Merge pull request #109 from Kodiologist/false-false

`lif` adjustments

NEWS.rst

@@ -13,6 +13,7 @@ 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`.
+* `lif` now treats `False` as false.
 
 New Features
 ------------------------------
@@ -29,6 +30,7 @@ Bug Fixes
 * `loop` now works when nested.
 * `macroexpand-all` no longer crashes on stub macros.
 * `macroexpand-all` now recognizes macro names properly.
+* `lif` now works when renamed, or when invoked with `hy.R`.
 
 0.7.0 (released 2024-09-22; uses Hy ≥ 1)
 ======================================================

hyrule/control.hy

@@ -204,10 +204,10 @@
 (defmacro lif [#* args]
   #[[A "Lispy if" similar to :hy:func:`if` and :hy:func:`cond
   <hy.core.macros.cond>`. Its most notable property is that it tests
-  the condition with ``(is-not condition None)`` instead of ``(bool
-  condition)``, so values such as the integer 0, the empty string, and
-  ``False`` are considered true, not false. The general
-  syntax is
+  the condition values against ``None`` and ``False`` with
+  :hy:func:`is-not <hy.pyops.is-not>`, rather than calling
+  :py:class:`bool`. Thus, values such as the integer 0 and the empty
+  string are considered true, not false. The general syntax is
   ::
 
       (lif
@@ -220,19 +220,24 @@
   ::
 
       (cond
-        (is-not condition1 None) result1
-        (is-not condition2 None) result2
+        (is-not None condition1 False) result1
+        (is-not None condition2 False) result2
         …
-        True                     else-value)
-
-  When no condition matches and there is no else-value, the result is ``None``.]]
-  (setv n (len args))
-  (when n
-        (if (= n 1)
-            (get args 0)
-            `(if (is-not ~(get args 0) None)
-                 ~(get args 1)
-                 (lif ~@(cut args 2 None))))))
+        True                           else-value)
+
+  When no condition obtains and there is no else-value, the result is ``None``.]]
+
+  (_lif args))
+
+(defn _lif [args]
+  (cond
+    (= (len args) 1)
+      (get args 0)
+    args (do
+      (setv [condition result #* rest] args)
+      `(if (is-not None ~condition False)
+        ~result
+        ~(_lif rest)))))
 
 
 (defmacro list-n [count-form #* body]

pytest.ini

@@ -3,3 +3,4 @@
 python_functions=test_* hyx_test_*
 filterwarnings =
     ignore::pytest.PytestReturnNotNoneWarning
+    ignore::SyntaxWarning

tests/test_control.hy

@@ -1,6 +1,7 @@
 (require
   hyrule [block branch ebranch case ecase cfor do-n lif list-n unless])
 (import
+  types [ModuleType]
   pytest)
 
 
@@ -314,11 +315,12 @@
 
 
 (defn test-lif []
-  ;; None is false
+  ;; `None` and `False` are false
   (assert (= (lif None "true" "false") "false"))
+  (assert (= (lif False "true" "false") "false"))
 
   ;; But everything else is True!  Even falsey things.
-  (for [x [True False 0 "some-string" "" (+ 1 2 3)]]
+  (for [x [True 0 "some-string" "" (+ 1 2 3)]]
     (assert (= (lif x "true" "false") "true")))
 
   ;; Test ellif [sic]
@@ -327,7 +329,14 @@
                   None 1
                   x 2
                   3)
-             2)))
+             2))
+
+  ;; It should still work with a different name.
+  (assert (=
+    (hy.eval '(foo  None 1  0 2  8 3)
+      :module (ModuleType "M")
+      :macros {"foo" (get-macro lif)})
+    2)))
 
 
 (defn test-list-n []