Would it be worth implementing some kind of typestate into the
language?
By typestate I mean a modifiable enum.
For example:
---
enum FState
{
none,
read,
write
}
struct File
{
//maybe another keyword other than enum
enum state = FState.none;
void openRead(string name)
{
//evalutaed in a way similar to static if
state = FState.read;
//...
}
void openWrite(string name)
{
state = FState.write;
//...
}
ubyte[] read(size_t) if (state == FState.read)
{
//...
}
void write(ubyte[]) if (state == FState.write)
{
//...
}
}
unittest
{
File f;
static assert(f.state == FState.none);
f.openRead("a.txt");
static assert(f.state == FState.read);
auto data = f.read(10);
}
---
We could use this "typestate" to implement:
Rust style memory management in a library
Safer Files (as shown)
Possibly other ideas
Thoughts?
