bazarr/libs/js2py/internals/operations.py

from __future__ import unicode_literals
from .simplex import *
from .conversions import *

# ------------------------------------------------------------------------------
# Unary operations


# -x
def minus_uop(self):
    return -to_number(self)


# +x
def plus_uop(self):  # +u
    return to_number(self)


# !x
def logical_negation_uop(self):  # !u  cant do 'not u' :(
    return not to_boolean(self)


# typeof x
def typeof_uop(self):
    if is_callable(self):
        return u'function'
    typ = Type(self).lower()
    if typ == u'null':
        typ = u'object'  # absolutely idiotic...
    return typ


# ~u
def bit_invert_uop(self):
    return float(to_int32(float(~to_int32(self))))


# void
def void_op(self):
    return undefined


UNARY_OPERATIONS = {
    '+': plus_uop,
    '-': minus_uop,
    '!': logical_negation_uop,
    '~': bit_invert_uop,
    'void': void_op,
    'typeof':
    typeof_uop,  # this one only for member expressions! for identifiers its slightly different...
}

# ------------------------------------------------------------------------------
# ----- binary ops -------

# Bitwise operators
#  <<, >>,  &, ^, |, ~


# <<
def bit_lshift_op(self, other):
    lnum = to_int32(self)
    rnum = to_uint32(other)
    shiftCount = rnum & 0x1F
    return float(to_int32(float(lnum << shiftCount)))


# >>
def bit_rshift_op(self, other):
    lnum = to_int32(self)
    rnum = to_uint32(other)
    shiftCount = rnum & 0x1F
    return float(to_int32(float(lnum >> shiftCount)))


# >>>
def bit_bshift_op(self, other):
    lnum = to_uint32(self)
    rnum = to_uint32(other)
    shiftCount = rnum & 0x1F
    return float(to_uint32(float(lnum >> shiftCount)))


# &
def bit_and_op(self, other):
    lnum = to_int32(self)
    rnum = to_int32(other)
    return float(to_int32(float(lnum & rnum)))


# ^
def bit_xor_op(self, other):
    lnum = to_int32(self)
    rnum = to_int32(other)
    return float(to_int32(float(lnum ^ rnum)))


# |
def bit_or_op(self, other):
    lnum = to_int32(self)
    rnum = to_int32(other)
    return float(to_int32(float(lnum | rnum)))


# Additive operators
# + and - are implemented here


# +
def add_op(self, other):
    if type(self) is float and type(other) is float:
        return self + other
    if type(self) is unicode and type(other) is unicode:
        return self + other
    # standard way...
    a = to_primitive(self)
    b = to_primitive(other)
    if type(a) is unicode or type(b) is unicode:  # string wins hehe
        return to_string(a) + to_string(b)
    return to_number(a) + to_number(b)


# -
def sub_op(self, other):
    return to_number(self) - to_number(other)


# Multiplicative operators
# *, / and % are implemented here


# *
def mul_op(self, other):
    return to_number(self) * to_number(other)


# /
def div_op(self, other):
    a = to_number(self)
    b = to_number(other)
    if b:
        return a / float(b)  # ensure at least one is a float.
    if not a or a != a:
        return NaN
    return Infinity if a > 0 else -Infinity


# %
def mod_op(self, other):
    a = to_number(self)
    b = to_number(other)
    if abs(a) == Infinity or not b:
        return NaN
    if abs(b) == Infinity:
        return a
    pyres = a % b  # different signs in python and javascript
    # python has the same sign as b and js has the same
    # sign as a.
    if a < 0 and pyres > 0:
        pyres -= abs(b)
    elif a > 0 and pyres < 0:
        pyres += abs(b)
    return float(pyres)


# Comparisons
# <, <=, !=, ==, >=, > are implemented here.
def abstract_relational_comparison(self, other,
                                   self_first=True):  # todo speed up!
    ''' self<other if self_first else other<self.
       Returns the result of the question: is self smaller than other?
       in case self_first is false it returns the answer of:
                                           is other smaller than self.
       result is PyJs type: bool or undefined'''

    px = to_primitive(self, 'Number')
    py = to_primitive(other, 'Number')
    if not self_first:  # reverse order
        px, py = py, px
    if not (Type(px) == 'String' and Type(py) == 'String'):
        px, py = to_number(px), to_number(py)
        if is_nan(px) or is_nan(py):
            return None  # watch out here!
        return px < py  # same cmp algorithm
    else:
        # I am pretty sure that python has the same
        # string cmp algorithm but I have to confirm it
        return px < py


# <
def less_op(self, other):
    res = abstract_relational_comparison(self, other, True)
    if res is None:
        return False
    return res


# <=
def less_eq_op(self, other):
    res = abstract_relational_comparison(self, other, False)
    if res is None:
        return False
    return not res


# >=
def greater_eq_op(self, other):
    res = abstract_relational_comparison(self, other, True)
    if res is None:
        return False
    return not res


# >
def greater_op(self, other):
    res = abstract_relational_comparison(self, other, False)
    if res is None:
        return False
    return res


# equality


def abstract_equality_op(self, other):
    ''' returns the result of JS == compare.
       result is PyJs type: bool'''
    tx, ty = Type(self), Type(other)
    if tx == ty:
        if tx == 'Undefined' or tx == 'Null':
            return True
        if tx == 'Number' or tx == 'String' or tx == 'Boolean':
            return self == other
        return self is other  # Object
    elif (tx == 'Undefined' and ty == 'Null') or (ty == 'Undefined'
                                                  and tx == 'Null'):
        return True
    elif tx == 'Number' and ty == 'String':
        return abstract_equality_op(self, to_number(other))
    elif tx == 'String' and ty == 'Number':
        return abstract_equality_op(to_number(self), other)
    elif tx == 'Boolean':
        return abstract_equality_op(to_number(self), other)
    elif ty == 'Boolean':
        return abstract_equality_op(self, to_number(other))
    elif (tx == 'String' or tx == 'Number') and is_object(other):
        return abstract_equality_op(self, to_primitive(other))
    elif (ty == 'String' or ty == 'Number') and is_object(self):
        return abstract_equality_op(to_primitive(self), other)
    else:
        return False


def abstract_inequality_op(self, other):
    return not abstract_equality_op(self, other)


def strict_equality_op(self, other):
    typ = Type(self)
    if typ != Type(other):
        return False
    if typ == 'Undefined' or typ == 'Null':
        return True
    if typ == 'Boolean' or typ == 'String' or typ == 'Number':
        return self == other
    else:  # object
        return self is other  # Id compare.


def strict_inequality_op(self, other):
    return not strict_equality_op(self, other)


def instanceof_op(self, other):
    '''checks if self is instance of other'''
    if not hasattr(other, 'has_instance'):
        return False
    return other.has_instance(self)


def in_op(self, other):
    '''checks if self is in other'''
    if not is_object(other):
        raise MakeError(
            'TypeError',
            "You can\'t use 'in' operator to search in non-objects")
    return other.has_property(to_string(self))


BINARY_OPERATIONS = {
    '+': add_op,
    '-': sub_op,
    '*': mul_op,
    '/': div_op,
    '%': mod_op,
    '<<': bit_lshift_op,
    '>>': bit_rshift_op,
    '>>>': bit_bshift_op,
    '|': bit_or_op,
    '&': bit_and_op,
    '^': bit_xor_op,
    '==': abstract_equality_op,
    '!=': abstract_inequality_op,
    '===': strict_equality_op,
    '!==': strict_inequality_op,
    '<': less_op,
    '<=': less_eq_op,
    '>': greater_op,
    '>=': greater_eq_op,
    'in': in_op,
    'instanceof': instanceof_op,
}