Data.ByteString candidate 3

Donald Bruce Stewart dons at cse.unsw.edu.au
Wed Apr 26 19:14:57 EDT 2006


ashley:
> Donald Bruce Stewart wrote:
> 
> >Ok, here's what I've done:
> >    http://www.cse.unsw.edu.au/~dons/fps/new/
> 
> >The code has been partioned into:
> >    Data.ByteString         a Word8 only layer. All functions are in terms 
> >    of Word8
> 
> Do the file-handling Word8 functions always work correctly, or do they 
> do some kind of round-trip Char conversion? We've needed Word8 file 
> access, so this would be very helpful. For instance:
> 
>  writeFile "myfile" (pack [0..255])
> 
> This should always write exactly the bytes 0 to 255, with no 
> text-related weirdness such as charset remapping or newline conversion.

There is no round trip at all. Nothing is converted to Char in the Word8
code:

Prelude> Data.ByteString.writeFile "myfile" (Data.ByteString.pack [0..255])

$ od -t 'd1' myfile
0000000    0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
0000020   16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
0000040   32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47
0000060   48  49  50  51  52  53  54  55  56  57  58  59  60  61  62  63
0000100   64  65  66  67  68  69  70  71  72  73  74  75  76  77  78  79
0000120   80  81  82  83  84  85  86  87  88  89  90  91  92  93  94  95
0000140   96  97  98  99 100 101 102 103 104 105 106 107 108 109 110 111
0000160  112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
0000200  128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
0000220  144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
0000240  160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175
0000260  176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
0000300  192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
0000320  208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
0000340  224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
0000360  240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255

-- Don


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