SwiftIntTypes.py

# ===--- SwiftIntTypes.py ----------------------------*- coding: utf-8 -*-===//
#
# This source file is part of the Swift.org open source project
#
# Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
# Licensed under Apache License v2.0 with Runtime Library Exception
#
# See http://swift.org/LICENSE.txt for license information
# See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors

# Bit counts for all int types
_all_integer_type_bitwidths = [8, 16, 32, 64]

# Number of bits in the biggest int type
int_max_bits = max(_all_integer_type_bitwidths)


def int_max(bits, signed):
    bits = bits - 1 if signed else bits
    bits = max(bits, 0)
    return (1 << bits) - 1


def int_min(bits, signed):
    return (-1 * int_max(bits, signed) - 1) if signed else 0


class SwiftIntegerType(object):

    def __init__(self, is_word, bits, is_signed):
        self.is_word = is_word
        self.bits = bits
        self.is_signed = is_signed

        if is_word:
            self.possible_bitwidths = [32, 64]
        else:
            self.possible_bitwidths = [bits]

        self.min = int_min(bits, is_signed)
        self.max = int_max(bits, is_signed)

        # Derived properties
        self.stdlib_name = \
            ('' if is_signed else 'U') + \
            'Int' + \
            ('' if is_word else str(bits))

        self.builtin_name = 'Int' + str(bits)

    def get_opposite_signedness(self):
        return SwiftIntegerType(self.is_word, self.bits, not self.is_signed)

    def __eq__(self, other):
        return self.is_word == other.is_word and \
            self.bits == other.bits and \
            self.is_signed == other.is_signed

    def __ne__(self, other):
        return not self.__eq__(other)


def all_integer_types(word_bits):
    for bitwidth in _all_integer_type_bitwidths:
        for is_signed in [False, True]:
            yield SwiftIntegerType(
                is_word=False, bits=bitwidth,
                is_signed=is_signed)

    for is_signed in [False, True]:
        yield SwiftIntegerType(
            is_word=True, bits=word_bits,
            is_signed=is_signed)

# 'truncatingBitPattern' initializer is defined if the conversion is truncating
# on any platform that Swift supports.


def should_define_truncating_bit_pattern_init(src_ty, dst_ty):
    # Don't define a truncating conversion between a type and itself.
    if src_ty == dst_ty:
        return False

    # Conversion to opposite signedness is never truncating.
    if src_ty == dst_ty.get_opposite_signedness():
        return False

    for src_ty_bits in src_ty.possible_bitwidths:
        for dst_ty_bits in dst_ty.possible_bitwidths:
            if src_ty_bits > dst_ty_bits:
                return True

    return False


def all_integer_type_names():
    return [self_ty.stdlib_name for self_ty in all_integer_types(0)]


def all_real_number_type_names():
    # FIXME , 'Float80' Revert until I figure out a test failure  # Float80
    # for i386 & x86_64
    return ['Float', 'Double']


def all_numeric_type_names():
    return all_integer_type_names() + all_real_number_type_names()


def numeric_type_names_macintosh_only():
    return ['Float80']

# Swift_Programming_Language/Expressions.html


def all_integer_binary_operator_names():
    return ['%', '<<', '>>', '&*', '&', '&+', '&-', '|', '^']


def all_integer_or_real_binary_operator_names():
    return ['*', '/', '+', '-', '..<', '...']


def all_arithmetic_comparison_operator_names():
    return ['<', '<=', '>', '>=', '==', '!=']


def all_integer_assignment_operator_names():
    return ['%=', '<<=', '>>=', '&=', '^=', '|=']


def all_integer_or_real_assignment_operator_names():
    return ['=', '*=', '/=', '+=', '-=']