Destroy MarkerEvaluation for being pointless, fix two silly mistakes in tests and update packaging changes.

1 files changed, 21 insertions, 160 deletions

diff --git a/pkg_resources/__init__.py b/pkg_resources/__init__.py
index d81430c7..aa221347 100644
--- a/pkg_resources/__init__.py
+++ b/pkg_resources/__init__.py
@@ -1407,170 +1407,31 @@ def to_filename(name):
     return name.replace('-','_')
 
 
-class MarkerEvaluation(object):
-    values = {
-        'os_name': lambda: os.name,
-        'sys_platform': lambda: sys.platform,
-        'python_full_version': platform.python_version,
-        'python_version': lambda: platform.python_version()[:3],
-        'platform_version': platform.version,
-        'platform_machine': platform.machine,
-        'platform_python_implementation': platform.python_implementation,
-        'python_implementation': platform.python_implementation,
-    }
-
-    @classmethod
-    def is_invalid_marker(cls, text):
-        """
-        Validate text as a PEP 508 environment marker; return an exception
-        if invalid or False otherwise.
-        """
-        try:
-            cls.evaluate_marker(text)
-        except packaging.markers.InvalidMarker as e:
-            e.filename = None
-            e.lineno = None
-            return e
-        return False
-
-    @staticmethod
-    def normalize_exception(exc):
-        """
-        Given a SyntaxError from a marker evaluation, normalize the error
-        message:
-         - Remove indications of filename and line number.
-         - Replace platform-specific error messages with standard error
-           messages.
-        """
-        subs = {
-            'unexpected EOF while parsing': 'invalid syntax',
-            'parenthesis is never closed': 'invalid syntax',
-        }
-        exc.filename = None
-        exc.lineno = None
-        exc.msg = subs.get(exc.msg, exc.msg)
-        return exc
-
-    @classmethod
-    def and_test(cls, nodelist):
-        # MUST NOT short-circuit evaluation, or invalid syntax can be skipped!
-        items = [
-            cls.interpret(nodelist[i])
-            for i in range(1, len(nodelist), 2)
-        ]
-        return functools.reduce(operator.and_, items)
-
-    @classmethod
-    def test(cls, nodelist):
-        # MUST NOT short-circuit evaluation, or invalid syntax can be skipped!
-        items = [
-            cls.interpret(nodelist[i])
-            for i in range(1, len(nodelist), 2)
-        ]
-        return functools.reduce(operator.or_, items)
-
-    @classmethod
-    def atom(cls, nodelist):
-        t = nodelist[1][0]
-        if t == token.LPAR:
-            if nodelist[2][0] == token.RPAR:
-                raise SyntaxError("Empty parentheses")
-            return cls.interpret(nodelist[2])
-        msg = "Language feature not supported in environment markers"
-        raise SyntaxError(msg)
-
-    @classmethod
-    def comparison(cls, nodelist):
-        if len(nodelist) > 4:
-            msg = "Chained comparison not allowed in environment markers"
-            raise SyntaxError(msg)
-        comp = nodelist[2][1]
-        cop = comp[1]
-        if comp[0] == token.NAME:
-            if len(nodelist[2]) == 3:
-                if cop == 'not':
-                    cop = 'not in'
-                else:
-                    cop = 'is not'
-        try:
-            cop = cls.get_op(cop)
-        except KeyError:
-            msg = repr(cop) + " operator not allowed in environment markers"
-            raise SyntaxError(msg)
-        return cop(cls.evaluate(nodelist[1]), cls.evaluate(nodelist[3]))
-
-    @classmethod
-    def get_op(cls, op):
-        ops = {
-            symbol.test: cls.test,
-            symbol.and_test: cls.and_test,
-            symbol.atom: cls.atom,
-            symbol.comparison: cls.comparison,
-            'not in': lambda x, y: x not in y,
-            'in': lambda x, y: x in y,
-            '==': operator.eq,
-            '!=': operator.ne,
-            '<':  operator.lt,
-            '>':  operator.gt,
-            '<=': operator.le,
-            '>=': operator.ge,
-        }
-        if hasattr(symbol, 'or_test'):
-            ops[symbol.or_test] = cls.test
-        return ops[op]
-
-    @classmethod
-    def evaluate_marker(cls, text, extra=None):
-        """
-        Evaluate a PEP 508 environment marker on CPython 2.4+.
-        Return a boolean indicating the marker result in this environment.
-        Raise InvalidMarker if marker is invalid.
-
-        This implementation uses the 'pyparsing' module.
-        """
-        marker = packaging.markers.Marker(text)
-        return marker.evaluate()
+def invalid_marker(text):
+    """
+    Validate text as a PEP 508 environment marker; return an exception
+    if invalid or False otherwise.
+    """
+    try:
+        evaluate_marker(text)
+    except packaging.markers.InvalidMarker as e:
+        e.filename = None
+        e.lineno = None
+        return e
+    return False
 
-    @classmethod
-    def interpret(cls, nodelist):
-        while len(nodelist)==2: nodelist = nodelist[1]
-        try:
-            op = cls.get_op(nodelist[0])
-        except KeyError:
-            raise SyntaxError("Comparison or logical expression expected")
-        return op(nodelist)
 
-    @classmethod
-    def evaluate(cls, nodelist):
-        while len(nodelist)==2: nodelist = nodelist[1]
-        kind = nodelist[0]
-        name = nodelist[1]
-        if kind==token.NAME:
-            try:
-                op = cls.values[name]
-            except KeyError:
-                raise SyntaxError("Unknown name %r" % name)
-            return op()
-        if kind==token.STRING:
-            s = nodelist[1]
-            if not cls._safe_string(s):
-                raise SyntaxError(
-                    "Only plain strings allowed in environment markers")
-            return s[1:-1]
-        msg = "Language feature not supported in environment markers"
-        raise SyntaxError(msg)
+def evaluate_marker(text, extra=None):
+    """
+    Evaluate a PEP 508 environment marker.
+    Return a boolean indicating the marker result in this environment.
+    Raise InvalidMarker if marker is invalid.
 
-    @staticmethod
-    def _safe_string(cand):
-        return (
-            cand[:1] in "'\"" and
-            not cand.startswith('"""') and
-            not cand.startswith("'''") and
-            '\\' not in cand
-        )
+    This implementation uses the 'pyparsing' module.
+    """
+    marker = packaging.markers.Marker(text)
+    return marker.evaluate()
 
-invalid_marker = MarkerEvaluation.is_invalid_marker
-evaluate_marker = MarkerEvaluation.evaluate_marker
 
 class NullProvider:
     """Try to implement resources and metadata for arbitrary PEP 302 loaders"""