diff options
Diffstat (limited to 'jython-tosca-parser/src/main/resources/Lib/site-packages/pip/_vendor/distlib/markers.py')
| -rw-r--r-- | jython-tosca-parser/src/main/resources/Lib/site-packages/pip/_vendor/distlib/markers.py | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/jython-tosca-parser/src/main/resources/Lib/site-packages/pip/_vendor/distlib/markers.py b/jython-tosca-parser/src/main/resources/Lib/site-packages/pip/_vendor/distlib/markers.py new file mode 100644 index 0000000..afb19c6 --- /dev/null +++ b/jython-tosca-parser/src/main/resources/Lib/site-packages/pip/_vendor/distlib/markers.py @@ -0,0 +1,190 @@ +# -*- coding: utf-8 -*- +# +# Copyright (C) 2012-2013 Vinay Sajip. +# Licensed to the Python Software Foundation under a contributor agreement. +# See LICENSE.txt and CONTRIBUTORS.txt. +# +"""Parser for the environment markers micro-language defined in PEP 345.""" + +import ast +import os +import sys +import platform + +from .compat import python_implementation, string_types +from .util import in_venv + +__all__ = ['interpret'] + + +class Evaluator(object): + """ + A limited evaluator for Python expressions. + """ + + operators = { + 'eq': lambda x, y: x == y, + 'gt': lambda x, y: x > y, + 'gte': lambda x, y: x >= y, + 'in': lambda x, y: x in y, + 'lt': lambda x, y: x < y, + 'lte': lambda x, y: x <= y, + 'not': lambda x: not x, + 'noteq': lambda x, y: x != y, + 'notin': lambda x, y: x not in y, + } + + allowed_values = { + 'sys_platform': sys.platform, + 'python_version': '%s.%s' % sys.version_info[:2], + # parsing sys.platform is not reliable, but there is no other + # way to get e.g. 2.7.2+, and the PEP is defined with sys.version + 'python_full_version': sys.version.split(' ', 1)[0], + 'os_name': os.name, + 'platform_in_venv': str(in_venv()), + 'platform_release': platform.release(), + 'platform_version': platform.version(), + 'platform_machine': platform.machine(), + 'platform_python_implementation': python_implementation(), + } + + def __init__(self, context=None): + """ + Initialise an instance. + + :param context: If specified, names are looked up in this mapping. + """ + self.context = context or {} + self.source = None + + def get_fragment(self, offset): + """ + Get the part of the source which is causing a problem. + """ + fragment_len = 10 + s = '%r' % (self.source[offset:offset + fragment_len]) + if offset + fragment_len < len(self.source): + s += '...' + return s + + def get_handler(self, node_type): + """ + Get a handler for the specified AST node type. + """ + return getattr(self, 'do_%s' % node_type, None) + + def evaluate(self, node, filename=None): + """ + Evaluate a source string or node, using ``filename`` when + displaying errors. + """ + if isinstance(node, string_types): + self.source = node + kwargs = {'mode': 'eval'} + if filename: + kwargs['filename'] = filename + try: + node = ast.parse(node, **kwargs) + except SyntaxError as e: + s = self.get_fragment(e.offset) + raise SyntaxError('syntax error %s' % s) + node_type = node.__class__.__name__.lower() + handler = self.get_handler(node_type) + if handler is None: + if self.source is None: + s = '(source not available)' + else: + s = self.get_fragment(node.col_offset) + raise SyntaxError("don't know how to evaluate %r %s" % ( + node_type, s)) + return handler(node) + + def get_attr_key(self, node): + assert isinstance(node, ast.Attribute), 'attribute node expected' + return '%s.%s' % (node.value.id, node.attr) + + def do_attribute(self, node): + if not isinstance(node.value, ast.Name): + valid = False + else: + key = self.get_attr_key(node) + valid = key in self.context or key in self.allowed_values + if not valid: + raise SyntaxError('invalid expression: %s' % key) + if key in self.context: + result = self.context[key] + else: + result = self.allowed_values[key] + return result + + def do_boolop(self, node): + result = self.evaluate(node.values[0]) + is_or = node.op.__class__ is ast.Or + is_and = node.op.__class__ is ast.And + assert is_or or is_and + if (is_and and result) or (is_or and not result): + for n in node.values[1:]: + result = self.evaluate(n) + if (is_or and result) or (is_and and not result): + break + return result + + def do_compare(self, node): + def sanity_check(lhsnode, rhsnode): + valid = True + if isinstance(lhsnode, ast.Str) and isinstance(rhsnode, ast.Str): + valid = False + #elif (isinstance(lhsnode, ast.Attribute) + # and isinstance(rhsnode, ast.Attribute)): + # klhs = self.get_attr_key(lhsnode) + # krhs = self.get_attr_key(rhsnode) + # valid = klhs != krhs + if not valid: + s = self.get_fragment(node.col_offset) + raise SyntaxError('Invalid comparison: %s' % s) + + lhsnode = node.left + lhs = self.evaluate(lhsnode) + result = True + for op, rhsnode in zip(node.ops, node.comparators): + sanity_check(lhsnode, rhsnode) + op = op.__class__.__name__.lower() + if op not in self.operators: + raise SyntaxError('unsupported operation: %r' % op) + rhs = self.evaluate(rhsnode) + result = self.operators[op](lhs, rhs) + if not result: + break + lhs = rhs + lhsnode = rhsnode + return result + + def do_expression(self, node): + return self.evaluate(node.body) + + def do_name(self, node): + valid = False + if node.id in self.context: + valid = True + result = self.context[node.id] + elif node.id in self.allowed_values: + valid = True + result = self.allowed_values[node.id] + if not valid: + raise SyntaxError('invalid expression: %s' % node.id) + return result + + def do_str(self, node): + return node.s + + +def interpret(marker, execution_context=None): + """ + Interpret a marker and return a result depending on environment. + + :param marker: The marker to interpret. + :type marker: str + :param execution_context: The context used for name lookup. + :type execution_context: mapping + """ + return Evaluator(execution_context).evaluate(marker.strip()) |