Added default reader features for matching Python version ranges (#593)

Author: chrisrink10

.circleci/config.yml

@@ -34,7 +34,8 @@ jobs:
 
   test-pypy:
     docker:
-      - image: pypy:3.6-7.2-slim-stretch
+      - image: pypy:3.6-7-slim-buster
+    parallelism: 3
     steps:
       - checkout
       - restore_cache:
@@ -46,7 +47,14 @@ jobs:
       - run:
           name: Run Tests
           command: |
-            tox -e pypy3
+            # Split tests by timing and print out the test files on each node
+            CCI_NODE_TESTS=$(circleci tests glob "tests/**/*_test.py" "tests/**/test_*.py" | circleci tests split --split-by=timings)
+            printf "Test files:\n"
+            echo "$CCI_NODE_TESTS"
+            printf "\n"
+
+            # Run the tests on the subset defined for this node
+            tox -e pypy3 -- $CCI_NODE_TESTS
       - save_cache:
           key: deps9-{{ .Branch }}-{{ checksum "tox.ini" }}-{{ checksum "Pipfile.lock" }}
           paths:

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  * Added `*basilisp-version*` and `*python-version*` Vars to `basilisp.core` (#584)
  * Added support for function decorators to `defn` (#585)
  * Added the current Python version (`:lpy36`, `:lpy37`, etc.) as a default reader feature for reader conditionals (#585)
+ * Added default reader features for matching Python version ranges (`:lpy36+`, `:lpy38-`, etc.) (#593)
  * Added `lazy-cat` function for lazily concatenating sequences (#588)
 
 ### Changed

src/basilisp/lang/reader.py

@@ -4,7 +4,6 @@
 import functools
 import io
 import re
-import sys
 import uuid
 from datetime import datetime
 from fractions import Fraction
@@ -50,7 +49,13 @@
     IWithMeta,
 )
 from basilisp.lang.obj import seq_lrepr as _seq_lrepr
-from basilisp.lang.runtime import Namespace, Var, get_current_ns, lrepr
+from basilisp.lang.runtime import (
+    READER_COND_DEFAULT_FEATURE_SET,
+    Namespace,
+    Var,
+    get_current_ns,
+    lrepr,
+)
 from basilisp.lang.typing import IterableLispForm, LispForm, ReaderForm
 from basilisp.lang.util import munge
 from basilisp.util import Maybe, partition
@@ -73,16 +78,6 @@
 READER_LINE_KW = keyword.keyword("line", ns="basilisp.lang.reader")
 READER_COL_KW = keyword.keyword("col", ns="basilisp.lang.reader")
 
-READER_COND_BASILISP_PY_VERSION_FEATURE_KW = keyword.keyword(
-    f"lpy{sys.version_info.major}{sys.version_info.minor}"
-)
-READER_COND_BASILISP_FEATURE_KW = keyword.keyword("lpy")
-READER_COND_DEFAULT_FEATURE_KW = keyword.keyword("default")
-READER_COND_DEFAULT_FEATURE_SET = lset.s(
-    READER_COND_BASILISP_FEATURE_KW,
-    READER_COND_DEFAULT_FEATURE_KW,
-    READER_COND_BASILISP_PY_VERSION_FEATURE_KW,
-)
 READER_COND_FORM_KW = keyword.keyword("form")
 READER_COND_SPLICING_KW = keyword.keyword("splicing?")
 

src/basilisp/lang/runtime.py

@@ -66,9 +66,11 @@
 NS_VAR_SYM = sym.symbol(NS_VAR_NAME, ns=CORE_NS)
 NS_VAR_NS = CORE_NS
 REPL_DEFAULT_NS = "basilisp.user"
+SUPPORTED_PYTHON_VERSIONS = frozenset({(3, 6), (3, 7), (3, 8)})
 
 # Private string constants
 _COMPILER_OPTIONS_VAR_NAME = "*compiler-options*"
+_DEFAULT_READER_FEATURES_VAR_NAME = "*default-reader-features*"
 _GENERATED_PYTHON_VAR_NAME = "*generated-python*"
 _PRINT_GENERATED_PY_VAR_NAME = "*print-generated-python*"
 _PRINT_DUP_VAR_NAME = "*print-dup*"
@@ -132,6 +134,41 @@
     _VAR,
 )
 
+
+# Reader Conditional default features
+def _supported_python_versions_features() -> Iterable[kw.Keyword]:
+    """Yield successive reader features corresponding to the various Python
+    `major`.`minor` versions the current Python VM corresponds to amongst the
+    set of supported Python versions.
+
+    For example, for Python 3.6, we emit:
+     - :lpy36  - to exactly match Basilisp running on Python 3.6
+     - :lpy36+ - to match Basilisp running on Python 3.6 and later versions
+     - :lpy36- - to match Basilisp running on Python 3.6 and earlier versions
+     - :lpy37- - to match Basilisp running on Python 3.7 and earlier versions
+     - :lpy38- - to match Basilisp running on Python 3.8 and earlier versions"""
+    feature_kw = lambda major, minor, suffix="": kw.keyword(
+        f"lpy{major}{minor}{suffix}"
+    )
+
+    yield feature_kw(sys.version_info.major, sys.version_info.minor)
+
+    current = (sys.version_info.major, sys.version_info.minor)
+    for version in SUPPORTED_PYTHON_VERSIONS:
+        if current <= version:
+            yield feature_kw(version[0], version[1], suffix="-")
+        if current >= version:
+            yield feature_kw(version[0], version[1], suffix="+")
+
+
+READER_COND_BASILISP_FEATURE_KW = kw.keyword("lpy")
+READER_COND_DEFAULT_FEATURE_KW = kw.keyword("default")
+READER_COND_DEFAULT_FEATURE_SET = lset.s(
+    READER_COND_BASILISP_FEATURE_KW,
+    READER_COND_DEFAULT_FEATURE_KW,
+    *_supported_python_versions_features(),
+)
+
 CompletionMatcher = Callable[[Tuple[sym.Symbol, Any]], bool]
 CompletionTrimmer = Callable[[Tuple[sym.Symbol, Any]], str]
 
@@ -173,7 +210,7 @@ def __repr__(self):  # pragma: no cover
         return f"Unbound(var={self.var})"
 
     def __eq__(self, other):
-        return isinstance(other, Unbound) and self.var == other.var
+        return self is other or (isinstance(other, Unbound) and self.var == other.var)
 
 
 class Var(IDeref, ReferenceBase):
@@ -1767,6 +1804,14 @@ def in_ns(s: sym.Symbol):
         dynamic=True,
     )
 
+    # Dynamic Var for introspecting the default reader featureset
+    Var.intern(
+        CORE_NS_SYM,
+        sym.symbol(_DEFAULT_READER_FEATURES_VAR_NAME),
+        READER_COND_DEFAULT_FEATURE_SET,
+        dynamic=True,
+    )
+
     # Dynamic Vars examined by the compiler for generating Python code for debugging
     Var.intern(
         CORE_NS_SYM,

tests/basilisp/runtime_test.py

@@ -1,3 +1,4 @@
+import sys
 from decimal import Decimal
 from fractions import Fraction
 
@@ -17,6 +18,38 @@
 from tests.basilisp.helpers import get_or_create_ns
 
 
+def test_is_supported_python_version():
+    v = sys.version_info
+    assert (v.major, v.minor) in runtime.SUPPORTED_PYTHON_VERSIONS
+
+
+@pytest.mark.parametrize(
+    "feature",
+    {
+        (3, 6): frozenset(
+            map(
+                keyword.keyword,
+                ["lpy36", "default", "lpy", "lpy36-", "lpy36+", "lpy37-", "lpy38-"],
+            )
+        ),
+        (3, 7): frozenset(
+            map(
+                keyword.keyword,
+                ["lpy37", "default", "lpy", "lpy37-", "lpy37+", "lpy36+", "lpy38-"],
+            )
+        ),
+        (3, 8): frozenset(
+            map(
+                keyword.keyword,
+                ["lpy38", "default", "lpy", "lpy38-", "lpy38+", "lpy37+", "lpy36+"],
+            )
+        ),
+    }[(sys.version_info.major, sys.version_info.minor)],
+)
+def test_reader_default_featureset(feature):
+    assert feature in runtime.READER_COND_DEFAULT_FEATURE_SET
+
+
 def test_first():
     assert None is runtime.first(None)
     assert None is runtime.first(llist.l())