Fix Python SyntaxWarnings generated by compiled code (#998)

Fixes #996

Author: chrisrink10

CHANGELOG.md

@@ -11,18 +11,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  * Added `*default-data-reader-fn*` (#924)
  * Added `basilisp.pprint/print-table` function (#983)
  * Added `basilisp.core/read-all` function (#986)
- * Added various compiler arguments to cli commands (#989)
+ * Added various compiler arguments to CLI commands (#989)
 
 ### Changed
- * Improved on the nREPL server exception messages by matching that of the REPL user friendly format (#968)
+ * Improved on the nREPL server exception messages by matching that of the REPL user-friendly format (#968)
  * Types created via `deftype` and `reify` may declare supertypes as abstract (taking precedence over true `abc.ABC` types) and specify their member list using `^:abstract-members` metadata (#942)
- * Load functions (`load`, `load-file`, `load-reader`, etc) now return the value of the last form evaluated. (#984)
+ * Load functions (`load`, `load-file`, `load-reader`, etc.) now return the value of the last form evaluated. (#984)
 
 ### Fixed
- * Fixed inconsistent behavior with `basilisp.core/with` when the `body` contains more than one form (#981)
- * Fixed an issue with `basilisp.core/time` failing when called outside of the core ns (#991)
- * Fixed an issue with `basilisp.core/promise` where a thread waiting for a value from another thread might not wake up immediately upon delivery (#983).
- * Fixed using keyword as a function not returning the default value in some cases (#997)
+ * Fix inconsistent behavior with `basilisp.core/with` when the `body` contains more than one form (#981)
+ * Fix an issue with `basilisp.core/time` failing when called outside `basilisp.core` (#991)
+ * Fix an issue with `basilisp.core/promise` where a thread waiting for a value from another thread might not wake up immediately upon delivery (#983).
+ * Fix using keyword as a function not returning the default value in some cases (#997)
+ * Fix an issue where Python `SyntaxWarning`s would be emitted for certain compiled code (#???)
 
 ### Removed
  * Removed `python-dateutil` and `readerwriterlock` as dependencies, switching to standard library components instead (#976)

src/basilisp/core.lpy

@@ -1606,7 +1606,7 @@
   [x]
   (python/int x))
 
-(defn ^:inline boolean
+(defn ^:no-inline boolean
   "Coerce ``x`` to a boolean.
 
   Only ``false`` and ``nil`` are logical false and will return ``false``\\. All

src/basilisp/lang/compiler/optimizer.py

@@ -20,6 +20,12 @@ def _filter_dead_code(nodes: Iterable[ast.stmt]) -> List[ast.stmt]:
     return new_nodes
 
 
+def _needs_eq_operator(arg: ast.expr) -> bool:
+    return isinstance(arg, ast.Constant) and all(
+        arg.value is not v for v in (True, False, None, ...)
+    )
+
+
 @functools.singledispatch
 def _optimize_operator_call(  # pylint: disable=unused-argument
     fn: ast.AST, node: ast.Call
@@ -73,14 +79,25 @@ def _optimize_operator_call_attr(  # pylint: disable=too-many-return-statements
             "ne": ast.NotEq,
             "gt": ast.Gt,
             "ge": ast.GtE,
-            "is_": ast.Is,
-            "is_not": ast.IsNot,
         }.get(fn.attr)
         if compareop is not None:
             arg1, arg2 = node.args
             assert len(node.args) == 2
             return ast.Compare(arg1, [compareop()], [arg2])
 
+        isop = {
+            "is_": (ast.Is, ast.Eq),
+            "is_not": (ast.IsNot, ast.NotEq),
+        }.get(fn.attr)
+        if isop is not None:
+            isoper, eqoper = isop
+            arg1, arg2 = node.args
+            assert len(node.args) == 2
+            oper = (
+                eqoper if any(_needs_eq_operator(arg) for arg in node.args) else isoper
+            )
+            return ast.Compare(arg1, [oper()], [arg2])
+
         if fn.attr == "contains":
             arg1, arg2 = node.args
             assert len(node.args) == 2

src/basilisp/lang/util.py

@@ -14,6 +14,7 @@
 _DOUBLE_DOT_REPLACEMENT = "__DOT_DOT__"
 
 _MUNGE_REPLACEMENTS = {
+    "'": "__PRIME__",
     "+": "__PLUS__",
     "-": "_",
     "*": "__STAR__",

tests/basilisp/core_test.py

@@ -1083,7 +1083,7 @@ def test_ex_message_standard_exception(self):
         try:
             raise Exception("Exception Message")
         except Exception as e:
-            assert "Exception Message" is core.ex_message(e)
+            assert "Exception Message" == core.ex_message(e)
 
 
 class TestBitManipulation:

tests/basilisp/keyword_test.py

@@ -62,7 +62,7 @@ def test_keyword_as_function():
 
     assert kw == kw(lset.s(kw))
     assert None is kw(lset.s(1))
-    assert "hi" is kw(lset.s(1), default="hi")
+    assert "hi" == kw(lset.s(1), default="hi")
 
     assert 1 is kw(None, 1)
     assert None is kw(None, None)

tests/basilisp/symbol_test.py

@@ -56,7 +56,7 @@ def test_symbol_as_function():
 
     assert sym == sym(lset.s(sym))
     assert None is sym(lset.s(1))
-    assert "hi" is sym(lset.s(1), default="hi")
+    assert "hi" == sym(lset.s(1), default="hi")
 
     assert None is sym(lvector.v(1))