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use super::*;
use crate::AllocatedShape;
////////////////////////////////////////////////////////////////////////////////////////////////////
// Sets
////////////////////////////////////////////////////////////////////////////////////////////////////
impl<const BORROW: bool> Partial<'_, BORROW> {
/// Initializes a set (HashSet, BTreeSet, etc.) if it hasn't been initialized before.
/// This is a prerequisite to `begin_set_item`/`set`/`end` or the shorthand `insert`.
///
/// `init_set` does not clear the set if it was previously initialized.
/// `init_set` does not push a new frame to the stack, and thus does not
/// require `end` to be called afterwards.
pub fn init_set(mut self) -> Result<Self, ReflectError> {
crate::trace!("init_set()");
let frame = self.frames_mut().last_mut().unwrap();
match &frame.tracker {
Tracker::Scalar if !frame.is_init => {
// that's good, let's initialize it
}
Tracker::Scalar => {
// is_init is true - initialized (perhaps from a previous round?) but should be a set tracker, let's fix that:
frame.tracker = Tracker::Set {
current_child: false,
};
return Ok(self);
}
Tracker::Set { .. } => {
if frame.is_init {
// already initialized, nothing to do
return Ok(self);
}
}
_ => {
return Err(ReflectError::UnexpectedTracker {
message: "init_set called but tracker isn't something set-like",
current_tracker: frame.tracker.kind(),
});
}
};
// Check that we have a Set
let set_def = match &frame.allocated.shape().def {
Def::Set(set_def) => set_def,
_ => {
return Err(ReflectError::OperationFailed {
shape: frame.allocated.shape(),
operation: "init_set can only be called on Set types",
});
}
};
let init_fn = set_def.vtable.init_in_place_with_capacity;
// Initialize the set with default capacity (0)
unsafe {
init_fn(frame.data, 0);
}
// Update tracker to Set state and mark as initialized
frame.tracker = Tracker::Set {
current_child: false,
};
frame.is_init = true;
Ok(self)
}
/// Begins pushing an element to the set.
/// The element should be set using `set()` or similar methods, then `end()` to complete.
pub fn begin_set_item(mut self) -> Result<Self, ReflectError> {
crate::trace!("begin_set_item()");
let frame = self.frames_mut().last_mut().unwrap();
// Check that we have a Set that's been initialized
let set_def = match &frame.allocated.shape().def {
Def::Set(set_def) => set_def,
_ => {
return Err(ReflectError::OperationFailed {
shape: frame.allocated.shape(),
operation: "init_set_item can only be called on Set types",
});
}
};
// Verify the tracker is in Set state and initialized
match &mut frame.tracker {
Tracker::Set { current_child } if frame.is_init => {
if *current_child {
return Err(ReflectError::OperationFailed {
shape: frame.allocated.shape(),
operation: "already pushing an element, call end() first",
});
}
*current_child = true;
}
_ => {
return Err(ReflectError::OperationFailed {
shape: frame.allocated.shape(),
operation: "must call init_set() before begin_set_item()",
});
}
}
// Get the element shape
let element_shape = set_def.t();
// Allocate space for the new element
let element_layout = match element_shape.layout.sized_layout() {
Ok(layout) => layout,
Err(_) => {
return Err(ReflectError::Unsized {
shape: element_shape,
operation: "begin_set_item: calculating element layout",
});
}
};
let element_ptr: *mut u8 = unsafe { ::alloc::alloc::alloc(element_layout) };
let Some(element_ptr) = NonNull::new(element_ptr) else {
return Err(ReflectError::OperationFailed {
shape: frame.allocated.shape(),
operation: "failed to allocate memory for set element",
});
};
// Push a new frame for the element
self.frames_mut().push(Frame::new(
PtrUninit::new(element_ptr.as_ptr()),
AllocatedShape::new(element_shape, element_layout.size()),
FrameOwnership::Owned,
));
Ok(self)
}
}