Struct Files 

pub struct Files { /* private fields */ }

files: reading, writing, listing, and removing files under one root.

Implementations

impl Files

pub fn rooted(root: PathBuf) -> Self

The real filesystem, reachable only inside root.

The root is the host’s choice, never the program’s: no path a program writes can name a place outside it, so granting files grants exactly this directory.

root need not exist yet. Until it does, every read answers that the path is not there; the first write creates it, along with any directories the written path names below it, so a program does not have to know whether the host prepared the tree.

pub fn in_memory(files: BTreeMap<String, String>) -> Self

A fake filesystem that lives only in this process, for tests.

Each key is a /-separated relative path, exactly as a program would write it, and its value is the file’s contents. A path with no key of its own but with keys below it is a directory.

pub fn tree(&self) -> Tree

The fake tree as this host holds it, for a test to read back.

A test drives the program and then asks this what the run left behind, which is the only way to assert on a file the program wrote rather than on the console line that says it did. A rooted host answers an empty tree: what a run wrote is on the filesystem, under the root the test chose, where the test can go and read it.

Trait Implementations

impl HostApi for Files

fn module_schema(&self) -> ModuleSchema

The whole of what this module declares about itself: the name Cove source uses, the capability a host must grant for it, the operations it exposes, the types it declares, and the kinds of resource it can open.

fn call(&self, op: &str, args: Vec<Value>) -> Result<Value, RuntimeError>

Invokes one operation.

fn call_resource( &self, handle: &ResourceHandle, op: &str, args: Vec<Value>, _back: &mut dyn Reentry, ) -> Result<Value, RuntimeError>

Invokes one operation on a handle this module issued.

fn call_with( &self, op: &str, args: Vec<Value>, back: &mut dyn Reentry, ) -> Result<Value, RuntimeError>

Invokes one operation.