Enum ArenaError 

pub enum ArenaError {
    OutOfMemory,
    IndexOutOfBounds,
    IndexNotAllocated,
    InvalidArgument,
    TraceError,
    Cyclic,
    TypeError,
    ParseError,
    ArithmeticOverflow,
    DivisionByZero,
    UnboundVariable,
    NotCallable,
    ImmutableEnvironment,
}

Errors that can occur during arena and Lisp operations.

Each variant captures a specific failure mode, enabling precise diagnostics without heap-allocated error messages.

Variants

OutOfMemory

Arena is full, cannot allocate more cells.

IndexOutOfBounds

Index exceeds the arena’s capacity (>= N).

IndexNotAllocated

Index refers to a slot that has been freed or was never allocated.

InvalidArgument

An argument to an arena operation was invalid (e.g., zero-length contiguous allocation).

TraceError

An error occurred during garbage collection tracing. This can happen if the mark stack overflows or roots are invalid.

Cyclic

Cycle detected during structure traversal (e.g., graph traversal or recursive data structure operations).

TypeError

A value had the wrong type for the requested operation (e.g., expected a Number but found a Cons).

ParseError

A parse error occurred while reading an S-expression.

ArithmeticOverflow

Checked arithmetic overflowed (e.g., addition, negation).

DivisionByZero

Division or modulo by zero.

UnboundVariable

A variable was not found in the current or global environment.

NotCallable

Attempted to call a value that is not a function (lambda or builtin).

ImmutableEnvironment

Attempted to mutate an immutable environment (e.g., the ground environment).

Implementations

impl ArenaError

pub const fn as_str(&self) -> &'static str

Get a human-readable description of the error.

pub const fn is_out_of_memory(&self) -> bool

Check if this error indicates the arena is full.

pub const fn is_invalid_index(&self) -> bool

Check if this error indicates an invalid index (out of bounds or not allocated).

pub const fn is_trace_error(&self) -> bool

Check if this error is related to garbage collection.

Trait Implementations

impl Clone for ArenaError

fn clone(&self) -> ArenaError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ArenaError

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

Formats the value using the given formatter.

impl Display for ArenaError

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

Formats the value using the given formatter.

impl PartialEq for ArenaError

fn eq(&self, other: &ArenaError) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ArenaError

impl Eq for ArenaError

impl StructuralPartialEq for ArenaError