kjuulh/rhai
1
0
Fork 0
Code Issues 1 Pull Requests 1 Packages Projects Releases Wiki Activity
673bff7c76
rhai/src/engine.rs
Stephen Chung 6667a22c0c Code style and docs.
2021-03-17 13:30:47 +08:00

2671 lines
101 KiB
Rust
Raw Blame History

//! Main module defining the script evaluation [`Engine`].
use crate::ast::{Expr, FnCallExpr, FnCallHash, Ident, OpAssignment, ReturnType, Stmt, StmtBlock};
use crate::dynamic::{map_std_type_name, AccessMode, Union, Variant};
use crate::fn_native::{
CallableFunction, IteratorFn, OnDebugCallback, OnPrintCallback, OnProgressCallback,
OnVarCallback,
};
use crate::module::NamespaceRef;
use crate::optimize::OptimizationLevel;
use crate::packages::{Package, StandardPackage};
use crate::r#unsafe::unsafe_cast_var_name_to_lifetime;
use crate::stdlib::{
any::{type_name, TypeId},
borrow::Cow,
boxed::Box,
collections::{HashMap, HashSet},
fmt, format,
hash::{Hash, Hasher},
num::{NonZeroU8, NonZeroUsize},
ops::DerefMut,
string::{String, ToString},
vec::Vec,
};
use crate::syntax::CustomSyntax;
use crate::utils::{get_hasher, StraightHasherBuilder};
use crate::{
Dynamic, EvalAltResult, FnPtr, ImmutableString, Module, Position, RhaiResult, Scope, Shared,
StaticVec,
};
#[cfg(not(feature = "no_index"))]
use crate::{calc_fn_hash, stdlib::iter::empty, Array};
#[cfg(not(feature = "no_index"))]
pub const TYPICAL_ARRAY_SIZE: usize = 8; // Small arrays are typical
#[cfg(not(feature = "no_object"))]
use crate::Map;
#[cfg(not(feature = "no_object"))]
pub const TYPICAL_MAP_SIZE: usize = 8; // Small maps are typical
pub type Precedence = NonZeroU8;
/// _(INTERNALS)_ A stack of imported [modules][Module].
/// Exported under the `internals` feature only.
///
/// # Volatile Data Structure
///
/// This type is volatile and may change.
//
// # Implementation Notes
//
// We cannot use Cow<str> here because `eval` may load a [module][Module] and
// the module name will live beyond the AST of the eval script text.
// The best we can do is a shared reference.
#[derive(Debug, Clone, Default)]
pub struct Imports(StaticVec<ImmutableString>, StaticVec<Shared<Module>>);
impl Imports {
/// Get the length of this stack of imported [modules][Module].
#[inline(always)]
pub fn len(&self) -> usize {
self.0.len()
}
/// Is this stack of imported [modules][Module] empty?
#[inline(always)]
pub fn is_empty(&self) -> bool {
self.0.is_empty()
}
/// Get the imported [modules][Module] at a particular index.
#[inline(always)]
pub fn get(&self, index: usize) -> Option<Shared<Module>> {
self.1.get(index).cloned()
}
/// Get the index of an imported [modules][Module] by name.
#[inline(always)]
pub fn find(&self, name: &str) -> Option<usize> {
self.0
.iter()
.enumerate()
.rev()
.find_map(|(i, key)| if key.as_str() == name { Some(i) } else { None })
}
/// Push an imported [modules][Module] onto the stack.
#[inline(always)]
pub fn push(&mut self, name: impl Into<ImmutableString>, module: impl Into<Shared<Module>>) {
self.0.push(name.into());
self.1.push(module.into());
}
/// Truncate the stack of imported [modules][Module] to a particular length.
#[inline(always)]
pub fn truncate(&mut self, size: usize) {
self.0.truncate(size);
self.1.truncate(size);
}
/// Get an iterator to this stack of imported [modules][Module] in reverse order.
#[allow(dead_code)]
#[inline(always)]
pub fn iter(&self) -> impl Iterator<Item = (&str, &Module)> {
self.0
.iter()
.zip(self.1.iter())
.rev()
.map(|(name, module)| (name.as_str(), module.as_ref()))
}
/// Get an iterator to this stack of imported [modules][Module] in reverse order.
#[allow(dead_code)]
#[inline(always)]
pub(crate) fn iter_raw(&self) -> impl Iterator<Item = (&ImmutableString, &Shared<Module>)> {
self.0.iter().rev().zip(self.1.iter().rev())
}
/// Get an iterator to this stack of imported [modules][Module] in forward order.
#[allow(dead_code)]
#[inline(always)]
pub(crate) fn scan_raw(&self) -> impl Iterator<Item = (&ImmutableString, &Shared<Module>)> {
self.0.iter().zip(self.1.iter())
}
/// Get a consuming iterator to this stack of imported [modules][Module] in reverse order.
#[inline(always)]
pub fn into_iter(self) -> impl Iterator<Item = (ImmutableString, Shared<Module>)> {
self.0.into_iter().rev().zip(self.1.into_iter().rev())
}
/// Does the specified function hash key exist in this stack of imported [modules][Module]?
#[allow(dead_code)]
#[inline(always)]
pub fn contains_fn(&self, hash: u64) -> bool {
self.1.iter().any(|m| m.contains_qualified_fn(hash))
}
/// Get specified function via its hash key.
#[inline(always)]
pub fn get_fn(&self, hash: u64) -> Option<(&CallableFunction, Option<&ImmutableString>)> {
self.1
.iter()
.rev()
.find_map(|m| m.get_qualified_fn(hash).map(|f| (f, m.id_raw())))
}
/// Does the specified [`TypeId`][std::any::TypeId] iterator exist in this stack of
/// imported [modules][Module]?
#[allow(dead_code)]
#[inline(always)]
pub fn contains_iter(&self, id: TypeId) -> bool {
self.1.iter().any(|m| m.contains_qualified_iter(id))
}
/// Get the specified [`TypeId`][std::any::TypeId] iterator.
#[inline(always)]
pub fn get_iter(&self, id: TypeId) -> Option<IteratorFn> {
self.1.iter().rev().find_map(|m| m.get_qualified_iter(id))
}
}
#[cfg(not(feature = "unchecked"))]
#[cfg(debug_assertions)]
#[cfg(not(feature = "no_function"))]
pub const MAX_CALL_STACK_DEPTH: usize = 8;
#[cfg(not(feature = "unchecked"))]
#[cfg(debug_assertions)]
pub const MAX_EXPR_DEPTH: usize = 32;
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_function"))]
#[cfg(debug_assertions)]
pub const MAX_FUNCTION_EXPR_DEPTH: usize = 16;
#[cfg(not(feature = "unchecked"))]
#[cfg(not(debug_assertions))]
#[cfg(not(feature = "no_function"))]
pub const MAX_CALL_STACK_DEPTH: usize = 64;
#[cfg(not(feature = "unchecked"))]
#[cfg(not(debug_assertions))]
pub const MAX_EXPR_DEPTH: usize = 64;
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_function"))]
#[cfg(not(debug_assertions))]
pub const MAX_FUNCTION_EXPR_DEPTH: usize = 32;
pub const MAX_DYNAMIC_PARAMETERS: usize = 16;
pub const KEYWORD_PRINT: &str = "print";
pub const KEYWORD_DEBUG: &str = "debug";
pub const KEYWORD_TYPE_OF: &str = "type_of";
pub const KEYWORD_EVAL: &str = "eval";
pub const KEYWORD_FN_PTR: &str = "Fn";
pub const KEYWORD_FN_PTR_CALL: &str = "call";
pub const KEYWORD_FN_PTR_CURRY: &str = "curry";
#[cfg(not(feature = "no_closure"))]
pub const KEYWORD_IS_SHARED: &str = "is_shared";
pub const KEYWORD_IS_DEF_VAR: &str = "is_def_var";
#[cfg(not(feature = "no_function"))]
pub const KEYWORD_IS_DEF_FN: &str = "is_def_fn";
pub const KEYWORD_THIS: &str = "this";
#[cfg(not(feature = "no_object"))]
pub const FN_GET: &str = "get$";
#[cfg(not(feature = "no_object"))]
pub const FN_SET: &str = "set$";
#[cfg(not(feature = "no_index"))]
pub const FN_IDX_GET: &str = "index$get$";
#[cfg(not(feature = "no_index"))]
pub const FN_IDX_SET: &str = "index$set$";
#[cfg(not(feature = "no_function"))]
pub const FN_ANONYMOUS: &str = "anon$";
/// Standard equality comparison operator.
pub const OP_EQUALS: &str = "==";
/// Standard method function for containment testing.
///
/// The `in` operator is implemented as a call to this method.
pub const OP_CONTAINS: &str = "contains";
/// Method of chaining.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
pub enum ChainType {
/// Not a chaining type.
NonChaining,
/// Indexing.
Index,
/// Dotting.
Dot,
}
/// Value of a chaining argument.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
#[derive(Debug, Clone, Hash)]
pub enum ChainArgument {
/// Dot-property access.
Property(Position),
/// Arguments to a dot-function call.
FnCallArgs(StaticVec<Dynamic>, StaticVec<Position>),
/// Index value.
IndexValue(Dynamic, Position),
}
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
impl ChainArgument {
/// Return the `Dynamic` value.
///
/// # Panics
///
/// Panics if not `ChainArgument::IndexValue`.
#[inline(always)]
#[cfg(not(feature = "no_index"))]
pub fn as_index_value(self) -> Dynamic {
match self {
Self::Property(_) | Self::FnCallArgs(_, _) => {
panic!("expecting ChainArgument::IndexValue")
}
Self::IndexValue(value, _) => value,
}
}
/// Return the `StaticVec<Dynamic>` value.
///
/// # Panics
///
/// Panics if not `ChainArgument::FnCallArgs`.
#[inline(always)]
#[cfg(not(feature = "no_object"))]
pub fn as_fn_call_args(self) -> (StaticVec<Dynamic>, StaticVec<Position>) {
match self {
Self::Property(_) | Self::IndexValue(_, _) => {
panic!("expecting ChainArgument::FnCallArgs")
}
Self::FnCallArgs(values, positions) => (values, positions),
}
}
}
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
impl From<(StaticVec<Dynamic>, StaticVec<Position>)> for ChainArgument {
#[inline(always)]
fn from((values, positions): (StaticVec<Dynamic>, StaticVec<Position>)) -> Self {
Self::FnCallArgs(values, positions)
}
}
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
impl From<(Dynamic, Position)> for ChainArgument {
#[inline(always)]
fn from((value, pos): (Dynamic, Position)) -> Self {
Self::IndexValue(value, pos)
}
}
/// A type that encapsulates a mutation target for an expression with side effects.
#[derive(Debug)]
pub enum Target<'a> {
/// The target is a mutable reference to a `Dynamic` value somewhere.
Ref(&'a mut Dynamic),
/// The target is a mutable reference to a Shared `Dynamic` value.
/// It holds both the access guard and the original shared value.
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
LockGuard((crate::dynamic::DynamicWriteLock<'a, Dynamic>, Dynamic)),
/// The target is a temporary `Dynamic` value (i.e. the mutation can cause no side effects).
Value(Dynamic),
/// The target is a character inside a String.
/// This is necessary because directly pointing to a char inside a String is impossible.
#[cfg(not(feature = "no_index"))]
StringChar(&'a mut Dynamic, usize, Dynamic),
}
impl<'a> Target<'a> {
/// Is the `Target` a reference pointing to other data?
#[allow(dead_code)]
#[inline(always)]
pub fn is_ref(&self) -> bool {
match self {
Self::Ref(_) => true,
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Self::LockGuard(_) => true,
Self::Value(_) => false,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => false,
}
}
/// Is the `Target` an owned value?
#[allow(dead_code)]
#[inline(always)]
pub fn is_value(&self) -> bool {
match self {
Self::Ref(_) => false,
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Self::LockGuard(_) => false,
Self::Value(_) => true,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => false,
}
}
/// Is the `Target` a shared value?
#[allow(dead_code)]
#[inline(always)]
pub fn is_shared(&self) -> bool {
match self {
Self::Ref(r) => r.is_shared(),
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Self::LockGuard(_) => true,
Self::Value(r) => r.is_shared(),
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => false,
}
}
/// Is the `Target` a specific type?
#[allow(dead_code)]
#[inline(always)]
pub fn is<T: Variant + Clone>(&self) -> bool {
match self {
Target::Ref(r) => r.is::<T>(),
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Target::LockGuard((r, _)) => r.is::<T>(),
Target::Value(r) => r.is::<T>(),
#[cfg(not(feature = "no_index"))]
Target::StringChar(_, _, _) => TypeId::of::<T>() == TypeId::of::<char>(),
}
}
/// Get the value of the `Target` as a `Dynamic`, cloning a referenced value if necessary.
#[inline(always)]
pub fn take_or_clone(self) -> Dynamic {
match self {
Self::Ref(r) => r.clone(), // Referenced value is cloned
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Self::LockGuard((_, orig)) => orig, // Original value is simply taken
Self::Value(v) => v, // Owned value is simply taken
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ch) => ch, // Character is taken
}
}
/// Take a `&mut Dynamic` reference from the `Target`.
#[inline(always)]
pub fn take_ref(self) -> Option<&'a mut Dynamic> {
match self {
Self::Ref(r) => Some(r),
_ => None,
}
}
/// Convert a shared or reference `Target` into a target with an owned value.
#[inline(always)]
pub fn into_owned(self) -> Target<'static> {
self.take_or_clone().into()
}
/// Propagate a changed value back to the original source.
/// This has no effect except for string indexing.
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn propagate_changed_value(&mut self) {
match self {
Self::Ref(_) | Self::Value(_) => (),
#[cfg(not(feature = "no_closure"))]
Self::LockGuard(_) => (),
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ch) => {
let char_value = ch.clone();
self.set_value(char_value, Position::NONE).unwrap();
}
}
}
/// Update the value of the `Target`.
#[cfg(any(not(feature = "no_object"), not(feature = "no_index")))]
pub fn set_value(
&mut self,
new_val: Dynamic,
_pos: Position,
) -> Result<(), Box<EvalAltResult>> {
match self {
Self::Ref(r) => **r = new_val,
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Self::LockGuard((r, _)) => **r = new_val,
Self::Value(_) => panic!("cannot update a value"),
#[cfg(not(feature = "no_index"))]
Self::StringChar(s, index, _) => {
let s = &mut *s.write_lock::<ImmutableString>().unwrap();
// Replace the character at the specified index position
let new_ch = new_val.as_char().map_err(|err| {
Box::new(EvalAltResult::ErrorMismatchDataType(
"char".to_string(),
err.to_string(),
_pos,
))
})?;
let index = *index;
*s = s
.chars()
.enumerate()
.map(|(i, ch)| if i == index { new_ch } else { ch })
.collect();
}
}
Ok(())
}
}
impl<'a> From<&'a mut Dynamic> for Target<'a> {
#[inline(always)]
fn from(value: &'a mut Dynamic) -> Self {
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
if value.is_shared() {
// Cloning is cheap for a shared value
let container = value.clone();
return Self::LockGuard((value.write_lock::<Dynamic>().unwrap(), container));
}
Self::Ref(value)
}
}
impl AsRef<Dynamic> for Target<'_> {
#[inline(always)]
fn as_ref(&self) -> &Dynamic {
match self {
Self::Ref(r) => *r,
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Self::LockGuard((r, _)) => &**r,
Self::Value(ref r) => r,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ref r) => r,
}
}
}
impl AsMut<Dynamic> for Target<'_> {
#[inline(always)]
fn as_mut(&mut self) -> &mut Dynamic {
match self {
Self::Ref(r) => *r,
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "no_object"))]
Self::LockGuard((r, _)) => r.deref_mut(),
Self::Value(ref mut r) => r,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ref mut r) => r,
}
}
}
impl<T: Into<Dynamic>> From<T> for Target<'_> {
#[inline(always)]
fn from(value: T) -> Self {
Self::Value(value.into())
}
}
/// An entry in a function resolution cache.
#[derive(Debug, Clone)]
pub struct FnResolutionCacheEntry {
/// Function.
pub func: CallableFunction,
/// Optional source.
pub source: Option<ImmutableString>,
}
/// A function resolution cache.
pub type FnResolutionCache = HashMap<u64, Option<FnResolutionCacheEntry>, StraightHasherBuilder>;
/// _(INTERNALS)_ A type that holds all the current states of the [`Engine`].
/// Exported under the `internals` feature only.
///
/// # Volatile Data Structure
///
/// This type is volatile and may change.
#[derive(Debug, Clone, Default)]
pub struct State {
/// Source of the current context.
pub source: Option<ImmutableString>,
/// Normally, access to variables are parsed with a relative offset into the scope to avoid a lookup.
/// In some situation, e.g. after running an `eval` statement, subsequent offsets become mis-aligned.
/// When that happens, this flag is turned on to force a scope lookup by name.
pub always_search: bool,
/// Level of the current scope. The global (root) level is zero, a new block
/// (or function call) is one level higher, and so on.
pub scope_level: usize,
/// Number of operations performed.
pub operations: u64,
/// Number of modules loaded.
pub modules: usize,
/// Embedded module resolver.
#[cfg(not(feature = "no_module"))]
pub resolver: Option<Shared<crate::module::resolvers::StaticModuleResolver>>,
/// Function resolution cache and free list.
fn_resolution_caches: (StaticVec<FnResolutionCache>, Vec<FnResolutionCache>),
}
impl State {
/// Is the state currently at global (root) level?
#[inline(always)]
pub fn is_global(&self) -> bool {
self.scope_level == 0
}
/// Get a mutable reference to the current function resolution cache.
pub fn fn_resolution_cache_mut(&mut self) -> &mut FnResolutionCache {
if self.fn_resolution_caches.0.is_empty() {
self.fn_resolution_caches
.0
.push(HashMap::with_capacity_and_hasher(64, StraightHasherBuilder));
}
self.fn_resolution_caches.0.last_mut().unwrap()
}
/// Push an empty function resolution cache onto the stack and make it current.
#[allow(dead_code)]
pub fn push_fn_resolution_cache(&mut self) {
self.fn_resolution_caches
.0
.push(self.fn_resolution_caches.1.pop().unwrap_or_default());
}
/// Remove the current function resolution cache from the stack and make the last one current.
///
/// # Panics
///
/// Panics if there are no more function resolution cache in the stack.
pub fn pop_fn_resolution_cache(&mut self) {
let mut cache = self.fn_resolution_caches.0.pop().unwrap();
cache.clear();
self.fn_resolution_caches.1.push(cache);
}
}
/// _(INTERNALS)_ A type containing all the limits imposed by the [`Engine`].
/// Exported under the `internals` feature only.
///
/// # Volatile Data Structure
///
/// This type is volatile and may change.
#[cfg(not(feature = "unchecked"))]
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct Limits {
/// Maximum levels of call-stack to prevent infinite recursion.
///
/// Set to zero to effectively disable function calls.
///
/// Not available under `no_function`.
#[cfg(not(feature = "no_function"))]
pub max_call_stack_depth: usize,
/// Maximum depth of statements/expressions at global level.
pub max_expr_depth: Option<NonZeroUsize>,
/// Maximum depth of statements/expressions in functions.
///
/// Not available under `no_function`.
#[cfg(not(feature = "no_function"))]
pub max_function_expr_depth: Option<NonZeroUsize>,
/// Maximum number of operations allowed to run.
pub max_operations: Option<crate::stdlib::num::NonZeroU64>,
/// Maximum number of [modules][Module] allowed to load.
///
/// Set to zero to effectively disable loading any [module][Module].
///
/// Not available under `no_module`.
#[cfg(not(feature = "no_module"))]
pub max_modules: usize,
/// Maximum length of a [string][ImmutableString].
pub max_string_size: Option<NonZeroUsize>,
/// Maximum length of an [array][Array].
///
/// Not available under `no_index`.
#[cfg(not(feature = "no_index"))]
pub max_array_size: Option<NonZeroUsize>,
/// Maximum number of properties in an [object map][Map].
///
/// Not available under `no_object`.
#[cfg(not(feature = "no_object"))]
pub max_map_size: Option<NonZeroUsize>,
}
/// Context of a script evaluation process.
#[derive(Debug)]
pub struct EvalContext<'a, 'x, 'px, 'm, 's, 't, 'pt> {
pub(crate) engine: &'a Engine,
pub(crate) scope: &'x mut Scope<'px>,
pub(crate) mods: &'m mut Imports,
pub(crate) state: &'s mut State,
pub(crate) lib: &'a [&'a Module],
pub(crate) this_ptr: &'t mut Option<&'pt mut Dynamic>,
pub(crate) level: usize,
}
impl<'x, 'px> EvalContext<'_, 'x, 'px, '_, '_, '_, '_> {
/// The current [`Engine`].
#[inline(always)]
pub fn engine(&self) -> &Engine {
self.engine
}
/// The current source.
#[inline(always)]
pub fn source(&self) -> Option<&str> {
self.state.source.as_ref().map(|s| s.as_str())
}
/// The current [`Scope`].
#[inline(always)]
pub fn scope(&self) -> &Scope {
self.scope
}
/// Mutable reference to the current [`Scope`].
#[inline(always)]
pub fn scope_mut(&mut self) -> &mut &'x mut Scope<'px> {
&mut self.scope
}
/// Get an iterator over the current set of modules imported via `import` statements.
#[cfg(not(feature = "no_module"))]
#[inline(always)]
pub fn iter_imports(&self) -> impl Iterator<Item = (&str, &Module)> {
self.mods.iter()
}
/// _(INTERNALS)_ The current set of modules imported via `import` statements.
/// Available under the `internals` feature only.
#[cfg(feature = "internals")]
#[cfg(not(feature = "no_module"))]
#[inline(always)]
pub fn imports(&self) -> &Imports {
self.mods
}
/// Get an iterator over the namespaces containing definition of all script-defined functions.
#[inline(always)]
pub fn iter_namespaces(&self) -> impl Iterator<Item = &Module> {
self.lib.iter().cloned()
}
/// _(INTERNALS)_ The current set of namespaces containing definitions of all script-defined functions.
/// Available under the `internals` feature only.
#[cfg(feature = "internals")]
#[inline(always)]
pub fn namespaces(&self) -> &[&Module] {
self.lib
}
/// The current bound `this` pointer, if any.
#[inline(always)]
pub fn this_ptr(&self) -> Option<&Dynamic> {
self.this_ptr.as_ref().map(|v| &**v)
}
/// The current nesting level of function calls.
#[inline(always)]
pub fn call_level(&self) -> usize {
self.level
}
}
/// Rhai main scripting engine.
///
/// # Thread Safety
///
/// [`Engine`] is re-entrant.
///
/// Currently, [`Engine`] is neither [`Send`] nor [`Sync`].
/// Use the `sync` feature to make it [`Send`] `+` [`Sync`].
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// let result = engine.eval::<i64>("40 + 2")?;
///
/// println!("Answer: {}", result); // prints 42
/// # Ok(())
/// # }
/// ```
pub struct Engine {
/// A module containing all functions directly loaded into the Engine.
pub(crate) global_namespace: Module,
/// A collection of all modules loaded into the global namespace of the Engine.
pub(crate) global_modules: StaticVec<Shared<Module>>,
/// A collection of all sub-modules directly loaded into the Engine.
pub(crate) global_sub_modules: HashMap<ImmutableString, Shared<Module>>,
/// A module resolution service.
#[cfg(not(feature = "no_module"))]
pub(crate) module_resolver: Box<dyn crate::ModuleResolver>,
/// A hashmap mapping type names to pretty-print names.
pub(crate) type_names: HashMap<String, String>,
/// A hashset containing symbols to disable.
pub(crate) disabled_symbols: HashSet<String>,
/// A hashmap containing custom keywords and precedence to recognize.
pub(crate) custom_keywords: HashMap<String, Option<Precedence>>,
/// Custom syntax.
pub(crate) custom_syntax: HashMap<ImmutableString, CustomSyntax>,
/// Callback closure for resolving variable access.
pub(crate) resolve_var: Option<OnVarCallback>,
/// Callback closure for implementing the `print` command.
pub(crate) print: OnPrintCallback,
/// Callback closure for implementing the `debug` command.
pub(crate) debug: OnDebugCallback,
/// Callback closure for progress reporting.
pub(crate) progress: Option<OnProgressCallback>,
/// Optimize the AST after compilation.
pub(crate) optimization_level: OptimizationLevel,
/// Max limits.
#[cfg(not(feature = "unchecked"))]
pub(crate) limits: Limits,
/// Disable doc-comments?
pub(crate) disable_doc_comments: bool,
}
impl fmt::Debug for Engine {
#[inline(always)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str("Engine")
}
}
impl Default for Engine {
#[inline(always)]
fn default() -> Self {
Self::new()
}
}
/// Make getter function
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn make_getter(id: &str) -> String {
format!("{}{}", FN_GET, id)
}
/// Make setter function
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn make_setter(id: &str) -> String {
format!("{}{}", FN_SET, id)
}
/// Is this function an anonymous function?
#[cfg(not(feature = "no_function"))]
#[inline(always)]
pub fn is_anonymous_fn(fn_name: &str) -> bool {
fn_name.starts_with(FN_ANONYMOUS)
}
/// Print to stdout
#[inline(always)]
fn default_print(_s: &str) {
#[cfg(not(feature = "no_std"))]
#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
println!("{}", _s);
}
/// Debug to stdout
#[inline(always)]
fn default_debug(_s: &str, _source: Option<&str>, _pos: Position) {
#[cfg(not(feature = "no_std"))]
#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
if let Some(source) = _source {
println!("{} @ {:?} | {}", source, _pos, _s);
} else {
println!("{:?} | {}", _pos, _s);
}
}
impl Engine {
/// Create a new [`Engine`]
#[inline]
pub fn new() -> Self {
// Create the new scripting Engine
let mut engine = Self {
global_namespace: Default::default(),
global_modules: Default::default(),
global_sub_modules: Default::default(),
#[cfg(not(feature = "no_module"))]
#[cfg(not(feature = "no_std"))]
#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
module_resolver: Box::new(crate::module::resolvers::FileModuleResolver::new()),
#[cfg(not(feature = "no_module"))]
#[cfg(any(feature = "no_std", target_arch = "wasm32",))]
module_resolver: Box::new(crate::module::resolvers::DummyModuleResolver::new()),
type_names: Default::default(),
disabled_symbols: Default::default(),
custom_keywords: Default::default(),
custom_syntax: Default::default(),
// variable resolver
resolve_var: None,
// default print/debug implementations
print: Box::new(default_print),
debug: Box::new(default_debug),
// progress callback
progress: None,
// optimization level
optimization_level: if cfg!(feature = "no_optimize") {
OptimizationLevel::None
} else {
OptimizationLevel::Simple
},
#[cfg(not(feature = "unchecked"))]
limits: Limits {
#[cfg(not(feature = "no_function"))]
max_call_stack_depth: MAX_CALL_STACK_DEPTH,
max_expr_depth: NonZeroUsize::new(MAX_EXPR_DEPTH),
#[cfg(not(feature = "no_function"))]
max_function_expr_depth: NonZeroUsize::new(MAX_FUNCTION_EXPR_DEPTH),
max_operations: None,
#[cfg(not(feature = "no_module"))]
max_modules: usize::MAX,
max_string_size: None,
#[cfg(not(feature = "no_index"))]
max_array_size: None,
#[cfg(not(feature = "no_object"))]
max_map_size: None,
},
disable_doc_comments: false,
};
engine.register_global_module(StandardPackage::new().as_shared_module());
engine
}
/// Create a new [`Engine`] with minimal built-in functions.
///
/// Use [`register_global_module`][Engine::register_global_module] to add packages of functions.
#[inline(always)]
pub fn new_raw() -> Self {
Self {
global_namespace: Default::default(),
global_modules: Default::default(),
global_sub_modules: Default::default(),
#[cfg(not(feature = "no_module"))]
module_resolver: Box::new(crate::module::resolvers::DummyModuleResolver::new()),
type_names: Default::default(),
disabled_symbols: Default::default(),
custom_keywords: Default::default(),
custom_syntax: Default::default(),
resolve_var: None,
print: Box::new(|_| {}),
debug: Box::new(|_, _, _| {}),
progress: None,
optimization_level: if cfg!(feature = "no_optimize") {
OptimizationLevel::None
} else {
OptimizationLevel::Simple
},
#[cfg(not(feature = "unchecked"))]
limits: Limits {
#[cfg(not(feature = "no_function"))]
max_call_stack_depth: MAX_CALL_STACK_DEPTH,
max_expr_depth: NonZeroUsize::new(MAX_EXPR_DEPTH),
#[cfg(not(feature = "no_function"))]
max_function_expr_depth: NonZeroUsize::new(MAX_FUNCTION_EXPR_DEPTH),
max_operations: None,
#[cfg(not(feature = "no_module"))]
max_modules: usize::MAX,
max_string_size: None,
#[cfg(not(feature = "no_index"))]
max_array_size: None,
#[cfg(not(feature = "no_object"))]
max_map_size: None,
},
disable_doc_comments: false,
}
}
/// Search for a module within an imports stack.
#[inline]
pub(crate) fn search_imports(
&self,
mods: &Imports,
state: &mut State,
namespace: &NamespaceRef,
) -> Option<Shared<Module>> {
let root = &namespace[0].name;
// Qualified - check if the root module is directly indexed
let index = if state.always_search {
None
} else {
namespace.index()
};
if let Some(index) = index {
let offset = mods.len() - index.get();
Some(mods.get(offset).expect("invalid index in Imports"))
} else {
mods.find(root)
.map(|n| mods.get(n).expect("invalid index in Imports"))
.or_else(|| self.global_sub_modules.get(root).cloned())
}
}
/// Search for a variable within the scope or within imports,
/// depending on whether the variable name is namespace-qualified.
pub(crate) fn search_namespace<'s>(
&self,
scope: &'s mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &Expr,
) -> Result<(Target<'s>, Position), Box<EvalAltResult>> {
match expr {
Expr::Variable(v) => match v.as_ref() {
// Qualified variable
(_, Some((hash_var, modules)), Ident { name, pos, .. }) => {
let module = self.search_imports(mods, state, modules).ok_or_else(|| {
EvalAltResult::ErrorModuleNotFound(
modules[0].name.to_string(),
modules[0].pos,
)
})?;
let target = module.get_qualified_var(*hash_var).map_err(|mut err| {
match *err {
EvalAltResult::ErrorVariableNotFound(ref mut err_name, _) => {
*err_name = format!("{}{}", modules, name);
}
_ => (),
}
err.fill_position(*pos)
})?;
// Module variables are constant
let mut target = target.clone();
target.set_access_mode(AccessMode::ReadOnly);
Ok((target.into(), *pos))
}
// Normal variable access
_ => self.search_scope_only(scope, mods, state, lib, this_ptr, expr),
},
_ => unreachable!("Expr::Variable expected, but gets {:?}", expr),
}
}
/// Search for a variable within the scope
pub(crate) fn search_scope_only<'s>(
&self,
scope: &'s mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &Expr,
) -> Result<(Target<'s>, Position), Box<EvalAltResult>> {
let (index, _, Ident { name, pos, .. }) = match expr {
Expr::Variable(v) => v.as_ref(),
_ => unreachable!("Expr::Variable expected, but gets {:?}", expr),
};
// Check if the variable is `this`
if name.as_str() == KEYWORD_THIS {
if let Some(val) = this_ptr {
return Ok(((*val).into(), *pos));
} else {
return EvalAltResult::ErrorUnboundThis(*pos).into();
}
}
// Check if it is directly indexed
let index = if state.always_search { &None } else { index };
// Check the variable resolver, if any
if let Some(ref resolve_var) = self.resolve_var {
let index = index.map(NonZeroUsize::get).unwrap_or(0);
let context = EvalContext {
engine: self,
scope,
mods,
state,
lib,
this_ptr,
level: 0,
};
if let Some(mut result) =
resolve_var(name, index, &context).map_err(|err| err.fill_position(*pos))?
{
result.set_access_mode(AccessMode::ReadOnly);
return Ok((result.into(), *pos));
}
}
let index = if let Some(index) = index {
scope.len() - index.get()
} else {
// Find the variable in the scope
scope
.get_index(name)
.ok_or_else(|| EvalAltResult::ErrorVariableNotFound(name.to_string(), *pos))?
.0
};
let val = scope.get_mut_by_index(index);
// Check for data race - probably not necessary because the only place it should conflict is
// in a method call when the object variable is also used as a parameter.
// if cfg!(not(feature = "no_closure")) && val.is_locked() {
// return EvalAltResult::ErrorDataRace(name.into(), *pos).into();
// }
Ok((val.into(), *pos))
}
/// Chain-evaluate a dot/index chain.
/// [`Position`] in [`EvalAltResult`] is [`NONE`][Position::NONE] and must be set afterwards.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
fn eval_dot_index_chain_helper(
&self,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
target: &mut Target,
rhs: &Expr,
idx_values: &mut StaticVec<ChainArgument>,
chain_type: ChainType,
level: usize,
new_val: Option<((Dynamic, Position), (&Option<OpAssignment>, Position))>,
) -> Result<(Dynamic, bool), Box<EvalAltResult>> {
assert!(chain_type != ChainType::NonChaining);
let is_ref = target.is_ref();
let next_chain = match rhs {
Expr::Index(_, _) => ChainType::Index,
Expr::Dot(_, _) => ChainType::Dot,
_ => ChainType::NonChaining,
};
// Pop the last index value
let idx_val = idx_values.pop().unwrap();
let target_val = target.as_mut();
match chain_type {
#[cfg(not(feature = "no_index"))]
ChainType::Index => {
let pos = rhs.position();
match rhs {
// xxx[idx].expr... | xxx[idx][expr]...
Expr::Dot(x, x_pos) | Expr::Index(x, x_pos) => {
let idx_pos = x.lhs.position();
let idx_val = idx_val.as_index_value();
let obj_ptr = &mut self.get_indexed_mut(
mods, state, lib, target_val, idx_val, idx_pos, false, is_ref, true,
level,
)?;
self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, obj_ptr, &x.rhs, idx_values, next_chain,
level, new_val,
)
.map_err(|err| err.fill_position(*x_pos))
}
// xxx[rhs] op= new_val
_ if new_val.is_some() => {
let idx_val = idx_val.as_index_value();
let mut idx_val2 = idx_val.clone();
// `call_setter` is introduced to bypass double mutable borrowing of target
let _call_setter = match self.get_indexed_mut(
mods, state, lib, target_val, idx_val, pos, true, is_ref, false, level,
) {
// Indexed value is a reference - update directly
Ok(obj_ptr) => {
let ((new_val, new_pos), (op_info, op_pos)) = new_val.unwrap();
self.eval_op_assignment(
mods, state, lib, op_info, op_pos, obj_ptr, new_val, new_pos,
)?;
None
}
Err(err) => match *err {
// No index getter - try to call an index setter
#[cfg(not(feature = "no_index"))]
EvalAltResult::ErrorIndexingType(_, _) => Some(new_val.unwrap()),
// Any other error - return
err => return err.into(),
},
};
#[cfg(not(feature = "no_index"))]
if let Some(mut new_val) = _call_setter {
let val_type_name = target_val.type_name();
let ((_, val_pos), _) = new_val;
let hash_set =
FnCallHash::from_native(calc_fn_hash(empty(), FN_IDX_SET, 3));
let args = &mut [target_val, &mut idx_val2, &mut (new_val.0).0];
self.exec_fn_call(
mods, state, lib, FN_IDX_SET, hash_set, args, is_ref, true,
val_pos, None, level,
)
.map_err(|err| match *err {
EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
if fn_sig.ends_with("]=") =>
{
EvalAltResult::ErrorIndexingType(
self.map_type_name(val_type_name).into(),
Position::NONE,
)
}
err => err,
})?;
}
Ok((Dynamic::UNIT, true))
}
// xxx[rhs]
_ => {
let idx_val = idx_val.as_index_value();
self.get_indexed_mut(
mods, state, lib, target_val, idx_val, pos, false, is_ref, true, level,
)
.map(|v| (v.take_or_clone(), false))
}
}
}
#[cfg(not(feature = "no_object"))]
ChainType::Dot => {
match rhs {
// xxx.fn_name(arg_expr_list)
Expr::FnCall(x, pos) if x.namespace.is_none() && new_val.is_none() => {
let FnCallExpr { name, hash, .. } = x.as_ref();
let mut args = idx_val.as_fn_call_args();
self.make_method_call(
mods, state, lib, name, *hash, target, &mut args, *pos, level,
)
}
// xxx.fn_name(...) = ???
Expr::FnCall(_, _) if new_val.is_some() => {
unreachable!("method call cannot be assigned to")
}
// xxx.module::fn_name(...) - syntax error
Expr::FnCall(_, _) => {
unreachable!("function call in dot chain should not be namespace-qualified")
}
// {xxx:map}.id op= ???
Expr::Property(x) if target_val.is::<Map>() && new_val.is_some() => {
let Ident { name, pos, .. } = &x.2;
let index = name.clone().into();
let val = self.get_indexed_mut(
mods, state, lib, target_val, index, *pos, true, is_ref, false, level,
)?;
let ((new_val, new_pos), (op_info, op_pos)) = new_val.unwrap();
self.eval_op_assignment(
mods, state, lib, op_info, op_pos, val, new_val, new_pos,
)?;
Ok((Dynamic::UNIT, true))
}
// {xxx:map}.id
Expr::Property(x) if target_val.is::<Map>() => {
let Ident { name, pos, .. } = &x.2;
let index = name.clone().into();
let val = self.get_indexed_mut(
mods, state, lib, target_val, index, *pos, false, is_ref, false, level,
)?;
Ok((val.take_or_clone(), false))
}
// xxx.id = ???
Expr::Property(x) if new_val.is_some() => {
let (_, (setter, hash_set), Ident { pos, .. }) = x.as_ref();
let hash = FnCallHash::from_native(*hash_set);
let mut new_val = new_val;
let mut args = [target_val, &mut (new_val.as_mut().unwrap().0).0];
self.exec_fn_call(
mods, state, lib, setter, hash, &mut args, is_ref, true, *pos, None,
level,
)
.map(|(v, _)| (v, true))
}
// xxx.id
Expr::Property(x) => {
let ((getter, hash_get), _, Ident { pos, .. }) = x.as_ref();
let hash = FnCallHash::from_native(*hash_get);
let mut args = [target_val];
self.exec_fn_call(
mods, state, lib, getter, hash, &mut args, is_ref, true, *pos, None,
level,
)
.map(|(v, _)| (v, false))
}
// {xxx:map}.sub_lhs[expr] | {xxx:map}.sub_lhs.expr
Expr::Index(x, x_pos) | Expr::Dot(x, x_pos) if target_val.is::<Map>() => {
let mut val = match &x.lhs {
Expr::Property(p) => {
let Ident { name, pos, .. } = &p.2;
let index = name.clone().into();
self.get_indexed_mut(
mods, state, lib, target_val, index, *pos, false, is_ref, true,
level,
)?
}
// {xxx:map}.fn_name(arg_expr_list)[expr] | {xxx:map}.fn_name(arg_expr_list).expr
Expr::FnCall(x, pos) if x.namespace.is_none() => {
let FnCallExpr { name, hash, .. } = x.as_ref();
let mut args = idx_val.as_fn_call_args();
let (val, _) = self.make_method_call(
mods, state, lib, name, *hash, target, &mut args, *pos, level,
)?;
val.into()
}
// {xxx:map}.module::fn_name(...) - syntax error
Expr::FnCall(_, _) => unreachable!(
"function call in dot chain should not be namespace-qualified"
),
// Others - syntax error
expr => unreachable!("invalid dot expression: {:?}", expr),
};
self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, &mut val, &x.rhs, idx_values, next_chain,
level, new_val,
)
.map_err(|err| err.fill_position(*x_pos))
}
// xxx.sub_lhs[expr] | xxx.sub_lhs.expr
Expr::Index(x, x_pos) | Expr::Dot(x, x_pos) => {
match &x.lhs {
// xxx.prop[expr] | xxx.prop.expr
Expr::Property(p) => {
let ((getter, hash_get), (setter, hash_set), Ident { pos, .. }) =
p.as_ref();
let hash_get = FnCallHash::from_native(*hash_get);
let hash_set = FnCallHash::from_native(*hash_set);
let arg_values = &mut [target_val, &mut Default::default()];
let args = &mut arg_values[..1];
let (mut val, updated) = self.exec_fn_call(
mods, state, lib, getter, hash_get, args, is_ref, true, *pos,
None, level,
)?;
let val = &mut val;
let (result, may_be_changed) = self
.eval_dot_index_chain_helper(
mods,
state,
lib,
this_ptr,
&mut val.into(),
&x.rhs,
idx_values,
next_chain,
level,
new_val,
)
.map_err(|err| err.fill_position(*x_pos))?;
// Feed the value back via a setter just in case it has been updated
if updated || may_be_changed {
// Re-use args because the first &mut parameter will not be consumed
arg_values[1] = val;
self.exec_fn_call(
mods, state, lib, setter, hash_set, arg_values, is_ref,
true, *pos, None, level,
)
.or_else(
|err| match *err {
// If there is no setter, no need to feed it back because
// the property is read-only
EvalAltResult::ErrorDotExpr(_, _) => {
Ok((Dynamic::UNIT, false))
}
_ => Err(err),
},
)?;
}
Ok((result, may_be_changed))
}
// xxx.fn_name(arg_expr_list)[expr] | xxx.fn_name(arg_expr_list).expr
Expr::FnCall(f, pos) if f.namespace.is_none() => {
let FnCallExpr { name, hash, .. } = f.as_ref();
let mut args = idx_val.as_fn_call_args();
let (mut val, _) = self.make_method_call(
mods, state, lib, name, *hash, target, &mut args, *pos, level,
)?;
let val = &mut val;
let target = &mut val.into();
self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, target, &x.rhs, idx_values,
next_chain, level, new_val,
)
.map_err(|err| err.fill_position(*pos))
}
// xxx.module::fn_name(...) - syntax error
Expr::FnCall(_, _) => unreachable!(
"function call in dot chain should not be namespace-qualified"
),
// Others - syntax error
expr => unreachable!("invalid dot expression: {:?}", expr),
}
}
// Syntax error
_ => EvalAltResult::ErrorDotExpr("".into(), rhs.position()).into(),
}
}
chain_type => unreachable!("invalid ChainType: {:?}", chain_type),
}
}
/// Evaluate a dot/index chain.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
fn eval_dot_index_chain(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
expr: &Expr,
level: usize,
new_val: Option<((Dynamic, Position), (&Option<OpAssignment>, Position))>,
) -> RhaiResult {
let (crate::ast::BinaryExpr { lhs, rhs }, chain_type, op_pos) = match expr {
Expr::Index(x, pos) => (x.as_ref(), ChainType::Index, *pos),
Expr::Dot(x, pos) => (x.as_ref(), ChainType::Dot, *pos),
_ => unreachable!("index or dot chain expected, but gets {:?}", expr),
};
let idx_values = &mut Default::default();
self.eval_indexed_chain(
scope, mods, state, lib, this_ptr, rhs, chain_type, idx_values, 0, level,
)?;
match lhs {
// id.??? or id[???]
Expr::Variable(x) => {
let Ident {
name: var_name,
pos: var_pos,
..
} = &x.2;
self.inc_operations(state, *var_pos)?;
let (target, pos) =
self.search_namespace(scope, mods, state, lib, this_ptr, lhs)?;
// Constants cannot be modified
if target.as_ref().is_read_only() && new_val.is_some() {
return EvalAltResult::ErrorAssignmentToConstant(var_name.to_string(), pos)
.into();
}
let obj_ptr = &mut target.into();
self.eval_dot_index_chain_helper(
mods, state, lib, &mut None, obj_ptr, rhs, idx_values, chain_type, level,
new_val,
)
.map(|(v, _)| v)
.map_err(|err| err.fill_position(op_pos))
}
// {expr}.??? = ??? or {expr}[???] = ???
_ if new_val.is_some() => unreachable!("cannot assign to an expression"),
// {expr}.??? or {expr}[???]
expr => {
let value = self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?;
let obj_ptr = &mut value.into();
self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, obj_ptr, rhs, idx_values, chain_type, level,
new_val,
)
.map(|(v, _)| v)
.map_err(|err| err.fill_position(op_pos))
}
}
}
/// Evaluate a chain of indexes and store the results in a [`StaticVec`].
/// [`StaticVec`] is used to avoid an allocation in the overwhelming cases of
/// just a few levels of indexing.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
fn eval_indexed_chain(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
expr: &Expr,
parent_chain_type: ChainType,
idx_values: &mut StaticVec<ChainArgument>,
size: usize,
level: usize,
) -> Result<(), Box<EvalAltResult>> {
self.inc_operations(state, expr.position())?;
match expr {
Expr::FnCall(x, _) if parent_chain_type == ChainType::Dot && x.namespace.is_none() => {
let mut arg_positions: StaticVec<_> = Default::default();
let arg_values = x
.args
.iter()
.map(|arg_expr| {
arg_positions.push(arg_expr.position());
self.eval_expr(scope, mods, state, lib, this_ptr, arg_expr, level)
.map(Dynamic::flatten)
})
.collect::<Result<StaticVec<_>, _>>()?;
idx_values.push((arg_values, arg_positions).into());
}
Expr::FnCall(_, _) if parent_chain_type == ChainType::Dot => {
unreachable!("function call in dot chain should not be namespace-qualified")
}
Expr::Property(x) if parent_chain_type == ChainType::Dot => {
idx_values.push(ChainArgument::Property(x.2.pos))
}
Expr::Property(_) => unreachable!("unexpected Expr::Property for indexing"),
Expr::Index(x, _) | Expr::Dot(x, _) => {
let crate::ast::BinaryExpr { lhs, rhs, .. } = x.as_ref();
// Evaluate in left-to-right order
let lhs_val = match lhs {
Expr::Property(x) if parent_chain_type == ChainType::Dot => {
ChainArgument::Property(x.2.pos)
}
Expr::Property(_) => unreachable!("unexpected Expr::Property for indexing"),
Expr::FnCall(x, _)
if parent_chain_type == ChainType::Dot && x.namespace.is_none() =>
{
let mut arg_positions: StaticVec<_> = Default::default();
let arg_values = x
.args
.iter()
.map(|arg_expr| {
arg_positions.push(arg_expr.position());
self.eval_expr(scope, mods, state, lib, this_ptr, arg_expr, level)
.map(Dynamic::flatten)
})
.collect::<Result<StaticVec<_>, _>>()?;
(arg_values, arg_positions).into()
}
Expr::FnCall(_, _) if parent_chain_type == ChainType::Dot => {
unreachable!("function call in dot chain should not be namespace-qualified")
}
_ => self
.eval_expr(scope, mods, state, lib, this_ptr, lhs, level)
.map(|v| (v.flatten(), lhs.position()).into())?,
};
// Push in reverse order
let chain_type = match expr {
Expr::Index(_, _) => ChainType::Index,
Expr::Dot(_, _) => ChainType::Dot,
_ => unreachable!("index or dot chain expected, but gets {:?}", expr),
};
self.eval_indexed_chain(
scope, mods, state, lib, this_ptr, rhs, chain_type, idx_values, size, level,
)?;
idx_values.push(lhs_val);
}
_ => idx_values.push(
self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)
.map(|v| (v.flatten(), expr.position()).into())?,
),
}
Ok(())
}
/// Get the value at the indexed position of a base type.
/// [`Position`] in [`EvalAltResult`] may be None and should be set afterwards.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
fn get_indexed_mut<'t>(
&self,
_mods: &mut Imports,
state: &mut State,
_lib: &[&Module],
target: &'t mut Dynamic,
idx: Dynamic,
idx_pos: Position,
_create: bool,
_is_ref: bool,
_indexers: bool,
_level: usize,
) -> Result<Target<'t>, Box<EvalAltResult>> {
self.inc_operations(state, Position::NONE)?;
match target {
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Array(arr, _)) => {
// val_array[idx]
let index = idx
.as_int()
.map_err(|err| self.make_type_mismatch_err::<crate::INT>(err, idx_pos))?;
let arr_len = arr.len();
if index >= 0 {
arr.get_mut(index as usize)
.map(Target::from)
.ok_or_else(|| {
EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos).into()
})
} else {
EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos).into()
}
}
#[cfg(not(feature = "no_object"))]
Dynamic(Union::Map(map, _)) => {
// val_map[idx]
Ok(if _create {
let index = idx.take_immutable_string().map_err(|err| {
self.make_type_mismatch_err::<ImmutableString>(err, idx_pos)
})?;
map.entry(index).or_insert_with(Default::default).into()
} else {
let index = idx.read_lock::<ImmutableString>().ok_or_else(|| {
self.make_type_mismatch_err::<ImmutableString>("", idx_pos)
})?;
map.get_mut(&*index)
.map(Target::from)
.unwrap_or_else(|| Target::from(()))
})
}
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Str(s, _)) => {
// val_string[idx]
let chars_len = s.chars().count();
let index = idx
.as_int()
.map_err(|err| self.make_type_mismatch_err::<crate::INT>(err, idx_pos))?;
if index >= 0 {
let offset = index as usize;
let ch = s.chars().nth(offset).ok_or_else(|| {
EvalAltResult::ErrorStringBounds(chars_len, index, idx_pos)
})?;
Ok(Target::StringChar(target, offset, ch.into()))
} else {
EvalAltResult::ErrorStringBounds(chars_len, index, idx_pos).into()
}
}
#[cfg(not(feature = "no_index"))]
_ if _indexers => {
let type_name = target.type_name();
let mut idx = idx;
let args = &mut [target, &mut idx];
let hash_get = FnCallHash::from_native(calc_fn_hash(empty(), FN_IDX_GET, 2));
self.exec_fn_call(
_mods, state, _lib, FN_IDX_GET, hash_get, args, _is_ref, true, idx_pos, None,
_level,
)
.map(|(v, _)| v.into())
.map_err(|err| match *err {
EvalAltResult::ErrorFunctionNotFound(fn_sig, _) if fn_sig.ends_with(']') => {
Box::new(EvalAltResult::ErrorIndexingType(
type_name.into(),
Position::NONE,
))
}
_ => err,
})
}
_ => EvalAltResult::ErrorIndexingType(
self.map_type_name(target.type_name()).into(),
Position::NONE,
)
.into(),
}
}
/// Evaluate an expression.
pub(crate) fn eval_expr(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
expr: &Expr,
level: usize,
) -> RhaiResult {
self.inc_operations(state, expr.position())?;
let result = match expr {
Expr::DynamicConstant(x, _) => Ok(x.as_ref().clone()),
Expr::IntegerConstant(x, _) => Ok((*x).into()),
#[cfg(not(feature = "no_float"))]
Expr::FloatConstant(x, _) => Ok((*x).into()),
Expr::StringConstant(x, _) => Ok(x.clone().into()),
Expr::CharConstant(x, _) => Ok((*x).into()),
Expr::FnPointer(x, _) => Ok(FnPtr::new_unchecked(x.clone(), Default::default()).into()),
Expr::Variable(x) if (x.2).name == KEYWORD_THIS => this_ptr
.as_deref()
.cloned()
.ok_or_else(|| EvalAltResult::ErrorUnboundThis((x.2).pos).into()),
Expr::Variable(_) => self
.search_namespace(scope, mods, state, lib, this_ptr, expr)
.map(|(val, _)| val.take_or_clone()),
// Statement block
Expr::Stmt(x) if x.is_empty() => Ok(Dynamic::UNIT),
Expr::Stmt(x) => {
let statements = &x.statements;
self.eval_stmt_block(scope, mods, state, lib, this_ptr, statements, true, level)
}
// lhs[idx_expr]
#[cfg(not(feature = "no_index"))]
Expr::Index(_, _) => {
self.eval_dot_index_chain(scope, mods, state, lib, this_ptr, expr, level, None)
}
// lhs.dot_rhs
#[cfg(not(feature = "no_object"))]
Expr::Dot(_, _) => {
self.eval_dot_index_chain(scope, mods, state, lib, this_ptr, expr, level, None)
}
#[cfg(not(feature = "no_index"))]
Expr::Array(x, _) => {
let mut arr =
Array::with_capacity(crate::stdlib::cmp::max(TYPICAL_ARRAY_SIZE, x.len()));
for item in x.as_ref() {
arr.push(
self.eval_expr(scope, mods, state, lib, this_ptr, item, level)?
.flatten(),
);
}
Ok(Dynamic(Union::Array(Box::new(arr), AccessMode::ReadWrite)))
}
#[cfg(not(feature = "no_object"))]
Expr::Map(x, _) => {
let mut map =
Map::with_capacity(crate::stdlib::cmp::max(TYPICAL_MAP_SIZE, x.len()));
for (Ident { name: key, .. }, expr) in x.as_ref() {
map.insert(
key.clone(),
self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten(),
);
}
Ok(Dynamic(Union::Map(Box::new(map), AccessMode::ReadWrite)))
}
// Normal function call
Expr::FnCall(x, pos) if x.namespace.is_none() => {
let FnCallExpr {
name,
capture,
hash,
args,
..
} = x.as_ref();
self.make_function_call(
scope, mods, state, lib, this_ptr, name, args, *hash, *pos, *capture, level,
)
}
// Namespace-qualified function call
Expr::FnCall(x, pos) if x.namespace.is_some() => {
let FnCallExpr {
name,
namespace,
hash,
args,
..
} = x.as_ref();
let namespace = namespace.as_ref();
let hash = hash.native_hash();
self.make_qualified_function_call(
scope, mods, state, lib, this_ptr, namespace, name, args, hash, *pos, level,
)
}
Expr::And(x, _) => {
Ok((self
.eval_expr(scope, mods, state, lib, this_ptr, &x.lhs, level)?
.as_bool()
.map_err(|err| self.make_type_mismatch_err::<bool>(err, x.lhs.position()))?
&& // Short-circuit using &&
self
.eval_expr(scope, mods, state, lib, this_ptr, &x.rhs, level)?
.as_bool()
.map_err(|err| self.make_type_mismatch_err::<bool>(err, x.rhs.position()))?)
.into())
}
Expr::Or(x, _) => {
Ok((self
.eval_expr(scope, mods, state, lib, this_ptr, &x.lhs, level)?
.as_bool()
.map_err(|err| self.make_type_mismatch_err::<bool>(err, x.lhs.position()))?
|| // Short-circuit using ||
self
.eval_expr(scope, mods, state, lib, this_ptr, &x.rhs, level)?
.as_bool()
.map_err(|err| self.make_type_mismatch_err::<bool>(err, x.rhs.position()))?)
.into())
}
Expr::BoolConstant(x, _) => Ok((*x).into()),
Expr::Unit(_) => Ok(Dynamic::UNIT),
Expr::Custom(custom, _) => {
let expressions = custom
.keywords
.iter()
.map(Into::into)
.collect::<StaticVec<_>>();
let custom_def = self
.custom_syntax
.get(custom.tokens.first().unwrap())
.unwrap();
let mut context = EvalContext {
engine: self,
scope,
mods,
state,
lib,
this_ptr,
level,
};
(custom_def.func)(&mut context, &expressions)
}
_ => unreachable!("expression cannot be evaluated: {:?}", expr),
};
self.check_data_size(result, expr.position())
}
/// Evaluate a statements block.
pub(crate) fn eval_stmt_block(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
statements: &[Stmt],
restore_prev_state: bool,
level: usize,
) -> RhaiResult {
if statements.is_empty() {
return Ok(Dynamic::UNIT);
}
let mut _extra_fn_resolution_cache = false;
let prev_always_search = state.always_search;
let prev_scope_len = scope.len();
let prev_mods_len = mods.len();
if restore_prev_state {
state.scope_level += 1;
}
let result = statements.iter().try_fold(Dynamic::UNIT, |_, stmt| {
let _mods_len = mods.len();
let r = self.eval_stmt(scope, mods, state, lib, this_ptr, stmt, level)?;
#[cfg(not(feature = "no_module"))]
if matches!(stmt, Stmt::Import(_, _, _)) {
// Get the extra modules - see if any functions are marked global.
// Without global functions, the extra modules never affect function resolution.
if mods
.scan_raw()
.skip(_mods_len)
.any(|(_, m)| m.contains_indexed_global_functions())
{
if _extra_fn_resolution_cache {
// When new module is imported with global functions and there is already
// a new cache, clear it - notice that this is expensive as all function
// resolutions must start again
state.fn_resolution_cache_mut().clear();
} else if restore_prev_state {
// When new module is imported with global functions, push a new cache
state.push_fn_resolution_cache();
_extra_fn_resolution_cache = true;
} else {
// When the block is to be evaluated in-place, just clear the current cache
state.fn_resolution_cache_mut().clear();
}
}
}
Ok(r)
});
if _extra_fn_resolution_cache {
// If imports list is modified, pop the functions lookup cache
state.pop_fn_resolution_cache();
}
if restore_prev_state {
scope.rewind(prev_scope_len);
mods.truncate(prev_mods_len);
state.scope_level -= 1;
// The impact of new local variables goes away at the end of a block
// because any new variables introduced will go out of scope
state.always_search = prev_always_search;
}
result
}
pub(crate) fn eval_op_assignment(
&self,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
op_info: &Option<OpAssignment>,
op_pos: Position,
mut target: Target,
mut new_value: Dynamic,
new_value_pos: Position,
) -> Result<(), Box<EvalAltResult>> {
if target.as_ref().is_read_only() {
unreachable!("LHS should not be read-only");
}
if let Some(OpAssignment {
hash_op_assign,
hash_op,
op,
}) = op_info
{
let mut lock_guard;
let lhs_ptr_inner;
if cfg!(not(feature = "no_closure")) && target.is_shared() {
lock_guard = target.as_mut().write_lock::<Dynamic>().unwrap();
lhs_ptr_inner = lock_guard.deref_mut();
} else {
lhs_ptr_inner = target.as_mut();
}
let hash = *hash_op_assign;
let args = &mut [lhs_ptr_inner, &mut new_value];
match self.call_native_fn(mods, state, lib, op, hash, args, true, true, op_pos) {
Ok(_) => (),
Err(err) if matches!(err.as_ref(), EvalAltResult::ErrorFunctionNotFound(f, _) if f.starts_with(op.as_ref())) =>
{
// Expand to `var = var op rhs`
let op = &op[..op.len() - 1]; // extract operator without =
// Run function
let (value, _) = self.call_native_fn(
mods, state, lib, op, *hash_op, args, true, false, op_pos,
)?;
*args[0] = value.flatten();
}
err => return err.map(|_| ()),
}
Ok(())
} else {
// Normal assignment
target.set_value(new_value, new_value_pos)?;
Ok(())
}
}
/// Evaluate a statement.
///
/// # Safety
///
/// This method uses some unsafe code, mainly for avoiding cloning of local variable names via
/// direct lifetime casting.
pub(crate) fn eval_stmt(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
stmt: &Stmt,
level: usize,
) -> RhaiResult {
self.inc_operations(state, stmt.position())?;
let result = match stmt {
// No-op
Stmt::Noop(_) => Ok(Dynamic::UNIT),
// Expression as statement
Stmt::Expr(expr) => Ok(self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten()),
// var op= rhs
Stmt::Assignment(x, op_pos) if x.0.get_variable_access(false).is_some() => {
let (lhs_expr, rhs_expr, op_info) = x.as_ref();
let rhs_val = self
.eval_expr(scope, mods, state, lib, this_ptr, rhs_expr, level)?
.flatten();
let (lhs_ptr, pos) =
self.search_namespace(scope, mods, state, lib, this_ptr, lhs_expr)?;
if !lhs_ptr.is_ref() {
return EvalAltResult::ErrorAssignmentToConstant(
lhs_expr.get_variable_access(false).unwrap().to_string(),
pos,
)
.into();
}
self.inc_operations(state, pos)?;
if lhs_ptr.as_ref().is_read_only() {
// Assignment to constant variable
EvalAltResult::ErrorAssignmentToConstant(
lhs_expr.get_variable_access(false).unwrap().to_string(),
pos,
)
.into()
} else {
self.eval_op_assignment(
mods,
state,
lib,
op_info,
*op_pos,
lhs_ptr,
rhs_val,
rhs_expr.position(),
)?;
Ok(Dynamic::UNIT)
}
}
// lhs op= rhs
Stmt::Assignment(x, op_pos) => {
let (lhs_expr, rhs_expr, op_info) = x.as_ref();
let rhs_val = self
.eval_expr(scope, mods, state, lib, this_ptr, rhs_expr, level)?
.flatten();
let _new_val = Some(((rhs_val, rhs_expr.position()), (op_info, *op_pos)));
// Must be either `var[index] op= val` or `var.prop op= val`
match lhs_expr {
// name op= rhs (handled above)
Expr::Variable(_) => {
unreachable!("Expr::Variable case should already been handled")
}
// idx_lhs[idx_expr] op= rhs
#[cfg(not(feature = "no_index"))]
Expr::Index(_, _) => {
self.eval_dot_index_chain(
scope, mods, state, lib, this_ptr, lhs_expr, level, _new_val,
)?;
Ok(Dynamic::UNIT)
}
// dot_lhs.dot_rhs op= rhs
#[cfg(not(feature = "no_object"))]
Expr::Dot(_, _) => {
self.eval_dot_index_chain(
scope, mods, state, lib, this_ptr, lhs_expr, level, _new_val,
)?;
Ok(Dynamic::UNIT)
}
_ => unreachable!("cannot assign to expression: {:?}", lhs_expr),
}
}
// Block scope
Stmt::Block(statements, _) if statements.is_empty() => Ok(Dynamic::UNIT),
Stmt::Block(statements, _) => {
self.eval_stmt_block(scope, mods, state, lib, this_ptr, statements, true, level)
}
// If statement
Stmt::If(expr, x, _) => {
let (
StmtBlock {
statements: if_stmt,
..
},
StmtBlock {
statements: else_stmt,
..
},
) = x.as_ref();
self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.as_bool()
.map_err(|err| self.make_type_mismatch_err::<bool>(err, expr.position()))
.and_then(|guard_val| {
if guard_val {
if !if_stmt.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, if_stmt, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
} else {
if !else_stmt.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, else_stmt, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
}
})
}
// Switch statement
Stmt::Switch(match_expr, x, _) => {
let (table, def_stmt) = x.as_ref();
let value = self.eval_expr(scope, mods, state, lib, this_ptr, match_expr, level)?;
if value.is_hashable() {
let hasher = &mut get_hasher();
value.hash(hasher);
let hash = hasher.finish();
table.get(&hash).map(|StmtBlock { statements, .. }| {
if !statements.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, statements, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
})
} else {
// Non-hashable values never match any specific clause
None
}
.unwrap_or_else(|| {
// Default match clause
let def_stmt = &def_stmt.statements;
if !def_stmt.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, def_stmt, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
})
}
// While loop
Stmt::While(expr, body, _) => {
let body = &body.statements;
loop {
let condition = if !expr.is_unit() {
self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.as_bool()
.map_err(|err| {
self.make_type_mismatch_err::<bool>(err, expr.position())
})?
} else {
true
};
if !condition {
return Ok(Dynamic::UNIT);
}
if body.is_empty() {
continue;
}
match self.eval_stmt_block(scope, mods, state, lib, this_ptr, body, true, level)
{
Ok(_) => (),
Err(err) => match *err {
EvalAltResult::LoopBreak(false, _) => (),
EvalAltResult::LoopBreak(true, _) => return Ok(Dynamic::UNIT),
_ => return Err(err),
},
}
}
}
// Do loop
Stmt::Do(body, expr, is_while, _) => {
let body = &body.statements;
loop {
if !body.is_empty() {
match self
.eval_stmt_block(scope, mods, state, lib, this_ptr, body, true, level)
{
Ok(_) => (),
Err(err) => match *err {
EvalAltResult::LoopBreak(false, _) => continue,
EvalAltResult::LoopBreak(true, _) => return Ok(Dynamic::UNIT),
_ => return Err(err),
},
}
}
if self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.as_bool()
.map_err(|err| self.make_type_mismatch_err::<bool>(err, expr.position()))?
{
if !*is_while {
return Ok(Dynamic::UNIT);
}
} else {
if *is_while {
return Ok(Dynamic::UNIT);
}
}
}
}
// For loop
Stmt::For(expr, x, _) => {
let (name, StmtBlock { statements, pos }) = x.as_ref();
let iter_obj = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten();
let iter_type = iter_obj.type_id();
// lib should only contain scripts, so technically they cannot have iterators
// Search order:
// 1) Global namespace - functions registered via Engine::register_XXX
// 2) Global modules - packages
// 3) Imported modules - functions marked with global namespace
// 4) Global sub-modules - functions marked with global namespace
let func = self
.global_namespace
.get_iter(iter_type)
.or_else(|| {
self.global_modules
.iter()
.find_map(|m| m.get_iter(iter_type))
})
.or_else(|| mods.get_iter(iter_type))
.or_else(|| {
self.global_sub_modules
.values()
.find_map(|m| m.get_qualified_iter(iter_type))
});
if let Some(func) = func {
// Add the loop variable
let var_name: Cow<'_, str> = if state.is_global() {
name.clone().into()
} else {
unsafe_cast_var_name_to_lifetime(name).into()
};
scope.push(var_name, ());
let index = scope.len() - 1;
state.scope_level += 1;
for iter_value in func(iter_obj) {
let loop_var = scope.get_mut_by_index(index);
let value = iter_value.flatten();
if cfg!(not(feature = "no_closure")) && loop_var.is_shared() {
*loop_var.write_lock().unwrap() = value;
} else {
*loop_var = value;
}
self.inc_operations(state, *pos)?;
if statements.is_empty() {
continue;
}
match self.eval_stmt_block(
scope, mods, state, lib, this_ptr, statements, true, level,
) {
Ok(_) => (),
Err(err) => match *err {
EvalAltResult::LoopBreak(false, _) => (),
EvalAltResult::LoopBreak(true, _) => break,
_ => return Err(err),
},
}
}
state.scope_level -= 1;
scope.rewind(scope.len() - 1);
Ok(Dynamic::UNIT)
} else {
EvalAltResult::ErrorFor(expr.position()).into()
}
}
// Continue statement
Stmt::Continue(pos) => EvalAltResult::LoopBreak(false, *pos).into(),
// Break statement
Stmt::Break(pos) => EvalAltResult::LoopBreak(true, *pos).into(),
// Try/Catch statement
Stmt::TryCatch(x, _, _) => {
let (
StmtBlock {
statements: try_body,
..
},
err_var,
StmtBlock {
statements: catch_body,
..
},
) = x.as_ref();
let result = self
.eval_stmt_block(scope, mods, state, lib, this_ptr, try_body, true, level)
.map(|_| Dynamic::UNIT);
match result {
Ok(_) => result,
Err(err) if err.is_pseudo_error() => Err(err),
Err(err) if !err.is_catchable() => Err(err),
Err(mut err) => {
let err_value = match *err {
EvalAltResult::ErrorRuntime(ref x, _) => x.clone(),
#[cfg(feature = "no_object")]
_ => {
err.take_position();
err.to_string().into()
}
#[cfg(not(feature = "no_object"))]
_ => {
use crate::INT;
let mut err_map: Map = Default::default();
let err_pos = err.take_position();
err_map.insert("message".into(), err.to_string().into());
if let Some(ref source) = state.source {
err_map.insert("source".into(), source.clone().into());
}
if err_pos.is_none() {
// No position info
} else {
err_map.insert(
"line".into(),
(err_pos.line().unwrap() as INT).into(),
);
err_map.insert(
"position".into(),
if err_pos.is_beginning_of_line() {
0
} else {
err_pos.position().unwrap() as INT
}
.into(),
);
}
err.dump_fields(&mut err_map);
err_map.into()
}
};
let orig_scope_len = scope.len();
state.scope_level += 1;
if let Some(Ident { name, .. }) = err_var {
scope.push(unsafe_cast_var_name_to_lifetime(&name), err_value);
}
let result = self.eval_stmt_block(
scope, mods, state, lib, this_ptr, catch_body, true, level,
);
state.scope_level -= 1;
scope.rewind(orig_scope_len);
match result {
Ok(_) => Ok(Dynamic::UNIT),
Err(result_err) => match *result_err {
// Re-throw exception
EvalAltResult::ErrorRuntime(Dynamic(Union::Unit(_, _)), pos) => {
err.set_position(pos);
Err(err)
}
_ => Err(result_err),
},
}
}
}
}
// Return value
Stmt::Return(ReturnType::Return, Some(expr), pos) => {
let value = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten();
EvalAltResult::Return(value, *pos).into()
}
// Empty return
Stmt::Return(ReturnType::Return, None, pos) => {
EvalAltResult::Return(Default::default(), *pos).into()
}
// Throw value
Stmt::Return(ReturnType::Exception, Some(expr), pos) => {
let value = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten();
EvalAltResult::ErrorRuntime(value, *pos).into()
}
// Empty throw
Stmt::Return(ReturnType::Exception, None, pos) => {
EvalAltResult::ErrorRuntime(Dynamic::UNIT, *pos).into()
}
// Let/const statement
Stmt::Let(expr, Ident { name, .. }, export, _)
| Stmt::Const(expr, Ident { name, .. }, export, _) => {
let entry_type = match stmt {
Stmt::Let(_, _, _, _) => AccessMode::ReadWrite,
Stmt::Const(_, _, _, _) => AccessMode::ReadOnly,
_ => unreachable!("should be Stmt::Let or Stmt::Const, but gets {:?}", stmt),
};
let value = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten();
let (var_name, _alias): (Cow<'_, str>, _) = if state.is_global() {
(
name.to_string().into(),
if *export { Some(name.clone()) } else { None },
)
} else if *export {
unreachable!("exported variable not on global level");
} else {
(unsafe_cast_var_name_to_lifetime(name).into(), None)
};
scope.push_dynamic_value(var_name, entry_type, value);
#[cfg(not(feature = "no_module"))]
if let Some(alias) = _alias {
scope.add_entry_alias(scope.len() - 1, alias);
}
Ok(Dynamic::UNIT)
}
// Import statement
#[cfg(not(feature = "no_module"))]
Stmt::Import(expr, export, _pos) => {
// Guard against too many modules
#[cfg(not(feature = "unchecked"))]
if state.modules >= self.max_modules() {
return EvalAltResult::ErrorTooManyModules(*_pos).into();
}
if let Some(path) = self
.eval_expr(scope, mods, state, lib, this_ptr, &expr, level)?
.try_cast::<ImmutableString>()
{
use crate::ModuleResolver;
let expr_pos = expr.position();
let module = state
.resolver
.as_ref()
.and_then(|r| match r.resolve(self, &path, expr_pos) {
Ok(m) => return Some(Ok(m)),
Err(err) => match *err {
EvalAltResult::ErrorModuleNotFound(_, _) => None,
_ => return Some(Err(err)),
},
})
.unwrap_or_else(|| self.module_resolver.resolve(self, &path, expr_pos))?;
if let Some(name) = export.as_ref().map(|x| x.name.clone()) {
if !module.is_indexed() {
// Index the module (making a clone copy if necessary) if it is not indexed
let mut module = crate::fn_native::shared_take_or_clone(module);
module.build_index();
mods.push(name, module);
} else {
mods.push(name, module);
}
}
state.modules += 1;
Ok(Dynamic::UNIT)
} else {
Err(self.make_type_mismatch_err::<ImmutableString>("", expr.position()))
}
}
// Export statement
#[cfg(not(feature = "no_module"))]
Stmt::Export(list, _) => {
for (Ident { name, pos, .. }, rename) in list.iter() {
// Mark scope variables as public
if let Some(index) = scope.get_index(name).map(|(i, _)| i) {
let alias = rename.as_ref().map(|x| &x.name).unwrap_or_else(|| name);
scope.add_entry_alias(index, alias.clone());
} else {
return EvalAltResult::ErrorVariableNotFound(name.to_string(), *pos).into();
}
}
Ok(Dynamic::UNIT)
}
// Share statement
#[cfg(not(feature = "no_closure"))]
Stmt::Share(x) => {
if let Some((index, _)) = scope.get_index(&x.name) {
let val = scope.get_mut_by_index(index);
if !val.is_shared() {
// Replace the variable with a shared value.
*val = crate::stdlib::mem::take(val).into_shared();
}
}
Ok(Dynamic::UNIT)
}
};
self.check_data_size(result, stmt.position())
}
/// Check a result to ensure that the data size is within allowable limit.
/// [`Position`] in [`EvalAltResult`] may be None and should be set afterwards.
#[cfg(feature = "unchecked")]
#[inline(always)]
fn check_data_size(&self, result: RhaiResult, _pos: Position) -> RhaiResult {
result
}
/// Check a result to ensure that the data size is within allowable limit.
#[cfg(not(feature = "unchecked"))]
#[inline(always)]
fn check_data_size(&self, result: RhaiResult, pos: Position) -> RhaiResult {
// Simply return all errors
if result.is_err() {
return result;
}
// If no data size limits, just return
let mut has_limit = self.limits.max_string_size.is_some();
#[cfg(not(feature = "no_index"))]
{
has_limit = has_limit || self.limits.max_array_size.is_some();
}
#[cfg(not(feature = "no_object"))]
{
has_limit = has_limit || self.limits.max_map_size.is_some();
}
if !has_limit {
return result;
}
// Recursively calculate the size of a value (especially `Array` and `Map`)
fn calc_size(value: &Dynamic) -> (usize, usize, usize) {
match value {
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Array(arr, _)) => {
let mut arrays = 0;
let mut maps = 0;
arr.iter().for_each(|value| match value {
Dynamic(Union::Array(_, _)) => {
let (a, m, _) = calc_size(value);
arrays += a;
maps += m;
}
#[cfg(not(feature = "no_object"))]
Dynamic(Union::Map(_, _)) => {
let (a, m, _) = calc_size(value);
arrays += a;
maps += m;
}
_ => arrays += 1,
});
(arrays, maps, 0)
}
#[cfg(not(feature = "no_object"))]
Dynamic(Union::Map(map, _)) => {
let mut arrays = 0;
let mut maps = 0;
map.values().for_each(|value| match value {
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Array(_, _)) => {
let (a, m, _) = calc_size(value);
arrays += a;
maps += m;
}
Dynamic(Union::Map(_, _)) => {
let (a, m, _) = calc_size(value);
arrays += a;
maps += m;
}
_ => maps += 1,
});
(arrays, maps, 0)
}
Dynamic(Union::Str(s, _)) => (0, 0, s.len()),
_ => (0, 0, 0),
}
}
let (_arr, _map, s) = calc_size(result.as_ref().unwrap());
if s > self
.limits
.max_string_size
.map_or(usize::MAX, NonZeroUsize::get)
{
return EvalAltResult::ErrorDataTooLarge("Length of string".to_string(), pos).into();
}
#[cfg(not(feature = "no_index"))]
if _arr
> self
.limits
.max_array_size
.map_or(usize::MAX, NonZeroUsize::get)
{
return EvalAltResult::ErrorDataTooLarge("Size of array".to_string(), pos).into();
}
#[cfg(not(feature = "no_object"))]
if _map
> self
.limits
.max_map_size
.map_or(usize::MAX, NonZeroUsize::get)
{
return EvalAltResult::ErrorDataTooLarge("Size of object map".to_string(), pos).into();
}
result
}
/// Check if the number of operations stay within limit.
#[inline]
pub(crate) fn inc_operations(
&self,
state: &mut State,
pos: Position,
) -> Result<(), Box<EvalAltResult>> {
state.operations += 1;
#[cfg(not(feature = "unchecked"))]
// Guard against too many operations
if self.max_operations() > 0 && state.operations > self.max_operations() {
return EvalAltResult::ErrorTooManyOperations(pos).into();
}
// Report progress - only in steps
if let Some(progress) = &self.progress {
if let Some(token) = progress(state.operations) {
// Terminate script if progress returns a termination token
return EvalAltResult::ErrorTerminated(token, pos).into();
}
}
Ok(())
}
/// Pretty-print a type name.
///
/// If a type is registered via [`register_type_with_name`][Engine::register_type_with_name],
/// the type name provided for the registration will be used.
#[inline(always)]
pub fn map_type_name<'a>(&'a self, name: &'a str) -> &'a str {
self.type_names
.get(name)
.map(String::as_str)
.unwrap_or_else(|| map_std_type_name(name))
}
/// Make a `Box<`[`EvalAltResult<ErrorMismatchDataType>`][EvalAltResult::ErrorMismatchDataType]`>`.
#[inline(always)]
pub(crate) fn make_type_mismatch_err<T>(&self, typ: &str, pos: Position) -> Box<EvalAltResult> {
EvalAltResult::ErrorMismatchDataType(
self.map_type_name(type_name::<T>()).into(),
typ.into(),
pos,
)
.into()
}
}
Reference in New Issue View Git Blame Copy Permalink