Enum FromPathError 

#[non_exhaustive]
pub enum FromPathError {
    Io(Error),
    NonUtf8Path,
    Unreadable,
    UnknownLanguage,
    Parse(MetricsError),
}

Error returned by Ast::from_path.

from_path reads, language-detects, and parses a file in one call, so it can fail in more ways than the in-memory Ast::parse (which only reports MetricsError). Unlike analyze, from_path does not silently skip files: every reason it cannot produce a tree surfaces as a distinct variant so the caller — who asked for this file’s tree — learns why.

The enum is #[non_exhaustive]; match with a trailing _ arm to stay forward-compatible.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Io(Error)

The file could not be read (a genuine I/O fault: missing file, permission denied, hardware error). Carries the underlying std::io::Error.

NonUtf8Path

The path is not valid UTF-8. The path doubles as the resulting FuncSpace name (an identifier used as a map key and in JSON output), so a lossy conversion is rejected rather than silently corrupting correlation — mirroring analyze’s strict default.

Unreadable

The file is empty, too small, binary, or encoded in an unsupported encoding (UTF-16, invalid UTF-8) — the same files analyze skips. from_path reuses the library’s text reader for byte-exact metric parity with analyze, so these inputs cannot yield a tree.

UnknownLanguage

No language is registered for the path (unknown extension and no recognizable shebang / mode line).

Parse(MetricsError)

The detected language’s per-language Cargo feature is not enabled in this build (carries the MetricsError::LanguageDisabled raised by Ast::parse).

Trait Implementations

impl Debug for FromPathError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for FromPathError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for FromPathError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<MetricsError> for FromPathError

fn from(e: MetricsError) -> Self

Converts to this type from the input type.