我正在尝试一次从文件中读取一定数量的字节（如果我一次性读取了整个文件，则效果很好）。我在以下代码中添加了引号（/^[A-Z]+(?:'?[A-Z])?$/i.test("asdgrr'ssde"); // false
/^[A-Z]+(?:'?[A-Z])?$/i.test("asdgrr's"); // true
/^[A-Z]+(?:'?[A-Z])?$/i.test("asdgrr'S"); // true
/^[A-Z]+(?:'?[A-Z])?$/i.test("ATRr'g"); // true
/^[A-Z]+(?:'?[A-Z])?$/i.test("AGTrr'ssde"); // false
/^[A-Z]+(?:'?[A-Z])?$/i.test("asdssde"); // true
/^[A-Z]+(?:'?[A-Z])?$/i.test("arr'ss'de"); // false
，以帮助消除while循环中的修饰符子句错误，但现在我得到了ReadLemma。有关如何解决此问题的任何想法？
Error: an assume statement cannot be compiled读取功能是从文件读取的功能。如我所说，如果我读取文件的全部内容，它将很好地工作。没有引理，我得到这个错误include "Io.dfy"
lemma ReadLemma(fs: FileStream, file_offset: nat32, buffer: array?<byte>, num_bytes: int32)
requires fs.IsOpen();
requires fs.env.Valid();
requires fs.env.ok.ok();
requires fs.Name() in fs.env.files.state();
ensures fresh(buffer);
{
assume false;
}
method {:main} Main(ghost env: HostEnvironment?)
requires env != null && env.Valid() && env.ok.ok()
modifies env.ok
modifies env.files
{
var argc := HostConstants.NumCommandLineArgs(env);
if argc != 3 {
print "[USAGE]: mono cp.exe SrcFilename DstFilename!\n";
return;
}
var src := HostConstants.GetCommandLineArg(1, env);
var dst := HostConstants.GetCommandLineArg(2, env);
var srcResult := FileStream.FileExists(src, env);
var dstResult := FileStream.FileExists(dst, env);
if !srcResult {
print "Source File Does Not Exist!\n";
return;
}
if dstResult {
print "Destiny File Already Exist!\n";
return;
}
var srcSuccess, srcFs := FileStream.Open(src, env);
if !srcSuccess {
print "Failed to open src file!\n";
return;
}
var dstSuccess, dstFs := FileStream.Open(dst, env);
if !dstSuccess {
print "Failed to open dst file!\n";
return;
}
var success, len: int32 := FileStream.FileLength(src, env);
if !success {
print "Couldn't get stream size!\n";
return;
}
var BYTES_TO_READ := 256;
var file_offset, buffer, start, srcOk, dstOk := 0, new byte[BYTES_TO_READ], 0, true, true;
while file_offset as int + BYTES_TO_READ as int < len as int
decreases len as int - (file_offset as int + BYTES_TO_READ as int);
invariant srcFs.IsOpen() && srcFs.env.Valid() && srcFs.env.ok.ok()
invariant srcFs.Name() in srcFs.env.files.state()
{
ReadLemma(srcFs, file_offset as nat32, buffer, BYTES_TO_READ);
srcOk := srcFs.Read(file_offset as nat32, buffer, start, BYTES_TO_READ);
dstOk := dstFs.Write(file_offset as nat32, buffer, start, BYTES_TO_READ);
file_offset := file_offset + BYTES_TO_READ;
}
}
。