Python ast.Eq() Examples

def test_MutateAST_visit_compare(idx, mut_op, lineno, compare_file, compare_expected_locs):
    """Test mutation of the == to != in the compare op."""
    tree = Genome(compare_file).ast

    # apply the mutation to the original tree copy
    testing_tree = deepcopy(tree)
    mutated_tree = MutateAST(target_idx=compare_expected_locs[idx], mutation=mut_op).visit(
        testing_tree
    )

    # revisit in read-only mode to gather the locations of the new nodes
    mast = MutateAST(readonly=True)
    mast.visit(mutated_tree)

    assert len(mast.locs) == 3

    # check that the lineno marked for mutation is changed, otherwise original ops should
    # still be present without modification
    for loc in mast.locs:
        if loc.lineno == lineno and loc.col_offset == 11:
            assert loc.op_type == mut_op
        else:
            assert loc.op_type in {ast.Eq, ast.Is, ast.In}  # based on compare_file fixture 

def verify_ast(expr, variables_and_values):
  """Verifies that |expr| is of the form
  expr ::= expr ( "or" | "and" ) expr
         | identifier "==" ( string | int )
  Also collects the variable identifiers and string/int values in the dict
  |variables_and_values|, in the form {'var': set([val1, val2, ...]), ...}.
  """
  assert isinstance(expr, (ast.BoolOp, ast.Compare))
  if isinstance(expr, ast.BoolOp):
    assert isinstance(expr.op, (ast.And, ast.Or))
    for subexpr in expr.values:
      verify_ast(subexpr, variables_and_values)
  else:
    assert isinstance(expr.left.ctx, ast.Load)
    assert len(expr.ops) == 1
    assert isinstance(expr.ops[0], ast.Eq)
    var_values = variables_and_values.setdefault(expr.left.id, set())
    rhs = expr.comparators[0]
    assert isinstance(rhs, (ast.Str, ast.Num))
    var_values.add(rhs.n if isinstance(rhs, ast.Num) else rhs.s) 

def cmpop(self, op):
    if isinstance(op, ast.Eq):
      return Operator.eq
    elif isinstance(op, ast.NotEq):
      return Operator.ne
    elif isinstance(op, ast.Lt):
      return Operator.lt
    elif isinstance(op, ast.LtE):
      return Operator.le
    elif isinstance(op, ast.Gt):
      return Operator.gt
    elif isinstance(op, ast.GtE):
      return Operator.ge
    else:
      raise Exception('Unexpected CmpOp (%s)'%(op.__class__))

  #Parses a function call (AST Call) 

def gen_compare(self, condition, yes_block, no_block):
        # print(dir(c), c.ops, c.comparators)
        # TODO: chained operators! ( 'a < b < c < d' )
        assert len(condition.ops) == len(condition.comparators)
        assert len(condition.ops) == 1
        op_map = {
            ast.Gt: ">",
            ast.GtE: ">=",
            ast.Lt: "<",
            ast.LtE: "<=",
            ast.Eq: "==",
            ast.NotEq: "!=",
        }

        a = self.gen_expr(condition.left)
        op = op_map[type(condition.ops[0])]
        b = self.gen_expr(condition.comparators[0])
        if a.ty is not b.ty:
            self.error(condition, "Type mismatch, types must be the same.")

        self.emit(ir.CJump(a, op, b, yes_block, no_block)) 

def visit_Assert(self, node):
        if is_binary_comparison(node):
            if is_comparison_type(node, ast.Eq):
                return make_call_node(node, assert_equal.__name__)
            elif is_comparison_type(node, ast.NotEq):
                return make_call_node(node, assert_not_equal.__name__)
            elif is_comparison_type(node, ast.In):
                return make_call_node(node, assert_in.__name__)
            elif is_comparison_type(node, ast.NotIn):
                return make_call_node(node, assert_not_in.__name__)
            elif is_comparison_type(node, ast.Is):
                return make_call_node(node, assert_is.__name__)
            elif is_comparison_type(node, ast.IsNot):
                return make_call_node(node, assert_is_not.__name__)
            elif is_comparison_type(node, ast.Lt):
                return make_call_node(node, assert_less_than.__name__)
            elif is_comparison_type(node, ast.LtE):
                return make_call_node(node, assert_less_than_equal_to.__name__)
            elif is_comparison_type(node, ast.Gt):
                return make_call_node(node, assert_greater_than.__name__)
            elif is_comparison_type(node, ast.GtE):
                return make_call_node(node, assert_greater_than_equal_to.__name__)

        return node 

def comp_op_rewrite(op: t.Union[Tokenizer, t.List[Tokenizer]]):
    """
    ('<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not')
    """
    if isinstance(op, list):
        op = tuple(map(lambda it: it.value, op))
    else:
        op = op.value

    return {
        '<': ast.Lt,
        '>': ast.Gt,
        '==': ast.Eq,
        '>=': ast.GtE,
        '<=': ast.LtE,
        '<>': lambda: raise_exp(NotImplemented),
        '!=': ast.NotEq,
        'in': ast.In,
        ('is', ): ast.Is,
        ('is', 'not'): ast.IsNot,
        ('not', 'in'): ast.NotIn,
    }[op]() 

def _check_compares(self, node: ast.Compare) -> None:
        is_all_equals = all(isinstance(op, ast.Eq) for op in node.ops)
        is_all_notequals = all(isinstance(op, ast.NotEq) for op in node.ops)
        can_be_longer = is_all_notequals or is_all_equals

        threshold = constants.MAX_COMPARES
        if can_be_longer:
            threshold += 1

        if len(node.ops) > threshold:
            self.add_violation(
                complexity.TooLongCompareViolation(
                    node,
                    text=str(len(node.ops)),
                    baseline=threshold,
                ),
            ) 

def visit_Compare(self, node):
        node.obj = bool()
        for n in [node.left] + node.comparators:
            self.visit(n)
        op, arg = node.ops[0], node.comparators[0]
# #         node.expr.target = self.getObj(arg)
# #         arg.target = self.getObj(node.expr)
        # detect specialized case for the test
        if isinstance(op, ast.Eq) and isinstance(node.left, ast.Name):
            # check wether it can be a case
            val = arg.obj
            if isinstance(val, bool):
                val = int(val)  # cast bool to int first
            if isinstance(val, (EnumItemType, int)):
                node.case = (node.left, val)
            # check whether it can be part of an edge check
            n = node.left.id
            if n in self.tree.sigdict:
                sig = self.tree.sigdict[n]
                v = self.getValue(arg)
                if v is not None:
                    if v == 0:
                        node.edge = sig.negedge
                    elif v == 1:
                        node.edge = sig.posedge 

def _check_constant(self, op: ast.cmpop, comparator: ast.expr) -> None:
        if not isinstance(op, (ast.Eq, ast.NotEq, ast.Is, ast.IsNot)):
            return
        real = get_assigned_expr(comparator)
        if not isinstance(real, (ast.List, ast.Dict, ast.Tuple)):
            return

        length = len(real.keys) if isinstance(
            real, ast.Dict,
        ) else len(real.elts)

        if not length:
            self.add_violation(FalsyConstantCompareViolation(comparator)) 

def visit_Compare (self, node):
        if len (node.comparators) > 1:
            self.emit ('(')

        left = node.left
        for index, (op, right) in enumerate (zip (node.ops, node.comparators)):
            if index:
                self.emit (' && ')

            if type (op) in (ast.In, ast.NotIn) or (self.allowOperatorOverloading and type (op) in (
                ast.Eq, ast.NotEq, ast.Lt, ast.LtE, ast.Gt, ast.GtE
            )):
                self.emit ('{} ('.format (self.filterId (

                    # Non-overloaded
                    '__in__' if type (op) == ast.In else
                    '!__in__' if type (op) == ast.NotIn else

                    # Overloaded
                    '__eq__' if type (op) == ast.Eq else
                    '__ne__' if type (op) == ast.NotEq else
                    '__lt__' if type (op) == ast.Lt else
                    '__le__' if type (op) == ast.LtE else
                    '__gt__' if type (op) == ast.Gt else
                    '__ge__' if type (op) == ast.GtE else

                    'Never here'
                )))
                self.visitSubExpr (node, left)
                self.emit (', ')
                self.visitSubExpr (node, right)
                self.emit (')')
            else:
                self.visitSubExpr (node, left)
                self.emit (' {0} '.format (self.operators [type (op)][0]))
                self.visitSubExpr (node, right)

            left = right

        if len (node.comparators) > 1:
            self.emit(')') 

def translate_In(self, op):
        return ast.Eq() if isinstance(op, ast.In) else op 

def visit_Assign(self, node, **kwargs):
        cmpr = ast.Compare(ops=[ast.Eq()], left=node.targets[0],
                           comparators=[node.value])
        return self.visit(cmpr) 

def _(
    src=each("assert x == y", "assert x is y", "assert x < y", "assert x is not y"),
    node_type=each(ast.Eq, ast.Is, ast.Lt, ast.IsNot),
):
    assert_node = ast.parse(src).body[0]
    assert is_comparison_type(assert_node, node_type) 

def gt_operator(d: ast.Eq):
    return "==" 

def compare_expected_locs():
    """The compare expected locations based on the fixture"""
    # Py 3.7
    if sys.version_info < (3, 8):
        return [
            LocIndex(ast_class="Compare", lineno=2, col_offset=11, op_type=ast.Eq),
            LocIndex(ast_class="CompareIs", lineno=5, col_offset=11, op_type=ast.Is),
            LocIndex(ast_class="CompareIn", lineno=8, col_offset=11, op_type=ast.In),
        ]
    # Py 3.8
    return [
        LocIndex(
            ast_class="Compare",
            lineno=2,
            col_offset=11,
            op_type=ast.Eq,
            end_lineno=2,
            end_col_offset=17,
        ),
        LocIndex(
            ast_class="CompareIs",
            lineno=5,
            col_offset=11,
            op_type=ast.Is,
            end_lineno=5,
            end_col_offset=17,
        ),
        LocIndex(
            ast_class="CompareIn",
            lineno=8,
            col_offset=11,
            op_type=ast.In,
            end_lineno=8,
            end_col_offset=17,
        ),
    ]


####################################################################################################
# TRANSFORMERS: IF FIXTURES
#################################################################################################### 

def translate_In(self, op):
        return ast.Eq() if isinstance(op, ast.In) else op 

def visit_Assign(self, node, **kwargs):
        cmpr = ast.Compare(ops=[ast.Eq()], left=node.targets[0],
                           comparators=[node.value])
        return self.visit(cmpr) 

def p_comp_op_3(p):
    '''comp_op : EQEQUAL'''
    #                  1
    p[0] = ast.Eq(rule=inspect.currentframe().f_code.co_name) 

def create_match_check(self, pattern: Pattern, data):
        """Given an ADT match pattern and a (Python) expression pointing to
        an ADT value, this generates a Python expression that checks if the
        ADT value matches the given pattern (returning True or False)."""

        # wildcard or var match everything
        if isinstance(pattern, (relay.PatternWildcard, relay.PatternVar)):
            return NameConstant(True)

        conds = []

        if isinstance(pattern, relay.PatternConstructor):
            # constructor patterns check whether the constructors match
            # and also the matches of any nested patterns

            # equiv: (arg.tag == patern_constructor.tag)
            conds.append(ast.Compare(ast.Attribute(data, 'tag', Load()),
                                     [ast.Eq()],
                                     [ast.Num(pattern.constructor.tag)]))

        assert isinstance(pattern, (relay.PatternConstructor, relay.PatternTuple))
        # now check for any nested patterns
        for i in range(len(pattern.patterns)):
            nested_pat = pattern.patterns[i]
            # can safely skip var or wildcard patterns: they will
            # never cause a check to fail
            if not isinstance(nested_pat, relay.PatternConstructor):
                continue

            # index into the value corresponding to the subpattern
            field_index = ast.Subscript(ast.Attribute(data, 'fields', Load()),
                                        ast.Index(Num(i)), Load())
            conds.append(self.create_match_check(nested_pat, field_index))

        # if we do not need to check nested pattern, just return the single check
        if len(conds) == 1:
            return conds[0]
        # otherwise AND together any nested checks
        return ast.BoolOp(ast.And(), conds) 

def visit_Compare(self, node: ast.Compare) -> Any:
        """Recursively visit the comparators and apply the operations on them."""
        # pylint: disable=too-many-branches
        left = self.visit(node=node.left)

        comparators = [self.visit(node=comparator) for comparator in node.comparators]

        result = None  # type: Optional[Any]
        for comparator, op in zip(comparators, node.ops):
            if isinstance(op, ast.Eq):
                comparison = left == comparator
            elif isinstance(op, ast.NotEq):
                comparison = left != comparator
            elif isinstance(op, ast.Lt):
                comparison = left < comparator
            elif isinstance(op, ast.LtE):
                comparison = left <= comparator
            elif isinstance(op, ast.Gt):
                comparison = left > comparator
            elif isinstance(op, ast.GtE):
                comparison = left >= comparator
            elif isinstance(op, ast.Is):
                comparison = left is comparator
            elif isinstance(op, ast.IsNot):
                comparison = left is not comparator
            elif isinstance(op, ast.In):
                comparison = left in comparator
            elif isinstance(op, ast.NotIn):
                comparison = left not in comparator
            else:
                raise NotImplementedError("Unhandled op of {}: {}".format(node, op))

            if result is None:
                result = comparison
            else:
                result = result and comparison

            left = comparator

        self.recomputed_values[node] = result
        return result 

def translate_In(self, op):
        return ast.Eq() if isinstance(op, ast.In) else op 

def visit_Assign(self, node, **kwargs):
        cmpr = ast.Compare(ops=[ast.Eq()], left=node.targets[0],
                           comparators=[node.value])
        return self.visit(cmpr) 

def __init__( s, component ):
    super().__init__( component )
    s.loop_var_env = set()
    s.tmp_var_env = set()

    # opmap maps an ast operator to its RTLIR counterpart.
    s.opmap = {
      # Bool operators
      # Note: we do not support boolean operators because Python does
      # not allow overloading And and Or operators. Using them in
      # expressions might lead to inconsistent semantics.
      # ast.And    : bir.And(),       ast.Or     : bir.Or(),
      # Unary operators
      # Note: ast.Not is disallowed because it is a boolean operator
      # ast.Not    : bir.Not(),
      ast.Invert : bir.Invert(),
      ast.UAdd   : bir.UAdd(),      ast.USub   : bir.USub(),
      # Binary operators
      ast.Add    : bir.Add(),       ast.Sub    : bir.Sub(),
      ast.Mult   : bir.Mult(),      ast.Div    : bir.Div(),
      ast.Mod    : bir.Mod(),       ast.Pow    : bir.Pow(),
      ast.LShift : bir.ShiftLeft(), ast.RShift : bir.ShiftRightLogic(),
      ast.BitOr  : bir.BitOr(),     ast.BitAnd : bir.BitAnd(),
      ast.BitXor : bir.BitXor(),
      # Compare bir.bir.operators
      ast.Eq     : bir.Eq(),        ast.NotEq  : bir.NotEq(),
      ast.Lt     : bir.Lt(),        ast.LtE    : bir.LtE(),
      ast.Gt     : bir.Gt(),        ast.GtE    : bir.GtE()
    }

  # Override 

def translate_In(self, op):
        return ast.Eq() if isinstance(op, ast.In) else op 

def visit_Assign(self, node, **kwargs):
        cmpr = ast.Compare(ops=[ast.Eq()], left=node.targets[0],
                           comparators=[node.value])
        return self.visit(cmpr) 

def invert(node):
    """
    Invert the operation in an ast node object (get its negation).

    Args:
        node: An ast node object.

    Returns:
        An ast node object containing the inverse (negation) of the input node.
    """
    inverse = {ast.Eq: ast.NotEq,
               ast.NotEq: ast.Eq,
               ast.Lt: ast.GtE,
               ast.LtE: ast.Gt,
               ast.Gt: ast.LtE,
               ast.GtE: ast.Lt,
               ast.Is: ast.IsNot,
               ast.IsNot: ast.Is,
               ast.In: ast.NotIn,
               ast.NotIn: ast.In}

    if type(node) == ast.Compare:
        op = type(node.ops[0])
        inverse_node = ast.Compare(left=node.left, ops=[inverse[op]()],
                                   comparators=node.comparators)
    elif isinstance(node, ast.BinOp) and type(node.op) in inverse:
        op = type(node.op)
        inverse_node = ast.BinOp(node.left, inverse[op](), node.right)
    elif type(node) == ast.NameConstant and node.value in [True, False]:
        inverse_node = ast.NameConstant(value=not node.value)
    else:
        inverse_node = ast.UnaryOp(op=ast.Not(), operand=node)

    return inverse_node 

def _eq(test: ast.Compare, n: int) -> bool:
        return (
            isinstance(test.ops[0], ast.Eq) and
            isinstance(test.comparators[0], ast.Num) and
            test.comparators[0].n == n
        ) 

def translate_In(self, op):
        return ast.Eq() if isinstance(op, ast.In) else op 

def visit_Assign(self, node, **kwargs):
        cmpr = ast.Compare(ops=[ast.Eq()], left=node.targets[0],
                           comparators=[node.value])
        return self.visit(cmpr) 

def compare_ast_to_ir2(ast_node: ast.Compare,
                       compilation_context: CompilationContext,
                       in_match_pattern: bool,
                       check_var_reference: Callable[[ast.Name], None],
                       match_lambda_argument_names: Set[str],
                       current_stmt_line: int):
    if len(ast_node.ops) != 1 or len(ast_node.comparators) != 1:
        raise CompilationError(compilation_context, ast_node, 'Comparison not supported.')  # pragma: no cover

    if in_match_pattern:
        raise CompilationError(compilation_context, ast_node,
                               'Comparisons are not allowed in match patterns')

    lhs = ast_node.left
    op = ast_node.ops[0]
    rhs = ast_node.comparators[0]

    if isinstance(op, ast.Eq):
        return eq_ast_to_ir2(lhs, rhs, compilation_context, in_match_pattern, check_var_reference, current_stmt_line)
    elif isinstance(op, ast.NotEq):
        return not_eq_ast_to_ir2(lhs, rhs, compilation_context, in_match_pattern, check_var_reference, current_stmt_line)
    elif isinstance(op, ast.In):
        return in_ast_to_ir2(lhs, rhs, compilation_context, in_match_pattern, check_var_reference, current_stmt_line)
    elif isinstance(op, ast.Lt):
        return int_comparison_ast_to_ir2(lhs, rhs, '<', compilation_context, in_match_pattern, check_var_reference, current_stmt_line)
    elif isinstance(op, ast.LtE):
        return int_comparison_ast_to_ir2(lhs, rhs, '<=', compilation_context, in_match_pattern, check_var_reference, current_stmt_line)
    elif isinstance(op, ast.Gt):
        return int_comparison_ast_to_ir2(lhs, rhs, '>', compilation_context, in_match_pattern, check_var_reference, current_stmt_line)
    elif isinstance(op, ast.GtE):
        return int_comparison_ast_to_ir2(lhs, rhs, '>=', compilation_context, in_match_pattern, check_var_reference, current_stmt_line)
    else:
        raise CompilationError(compilation_context, ast_node, 'Comparison not supported.')  # pragma: no cover