1 | """
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2 | Math operations, e.g. for arbitrary precision integers
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3 |
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4 | They are currently int64_t, rather than C int, but we want to upgrade to
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5 | heap-allocated integers.
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6 |
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7 | Regular int ops can use the normal operators + - * /, or maybe i_add() if we
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8 | really want. Does that make code gen harder or worse?
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9 |
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10 | Float ops could be + - * / too, but it feels nicer to develop a formal
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11 | interface?
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12 | """
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13 | from __future__ import print_function
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14 |
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15 | from typing import Tuple
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16 |
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17 |
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18 | class BigInt(object):
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19 |
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20 | def __init__(self, i):
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21 | # type: (int) -> None
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22 | self.i = i
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23 |
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24 | def __eq__(self, other):
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25 | # type: (object) -> bool
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26 |
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27 | # Disabled check
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28 | # Prevent possible mistakes. Could do this with other operators
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29 | # raise AssertionError('Use mops.Equal()')
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30 |
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31 | if not isinstance(other, BigInt):
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32 | raise AssertionError()
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33 |
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34 | # Used for hashing
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35 | return self.i == other.i
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36 |
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37 | def __gt__(self, other):
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38 | # type: (object) -> bool
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39 | raise AssertionError('Use functions in mops.py')
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40 |
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41 | def __ge__(self, other):
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42 | # type: (object) -> bool
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43 | raise AssertionError('Use functions in mops.py')
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44 |
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45 | def __hash__(self):
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46 | # type: () -> int
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47 | """For dict lookups."""
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48 | return hash(self.i)
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49 |
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50 |
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51 | ZERO = BigInt(0)
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52 | ONE = BigInt(1)
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53 | MINUS_ONE = BigInt(-1)
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54 | MINUS_TWO = BigInt(-2) # for printf
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55 |
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56 |
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57 | def ToStr(b):
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58 | # type: (BigInt) -> str
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59 | return str(b.i)
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60 |
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61 |
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62 | def ToOctal(b):
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63 | # type: (BigInt) -> str
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64 | return '%o' % b.i
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65 |
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66 |
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67 | def ToHexUpper(b):
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68 | # type: (BigInt) -> str
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69 | return '%X' % b.i
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70 |
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71 |
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72 | def ToHexLower(b):
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73 | # type: (BigInt) -> str
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74 | return '%x' % b.i
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75 |
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76 |
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77 | def FromStr(s, base=10):
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78 | # type: (str, int) -> BigInt
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79 | return BigInt(int(s, base))
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80 |
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81 |
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82 | def BigTruncate(b):
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83 | # type: (BigInt) -> int
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84 | """Only truncates in C++"""
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85 | return b.i
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86 |
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87 |
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88 | def IntWiden(i):
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89 | # type: (int) -> BigInt
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90 | """Only widens in C++"""
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91 | return BigInt(i)
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92 |
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93 |
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94 | def FromC(i):
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95 | # type: (int) -> BigInt
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96 | """A no-op in C, for RLIM_INFINITY"""
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97 | return BigInt(i)
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98 |
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99 |
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100 | def FromBool(b):
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101 | # type: (bool) -> BigInt
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102 | """Only widens in C++"""
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103 | return BigInt(1) if b else BigInt(0)
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104 |
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105 |
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106 | def ToFloat(b):
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107 | # type: (BigInt) -> float
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108 | """Used by float(42) in Oils"""
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109 | return float(b.i)
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110 |
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111 |
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112 | def FromFloat(f):
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113 | # type: (float) -> Tuple[bool, BigInt]
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114 | """Used by int(3.14) in Oils"""
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115 | try:
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116 | big = int(f)
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117 | except ValueError: # NAN
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118 | return False, MINUS_ONE
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119 | except OverflowError: # INFINITY
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120 | return False, MINUS_ONE
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121 | return True, BigInt(big)
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122 |
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123 |
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124 | # Can't use operator overloading
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125 |
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126 |
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127 | def Negate(b):
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128 | # type: (BigInt) -> BigInt
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129 | return BigInt(-b.i)
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130 |
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131 |
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132 | def Add(a, b):
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133 | # type: (BigInt, BigInt) -> BigInt
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134 | return BigInt(a.i + b.i)
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135 |
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136 |
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137 | def Sub(a, b):
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138 | # type: (BigInt, BigInt) -> BigInt
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139 | return BigInt(a.i - b.i)
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140 |
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141 |
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142 | def Mul(a, b):
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143 | # type: (BigInt, BigInt) -> BigInt
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144 | return BigInt(a.i * b.i)
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145 |
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146 |
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147 | def Div(a, b):
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148 | # type: (BigInt, BigInt) -> BigInt
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149 | """Integer division.
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150 |
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151 | Oils rounds toward zero.
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152 |
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153 | Python rounds toward negative infinity, while C++ rounds toward zero. We
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154 | have to work around Python a bit.
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155 | """
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156 | assert b.i != 0, b.i # divisor can't be zero -- caller checks
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157 |
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158 | # Only use Python // on non-negative numbers. Apply sign afterward.
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159 | sign = 1
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160 |
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161 | if a.i < 0:
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162 | pa = -a.i
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163 | sign = -1
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164 | else:
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165 | pa = a.i
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166 |
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167 | if b.i < 0:
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168 | pb = -b.i
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169 | sign = -sign
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170 | else:
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171 | pb = b.i
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172 |
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173 | return BigInt(sign * (pa // pb))
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174 |
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175 |
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176 | def Rem(a, b):
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177 | # type: (BigInt, BigInt) -> BigInt
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178 | """Integer remainder."""
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179 | assert b.i != 0, b.i # YSH divisor must be positive, but OSH can be negative
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180 |
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181 | # Only use Python % on non-negative numbers. Apply sign afterward.
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182 | if a.i < 0:
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183 | pa = -a.i
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184 | sign = -1
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185 | else:
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186 | pa = a.i
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187 | sign = 1
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188 |
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189 | if b.i < 0:
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190 | pb = -b.i
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191 | else:
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192 | pb = b.i
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193 |
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194 | return BigInt(sign * (pa % pb))
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195 |
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196 |
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197 | def Equal(a, b):
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198 | # type: (BigInt, BigInt) -> bool
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199 | return a.i == b.i
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200 |
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201 |
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202 | def Greater(a, b):
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203 | # type: (BigInt, BigInt) -> bool
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204 | return a.i > b.i
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205 |
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206 |
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207 | # GreaterEq, Less, LessEq can all be expressed as the 2 ops above
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208 |
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209 |
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210 | def LShift(a, b):
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211 | # type: (BigInt, BigInt) -> BigInt
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212 | assert b.i >= 0, b.i # Must be checked by caller
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213 | return BigInt(a.i << b.i)
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214 |
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215 |
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216 | def RShift(a, b):
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217 | # type: (BigInt, BigInt) -> BigInt
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218 | assert b.i >= 0, b.i # Must be checked by caller
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219 | return BigInt(a.i >> b.i)
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220 |
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221 |
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222 | def BitAnd(a, b):
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223 | # type: (BigInt, BigInt) -> BigInt
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224 | return BigInt(a.i & b.i)
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225 |
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226 |
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227 | def BitOr(a, b):
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228 | # type: (BigInt, BigInt) -> BigInt
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229 | return BigInt(a.i | b.i)
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230 |
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231 |
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232 | def BitXor(a, b):
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233 | # type: (BigInt, BigInt) -> BigInt
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234 | return BigInt(a.i ^ b.i)
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235 |
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236 |
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237 | def BitNot(a):
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238 | # type: (BigInt) -> BigInt
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239 | return BigInt(~a.i)
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