Enum CalcError 

pub enum CalcError {
    ParseInt(ParseIntError),
    FromUtf8(FromUtf8Error),
    SymTab(SymTabError),
}

Represents all possible errors that can occur within the calculator.

The CalcError enum aggregates various error sources encountered during lexical analysis, parsing, and symbol-table operations. It implements std::error::Error via thiserror::Error, allowing ergonomic error propagation with the ? operator.

Each variant wraps a more specific underlying error type.

Variants

• CalcError::ParseInt:
  Returned when a numeric literal cannot be parsed into an integer, typically originating from std::num::ParseIntError.

• CalcError::FromUtf8:
  Returned when the input contains invalid UTF-8 byte sequences and cannot be decoded into a String.

• CalcError::SymTab:
  Wraps an error from the symbol table subsystem (SymTabError).

Example

// Example of a parse error bubbling up as CalcError::ParseInt
let result: Result<i64, CalcError> = i64::from_str("notanumber").map_err(CalcError::from);
assert!(matches!(result.unwrap_err(), CalcError::ParseInt(_)));

// Example of a symbol-table error propagation
let sym_err = SymTabError::InvalidIndex { index: 10, len: 3 };
let err = CalcError::from(sym_err);
assert!(matches!(err, CalcError::SymTab(_)));

Variants

ParseInt(ParseIntError)

An integer literal could not be parsed from its string representation.

Typically originates from std::num::ParseIntError.

FromUtf8(FromUtf8Error)

Failed to decode UTF-8 bytes from input.

Wraps a std::string::FromUtf8Error.

SymTab(SymTabError)

A symbol-table operation failed.

Wraps a SymTabError produced by symbol-table lookups or updates.

Trait Implementations

impl Debug for CalcError

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

Formats the value using the given formatter.

impl Display for CalcError

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

Formats the value using the given formatter.

impl Error for CalcError

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<FromUtf8Error> for CalcError

fn from(source: FromUtf8Error) -> Self

Converts to this type from the input type.

impl From<ParseIntError> for CalcError

fn from(source: ParseIntError) -> Self

Converts to this type from the input type.

impl From<SymTabError> for CalcError

fn from(source: SymTabError) -> Self

Converts to this type from the input type.