Enum VmError 

pub enum VmError {
    UnknownDecorator {
        name: String,
        node_id: NodeIndex,
    },
    UnknownLabel(String),
    UndefinedVariable(String),
    TypeError(String),
    InvalidExpression(String),
    ChoiceOutOfBounds {
        index: usize,
        len: usize,
    },
    IndexOutOfBounds {
        index: i64,
        len: usize,
    },
    CompilerError(CompilerError),
    NotImplemented(String),
    ExternNotProvided(String),
    UnknownMethod(String),
    UndefinedFunction(String),
    ConstraintViolation {
        decorator: String,
        constraint: String,
        actual_event: String,
    },
    NonExhaustiveMatch(String),
    BudgetExceeded,
    StackOverflow(usize),
}

Errors that can occur during VM construction or execution.

Variants

UnknownDecorator

A decorator name used in the script was not registered in the DecoratorRegistry.

Fields

name: String

The unregistered decorator name.

node_id: NodeIndex

The IR node at which the unknown decorator appeared.

UnknownLabel(String)

A jump targeted a label not present in the compiled graph.

Should never occur after a successful compilation pass, but is kept as a defensive runtime error.

UndefinedVariable(String)

A variable was referenced before it was declared.

TypeError(String)

A runtime type mismatch (e.g. adding a string to an integer).

InvalidExpression(String)

An AST node appeared in an expression context where it is not valid.

ChoiceOutOfBounds

The player supplied a choice index that is out of bounds.

Fields

index: usize

The supplied index.

len: usize

The number of available options.

IndexOutOfBounds

A list index was out of bounds.

Fields

index: i64

The supplied index (may be negative for reverse-indexing attempts).

len: usize

The length of the list.

CompilerError(CompilerError)

An error propagated from the compiler (e.g. when constructing test graphs).

NotImplemented(String)

A language feature that is not yet implemented was encountered.

ExternNotProvided(String)

A value declared with extern was not injected by the host runtime before script execution started.

UnknownMethod(String)

A method was called on a value type that does not support it.

For example, calling .push() on an integer would produce this error.

UndefinedFunction(String)

A free-function call referenced a name that is not defined in any reachable scope.

ConstraintViolation

A script-defined decorator was applied to an event kind it does not accept, as declared by its <event: …> constraint clause.

Fields

decorator: String

The name of the decorator whose constraint was violated.

constraint: String

The constraint declared on the decorator (e.g. "choice").

actual_event: String

The actual event kind it was applied to (e.g. "dialogue").

NonExhaustiveMatch(String)

A match expression had no arm that matched the scrutinee and no wildcard / default arm was present.

BudgetExceeded

The script exceeded its step budget (infinite loop guard).

The default budget is 1 000 000 steps. Call Vm::set_step_budget to raise, lower, or disable the limit.

StackOverflow(usize)

The call stack depth limit was reached.

The default limit is 256 frames. Indicates unbounded mutual recursion or a pathological LetCall cycle in the script.

Trait Implementations

impl Debug for VmError

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

Formats the value using the given formatter.

impl Display for VmError

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

Formats the value using the given formatter.

impl Error for VmError

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<CompilerError> for VmError

fn from(source: CompilerError) -> Self

Converts to this type from the input type.