rhai/src/result.rs
2020-10-29 11:37:51 +08:00

411 lines
17 KiB
Rust

//! Module containing error definitions for the evaluation process.
use crate::dynamic::Dynamic;
use crate::parse_error::ParseErrorType;
use crate::token::Position;
use crate::utils::ImmutableString;
use crate::INT;
#[cfg(not(feature = "no_function"))]
use crate::engine::is_anonymous_fn;
use crate::stdlib::{
boxed::Box,
error::Error,
fmt,
string::{String, ToString},
};
/// Evaluation result.
///
/// All wrapped `Position` values represent the location in the script where the error occurs.
///
/// # Thread Safety
///
/// Currently, `EvalAltResult` is neither `Send` nor `Sync`. Turn on the `sync` feature to make it `Send + Sync`.
#[derive(Debug)]
#[non_exhaustive]
pub enum EvalAltResult {
/// System error. Wrapped values are the error message and the internal error.
#[cfg(not(feature = "sync"))]
ErrorSystem(String, Box<dyn Error>),
/// System error. Wrapped values are the error message and the internal error.
#[cfg(feature = "sync")]
ErrorSystem(String, Box<dyn Error + Send + Sync>),
/// Syntax error.
ErrorParsing(ParseErrorType, Position),
/// Usage of an unknown variable. Wrapped value is the variable name.
ErrorVariableNotFound(String, Position),
/// Call to an unknown function. Wrapped value is the function signature.
ErrorFunctionNotFound(String, Position),
/// An error has occurred inside a called function.
/// Wrapped values are the function name and the interior error.
ErrorInFunctionCall(String, Box<EvalAltResult>, Position),
/// Usage of an unknown module. Wrapped value is the module name.
ErrorModuleNotFound(String, Position),
/// An error has occurred while loading a module.
/// Wrapped value are the module name and the interior error.
ErrorInModule(String, Box<EvalAltResult>, Position),
/// Access to `this` that is not bound.
ErrorUnboundThis(Position),
/// Data is not of the required type.
/// Wrapped values are the type requested and type of the actual result.
ErrorMismatchDataType(String, String, Position),
/// Returned type is not the same as the required output type.
/// Wrapped values are the type requested and type of the actual result.
ErrorMismatchOutputType(String, String, Position),
/// Array access out-of-bounds.
/// Wrapped values are the current number of elements in the array and the index number.
ErrorArrayBounds(usize, INT, Position),
/// String indexing out-of-bounds.
/// Wrapped values are the current number of characters in the string and the index number.
ErrorStringBounds(usize, INT, Position),
/// Trying to index into a type that is not an array, an object map, or a string, and has no indexer function defined.
/// Wrapped value is the type name.
ErrorIndexingType(String, Position),
/// Invalid arguments for `in` operator.
ErrorInExpr(Position),
/// The `for` statement encounters a type that is not an iterator.
ErrorFor(Position),
/// Data race detected when accessing a variable. Wrapped value is the variable name.
ErrorDataRace(String, Position),
/// Assignment to a constant variable. Wrapped value is the variable name.
ErrorAssignmentToConstant(String, Position),
/// Inappropriate property access. Wrapped value is the property name.
ErrorDotExpr(String, Position),
/// Arithmetic error encountered. Wrapped value is the error message.
ErrorArithmetic(String, Position),
/// Number of operations over maximum limit.
ErrorTooManyOperations(Position),
/// Modules over maximum limit.
ErrorTooManyModules(Position),
/// Call stack over maximum limit.
ErrorStackOverflow(Position),
/// Data value over maximum size limit. Wrapped values are the type name, maximum size and current size.
ErrorDataTooLarge(String, usize, usize, Position),
/// The script is prematurely terminated.
ErrorTerminated(Position),
/// Run-time error encountered. Wrapped value is the error.
ErrorRuntime(Dynamic, Position),
/// Breaking out of loops - not an error if within a loop.
/// The wrapped value, if true, means breaking clean out of the loop (i.e. a `break` statement).
/// The wrapped value, if false, means breaking the current context (i.e. a `continue` statement).
LoopBreak(bool, Position),
/// Not an error: Value returned from a script via the `return` keyword.
/// Wrapped value is the result value.
Return(Dynamic, Position),
}
impl EvalAltResult {
pub(crate) fn desc(&self) -> &str {
match self {
#[allow(deprecated)]
Self::ErrorSystem(_, s) => s.description(),
Self::ErrorParsing(p, _) => p.desc(),
Self::ErrorInFunctionCall(_, _, _) => "Error in called function",
Self::ErrorInModule(_, _, _) => "Error in module",
Self::ErrorFunctionNotFound(_, _) => "Function not found",
Self::ErrorUnboundThis(_) => "'this' is not bound",
Self::ErrorMismatchDataType(_, _, _) => "Data type is incorrect",
Self::ErrorIndexingType(_, _) => {
"Indexing can only be performed on an array, an object map, a string, or a type with an indexer function defined"
}
Self::ErrorArrayBounds(_, index, _) if *index < 0 => {
"Array access expects non-negative index"
}
Self::ErrorArrayBounds(0, _, _) => "Empty array has nothing to access",
Self::ErrorArrayBounds(_, _, _) => "Array index out of bounds",
Self::ErrorStringBounds(_, index, _) if *index < 0 => {
"Indexing a string expects a non-negative index"
}
Self::ErrorStringBounds(0, _, _) => "Empty string has nothing to index",
Self::ErrorStringBounds(_, _, _) => "String index out of bounds",
Self::ErrorFor(_) => "For loop expects an array, object map, or range",
Self::ErrorVariableNotFound(_, _) => "Variable not found",
Self::ErrorModuleNotFound(_, _) => "Module not found",
Self::ErrorDataRace(_, _) => "Data race detected when accessing variable",
Self::ErrorAssignmentToConstant(_, _) => "Assignment to a constant variable",
Self::ErrorMismatchOutputType(_, _, _) => "Output type is incorrect",
Self::ErrorInExpr(_) => "Malformed 'in' expression",
Self::ErrorDotExpr(_, _) => "Malformed dot expression",
Self::ErrorArithmetic(_, _) => "Arithmetic error",
Self::ErrorTooManyOperations(_) => "Too many operations",
Self::ErrorTooManyModules(_) => "Too many modules imported",
Self::ErrorStackOverflow(_) => "Stack overflow",
Self::ErrorDataTooLarge(_, _, _, _) => "Data size exceeds maximum limit",
Self::ErrorTerminated(_) => "Script terminated.",
Self::ErrorRuntime(_, _) => "Runtime error",
Self::LoopBreak(true, _) => "Break statement not inside a loop",
Self::LoopBreak(false, _) => "Continue statement not inside a loop",
Self::Return(_, _) => "[Not Error] Function returns value",
}
}
}
impl Error for EvalAltResult {}
impl fmt::Display for EvalAltResult {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let desc = self.desc();
let pos = self.position();
match self {
Self::ErrorSystem(s, _) if s.is_empty() => f.write_str(desc)?,
Self::ErrorSystem(s, _) => write!(f, "{}: {}", s, desc)?,
Self::ErrorParsing(p, _) => write!(f, "Syntax error: {}", p)?,
#[cfg(not(feature = "no_function"))]
Self::ErrorInFunctionCall(s, err, _) if is_anonymous_fn(s) => {
write!(f, "Error in call to closure: {}", err)?
}
Self::ErrorInFunctionCall(s, err, _) => {
write!(f, "Error in call to function '{}': {}", s, err)?
}
Self::ErrorInModule(s, err, _) if s.is_empty() => {
write!(f, "Error in module: {}", err)?
}
Self::ErrorInModule(s, err, _) => write!(f, "Error in module '{}': {}", s, err)?,
Self::ErrorFunctionNotFound(s, _)
| Self::ErrorVariableNotFound(s, _)
| Self::ErrorDataRace(s, _)
| Self::ErrorModuleNotFound(s, _) => write!(f, "{}: '{}'", desc, s)?,
Self::ErrorDotExpr(s, _) if !s.is_empty() => write!(f, "{}", s)?,
Self::ErrorIndexingType(_, _)
| Self::ErrorUnboundThis(_)
| Self::ErrorFor(_)
| Self::ErrorInExpr(_)
| Self::ErrorDotExpr(_, _)
| Self::ErrorTooManyOperations(_)
| Self::ErrorTooManyModules(_)
| Self::ErrorStackOverflow(_)
| Self::ErrorTerminated(_) => f.write_str(desc)?,
Self::ErrorRuntime(d, _) if d.is::<ImmutableString>() => {
let s = d.as_str().unwrap();
write!(f, "{}: {}", desc, if s.is_empty() { desc } else { s })?
}
Self::ErrorRuntime(d, _) if d.is::<()>() => f.write_str(desc)?,
Self::ErrorRuntime(d, _) => write!(f, "{}: {}", desc, d)?,
Self::ErrorAssignmentToConstant(s, _) => write!(f, "{}: '{}'", desc, s)?,
Self::ErrorMismatchOutputType(r, s, _) => {
write!(f, "Output type is incorrect: {} (expecting {})", r, s)?
}
Self::ErrorMismatchDataType(r, s, _) if r.is_empty() => {
write!(f, "Data type is incorrect, expecting {}", s)?
}
Self::ErrorMismatchDataType(r, s, _) => {
write!(f, "Data type is incorrect: {} (expecting {})", r, s)?
}
Self::ErrorArithmetic(s, _) => f.write_str(s)?,
Self::LoopBreak(_, _) => f.write_str(desc)?,
Self::Return(_, _) => f.write_str(desc)?,
Self::ErrorArrayBounds(_, index, _) if *index < 0 => {
write!(f, "{}: {} < 0", desc, index)?
}
Self::ErrorArrayBounds(0, _, _) => f.write_str(desc)?,
Self::ErrorArrayBounds(1, index, _) => write!(
f,
"Array index {} is out of bounds: only one element in the array",
index
)?,
Self::ErrorArrayBounds(max, index, _) => write!(
f,
"Array index {} is out of bounds: only {} elements in the array",
index, max
)?,
Self::ErrorStringBounds(_, index, _) if *index < 0 => {
write!(f, "{}: {} < 0", desc, index)?
}
Self::ErrorStringBounds(0, _, _) => f.write_str(desc)?,
Self::ErrorStringBounds(1, index, _) => write!(
f,
"String index {} is out of bounds: only one character in the string",
index
)?,
Self::ErrorStringBounds(max, index, _) => write!(
f,
"String index {} is out of bounds: only {} characters in the string",
index, max
)?,
Self::ErrorDataTooLarge(typ, max, size, _) => {
write!(f, "{} ({}) exceeds the maximum limit ({})", typ, size, max)?
}
}
// Do not write any position if None
if !pos.is_none() {
write!(f, " ({})", pos)?;
}
Ok(())
}
}
impl<T: AsRef<str>> From<T> for EvalAltResult {
#[inline(always)]
fn from(err: T) -> Self {
Self::ErrorRuntime(err.as_ref().to_string().into(), Position::none())
}
}
impl<T: AsRef<str>> From<T> for Box<EvalAltResult> {
#[inline(always)]
fn from(err: T) -> Self {
Box::new(EvalAltResult::ErrorRuntime(
err.as_ref().to_string().into(),
Position::none(),
))
}
}
impl EvalAltResult {
/// Can this error be caught?
pub fn is_catchable(&self) -> bool {
match self {
Self::ErrorSystem(_, _) => false,
Self::ErrorParsing(_, _) => unreachable!(),
Self::ErrorFunctionNotFound(_, _)
| Self::ErrorInFunctionCall(_, _, _)
| Self::ErrorInModule(_, _, _)
| Self::ErrorUnboundThis(_)
| Self::ErrorMismatchDataType(_, _, _)
| Self::ErrorArrayBounds(_, _, _)
| Self::ErrorStringBounds(_, _, _)
| Self::ErrorIndexingType(_, _)
| Self::ErrorFor(_)
| Self::ErrorVariableNotFound(_, _)
| Self::ErrorModuleNotFound(_, _)
| Self::ErrorDataRace(_, _)
| Self::ErrorAssignmentToConstant(_, _)
| Self::ErrorMismatchOutputType(_, _, _)
| Self::ErrorInExpr(_)
| Self::ErrorDotExpr(_, _)
| Self::ErrorArithmetic(_, _)
| Self::ErrorRuntime(_, _) => true,
Self::ErrorTooManyOperations(_)
| Self::ErrorTooManyModules(_)
| Self::ErrorStackOverflow(_)
| Self::ErrorDataTooLarge(_, _, _, _)
| Self::ErrorTerminated(_) => false,
Self::LoopBreak(_, _) | Self::Return(_, _) => unreachable!(),
}
}
/// Is this error a system exception?
pub fn is_system_exception(&self) -> bool {
match self {
Self::ErrorSystem(_, _) => true,
Self::ErrorParsing(_, _) => unreachable!(),
Self::ErrorTooManyOperations(_)
| Self::ErrorTooManyModules(_)
| Self::ErrorStackOverflow(_)
| Self::ErrorDataTooLarge(_, _, _, _) => true,
Self::ErrorTerminated(_) => true,
Self::LoopBreak(_, _) | Self::Return(_, _) => unreachable!(),
_ => false,
}
}
/// Get the `Position` of this error.
pub fn position(&self) -> Position {
match self {
Self::ErrorSystem(_, _) => Position::none(),
Self::ErrorParsing(_, pos)
| Self::ErrorFunctionNotFound(_, pos)
| Self::ErrorInFunctionCall(_, _, pos)
| Self::ErrorInModule(_, _, pos)
| Self::ErrorUnboundThis(pos)
| Self::ErrorMismatchDataType(_, _, pos)
| Self::ErrorArrayBounds(_, _, pos)
| Self::ErrorStringBounds(_, _, pos)
| Self::ErrorIndexingType(_, pos)
| Self::ErrorFor(pos)
| Self::ErrorVariableNotFound(_, pos)
| Self::ErrorModuleNotFound(_, pos)
| Self::ErrorDataRace(_, pos)
| Self::ErrorAssignmentToConstant(_, pos)
| Self::ErrorMismatchOutputType(_, _, pos)
| Self::ErrorInExpr(pos)
| Self::ErrorDotExpr(_, pos)
| Self::ErrorArithmetic(_, pos)
| Self::ErrorTooManyOperations(pos)
| Self::ErrorTooManyModules(pos)
| Self::ErrorStackOverflow(pos)
| Self::ErrorDataTooLarge(_, _, _, pos)
| Self::ErrorTerminated(pos)
| Self::ErrorRuntime(_, pos)
| Self::LoopBreak(_, pos)
| Self::Return(_, pos) => *pos,
}
}
/// Override the `Position` of this error.
pub fn set_position(&mut self, new_position: Position) {
match self {
Self::ErrorSystem(_, _) => (),
Self::ErrorParsing(_, pos)
| Self::ErrorFunctionNotFound(_, pos)
| Self::ErrorInFunctionCall(_, _, pos)
| Self::ErrorInModule(_, _, pos)
| Self::ErrorUnboundThis(pos)
| Self::ErrorMismatchDataType(_, _, pos)
| Self::ErrorArrayBounds(_, _, pos)
| Self::ErrorStringBounds(_, _, pos)
| Self::ErrorIndexingType(_, pos)
| Self::ErrorFor(pos)
| Self::ErrorVariableNotFound(_, pos)
| Self::ErrorModuleNotFound(_, pos)
| Self::ErrorDataRace(_, pos)
| Self::ErrorAssignmentToConstant(_, pos)
| Self::ErrorMismatchOutputType(_, _, pos)
| Self::ErrorInExpr(pos)
| Self::ErrorDotExpr(_, pos)
| Self::ErrorArithmetic(_, pos)
| Self::ErrorTooManyOperations(pos)
| Self::ErrorTooManyModules(pos)
| Self::ErrorStackOverflow(pos)
| Self::ErrorDataTooLarge(_, _, _, pos)
| Self::ErrorTerminated(pos)
| Self::ErrorRuntime(_, pos)
| Self::LoopBreak(_, pos)
| Self::Return(_, pos) => *pos = new_position,
}
}
/// Consume the current `EvalAltResult` and return a new one with the specified `Position`
/// if the current position is `Position::None`.
#[inline(always)]
pub(crate) fn fill_position(mut self: Box<Self>, new_position: Position) -> Box<Self> {
if self.position().is_none() {
self.set_position(new_position);
}
self
}
}
impl<T> From<EvalAltResult> for Result<T, Box<EvalAltResult>> {
#[inline(always)]
fn from(err: EvalAltResult) -> Self {
Err(err.into())
}
}