) (outer (hy.models.Expression (map inner form))))
-    (coll? form)
-      (walk inner outer (list form))
-    True
-      (outer form)))
-
 (defn by2s [x]
   #[[Returns the given iterable in pairs.
     (list (by2s (range 6))) => [#(0 1) #(2 3) #(4 5)] #]]

hyrule/control.hy

@@ -1,7 +1,7 @@
 (require
   hyrule.macrotools [defmacro!])
 (import
-  hyrule.collections [prewalk by2s]
+  hyrule.collections [by2s]
   hyrule.iterables [coll?]
   hyrule.misc [inc])
 
@@ -267,7 +267,7 @@
 
   Don't forget to ``(import hyrule [recur])``. The :hy:class:`recur` object holds the arguments for the next call. When the function returns a :hy:class:`recur`, ``loop`` calls it again with the new arguments. Otherwise, ``loop`` ends and the final value is returned. Thus, what would be a nested set of recursive calls becomes a series of calls that are resolved entirely in sequence.
 
-  Note that while ``loop`` uses the same syntax as ordinary function definitions for its lambda list, all arguments other than ``#* args`` and ``#* kwargs`` must have a default value, because the function will first be called with no arguments."
+  Note that while ``loop`` uses the same syntax as ordinary function definitions for its lambda list, all parameters other than ``#* args`` and ``#** kwargs`` must have a default value, because the function will first be called with no arguments."
 
   `(do
     (defn ~g!f ~bindings

hyrule/macrotools.hy

@@ -1,7 +1,6 @@
 (import
   hy.compiler [HyASTCompiler calling-module]
-  hyrule.iterables [coll? flatten]
-  hyrule.collections [walk])
+  hyrule.iterables [coll? flatten])
 
 
 (defmacro defmacro-kwargs [name params #* body]
@@ -199,44 +198,61 @@
         (setv ~~gs ~~os)
         ~~res)))
 
-(defn macroexpand-all [form [ast-compiler None]]
-  "Recursively performs all possible macroexpansions in form, using the ``require`` context of ``module-name``.
-  `macroexpand-all` assumes the calling module's context if unspecified.
-  "
-  (setv quote-level 0
-        ast-compiler (or ast-compiler (HyASTCompiler (calling-module))))
-  (defn traverse [form]
-    (walk expand (fn [x] x) form))
-  (defn expand [form]
+(defn macroexpand-all [model [module None] [macros None]]
+  "As :hy:func:`hy.macroexpand`, but with recursive descent through the input model, attempting to expand all macro calls throughout the tree::
+
+    (defmacro m [] 5)
+    (print (hy.repr (hy.macroexpand '(m))))
+      ; => '5
+    (print (hy.repr (hy.macroexpand '(do (m)))))
+      ; => '(do (m))
+    (print (hy.repr (macroexpand-all '(do (m)))))
+      ; => '(do 5)
+
+  ``macroexpand-all`` even expands macros in unquoted portions of quasiquoted forms::
+
+    (print (hy.repr (macroexpand-all '(do `[4 (m) ~(m) 6]))))
+      ; => '(do `[4 (m) ~5 6])"
+
+  (setv  quote-level 0  module (or module (hy.compiler.calling-module)))
+
+  (defn expand [m]
+
+    (when (not (and (isinstance m hy.models.Expression) m))
+      (return))
+    (setv [head #* args] m)
+    (when (not (isinstance head hy.models.Symbol))
+      (return))
+    (setv mhead (hy.mangle head))
     (nonlocal quote-level)
-    ;; manages quote levels
-    (defn +quote [[x 1]]
-      (nonlocal quote-level)
-      (setv head (get form 0))
-      (+= quote-level x)
-      (when (< quote-level 0)
-        (raise (TypeError "unquote outside of quasiquote")))
-      (setv res (traverse (cut form 1 None)))
-      (-= quote-level x)
-      `(~head ~@res))
-    (if (and (isinstance form hy.models.Expression) form)
-        (cond quote-level
-               (cond (in (get form 0) '[unquote unquote-splice])
-                       (+quote -1)
-                     (= (get form 0) 'quasiquote) (+quote)
-                     True (traverse form))
-              (= (get form 0) 'quote) form
-              (= (get form 0) 'quasiquote) (+quote)
-              (= (get form 0) (hy.models.Symbol "require")) (do
-               (ast-compiler.compile form)
-               (return))
-              (in (get form 0) '[except unpack-mapping])
-               (hy.models.Expression [(get form 0) #* (traverse (cut form 1 None))])
-              True (traverse (hy.macros.macroexpand form ast-compiler.module ast-compiler :result-ok False)))
-        (if (coll? form)
-            (traverse form)
-            form)))
-  (expand form))
+    (when (and (= quote-level 0) (= mhead "quote"))
+      (return m))
+
+    (setv quote-adjustment None)
+    (cond
+      (and quote-level (in mhead ["unquote" "unquote_splice"]))
+        (setv quote-adjustment -1)
+      (= mhead "quasiquote")
+        (setv quote-adjustment 1))
+    (when quote-adjustment
+      (+= quote-level quote-adjustment))
+    (setv new (if
+       (or
+         quote-level
+         quote-adjustment
+         (in mhead (.split "unquote unquote_splice unpack_mapping except hyx_exceptXasteriskX finally else")))
+           ; These stub macros would cause a crash if we tried to
+           ; expand them.
+      `(~head ~@(gfor  e args  (map-model e expand)))
+      (map-hyseq
+        (hy.macroexpand m module macros)
+        (fn [e] (map-model e expand)))))
+    (when quote-adjustment
+      (-= quote-level quote-adjustment))
+
+    new)
+
+  (map-model model expand))
 
 
 (defn map-model [x f]

tests/test_macrotools.hy

@@ -107,7 +107,23 @@
              'f"{(a 1)}"))
 
   (assert (= (get (macroexpand-all '(require-macro)) -1)
-             '(setv blah 1))))
+             '(setv blah 1)))
+
+  ; Avoid crashing on stub macros like `else`.
+  (assert (= (macroexpand-all '(for [c "ab"] (else (foo-walk))))
+             '(for [c "ab"] (else 42))))
+
+  ; Check quoting.
+  (assert (= (macroexpand-all ''(foo-walk))
+             ''(foo-walk)))
+  (assert (= (macroexpand-all `(do (foo-walk)))
+             '(do 42)))
+  (assert (= (macroexpand-all '`(do (foo-walk)))
+             '`(do (foo-walk))))
+  (assert (= (macroexpand-all '`(do ~(foo-walk)))
+             '`(do ~42)))
+  (assert (= (macroexpand-all '`(do (unquote_splice (foo-walk))))
+             '`(do (unquote_splice 42)))))
 
 
 (defn test-map-hyseq []