Simplify gensym format

NEWS.rst

@@ -15,6 +15,9 @@ New Features
 * Added a special form `setx` to create Python 3.8 assignment expressions.
 * New list? function.
 * New tuple? function.
+* Gensyms now have a simpler format that's more concise when
+  mangled (e.g., `_hyx_XsemicolonXfooXvertical_lineX1235` is now
+  `_hyx_fooXUffffX1`).
 
 Bug Fixes
 ------------------------------

docs/language/api.rst

@@ -968,10 +968,10 @@ written without accidental variable name clashes.
 .. code-block:: clj
 
    => (gensym)
-   u':G_1235'
+   HySymbol('_G\uffff1')
 
    => (gensym "x")
-   u':x_1236'
+   HySymbol('_x\uffff2')
 
 .. seealso::
 

hy/core/language.hy

@@ -214,7 +214,7 @@ Return series of accumulated sums (or other binary function results)."
   (instance? HySymbol s))
 
 (import [threading [Lock]])
-(setv _gensym_counter 1234)
+(setv _gensym_counter 0)
 (setv _gensym_lock (Lock))
 
 (defn gensym [&optional [g "G"]]
@@ -224,7 +224,7 @@ Return series of accumulated sums (or other binary function results)."
   (global _gensym_lock)
   (.acquire _gensym_lock)
   (try (do (setv _gensym_counter (inc _gensym_counter))
-           (setv new_symbol (HySymbol (.format "_;{0}|{1}" g _gensym_counter))))
+           (setv new_symbol (HySymbol (.format "_{}\uffff{}" g _gensym_counter))))
        (finally (.release _gensym_lock)))
   new_symbol)
 

tests/native_tests/core.hy

@@ -282,12 +282,12 @@ result['y in globals'] = 'y' in globals()")
   (import [hy.models [HySymbol]])
   (setv s1 (gensym))
   (assert (isinstance s1 HySymbol))
-  (assert (= 0 (.find s1 "_;G|")))
+  (assert (= 0 (.find s1 "_G\uffff")))
   (setv s2 (gensym "xx"))
   (setv s3 (gensym "xx"))
-  (assert (= 0 (.find s2 "_;xx|")))
+  (assert (= 0 (.find s2 "_xx\uffff")))
   (assert (not (= s2 s3)))
-  (assert (not (= (str s2) (str s3)))))
+  (assert (not (= (string s2) (string s3)))))
 
 (defn test-identity []
   "NATIVE: testing the identity function"

tests/native_tests/native_macros.hy

@@ -166,9 +166,9 @@
   (setv _ast2 (hy-compile (hy-parse macro1) __name__))
   (setv s1 (to_source _ast1))
   (setv s2 (to_source _ast2))
-  ;; and make sure there is something new that starts with _;G|
-  (assert (in (mangle "_;G|") s1))
-  (assert (in (mangle "_;G|") s2))
+  ;; and make sure there is something new that starts with _G\uffff
+  (assert (in (mangle "_G\uffff") s1))
+  (assert (in (mangle "_G\uffff") s2))
   ;; but make sure the two don't match each other
   (assert (not (= s1 s2))))
 
@@ -193,8 +193,8 @@
   (setv _ast2 (hy-compile (hy-parse macro1) __name__))
   (setv s1 (to_source _ast1))
   (setv s2 (to_source _ast2))
-  (assert (in (mangle "_;a|") s1))
-  (assert (in (mangle "_;a|") s2))
+  (assert (in (mangle "_a\uffff") s1))
+  (assert (in (mangle "_a\uffff") s2))
   (assert (not (= s1 s2))))
 
 (defn test-defmacro/g! []
@@ -217,8 +217,8 @@
   (setv _ast2 (hy-compile (hy-parse macro1) __name__))
   (setv s1 (to_source _ast1))
   (setv s2 (to_source _ast2))
-  (assert (in (mangle "_;res|") s1))
-  (assert (in (mangle "_;res|") s2))
+  (assert (in (mangle "_res\uffff") s1))
+  (assert (in (mangle "_res\uffff") s2))
   (assert (not (= s1 s2)))
 
   ;; defmacro/g! didn't like numbers initially because they
@@ -247,8 +247,8 @@
   (setv _ast2 (hy-compile (hy-parse macro1) __name__))
   (setv s1 (to_source _ast1))
   (setv s2 (to_source _ast2))
-  (assert (in (mangle "_;res|") s1))
-  (assert (in (mangle "_;res|") s2))
+  (assert (in (mangle "_res\uffff") s1))
+  (assert (in (mangle "_res\uffff") s2))
   (assert (not (= s1 s2)))
 
   ;; defmacro/g! didn't like numbers initially because they