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eda80488d5
rhai/src/engine.rs
Stephen Chung eda80488d5 Fix builds.
2021-12-15 12:46:25 +08:00

3497 lines
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//! Main module defining the script evaluation [`Engine`].
use crate::ast::{Expr, FnCallExpr, Ident, OpAssignment, Stmt, AST_OPTION_FLAGS::*};
use crate::custom_syntax::CustomSyntax;
use crate::func::{
get_hasher,
native::{OnDebugCallback, OnParseTokenCallback, OnPrintCallback, OnVarCallback},
CallableFunction, IteratorFn,
};
use crate::module::NamespaceRef;
use crate::packages::{Package, StandardPackage};
use crate::r#unsafe::unsafe_cast_var_name_to_lifetime;
use crate::tokenizer::Token;
use crate::types::dynamic::{map_std_type_name, AccessMode, Union, Variant};
use crate::{
calc_fn_params_hash, combine_hashes, Dynamic, EvalAltResult, Identifier, ImmutableString,
Module, Position, RhaiResult, Scope, Shared, StaticVec, INT,
};
#[cfg(feature = "no_std")]
use std::prelude::v1::*;
use std::{
any::{type_name, TypeId},
borrow::Cow,
collections::{BTreeMap, BTreeSet},
fmt,
hash::{Hash, Hasher},
iter::{FromIterator, Rev, Zip},
num::{NonZeroU8, NonZeroUsize},
ops::{Deref, DerefMut},
};
pub type Precedence = NonZeroU8;
/// _(internals)_ A stack of imported [modules][Module] plus mutable runtime global states.
/// Exported under the `internals` feature only.
//
// # Implementation Notes
//
// This implementation splits the module names from the shared modules to improve data locality.
// Most usage will be looking up a particular key from the list and then getting the module that
// corresponds to that key.
#[derive(Clone)]
pub struct Imports {
/// Stack of module names.
//
// # 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.
keys: StaticVec<Identifier>,
/// Stack of imported modules.
modules: StaticVec<Shared<Module>>,
/// Source of the current context.
pub source: Option<Identifier>,
/// Number of operations performed.
pub num_operations: u64,
/// Number of modules loaded.
pub num_modules: usize,
/// Function call hashes to index getters and setters.
///
/// Not available under `no_index` and `no_object`.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
fn_hash_indexing: (u64, u64),
/// Embedded module resolver.
///
/// Not available under `no_module`.
#[cfg(not(feature = "no_module"))]
pub embedded_module_resolver: Option<Shared<crate::module::resolvers::StaticModuleResolver>>,
/// Cache of globally-defined constants.
///
/// Not available under `no_module` and `no_function`.
#[cfg(not(feature = "no_module"))]
#[cfg(not(feature = "no_function"))]
global_constants: Option<Shared<crate::Locked<BTreeMap<Identifier, Dynamic>>>>,
}
impl Default for Imports {
#[inline(always)]
fn default() -> Self {
Self::new()
}
}
impl Imports {
/// Create a new stack of imported [modules][Module].
#[inline(always)]
#[must_use]
pub const fn new() -> Self {
Self {
keys: StaticVec::new_const(),
modules: StaticVec::new_const(),
source: None,
num_operations: 0,
num_modules: 0,
#[cfg(not(feature = "no_module"))]
embedded_module_resolver: None,
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
fn_hash_indexing: (0, 0),
#[cfg(not(feature = "no_module"))]
#[cfg(not(feature = "no_function"))]
global_constants: None,
}
}
/// Get the length of this stack of imported [modules][Module].
#[inline(always)]
#[must_use]
pub fn len(&self) -> usize {
self.keys.len()
}
/// Is this stack of imported [modules][Module] empty?
#[inline(always)]
#[must_use]
pub fn is_empty(&self) -> bool {
self.keys.is_empty()
}
/// Get the imported [module][Module] at a particular index.
#[inline(always)]
#[must_use]
pub fn get(&self, index: usize) -> Option<Shared<Module>> {
self.modules.get(index).cloned()
}
/// Get the imported [module][Module] at a particular index.
#[allow(dead_code)]
#[inline(always)]
#[must_use]
pub(crate) fn get_mut(&mut self, index: usize) -> Option<&mut Shared<Module>> {
self.modules.get_mut(index)
}
/// Get the index of an imported [module][Module] by name.
#[inline]
#[must_use]
pub fn find(&self, name: impl AsRef<str>) -> Option<usize> {
let name = name.as_ref();
let len = self.keys.len();
self.keys.iter().rev().enumerate().find_map(|(i, key)| {
if key == name {
Some(len - 1 - i)
} else {
None
}
})
}
/// Push an imported [module][Module] onto the stack.
#[inline(always)]
pub fn push(&mut self, name: impl Into<Identifier>, module: impl Into<Shared<Module>>) {
self.keys.push(name.into());
self.modules.push(module.into());
}
/// Truncate the stack of imported [modules][Module] to a particular length.
#[inline(always)]
pub fn truncate(&mut self, size: usize) {
self.keys.truncate(size);
self.modules.truncate(size);
}
/// Get an iterator to this stack of imported [modules][Module] in reverse order.
#[allow(dead_code)]
#[inline]
pub fn iter(&self) -> impl Iterator<Item = (&str, &Module)> {
self.keys
.iter()
.rev()
.zip(self.modules.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]
pub(crate) fn iter_raw(&self) -> impl Iterator<Item = (&Identifier, &Shared<Module>)> {
self.keys.iter().rev().zip(self.modules.iter().rev())
}
/// Get an iterator to this stack of imported [modules][Module] in forward order.
#[allow(dead_code)]
#[inline]
pub(crate) fn scan_raw(&self) -> impl Iterator<Item = (&Identifier, &Shared<Module>)> {
self.keys.iter().zip(self.modules.iter())
}
/// Does the specified function hash key exist in this stack of imported [modules][Module]?
#[allow(dead_code)]
#[inline]
#[must_use]
pub fn contains_fn(&self, hash: u64) -> bool {
self.modules.iter().any(|m| m.contains_qualified_fn(hash))
}
/// Get the specified function via its hash key from this stack of imported [modules][Module].
#[inline]
#[must_use]
pub fn get_fn(&self, hash: u64) -> Option<(&CallableFunction, Option<&Identifier>)> {
self.modules
.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]
#[must_use]
pub fn contains_iter(&self, id: TypeId) -> bool {
self.modules.iter().any(|m| m.contains_qualified_iter(id))
}
/// Get the specified [`TypeId`][std::any::TypeId] iterator from this stack of imported
/// [modules][Module].
#[inline]
#[must_use]
pub fn get_iter(&self, id: TypeId) -> Option<IteratorFn> {
self.modules
.iter()
.rev()
.find_map(|m| m.get_qualified_iter(id))
}
/// Get a mutable reference to the cache of globally-defined constants.
#[cfg(not(feature = "no_module"))]
#[cfg(not(feature = "no_function"))]
#[must_use]
pub(crate) fn global_constants_mut<'a>(
&'a mut self,
) -> Option<impl DerefMut<Target = BTreeMap<Identifier, Dynamic>> + 'a> {
if let Some(ref global_constants) = self.global_constants {
Some(crate::func::native::shared_write_lock(global_constants))
} else {
None
}
}
/// Set a constant into the cache of globally-defined constants.
#[cfg(not(feature = "no_module"))]
#[cfg(not(feature = "no_function"))]
pub(crate) fn set_global_constant(&mut self, name: impl Into<Identifier>, value: Dynamic) {
if self.global_constants.is_none() {
let dict: crate::Locked<_> = BTreeMap::new().into();
self.global_constants = Some(dict.into());
}
crate::func::native::shared_write_lock(self.global_constants.as_mut().expect("`Some`"))
.insert(name.into(), value);
}
/// Get the pre-calculated index getter hash.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
#[must_use]
pub(crate) fn hash_idx_get(&mut self) -> u64 {
if self.fn_hash_indexing != (0, 0) {
self.fn_hash_indexing.0
} else {
let n1 = crate::calc_fn_hash(FN_IDX_GET, 2);
let n2 = crate::calc_fn_hash(FN_IDX_SET, 3);
self.fn_hash_indexing = (n1, n2);
n1
}
}
/// Get the pre-calculated index setter hash.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
#[must_use]
pub(crate) fn hash_idx_set(&mut self) -> u64 {
if self.fn_hash_indexing != (0, 0) {
self.fn_hash_indexing.1
} else {
let n1 = crate::calc_fn_hash(FN_IDX_GET, 2);
let n2 = crate::calc_fn_hash(FN_IDX_SET, 3);
self.fn_hash_indexing = (n1, n2);
n2
}
}
}
impl IntoIterator for Imports {
type Item = (Identifier, Shared<Module>);
type IntoIter =
Zip<Rev<smallvec::IntoIter<[Identifier; 3]>>, Rev<smallvec::IntoIter<[Shared<Module>; 3]>>>;
#[inline]
fn into_iter(self) -> Self::IntoIter {
self.keys
.into_iter()
.rev()
.zip(self.modules.into_iter().rev())
}
}
impl<K: Into<Identifier>, M: Into<Shared<Module>>> FromIterator<(K, M)> for Imports {
fn from_iter<T: IntoIterator<Item = (K, M)>>(iter: T) -> Self {
let mut lib = Self::new();
lib.extend(iter);
lib
}
}
impl<K: Into<Identifier>, M: Into<Shared<Module>>> Extend<(K, M)> for Imports {
fn extend<T: IntoIterator<Item = (K, M)>>(&mut self, iter: T) {
iter.into_iter().for_each(|(k, m)| {
self.keys.push(k.into());
self.modules.push(m.into());
})
}
}
impl fmt::Debug for Imports {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str("Imports")?;
if self.is_empty() {
f.debug_map().finish()
} else {
f.debug_map()
.entries(self.keys.iter().zip(self.modules.iter()))
.finish()
}
}
}
#[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_function"))]
#[cfg(not(feature = "no_module"))]
pub const KEYWORD_GLOBAL: &str = "global";
#[cfg(not(feature = "no_object"))]
pub const FN_GET: &str = "get$";
#[cfg(not(feature = "no_object"))]
pub const FN_SET: &str = "set$";
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
pub const FN_IDX_GET: &str = "index$get$";
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
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";
/// Standard exclusive range operator.
pub const OP_EXCLUSIVE_RANGE: &str = "..";
/// Standard inclusive range operator.
pub const OP_INCLUSIVE_RANGE: &str = "..=";
/// Standard concatenation operator token.
pub const TOKEN_OP_CONCAT: Token = Token::PlusAssign;
/// Method of chaining.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
enum ChainType {
/// Indexing.
#[cfg(not(feature = "no_index"))]
Indexing,
/// Dotting.
#[cfg(not(feature = "no_object"))]
Dotting,
}
/// Value of a chaining argument.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
#[derive(Debug, Clone, Hash)]
enum ChainArgument {
/// Dot-property access.
#[cfg(not(feature = "no_object"))]
Property(Position),
/// Arguments to a dot method call.
/// Wrapped values are the arguments plus the [position][Position] of the first argument.
#[cfg(not(feature = "no_object"))]
MethodCallArgs(StaticVec<Dynamic>, Position),
/// Index value and [position][Position].
#[cfg(not(feature = "no_index"))]
IndexValue(Dynamic, Position),
}
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
impl ChainArgument {
/// Return the index value.
#[inline(always)]
#[cfg(not(feature = "no_index"))]
#[must_use]
pub fn into_index_value(self) -> Option<Dynamic> {
match self {
Self::IndexValue(value, _) => Some(value),
#[cfg(not(feature = "no_object"))]
_ => None,
}
}
/// Return the list of method call arguments.
#[inline(always)]
#[cfg(not(feature = "no_object"))]
#[must_use]
pub fn into_fn_call_args(self) -> Option<(StaticVec<Dynamic>, Position)> {
match self {
Self::MethodCallArgs(values, pos) => Some((values, pos)),
_ => None,
}
}
/// Return the [position][Position].
#[inline(always)]
#[must_use]
#[allow(dead_code)]
pub const fn position(&self) -> Position {
match self {
#[cfg(not(feature = "no_object"))]
ChainArgument::Property(pos) => *pos,
#[cfg(not(feature = "no_object"))]
ChainArgument::MethodCallArgs(_, pos) => *pos,
#[cfg(not(feature = "no_index"))]
ChainArgument::IndexValue(_, pos) => *pos,
}
}
}
#[cfg(not(feature = "no_object"))]
impl From<(StaticVec<Dynamic>, Position)> for ChainArgument {
#[inline(always)]
fn from((values, pos): (StaticVec<Dynamic>, Position)) -> Self {
Self::MethodCallArgs(values, pos)
}
}
#[cfg(not(feature = "no_index"))]
impl From<(Dynamic, Position)> for ChainArgument {
#[inline(always)]
fn from((value, pos): (Dynamic, Position)) -> Self {
Self::IndexValue(value, pos)
}
}
/// Get the chaining type for an [`Expr`].
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
fn match_chaining_type(expr: &Expr) -> ChainType {
match expr {
#[cfg(not(feature = "no_index"))]
Expr::Index(_, _, _) => ChainType::Indexing,
#[cfg(not(feature = "no_object"))]
Expr::Dot(_, _, _) => ChainType::Dotting,
_ => unreachable!("`expr` should only be `Index` or `Dot`, but got {:?}", expr),
}
}
/// 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.
RefMut(&'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"))]
LockGuard(
(
crate::types::dynamic::DynamicWriteLock<'a, Dynamic>,
Dynamic,
),
),
/// The target is a temporary `Dynamic` value (i.e. the mutation can cause no side effects).
TempValue(Dynamic),
/// The target is a bit inside an [`INT`][crate::INT].
/// This is necessary because directly pointing to a bit inside an [`INT`][crate::INT] is impossible.
#[cfg(not(feature = "no_index"))]
Bit(&'a mut Dynamic, Dynamic, u8),
/// The target is a range of bits inside an [`INT`][crate::INT].
/// This is necessary because directly pointing to a range of bits inside an [`INT`][crate::INT] is impossible.
#[cfg(not(feature = "no_index"))]
BitField(&'a mut Dynamic, INT, Dynamic, u8),
/// The target is a byte inside a Blob.
/// This is necessary because directly pointing to a byte (in [`Dynamic`] form) inside a blob is impossible.
#[cfg(not(feature = "no_index"))]
BlobByte(&'a mut Dynamic, usize, 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]
#[must_use]
pub const fn is_ref(&self) -> bool {
match self {
Self::RefMut(_) => true,
#[cfg(not(feature = "no_closure"))]
Self::LockGuard(_) => true,
Self::TempValue(_) => false,
#[cfg(not(feature = "no_index"))]
Self::Bit(_, _, _)
| Self::BitField(_, _, _, _)
| Self::BlobByte(_, _, _)
| Self::StringChar(_, _, _) => false,
}
}
/// Is the `Target` a temp value?
#[inline]
#[must_use]
pub const fn is_temp_value(&self) -> bool {
match self {
Self::RefMut(_) => false,
#[cfg(not(feature = "no_closure"))]
Self::LockGuard(_) => false,
Self::TempValue(_) => true,
#[cfg(not(feature = "no_index"))]
Self::Bit(_, _, _)
| Self::BitField(_, _, _, _)
| Self::BlobByte(_, _, _)
| Self::StringChar(_, _, _) => false,
}
}
/// Is the `Target` a shared value?
#[cfg(not(feature = "no_closure"))]
#[inline]
#[must_use]
pub fn is_shared(&self) -> bool {
match self {
Self::RefMut(r) => r.is_shared(),
#[cfg(not(feature = "no_closure"))]
Self::LockGuard(_) => true,
Self::TempValue(r) => r.is_shared(),
#[cfg(not(feature = "no_index"))]
Self::Bit(_, _, _)
| Self::BitField(_, _, _, _)
| Self::BlobByte(_, _, _)
| Self::StringChar(_, _, _) => false,
}
}
/// Is the `Target` a specific type?
#[allow(dead_code)]
#[inline]
#[must_use]
pub fn is<T: Variant + Clone>(&self) -> bool {
match self {
Self::RefMut(r) => r.is::<T>(),
#[cfg(not(feature = "no_closure"))]
Self::LockGuard((r, _)) => r.is::<T>(),
Self::TempValue(r) => r.is::<T>(),
#[cfg(not(feature = "no_index"))]
Self::Bit(_, _, _) => TypeId::of::<T>() == TypeId::of::<bool>(),
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, _, _) => TypeId::of::<T>() == TypeId::of::<INT>(),
#[cfg(not(feature = "no_index"))]
Self::BlobByte(_, _, _) => TypeId::of::<T>() == TypeId::of::<crate::Blob>(),
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => TypeId::of::<T>() == TypeId::of::<char>(),
}
}
/// Get the value of the `Target` as a `Dynamic`, cloning a referenced value if necessary.
#[inline]
#[must_use]
pub fn take_or_clone(self) -> Dynamic {
match self {
Self::RefMut(r) => r.clone(), // Referenced value is cloned
#[cfg(not(feature = "no_closure"))]
Self::LockGuard((_, orig)) => orig, // Original value is simply taken
Self::TempValue(v) => v, // Owned value is simply taken
#[cfg(not(feature = "no_index"))]
Self::Bit(_, value, _) => value, // Boolean is taken
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, value, _) => value, // INT is taken
#[cfg(not(feature = "no_index"))]
Self::BlobByte(_, _, value) => value, // Byte is taken
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ch) => ch, // Character is taken
}
}
/// Take a `&mut Dynamic` reference from the `Target`.
#[inline(always)]
#[must_use]
pub fn take_ref(self) -> Option<&'a mut Dynamic> {
match self {
Self::RefMut(r) => Some(r),
_ => None,
}
}
/// Convert a shared or reference `Target` into a target with an owned value.
#[inline(always)]
#[must_use]
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.
#[inline]
pub fn propagate_changed_value(&mut self) -> Result<(), Box<EvalAltResult>> {
match self {
Self::RefMut(_) | Self::TempValue(_) => (),
#[cfg(not(feature = "no_closure"))]
Self::LockGuard(_) => (),
#[cfg(not(feature = "no_index"))]
Self::Bit(value, new_val, index) => {
// Replace the bit at the specified index position
let new_bit = new_val.as_bool().map_err(|err| {
Box::new(EvalAltResult::ErrorMismatchDataType(
"bool".to_string(),
err.to_string(),
Position::NONE,
))
})?;
let value = &mut *value.write_lock::<crate::INT>().expect("`INT`");
let index = *index;
let mask = 1 << index;
if new_bit {
*value |= mask;
} else {
*value &= !mask;
}
}
#[cfg(not(feature = "no_index"))]
Self::BitField(value, mask, new_val, shift) => {
let shift = *shift;
let mask = *mask;
// Replace the bit at the specified index position
let new_value = new_val.as_int().map_err(|err| {
Box::new(EvalAltResult::ErrorMismatchDataType(
"integer".to_string(),
err.to_string(),
Position::NONE,
))
})?;
let new_value = (new_value << shift) & mask;
let value = &mut *value.write_lock::<crate::INT>().expect("`INT`");
*value &= !mask;
*value |= new_value;
}
#[cfg(not(feature = "no_index"))]
Self::BlobByte(value, index, new_val) => {
// Replace the byte at the specified index position
let new_byte = new_val.as_int().map_err(|err| {
Box::new(EvalAltResult::ErrorMismatchDataType(
"INT".to_string(),
err.to_string(),
Position::NONE,
))
})?;
let value = &mut *value.write_lock::<crate::Blob>().expect("`Blob`");
let index = *index;
if index < value.len() {
value[index] = (new_byte & 0x00ff) as u8;
} else {
unreachable!("blob index out of bounds: {}", index);
}
}
#[cfg(not(feature = "no_index"))]
Self::StringChar(s, index, new_val) => {
// 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(),
Position::NONE,
))
})?;
let s = &mut *s
.write_lock::<ImmutableString>()
.expect("`ImmutableString`");
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]
fn from(value: &'a mut Dynamic) -> Self {
#[cfg(not(feature = "no_closure"))]
if value.is_shared() {
// Cloning is cheap for a shared value
let container = value.clone();
return Self::LockGuard((value.write_lock::<Dynamic>().expect("`Dynamic`"), container));
}
Self::RefMut(value)
}
}
impl Deref for Target<'_> {
type Target = Dynamic;
#[inline]
fn deref(&self) -> &Dynamic {
match self {
Self::RefMut(r) => *r,
#[cfg(not(feature = "no_closure"))]
Self::LockGuard((r, _)) => &**r,
Self::TempValue(ref r) => r,
#[cfg(not(feature = "no_index"))]
Self::Bit(_, ref r, _)
| Self::BitField(_, _, ref r, _)
| Self::BlobByte(_, _, ref r)
| Self::StringChar(_, _, ref r) => r,
}
}
}
impl AsRef<Dynamic> for Target<'_> {
#[inline(always)]
fn as_ref(&self) -> &Dynamic {
self
}
}
impl DerefMut for Target<'_> {
#[inline]
fn deref_mut(&mut self) -> &mut Dynamic {
match self {
Self::RefMut(r) => *r,
#[cfg(not(feature = "no_closure"))]
Self::LockGuard((r, _)) => r.deref_mut(),
Self::TempValue(ref mut r) => r,
#[cfg(not(feature = "no_index"))]
Self::Bit(_, ref mut r, _)
| Self::BitField(_, _, ref mut r, _)
| Self::BlobByte(_, _, ref mut r)
| Self::StringChar(_, _, ref mut r) => r,
}
}
}
impl AsMut<Dynamic> for Target<'_> {
#[inline(always)]
fn as_mut(&mut self) -> &mut Dynamic {
self
}
}
impl<T: Into<Dynamic>> From<T> for Target<'_> {
#[inline(always)]
#[must_use]
fn from(value: T) -> Self {
Self::TempValue(value.into())
}
}
/// _(internals)_ An entry in a function resolution cache.
/// Exported under the `internals` feature only.
#[derive(Debug, Clone)]
pub struct FnResolutionCacheEntry {
/// Function.
pub func: CallableFunction,
/// Optional source.
pub source: Option<Identifier>,
}
/// _(internals)_ A function resolution cache.
/// Exported under the `internals` feature only.
pub type FnResolutionCache = BTreeMap<u64, Option<Box<FnResolutionCacheEntry>>>;
/// _(internals)_ A type that holds all the current states of the [`Engine`].
/// Exported under the `internals` feature only.
#[derive(Debug, Clone)]
pub struct EvalState {
/// 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, or after a custom syntax statement,
/// subsequent offsets may become mis-aligned.
/// When that happens, this flag is turned on to force a [`Scope`] search by name.
pub always_search_scope: 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,
/// Stack of function resolution caches.
fn_resolution_caches: StaticVec<FnResolutionCache>,
}
impl EvalState {
/// Create a new [`EvalState`].
#[inline(always)]
#[must_use]
pub const fn new() -> Self {
Self {
always_search_scope: false,
scope_level: 0,
fn_resolution_caches: StaticVec::new_const(),
}
}
/// Is the state currently at global (root) level?
#[inline(always)]
#[must_use]
pub const fn is_global(&self) -> bool {
self.scope_level == 0
}
/// Get the number of function resolution cache(s) in the stack.
#[inline(always)]
#[must_use]
pub fn fn_resolution_caches_len(&self) -> usize {
self.fn_resolution_caches.len()
}
/// Get a mutable reference to the current function resolution cache.
#[inline]
#[must_use]
pub fn fn_resolution_cache_mut(&mut self) -> &mut FnResolutionCache {
if self.fn_resolution_caches.is_empty() {
// Push a new function resolution cache if the stack is empty
self.push_fn_resolution_cache();
}
self.fn_resolution_caches.last_mut().expect("not empty")
}
/// Push an empty function resolution cache onto the stack and make it current.
#[allow(dead_code)]
#[inline(always)]
pub fn push_fn_resolution_cache(&mut self) {
self.fn_resolution_caches.push(BTreeMap::new());
}
/// Rewind the function resolution caches stack to a particular size.
#[inline(always)]
pub fn rewind_fn_resolution_caches(&mut self, len: usize) {
self.fn_resolution_caches.truncate(len);
}
}
/// Context of a script evaluation process.
#[derive(Debug)]
pub struct EvalContext<'a, 'x, 'px, 'm, 's, 'b, '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 EvalState,
pub(crate) lib: &'b [&'b Module],
pub(crate) this_ptr: &'t mut Option<&'pt mut Dynamic>,
pub(crate) level: usize,
}
impl<'x, 'px, 'pt> EvalContext<'_, 'x, 'px, '_, '_, '_, '_, 'pt> {
/// The current [`Engine`].
#[inline(always)]
#[must_use]
pub const fn engine(&self) -> &Engine {
self.engine
}
/// The current source.
#[inline(always)]
#[must_use]
pub fn source(&self) -> Option<&str> {
self.mods.source.as_ref().map(|s| s.as_str())
}
/// The current [`Scope`].
#[inline(always)]
#[must_use]
pub const fn scope(&self) -> &Scope<'px> {
self.scope
}
/// Mutable reference to the current [`Scope`].
#[inline(always)]
#[must_use]
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.
/// Exported under the `internals` feature only.
#[cfg(feature = "internals")]
#[cfg(not(feature = "no_module"))]
#[inline(always)]
#[must_use]
pub const fn imports(&self) -> &Imports {
self.mods
}
/// Get an iterator over the namespaces containing definition of all script-defined functions.
#[inline]
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.
/// Exported under the `internals` feature only.
#[cfg(feature = "internals")]
#[inline(always)]
#[must_use]
pub const fn namespaces(&self) -> &[&Module] {
self.lib
}
/// The current bound `this` pointer, if any.
#[inline(always)]
#[must_use]
pub fn this_ptr(&self) -> Option<&Dynamic> {
self.this_ptr.as_ref().map(|v| &**v)
}
/// Mutable reference to the current bound `this` pointer, if any.
#[inline(always)]
#[must_use]
pub fn this_ptr_mut(&mut self) -> Option<&mut &'pt mut Dynamic> {
self.this_ptr.as_mut()
}
/// The current nesting level of function calls.
#[inline(always)]
#[must_use]
pub const 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 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: BTreeMap<Identifier, Shared<Module>>,
/// A module resolution service.
#[cfg(not(feature = "no_module"))]
pub(crate) module_resolver: Option<Box<dyn crate::ModuleResolver>>,
/// A map mapping type names to pretty-print names.
pub(crate) type_names: BTreeMap<Identifier, Identifier>,
/// An empty [`ImmutableString`] for cloning purposes.
pub(crate) empty_string: ImmutableString,
/// A set of symbols to disable.
pub(crate) disabled_symbols: BTreeSet<Identifier>,
/// A map containing custom keywords and precedence to recognize.
pub(crate) custom_keywords: BTreeMap<Identifier, Option<Precedence>>,
/// Custom syntax.
pub(crate) custom_syntax: BTreeMap<Identifier, Box<CustomSyntax>>,
/// Callback closure for resolving variable access.
pub(crate) resolve_var: Option<OnVarCallback>,
/// Callback closure to remap tokens during parsing.
pub(crate) token_mapper: Option<Box<OnParseTokenCallback>>,
/// Callback closure for implementing the `print` command.
pub(crate) print: Option<OnPrintCallback>,
/// Callback closure for implementing the `debug` command.
pub(crate) debug: Option<OnDebugCallback>,
/// Callback closure for progress reporting.
#[cfg(not(feature = "unchecked"))]
pub(crate) progress: Option<crate::func::native::OnProgressCallback>,
/// Optimize the [`AST`][crate::AST] after compilation.
#[cfg(not(feature = "no_optimize"))]
pub(crate) optimization_level: crate::OptimizationLevel,
/// Language options.
pub(crate) options: crate::api::options::LanguageOptions,
/// Max limits.
#[cfg(not(feature = "unchecked"))]
pub(crate) limits: crate::api::limits::Limits,
}
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]
#[must_use]
pub fn make_getter(id: impl AsRef<str>) -> String {
format!("{}{}", FN_GET, id.as_ref())
}
/// Make setter function
#[cfg(not(feature = "no_object"))]
#[inline]
#[must_use]
pub fn make_setter(id: impl AsRef<str>) -> String {
format!("{}{}", FN_SET, id.as_ref())
}
/// Is this function an anonymous function?
#[cfg(not(feature = "no_function"))]
#[inline(always)]
#[must_use]
pub fn is_anonymous_fn(fn_name: impl AsRef<str>) -> bool {
fn_name.as_ref().starts_with(FN_ANONYMOUS)
}
/// Print to `stdout`
#[inline]
#[allow(unused_variables)]
fn print_to_stdout(s: &str) {
#[cfg(not(feature = "no_std"))]
#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
println!("{}", s);
}
/// Debug to `stdout`
#[inline]
#[allow(unused_variables)]
fn debug_to_stdout(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 if pos.is_none() {
println!("{}", s);
} else {
println!("{:?} | {}", pos, s);
}
}
impl Engine {
/// Create a new [`Engine`].
#[inline]
#[must_use]
pub fn new() -> Self {
// Create the new scripting Engine
let mut engine = Self::new_raw();
#[cfg(not(feature = "no_module"))]
#[cfg(not(feature = "no_std"))]
#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
{
engine.module_resolver =
Some(Box::new(crate::module::resolvers::FileModuleResolver::new()));
}
// default print/debug implementations
engine.print = Some(Box::new(print_to_stdout));
engine.debug = Some(Box::new(debug_to_stdout));
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]
#[must_use]
pub fn new_raw() -> Self {
let mut engine = Self {
global_modules: StaticVec::new_const(),
global_sub_modules: BTreeMap::new(),
#[cfg(not(feature = "no_module"))]
module_resolver: None,
type_names: BTreeMap::new(),
empty_string: ImmutableString::new(),
disabled_symbols: BTreeSet::new(),
custom_keywords: BTreeMap::new(),
custom_syntax: BTreeMap::new(),
resolve_var: None,
token_mapper: None,
print: None,
debug: None,
#[cfg(not(feature = "unchecked"))]
progress: None,
#[cfg(not(feature = "no_optimize"))]
optimization_level: crate::OptimizationLevel::default(),
options: crate::api::options::LanguageOptions::new(),
#[cfg(not(feature = "unchecked"))]
limits: crate::api::limits::Limits::new(),
};
// Add the global namespace module
let mut global_namespace = Module::new();
global_namespace.internal = true;
engine.global_modules.push(global_namespace.into());
engine
}
/// Get an empty [`ImmutableString`].
///
/// [`Engine`] keeps a single instance of an empty [`ImmutableString`] and uses this to create
/// shared instances for subsequent uses. This minimizes unnecessary allocations for empty strings.
#[inline(always)]
#[must_use]
pub fn const_empty_string(&self) -> ImmutableString {
self.empty_string.clone()
}
/// Search for a module within an imports stack.
#[inline]
#[must_use]
pub(crate) fn search_imports(
&self,
mods: &Imports,
state: &mut EvalState,
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_scope {
None
} else {
namespace.index()
};
if let Some(index) = index {
let offset = mods.len() - index.get();
Some(mods.get(offset).expect("within range"))
} else {
mods.find(root)
.map(|n| mods.get(n).expect("valid index"))
.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 EvalState,
lib: &[&Module],
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &Expr,
) -> Result<(Target<'s>, Position), Box<EvalAltResult>> {
match expr {
Expr::Variable(Some(_), _, _) => {
self.search_scope_only(scope, mods, state, lib, this_ptr, expr)
}
Expr::Variable(None, _var_pos, v) => match v.as_ref() {
// Normal variable access
(_, None, _) => self.search_scope_only(scope, mods, state, lib, this_ptr, expr),
// Qualified variable access
#[cfg(not(feature = "no_module"))]
(_, Some((namespace, hash_var)), var_name) => {
if let Some(module) = self.search_imports(mods, state, namespace) {
// foo:bar::baz::VARIABLE
return match module.get_qualified_var(*hash_var) {
Ok(target) => {
let mut target = target.clone();
// Module variables are constant
target.set_access_mode(AccessMode::ReadOnly);
Ok((target.into(), *_var_pos))
}
Err(err) => Err(match *err {
EvalAltResult::ErrorVariableNotFound(_, _) => {
EvalAltResult::ErrorVariableNotFound(
format!(
"{}{}{}",
namespace,
Token::DoubleColon.literal_syntax(),
var_name
),
namespace[0].pos,
)
.into()
}
_ => err.fill_position(*_var_pos),
}),
};
}
#[cfg(not(feature = "no_function"))]
if namespace.len() == 1 && namespace[0].name == KEYWORD_GLOBAL {
// global::VARIABLE
let global_constants = mods.global_constants_mut();
if let Some(mut guard) = global_constants {
if let Some(value) = guard.get_mut(var_name) {
let mut target: Target = value.clone().into();
// Module variables are constant
target.set_access_mode(AccessMode::ReadOnly);
return Ok((target.into(), *_var_pos));
}
}
return Err(EvalAltResult::ErrorVariableNotFound(
format!(
"{}{}{}",
namespace,
Token::DoubleColon.literal_syntax(),
var_name
),
namespace[0].pos,
)
.into());
}
Err(
EvalAltResult::ErrorModuleNotFound(namespace.to_string(), namespace[0].pos)
.into(),
)
}
#[cfg(feature = "no_module")]
(_, Some((_, _)), _) => unreachable!("qualified access under no_module"),
},
_ => unreachable!("Expr::Variable expected, but gets {:?}", expr),
}
}
/// Search for a variable within the scope
///
/// # Panics
///
/// Panics if `expr` is not [`Expr::Variable`].
pub(crate) fn search_scope_only<'s>(
&self,
scope: &'s mut Scope,
mods: &mut Imports,
state: &mut EvalState,
lib: &[&Module],
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &Expr,
) -> Result<(Target<'s>, Position), Box<EvalAltResult>> {
// Make sure that the pointer indirection is taken only when absolutely necessary.
let (index, var_pos) = match expr {
// Check if the variable is `this`
Expr::Variable(None, pos, v) if v.0.is_none() && v.2 == KEYWORD_THIS => {
return if let Some(val) = this_ptr {
Ok(((*val).into(), *pos))
} else {
Err(EvalAltResult::ErrorUnboundThis(*pos).into())
}
}
_ if state.always_search_scope => (0, expr.position()),
Expr::Variable(Some(i), pos, _) => (i.get() as usize, *pos),
Expr::Variable(None, pos, v) => (v.0.map(NonZeroUsize::get).unwrap_or(0), *pos),
_ => unreachable!("Expr::Variable expected, but gets {:?}", expr),
};
// Check the variable resolver, if any
if let Some(ref resolve_var) = self.resolve_var {
let context = EvalContext {
engine: self,
scope,
mods,
state,
lib,
this_ptr,
level: 0,
};
match resolve_var(
expr.get_variable_name(true).expect("`Variable`"),
index,
&context,
) {
Ok(Some(mut result)) => {
result.set_access_mode(AccessMode::ReadOnly);
return Ok((result.into(), var_pos));
}
Ok(None) => (),
Err(err) => return Err(err.fill_position(var_pos)),
}
}
let index = if index > 0 {
scope.len() - index
} else {
// Find the variable in the scope
let var_name = expr.get_variable_name(true).expect("`Variable`");
scope
.get_index(var_name)
.ok_or_else(|| EvalAltResult::ErrorVariableNotFound(var_name.to_string(), var_pos))?
.0
};
let val = scope.get_mut_by_index(index);
Ok((val.into(), var_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 EvalState,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
target: &mut Target,
root: (&str, Position),
rhs: &Expr,
terminate_chaining: bool,
idx_values: &mut StaticVec<ChainArgument>,
chain_type: ChainType,
level: usize,
new_val: Option<((Dynamic, Position), (Option<OpAssignment>, Position))>,
) -> Result<(Dynamic, bool), Box<EvalAltResult>> {
let is_ref_mut = target.is_ref();
let _terminate_chaining = terminate_chaining;
// Pop the last index value
let idx_val = idx_values.pop().expect("not empty");
match chain_type {
#[cfg(not(feature = "no_index"))]
ChainType::Indexing => {
let pos = rhs.position();
let root_pos = idx_val.position();
let idx_val = idx_val.into_index_value().expect("`ChainType::Index`");
match rhs {
// xxx[idx].expr... | xxx[idx][expr]...
Expr::Dot(x, term, x_pos) | Expr::Index(x, term, x_pos)
if !_terminate_chaining =>
{
let mut idx_val_for_setter = idx_val.clone();
let idx_pos = x.lhs.position();
let rhs_chain = match_chaining_type(rhs);
let (try_setter, result) = {
let mut obj = self.get_indexed_mut(
mods, state, lib, target, idx_val, idx_pos, false, true, level,
)?;
let is_obj_temp_val = obj.is_temp_value();
let obj_ptr = &mut obj;
match self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, obj_ptr, root, &x.rhs, *term,
idx_values, rhs_chain, level, new_val,
) {
Ok((result, true)) if is_obj_temp_val => {
(Some(obj.take_or_clone()), (result, true))
}
Ok(result) => (None, result),
Err(err) => return Err(err.fill_position(*x_pos)),
}
};
if let Some(mut new_val) = try_setter {
// Try to call index setter if value is changed
let hash_set =
crate::ast::FnCallHashes::from_native(mods.hash_idx_set());
let args = &mut [target, &mut idx_val_for_setter, &mut new_val];
if let Err(err) = self.exec_fn_call(
mods, state, lib, FN_IDX_SET, hash_set, args, is_ref_mut, true,
root_pos, None, level,
) {
// Just ignore if there is no index setter
if !matches!(*err, EvalAltResult::ErrorFunctionNotFound(_, _)) {
return Err(err);
}
}
}
self.check_data_size(target.as_ref())
.map_err(|err| err.fill_position(root.1))?;
Ok(result)
}
// xxx[rhs] op= new_val
_ if new_val.is_some() => {
let ((new_val, new_pos), (op_info, op_pos)) = new_val.expect("`Some`");
let mut idx_val_for_setter = idx_val.clone();
let try_setter = match self.get_indexed_mut(
mods, state, lib, target, idx_val, pos, true, false, level,
) {
// Indexed value is a reference - update directly
Ok(ref mut obj_ptr) => {
self.eval_op_assignment(
mods, state, lib, op_info, op_pos, obj_ptr, root, new_val,
)
.map_err(|err| err.fill_position(new_pos))?;
None
}
// Can't index - try to call an index setter
#[cfg(not(feature = "no_index"))]
Err(err) if matches!(*err, EvalAltResult::ErrorIndexingType(_, _)) => {
Some(new_val)
}
// Any other error
Err(err) => return Err(err),
};
if let Some(mut new_val) = try_setter {
// Try to call index setter
let hash_set =
crate::ast::FnCallHashes::from_native(mods.hash_idx_set());
let args = &mut [target, &mut idx_val_for_setter, &mut new_val];
self.exec_fn_call(
mods, state, lib, FN_IDX_SET, hash_set, args, is_ref_mut, true,
root_pos, None, level,
)?;
}
self.check_data_size(target.as_ref())
.map_err(|err| err.fill_position(root.1))?;
Ok((Dynamic::UNIT, true))
}
// xxx[rhs]
_ => self
.get_indexed_mut(mods, state, lib, target, idx_val, pos, false, true, level)
.map(|v| (v.take_or_clone(), false)),
}
}
#[cfg(not(feature = "no_object"))]
ChainType::Dotting => {
match rhs {
// xxx.fn_name(arg_expr_list)
Expr::FnCall(x, pos) if !x.is_qualified() && new_val.is_none() => {
let FnCallExpr { name, hashes, .. } = x.as_ref();
let call_args = &mut idx_val
.into_fn_call_args()
.expect("`ChainType::Dot` with `Expr::FnCallExpr`");
self.make_method_call(
mods, state, lib, name, *hashes, target, call_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.is::<crate::Map>() && new_val.is_some() => {
let (name, pos) = &x.2;
let ((new_val, new_pos), (op_info, op_pos)) = new_val.expect("`Some`");
let index = name.into();
{
let val_target = &mut self.get_indexed_mut(
mods, state, lib, target, index, *pos, true, false, level,
)?;
self.eval_op_assignment(
mods, state, lib, op_info, op_pos, val_target, root, new_val,
)
.map_err(|err| err.fill_position(new_pos))?;
}
self.check_data_size(target.as_ref())
.map_err(|err| err.fill_position(root.1))?;
Ok((Dynamic::UNIT, true))
}
// {xxx:map}.id
Expr::Property(x) if target.is::<crate::Map>() => {
let (name, pos) = &x.2;
let index = name.into();
let val = self.get_indexed_mut(
mods, state, lib, target, index, *pos, false, false, level,
)?;
Ok((val.take_or_clone(), false))
}
// xxx.id op= ???
Expr::Property(x) if new_val.is_some() => {
let ((getter, hash_get), (setter, hash_set), (name, pos)) = x.as_ref();
let ((mut new_val, new_pos), (op_info, op_pos)) = new_val.expect("`Some`");
if op_info.is_some() {
let hash = crate::ast::FnCallHashes::from_native(*hash_get);
let args = &mut [target.as_mut()];
let (mut orig_val, _) = self
.exec_fn_call(
mods, state, lib, getter, hash, args, is_ref_mut, true, *pos,
None, level,
)
.or_else(|err| match *err {
// Try an indexer if property does not exist
EvalAltResult::ErrorDotExpr(_, _) => {
let prop = name.into();
self.get_indexed_mut(
mods, state, lib, target, prop, *pos, false, true,
level,
)
.map(|v| (v.take_or_clone(), false))
.map_err(
|idx_err| match *idx_err {
EvalAltResult::ErrorIndexingType(_, _) => err,
_ => idx_err,
},
)
}
_ => Err(err),
})?;
self.eval_op_assignment(
mods,
state,
lib,
op_info,
op_pos,
&mut (&mut orig_val).into(),
root,
new_val,
)
.map_err(|err| err.fill_position(new_pos))?;
self.check_data_size(target.as_ref())
.map_err(|err| err.fill_position(root.1))?;
new_val = orig_val;
}
let hash = crate::ast::FnCallHashes::from_native(*hash_set);
let args = &mut [target.as_mut(), &mut new_val];
self.exec_fn_call(
mods, state, lib, setter, hash, args, is_ref_mut, true, *pos, None,
level,
)
.or_else(|err| match *err {
// Try an indexer if property does not exist
EvalAltResult::ErrorDotExpr(_, _) => {
let args = &mut [target, &mut name.into(), &mut new_val];
let hash_set =
crate::ast::FnCallHashes::from_native(mods.hash_idx_set());
let pos = Position::NONE;
self.exec_fn_call(
mods, state, lib, FN_IDX_SET, hash_set, args, is_ref_mut, true,
pos, None, level,
)
.map_err(
|idx_err| match *idx_err {
EvalAltResult::ErrorIndexingType(_, _) => err,
_ => idx_err,
},
)
}
_ => Err(err),
})
}
// xxx.id
Expr::Property(x) => {
let ((getter, hash_get), _, (name, pos)) = x.as_ref();
let hash = crate::ast::FnCallHashes::from_native(*hash_get);
let args = &mut [target.as_mut()];
self.exec_fn_call(
mods, state, lib, getter, hash, args, is_ref_mut, true, *pos, None,
level,
)
.map_or_else(
|err| match *err {
// Try an indexer if property does not exist
EvalAltResult::ErrorDotExpr(_, _) => {
let prop = name.into();
self.get_indexed_mut(
mods, state, lib, target, prop, *pos, false, true, level,
)
.map(|v| (v.take_or_clone(), false))
.map_err(|idx_err| {
match *idx_err {
EvalAltResult::ErrorIndexingType(_, _) => err,
_ => idx_err,
}
})
}
_ => Err(err),
},
// Assume getters are always pure
|(v, _)| Ok((v, false)),
)
}
// {xxx:map}.sub_lhs[expr] | {xxx:map}.sub_lhs.expr
Expr::Index(x, term, x_pos) | Expr::Dot(x, term, x_pos)
if target.is::<crate::Map>() =>
{
let val_target = &mut match x.lhs {
Expr::Property(ref p) => {
let (name, pos) = &p.2;
let index = name.into();
self.get_indexed_mut(
mods, state, lib, target, index, *pos, false, true, level,
)?
}
// {xxx:map}.fn_name(arg_expr_list)[expr] | {xxx:map}.fn_name(arg_expr_list).expr
Expr::FnCall(ref x, pos) if !x.is_qualified() => {
let FnCallExpr { name, hashes, .. } = x.as_ref();
let call_args = &mut idx_val.into_fn_call_args().expect(
"`chain_type` is `ChainType::Dot` with `Expr::FnCallExpr`",
);
let (val, _) = self.make_method_call(
mods, state, lib, name, *hashes, target, call_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
ref expr => unreachable!("invalid dot expression: {:?}", expr),
};
let rhs_chain = match_chaining_type(rhs);
self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, val_target, root, &x.rhs, *term,
idx_values, rhs_chain, level, new_val,
)
.map_err(|err| err.fill_position(*x_pos))
}
// xxx.sub_lhs[expr] | xxx.sub_lhs.expr
Expr::Index(x, term, x_pos) | Expr::Dot(x, term, x_pos) => {
match x.lhs {
// xxx.prop[expr] | xxx.prop.expr
Expr::Property(ref p) => {
let ((getter, hash_get), (setter, hash_set), (name, pos)) =
p.as_ref();
let rhs_chain = match_chaining_type(rhs);
let hash_get = crate::ast::FnCallHashes::from_native(*hash_get);
let hash_set = crate::ast::FnCallHashes::from_native(*hash_set);
let mut arg_values = [target.as_mut(), &mut Dynamic::UNIT.clone()];
let args = &mut arg_values[..1];
// Assume getters are always pure
let (mut val, _) = self
.exec_fn_call(
mods, state, lib, getter, hash_get, args, is_ref_mut, true,
*pos, None, level,
)
.or_else(|err| match *err {
// Try an indexer if property does not exist
EvalAltResult::ErrorDotExpr(_, _) => {
let prop = name.into();
self.get_indexed_mut(
mods, state, lib, target, prop, *pos, false, true,
level,
)
.map(|v| (v.take_or_clone(), false))
.map_err(
|idx_err| match *idx_err {
EvalAltResult::ErrorIndexingType(_, _) => err,
_ => idx_err,
},
)
}
_ => Err(err),
})?;
let val = &mut val;
let (result, may_be_changed) = self
.eval_dot_index_chain_helper(
mods,
state,
lib,
this_ptr,
&mut val.into(),
root,
&x.rhs,
*term,
idx_values,
rhs_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 may_be_changed {
// Re-use args because the first &mut parameter will not be consumed
let mut arg_values = [target.as_mut(), val];
let args = &mut arg_values;
self.exec_fn_call(
mods, state, lib, setter, hash_set, args, is_ref_mut, true,
*pos, None, level,
)
.or_else(
|err| match *err {
// Try an indexer if property does not exist
EvalAltResult::ErrorDotExpr(_, _) => {
let args =
&mut [target.as_mut(), &mut name.into(), val];
let hash_set =
crate::ast::FnCallHashes::from_native(
mods.hash_idx_set(),
);
self.exec_fn_call(
mods, state, lib, FN_IDX_SET, hash_set, args,
is_ref_mut, true, *pos, None, level,
)
.or_else(|idx_err| match *idx_err {
EvalAltResult::ErrorIndexingType(_, _) => {
// If there is no setter, no need to feed it back because
// the property is read-only
Ok((Dynamic::UNIT, false))
}
_ => Err(idx_err),
})
}
_ => Err(err),
},
)?;
self.check_data_size(target.as_ref())
.map_err(|err| err.fill_position(root.1))?;
}
Ok((result, may_be_changed))
}
// xxx.fn_name(arg_expr_list)[expr] | xxx.fn_name(arg_expr_list).expr
Expr::FnCall(ref f, pos) if !f.is_qualified() => {
let FnCallExpr { name, hashes, .. } = f.as_ref();
let rhs_chain = match_chaining_type(rhs);
let args = &mut idx_val.into_fn_call_args().expect(
"`chain_type` is `ChainType::Dot` with `Expr::FnCallExpr`",
);
let (mut val, _) = self.make_method_call(
mods, state, lib, name, *hashes, target, args, pos, level,
)?;
let val = &mut val;
let target = &mut val.into();
self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, target, root, &x.rhs, *term,
idx_values, rhs_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
ref expr => unreachable!("invalid dot expression: {:?}", expr),
}
}
// Syntax error
_ => Err(EvalAltResult::ErrorDotExpr("".into(), rhs.position()).into()),
}
}
}
}
/// 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 EvalState,
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, term, op_pos) = match expr {
#[cfg(not(feature = "no_index"))]
Expr::Index(x, term, pos) => (x.as_ref(), ChainType::Indexing, *term, *pos),
#[cfg(not(feature = "no_object"))]
Expr::Dot(x, term, pos) => (x.as_ref(), ChainType::Dotting, *term, *pos),
_ => unreachable!("index or dot chain expected, but gets {:?}", expr),
};
let idx_values = &mut StaticVec::new_const();
self.eval_dot_index_chain_arguments(
scope, mods, state, lib, this_ptr, rhs, term, chain_type, idx_values, 0, level,
)?;
match lhs {
// id.??? or id[???]
Expr::Variable(_, var_pos, x) => {
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, *var_pos)?;
let (mut target, _) =
self.search_namespace(scope, mods, state, lib, this_ptr, lhs)?;
let obj_ptr = &mut target;
let root = (x.2.as_str(), *var_pos);
self.eval_dot_index_chain_helper(
mods, state, lib, &mut None, obj_ptr, root, rhs, term, 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();
let root = ("", expr.position());
self.eval_dot_index_chain_helper(
mods, state, lib, this_ptr, obj_ptr, root, rhs, term, 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_dot_index_chain_arguments(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut EvalState,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
expr: &Expr,
terminate_chaining: bool,
parent_chain_type: ChainType,
idx_values: &mut StaticVec<ChainArgument>,
size: usize,
level: usize,
) -> Result<(), Box<EvalAltResult>> {
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, expr.position())?;
let _parent_chain_type = parent_chain_type;
match expr {
#[cfg(not(feature = "no_object"))]
Expr::FnCall(x, _) if _parent_chain_type == ChainType::Dotting && !x.is_qualified() => {
let crate::ast::FnCallExpr {
args, constants, ..
} = x.as_ref();
let (values, pos) = args.iter().try_fold(
(StaticVec::with_capacity(args.len()), Position::NONE),
|(mut values, mut pos), expr| -> Result<_, Box<EvalAltResult>> {
let (value, arg_pos) = self.get_arg_value(
scope, mods, state, lib, this_ptr, level, expr, constants,
)?;
if values.is_empty() {
pos = arg_pos;
}
values.push(value.flatten());
Ok((values, pos))
},
)?;
idx_values.push((values, pos).into());
}
#[cfg(not(feature = "no_object"))]
Expr::FnCall(_, _) if _parent_chain_type == ChainType::Dotting => {
unreachable!("function call in dot chain should not be namespace-qualified")
}
#[cfg(not(feature = "no_object"))]
Expr::Property(x) if _parent_chain_type == ChainType::Dotting => {
idx_values.push(ChainArgument::Property((x.2).1))
}
Expr::Property(_) => unreachable!("unexpected Expr::Property for indexing"),
Expr::Index(x, term, _) | Expr::Dot(x, term, _) if !terminate_chaining => {
let crate::ast::BinaryExpr { lhs, rhs, .. } = x.as_ref();
// Evaluate in left-to-right order
let lhs_val = match lhs {
#[cfg(not(feature = "no_object"))]
Expr::Property(x) if _parent_chain_type == ChainType::Dotting => {
ChainArgument::Property((x.2).1)
}
Expr::Property(_) => unreachable!("unexpected Expr::Property for indexing"),
#[cfg(not(feature = "no_object"))]
Expr::FnCall(x, _)
if _parent_chain_type == ChainType::Dotting && !x.is_qualified() =>
{
let crate::ast::FnCallExpr {
args, constants, ..
} = x.as_ref();
args.iter()
.try_fold(
(StaticVec::with_capacity(args.len()), Position::NONE),
|(mut values, mut pos), expr| -> Result<_, Box<EvalAltResult>> {
let (value, arg_pos) = self.get_arg_value(
scope, mods, state, lib, this_ptr, level, expr, constants,
)?;
if values.is_empty() {
pos = arg_pos
}
values.push(value.flatten());
Ok((values, pos))
},
)?
.into()
}
#[cfg(not(feature = "no_object"))]
Expr::FnCall(_, _) if _parent_chain_type == ChainType::Dotting => {
unreachable!("function call in dot chain should not be namespace-qualified")
}
#[cfg(not(feature = "no_object"))]
expr if _parent_chain_type == ChainType::Dotting => {
unreachable!("invalid dot expression: {:?}", expr);
}
#[cfg(not(feature = "no_index"))]
_ if _parent_chain_type == ChainType::Indexing => self
.eval_expr(scope, mods, state, lib, this_ptr, lhs, level)
.map(|v| (v.flatten(), lhs.position()).into())?,
expr => unreachable!("unknown chained expression: {:?}", expr),
};
// Push in reverse order
let chain_type = match_chaining_type(expr);
self.eval_dot_index_chain_arguments(
scope, mods, state, lib, this_ptr, rhs, *term, chain_type, idx_values, size,
level,
)?;
idx_values.push(lhs_val);
}
#[cfg(not(feature = "no_object"))]
_ if _parent_chain_type == ChainType::Dotting => {
unreachable!("invalid dot expression: {:?}", expr);
}
#[cfg(not(feature = "no_index"))]
_ if _parent_chain_type == ChainType::Indexing => idx_values.push(
self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)
.map(|v| (v.flatten(), expr.position()).into())?,
),
_ => unreachable!("unknown chained expression: {:?}", expr),
}
Ok(())
}
/// Get the value at the indexed position of a base type.
/// [`Position`] in [`EvalAltResult`] may be [`NONE`][Position::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 EvalState,
lib: &[&Module],
target: &'t mut Dynamic,
idx: Dynamic,
idx_pos: Position,
add_if_not_found: bool,
use_indexers: bool,
level: usize,
) -> Result<Target<'t>, Box<EvalAltResult>> {
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, Position::NONE)?;
let mut idx = idx;
let _add_if_not_found = add_if_not_found;
match target {
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Array(arr, _, _)) => {
// val_array[idx]
let index = idx
.as_int()
.map_err(|typ| self.make_type_mismatch_err::<crate::INT>(typ, idx_pos))?;
let arr_len = arr.len();
#[cfg(not(feature = "unchecked"))]
let arr_idx = if index < 0 {
// Count from end if negative
arr_len
- index
.checked_abs()
.ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos))
.and_then(|n| {
if n as usize > arr_len {
Err(EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos)
.into())
} else {
Ok(n as usize)
}
})?
} else {
index as usize
};
#[cfg(feature = "unchecked")]
let arr_idx = if index < 0 {
// Count from end if negative
arr_len - index.abs() as usize
} else {
index as usize
};
arr.get_mut(arr_idx)
.map(Target::from)
.ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos).into())
}
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Blob(arr, _, _)) => {
// val_blob[idx]
let index = idx
.as_int()
.map_err(|typ| self.make_type_mismatch_err::<crate::INT>(typ, idx_pos))?;
let arr_len = arr.len();
#[cfg(not(feature = "unchecked"))]
let arr_idx = if index < 0 {
// Count from end if negative
arr_len
- index
.checked_abs()
.ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos))
.and_then(|n| {
if n as usize > arr_len {
Err(EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos)
.into())
} else {
Ok(n as usize)
}
})?
} else {
index as usize
};
#[cfg(feature = "unchecked")]
let arr_idx = if index < 0 {
// Count from end if negative
arr_len - index.abs() as usize
} else {
index as usize
};
let value = arr
.get(arr_idx)
.map(|&v| (v as INT).into())
.ok_or_else(|| {
Box::new(EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos))
})?;
Ok(Target::BlobByte(target, arr_idx, value))
}
#[cfg(not(feature = "no_object"))]
Dynamic(Union::Map(map, _, _)) => {
// val_map[idx]
let index = idx.read_lock::<ImmutableString>().ok_or_else(|| {
self.make_type_mismatch_err::<ImmutableString>(idx.type_name(), idx_pos)
})?;
if _add_if_not_found && !map.contains_key(index.as_str()) {
map.insert(index.clone().into(), Dynamic::UNIT);
}
Ok(map
.get_mut(index.as_str())
.map(Target::from)
.unwrap_or_else(|| Target::from(Dynamic::UNIT)))
}
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Int(value, _, _))
if idx.is::<crate::ExclusiveRange>() || idx.is::<crate::InclusiveRange>() =>
{
#[cfg(not(feature = "only_i32"))]
type BASE = u64;
#[cfg(feature = "only_i32")]
type BASE = u32;
// val_int[range]
const BITS: usize = std::mem::size_of::<INT>() * 8;
let (shift, mask) = if let Some(range) = idx.read_lock::<crate::ExclusiveRange>() {
let start = range.start;
let end = range.end;
if start < 0 || start as usize >= BITS {
return Err(EvalAltResult::ErrorBitFieldBounds(BITS, start, idx_pos).into());
} else if end < 0 || end as usize >= BITS {
return Err(EvalAltResult::ErrorBitFieldBounds(BITS, end, idx_pos).into());
} else if end <= start {
(0, 0)
} else if end as usize == BITS && start == 0 {
// -1 = all bits set
(0, -1)
} else {
(
start as u8,
// 2^bits - 1
(((2 as BASE).pow((end - start) as u32) - 1) as INT) << start,
)
}
} else if let Some(range) = idx.read_lock::<crate::InclusiveRange>() {
let start = *range.start();
let end = *range.end();
if start < 0 || start as usize >= BITS {
return Err(EvalAltResult::ErrorBitFieldBounds(BITS, start, idx_pos).into());
} else if end < 0 || end as usize >= BITS {
return Err(EvalAltResult::ErrorBitFieldBounds(BITS, end, idx_pos).into());
} else if end < start {
(0, 0)
} else if end as usize == BITS - 1 && start == 0 {
// -1 = all bits set
(0, -1)
} else {
(
start as u8,
// 2^bits - 1
(((2 as BASE).pow((end - start + 1) as u32) - 1) as INT) << start,
)
}
} else {
unreachable!("`Range` or `RangeInclusive`");
};
let field_value = (*value & mask) >> shift;
Ok(Target::BitField(target, mask, field_value.into(), shift))
}
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Int(value, _, _)) => {
// val_int[idx]
let index = idx
.as_int()
.map_err(|typ| self.make_type_mismatch_err::<crate::INT>(typ, idx_pos))?;
const BITS: usize = std::mem::size_of::<INT>() * 8;
let (bit_value, offset) = if index >= 0 {
let offset = index as usize;
(
if offset >= BITS {
return Err(
EvalAltResult::ErrorBitFieldBounds(BITS, index, idx_pos).into()
);
} else {
(*value & (1 << offset)) != 0
},
offset as u8,
)
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
(
// Count from end if negative
if offset > BITS {
return Err(
EvalAltResult::ErrorBitFieldBounds(BITS, index, idx_pos).into()
);
} else {
(*value & (1 << (BITS - offset))) != 0
},
offset as u8,
)
} else {
return Err(EvalAltResult::ErrorBitFieldBounds(BITS, index, idx_pos).into());
};
Ok(Target::Bit(target, bit_value.into(), offset))
}
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Str(s, _, _)) => {
// val_string[idx]
let index = idx
.as_int()
.map_err(|typ| self.make_type_mismatch_err::<crate::INT>(typ, idx_pos))?;
let (ch, offset) = if index >= 0 {
let offset = index as usize;
(
s.chars().nth(offset).ok_or_else(|| {
let chars_len = s.chars().count();
EvalAltResult::ErrorStringBounds(chars_len, index, idx_pos)
})?,
offset,
)
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
(
// Count from end if negative
s.chars().rev().nth(offset - 1).ok_or_else(|| {
let chars_len = s.chars().count();
EvalAltResult::ErrorStringBounds(chars_len, index, idx_pos)
})?,
offset,
)
} else {
let chars_len = s.chars().count();
return Err(EvalAltResult::ErrorStringBounds(chars_len, index, idx_pos).into());
};
Ok(Target::StringChar(target, offset, ch.into()))
}
_ if use_indexers => {
let args = &mut [target, &mut idx];
let hash_get = crate::ast::FnCallHashes::from_native(mods.hash_idx_get());
let idx_pos = Position::NONE;
self.exec_fn_call(
mods, state, lib, FN_IDX_GET, hash_get, args, true, true, idx_pos, None, level,
)
.map(|(v, _)| v.into())
}
_ => Err(EvalAltResult::ErrorIndexingType(
format!(
"{} [{}]",
self.map_type_name(target.type_name()),
self.map_type_name(idx.type_name())
),
Position::NONE,
)
.into()),
}
}
/// Evaluate an expression.
pub(crate) fn eval_expr(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut EvalState,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
expr: &Expr,
level: usize,
) -> RhaiResult {
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, 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::Variable(None, var_pos, x) if x.0.is_none() && x.2 == KEYWORD_THIS => this_ptr
.as_deref()
.cloned()
.ok_or_else(|| EvalAltResult::ErrorUnboundThis(*var_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) => {
self.eval_stmt_block(scope, mods, state, lib, this_ptr, x, true, 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)
}
// `... ${...} ...`
Expr::InterpolatedString(x, pos) => {
let mut pos = *pos;
let mut result: Dynamic = self.const_empty_string().into();
x.iter().try_for_each(|expr| {
let item = self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?;
self.eval_op_assignment(
mods,
state,
lib,
Some(OpAssignment::new(TOKEN_OP_CONCAT)),
pos,
&mut (&mut result).into(),
("", Position::NONE),
item,
)
.map_err(|err| err.fill_position(expr.position()))?;
pos = expr.position();
self.check_data_size(&result)
.map_err(|err| err.fill_position(pos))
})?;
assert!(
result.is::<ImmutableString>(),
"interpolated string must be a string"
);
Ok(result)
}
#[cfg(not(feature = "no_index"))]
Expr::Array(x, _) => Ok(x
.iter()
.try_fold(
crate::Array::with_capacity(x.len()),
|mut arr, item| -> Result<_, Box<EvalAltResult>> {
arr.push(
self.eval_expr(scope, mods, state, lib, this_ptr, item, level)?
.flatten(),
);
Ok(arr)
},
)?
.into()),
#[cfg(not(feature = "no_object"))]
Expr::Map(x, _) => Ok(x
.0
.iter()
.try_fold(
x.1.clone(),
|mut map, (Ident { name: key, .. }, expr)| -> Result<_, Box<EvalAltResult>> {
let value_ref = map.get_mut(key.as_str()).expect("contains all keys");
*value_ref = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten();
Ok(map)
},
)?
.into()),
// Namespace-qualified function call
Expr::FnCall(x, pos) if x.is_qualified() => {
let FnCallExpr {
name,
namespace,
hashes,
args,
constants,
..
} = x.as_ref();
let namespace = namespace.as_ref().expect("qualified function call");
let hash = hashes.native;
self.make_qualified_function_call(
scope, mods, state, lib, this_ptr, namespace, name, args, constants, hash,
*pos, level,
)
}
// Normal function call
Expr::FnCall(x, pos) => {
let FnCallExpr {
name,
capture_parent_scope: capture,
hashes,
args,
constants,
..
} = x.as_ref();
self.make_function_call(
scope, mods, state, lib, this_ptr, name, args, constants, *hashes, *pos,
*capture, level,
)
}
Expr::And(x, _) => {
Ok((self
.eval_expr(scope, mods, state, lib, this_ptr, &x.lhs, level)?
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, x.lhs.position()))?
&& // Short-circuit using &&
self
.eval_expr(scope, mods, state, lib, this_ptr, &x.rhs, level)?
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, x.rhs.position()))?)
.into())
}
Expr::Or(x, _) => {
Ok((self
.eval_expr(scope, mods, state, lib, this_ptr, &x.lhs, level)?
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, x.lhs.position()))?
|| // Short-circuit using ||
self
.eval_expr(scope, mods, state, lib, this_ptr, &x.rhs, level)?
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, x.rhs.position()))?)
.into())
}
Expr::BoolConstant(x, _) => Ok((*x).into()),
Expr::Unit(_) => Ok(Dynamic::UNIT),
Expr::Custom(custom, _) => {
let expressions: StaticVec<_> = custom.inputs.iter().map(Into::into).collect();
let key_token = custom.tokens.first().expect("not empty");
let custom_def = self.custom_syntax.get(key_token).expect("must match");
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_return_value(result)
.map_err(|err| err.fill_position(expr.position()))
}
/// Evaluate a statements block.
pub(crate) fn eval_stmt_block(
&self,
scope: &mut Scope,
mods: &mut Imports,
state: &mut EvalState,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
statements: &[Stmt],
restore_orig_state: bool,
rewind_scope: bool,
level: usize,
) -> RhaiResult {
if statements.is_empty() {
return Ok(Dynamic::UNIT);
}
let orig_always_search_scope = state.always_search_scope;
let orig_scope_len = scope.len();
let orig_mods_len = mods.len();
let orig_fn_resolution_caches_len = state.fn_resolution_caches_len();
if rewind_scope {
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 state.fn_resolution_caches_len() > orig_fn_resolution_caches_len {
// 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_orig_state {
// When new module is imported with global functions, push a new cache
state.push_fn_resolution_cache();
} else {
// When the block is to be evaluated in-place, just clear the current cache
state.fn_resolution_cache_mut().clear();
}
}
}
Ok(r)
});
// If imports list is modified, pop the functions lookup cache
state.rewind_fn_resolution_caches(orig_fn_resolution_caches_len);
if rewind_scope {
scope.rewind(orig_scope_len);
state.scope_level -= 1;
}
if restore_orig_state {
mods.truncate(orig_mods_len);
// 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_scope = orig_always_search_scope;
}
result
}
/// Evaluate an op-assignment statement.
/// [`Position`] in [`EvalAltResult`] is [`NONE`][Position::NONE] and should be set afterwards.
pub(crate) fn eval_op_assignment(
&self,
mods: &mut Imports,
state: &mut EvalState,
lib: &[&Module],
op_info: Option<OpAssignment>,
op_pos: Position,
target: &mut Target,
root: (&str, Position),
new_val: Dynamic,
) -> Result<(), Box<EvalAltResult>> {
if target.is_read_only() {
// Assignment to constant variable
return Err(
EvalAltResult::ErrorAssignmentToConstant(root.0.to_string(), root.1).into(),
);
}
let mut new_val = new_val;
if let Some(OpAssignment {
hash_op_assign,
hash_op,
op,
}) = op_info
{
{
let mut lock_guard;
let lhs_ptr_inner;
#[cfg(not(feature = "no_closure"))]
let target_is_shared = target.is_shared();
#[cfg(feature = "no_closure")]
let target_is_shared = false;
if target_is_shared {
lock_guard = target.write_lock::<Dynamic>().expect("`Dynamic`");
lhs_ptr_inner = &mut *lock_guard;
} else {
lhs_ptr_inner = &mut *target;
}
let hash = hash_op_assign;
let args = &mut [lhs_ptr_inner, &mut new_val];
match self.call_native_fn(mods, state, lib, op, hash, args, true, true, op_pos) {
Err(err) if matches!(*err, EvalAltResult::ErrorFunctionNotFound(ref f, _) if f.starts_with(op)) =>
{
// 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(|_| ()),
}
}
} else {
// Normal assignment
*target.as_mut() = new_val;
}
target.propagate_changed_value()
}
/// 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 EvalState,
lib: &[&Module],
this_ptr: &mut Option<&mut Dynamic>,
stmt: &Stmt,
level: usize,
) -> RhaiResult {
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, 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.is_variable_access(false) => {
let (lhs_expr, op_info, rhs_expr) = x.as_ref();
let rhs_val = self
.eval_expr(scope, mods, state, lib, this_ptr, rhs_expr, level)?
.flatten();
let (mut lhs_ptr, pos) =
self.search_namespace(scope, mods, state, lib, this_ptr, lhs_expr)?;
let var_name = lhs_expr.get_variable_name(false).expect("`Variable`");
if !lhs_ptr.is_ref() {
return Err(EvalAltResult::ErrorAssignmentToConstant(
var_name.to_string(),
pos,
)
.into());
}
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, pos)?;
self.eval_op_assignment(
mods,
state,
lib,
*op_info,
*op_pos,
&mut lhs_ptr,
(var_name, pos),
rhs_val,
)
.map_err(|err| err.fill_position(rhs_expr.position()))?;
if op_info.is_some() {
self.check_data_size(lhs_ptr.as_ref())
.map_err(|err| err.fill_position(lhs_expr.position()))?;
}
Ok(Dynamic::UNIT)
}
// lhs op= rhs
Stmt::Assignment(x, op_pos) => {
let (lhs_expr, op_info, rhs_expr) = 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, true, level,
),
// If statement
Stmt::If(expr, x, _) => {
let guard_val = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, expr.position()))?;
if guard_val {
if !x.0.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, &x.0, true, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
} else {
if !x.1.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, &x.1, true, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
}
}
// Switch statement
Stmt::Switch(match_expr, x, _) => {
let (table, def_stmt, ranges) = x.as_ref();
let value = self.eval_expr(scope, mods, state, lib, this_ptr, match_expr, level)?;
let stmt_block = if value.is_hashable() {
let hasher = &mut get_hasher();
value.hash(hasher);
let hash = hasher.finish();
// First check hashes
if let Some(t) = table.get(&hash) {
if let Some(ref c) = t.0 {
if self
.eval_expr(scope, mods, state, lib, this_ptr, &c, level)
.and_then(|v| {
v.as_bool().map_err(|typ| {
self.make_type_mismatch_err::<bool>(typ, c.position())
})
})?
{
Some(&t.1)
} else {
None
}
} else {
Some(&t.1)
}
} else if value.is::<INT>() && !ranges.is_empty() {
// Then check integer ranges
let value = value.as_int().expect("`INT`");
let mut result = None;
for (_, _, _, condition, stmt_block) in
ranges.iter().filter(|&&(start, end, inclusive, _, _)| {
(!inclusive && (start..end).contains(&value))
|| (inclusive && (start..=end).contains(&value))
})
{
if let Some(c) = condition {
if !self
.eval_expr(scope, mods, state, lib, this_ptr, &c, level)
.and_then(|v| {
v.as_bool().map_err(|typ| {
self.make_type_mismatch_err::<bool>(typ, c.position())
})
})?
{
continue;
}
}
result = Some(stmt_block);
break;
}
result
} else {
// Nothing matches
None
}
} else {
// Non-hashable
None
};
if let Some(statements) = stmt_block {
if !statements.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, statements, true, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
} else {
// Default match clause
if !def_stmt.is_empty() {
self.eval_stmt_block(
scope, mods, state, lib, this_ptr, def_stmt, true, true, level,
)
} else {
Ok(Dynamic::UNIT)
}
}
}
// Loop
Stmt::While(Expr::Unit(_), body, _) => loop {
if !body.is_empty() {
match self
.eval_stmt_block(scope, mods, state, lib, this_ptr, body, true, true, level)
{
Ok(_) => (),
Err(err) => match *err {
EvalAltResult::LoopBreak(false, _) => (),
EvalAltResult::LoopBreak(true, _) => return Ok(Dynamic::UNIT),
_ => return Err(err),
},
}
} else {
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, body.position())?;
}
},
// While loop
Stmt::While(expr, body, _) => loop {
let condition = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, expr.position()))?;
if !condition {
return Ok(Dynamic::UNIT);
}
if !body.is_empty() {
match self
.eval_stmt_block(scope, mods, state, lib, this_ptr, body, true, 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, options, _) => loop {
let is_while = !options.contains(AST_OPTION_NEGATED);
if !body.is_empty() {
match self
.eval_stmt_block(scope, mods, state, lib, this_ptr, body, true, true, level)
{
Ok(_) => (),
Err(err) => match *err {
EvalAltResult::LoopBreak(false, _) => continue,
EvalAltResult::LoopBreak(true, _) => return Ok(Dynamic::UNIT),
_ => return Err(err),
},
}
}
let condition = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, expr.position()))?;
if condition ^ is_while {
return Ok(Dynamic::UNIT);
}
},
// For loop
Stmt::For(expr, x, _) => {
let (Ident { name, .. }, counter, statements) = 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_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 variables
let orig_scope_len = scope.len();
let counter_index = counter.as_ref().map(|Ident { name, .. }| {
scope.push(unsafe_cast_var_name_to_lifetime(name), 0 as INT);
scope.len() - 1
});
scope.push(unsafe_cast_var_name_to_lifetime(name), ());
let index = scope.len() - 1;
for (x, iter_value) in func(iter_obj).enumerate() {
// Increment counter
if let Some(c) = counter_index {
#[cfg(not(feature = "unchecked"))]
if x > INT::MAX as usize {
return Err(EvalAltResult::ErrorArithmetic(
format!("for-loop counter overflow: {}", x),
counter.as_ref().expect("`Some`").pos,
)
.into());
}
let mut counter_var = scope
.get_mut_by_index(c)
.write_lock::<INT>()
.expect("`INT`");
*counter_var = x as INT;
}
let loop_var = scope.get_mut_by_index(index);
let value = iter_value.flatten();
#[cfg(not(feature = "no_closure"))]
let loop_var_is_shared = loop_var.is_shared();
#[cfg(feature = "no_closure")]
let loop_var_is_shared = false;
if loop_var_is_shared {
let mut value_ref = loop_var.write_lock().expect("`Dynamic`");
*value_ref = value;
} else {
*loop_var = value;
}
#[cfg(not(feature = "unchecked"))]
self.inc_operations(&mut mods.num_operations, statements.position())?;
if statements.is_empty() {
continue;
}
let result = self.eval_stmt_block(
scope, mods, state, lib, this_ptr, statements, true, true, level,
);
match result {
Ok(_) => (),
Err(err) => match *err {
EvalAltResult::LoopBreak(false, _) => (),
EvalAltResult::LoopBreak(true, _) => break,
_ => return Err(err),
},
}
}
scope.rewind(orig_scope_len);
Ok(Dynamic::UNIT)
} else {
Err(EvalAltResult::ErrorFor(expr.position()).into())
}
}
// Continue/Break statement
Stmt::BreakLoop(options, pos) => {
Err(EvalAltResult::LoopBreak(options.contains(AST_OPTION_BREAK_OUT), *pos).into())
}
// Namespace-qualified function call
Stmt::FnCall(x, pos) if x.is_qualified() => {
let FnCallExpr {
name,
namespace,
hashes,
args,
constants,
..
} = x.as_ref();
let namespace = namespace.as_ref().expect("qualified function call");
let hash = hashes.native;
self.make_qualified_function_call(
scope, mods, state, lib, this_ptr, namespace, name, args, constants, hash,
*pos, level,
)
}
// Normal function call
Stmt::FnCall(x, pos) => {
let FnCallExpr {
name,
capture_parent_scope: capture,
hashes,
args,
constants,
..
} = x.as_ref();
self.make_function_call(
scope, mods, state, lib, this_ptr, name, args, constants, *hashes, *pos,
*capture, level,
)
}
// Try/Catch statement
Stmt::TryCatch(x, _) => {
let (try_stmt, err_var, catch_stmt) = x.as_ref();
let result = self
.eval_stmt_block(
scope, mods, state, lib, this_ptr, try_stmt, true, 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"))]
_ => {
let mut err_map = crate::Map::new();
let err_pos = err.take_position();
err_map.insert("message".into(), err.to_string().into());
if let Some(ref source) = mods.source {
err_map.insert("source".into(), source.as_str().into());
}
if err_pos.is_none() {
// No position info
} else {
let line = err_pos.line().expect("line number") as INT;
let position = if err_pos.is_beginning_of_line() {
0
} else {
err_pos.position().expect("character position")
} as INT;
err_map.insert("line".into(), line.into());
err_map.insert("position".into(), position.into());
}
err.dump_fields(&mut err_map);
err_map.into()
}
};
let orig_scope_len = scope.len();
err_var.as_ref().map(|Ident { name, .. }| {
scope.push(unsafe_cast_var_name_to_lifetime(name), err_value)
});
let result = self.eval_stmt_block(
scope, mods, state, lib, this_ptr, catch_stmt, true, true, level,
);
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),
},
}
}
}
}
// Throw value
Stmt::Return(options, Some(expr), pos) if options.contains(AST_OPTION_BREAK_OUT) => {
Err(EvalAltResult::ErrorRuntime(
self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten(),
*pos,
)
.into())
}
// Empty throw
Stmt::Return(options, None, pos) if options.contains(AST_OPTION_BREAK_OUT) => {
Err(EvalAltResult::ErrorRuntime(Dynamic::UNIT, *pos).into())
}
// Return value
Stmt::Return(_, Some(expr), pos) => Err(EvalAltResult::Return(
self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten(),
*pos,
)
.into()),
// Empty return
Stmt::Return(_, None, pos) => Err(EvalAltResult::Return(Dynamic::UNIT, *pos).into()),
// Let/const statement
Stmt::Var(expr, x, options, _) => {
let name = &x.name;
let entry_type = if options.contains(AST_OPTION_CONSTANT) {
AccessMode::ReadOnly
} else {
AccessMode::ReadWrite
};
let export = options.contains(AST_OPTION_PUBLIC);
let value = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
.flatten();
let (var_name, _alias): (Cow<'_, str>, _) = if state.is_global() {
#[cfg(not(feature = "no_function"))]
#[cfg(not(feature = "no_module"))]
if entry_type == AccessMode::ReadOnly && lib.iter().any(|&m| !m.is_empty()) {
mods.set_global_constant(name.clone(), value.clone());
}
(
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"))]
_alias.map(|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 mods.num_modules >= self.max_modules() {
return Err(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 source = mods.source.as_ref().map(|s| s.as_str());
let path_pos = expr.position();
let module = mods
.embedded_module_resolver
.as_ref()
.and_then(|r| match r.resolve(self, source, &path, path_pos) {
Err(err)
if matches!(*err, EvalAltResult::ErrorModuleNotFound(_, _)) =>
{
None
}
result => Some(result),
})
.or_else(|| {
self.module_resolver
.as_ref()
.map(|r| r.resolve(self, source, &path, path_pos))
})
.unwrap_or_else(|| {
Err(
EvalAltResult::ErrorModuleNotFound(path.to_string(), path_pos)
.into(),
)
})?;
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::func::native::shared_take_or_clone(module);
module.build_index();
mods.push(name, module);
} else {
mods.push(name, module);
}
}
mods.num_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, _) => {
list.iter().try_for_each(
|(Ident { name, pos, .. }, Ident { name: rename, .. })| {
// Mark scope variables as public
if let Some((index, _)) = scope.get_index(name) {
scope.add_entry_alias(
index,
if rename.is_empty() { name } else { rename }.clone(),
);
Ok(()) as Result<_, Box<EvalAltResult>>
} else {
Err(EvalAltResult::ErrorVariableNotFound(name.to_string(), *pos).into())
}
},
)?;
Ok(Dynamic::UNIT)
}
// Share statement
#[cfg(not(feature = "no_closure"))]
Stmt::Share(name) => {
if let Some((index, _)) = scope.get_index(name) {
let val = scope.get_mut_by_index(index);
if !val.is_shared() {
// Replace the variable with a shared value.
*val = std::mem::take(val).into_shared();
}
}
Ok(Dynamic::UNIT)
}
};
self.check_return_value(result)
.map_err(|err| err.fill_position(stmt.position()))
}
// Has a system function a Rust-native override?
pub(crate) fn has_native_fn_override(&self, hash_script: u64, arg_types: &[TypeId]) -> bool {
let hash_params = calc_fn_params_hash(arg_types.iter().cloned());
let hash = combine_hashes(hash_script, hash_params);
// First check the global namespace and packages, but skip modules that are standard because
// they should never conflict with system functions.
self.global_modules.iter().filter(|m| !m.standard).any(|m| m.contains_fn(hash))
// Then check sub-modules
|| self.global_sub_modules.values().any(|m| m.contains_qualified_fn(hash))
}
/// Check a result to ensure that the data size is within allowable limit.
fn check_return_value(&self, mut result: RhaiResult) -> RhaiResult {
if let Ok(ref mut r) = result {
// Concentrate all empty strings into one instance to save memory
if let Dynamic(crate::types::dynamic::Union::Str(s, _, _)) = r {
if s.is_empty() {
if !s.ptr_eq(&self.empty_string) {
*s = self.const_empty_string();
}
return result;
}
}
#[cfg(not(feature = "unchecked"))]
self.check_data_size(&r)?;
}
result
}
#[cfg(feature = "unchecked")]
#[inline(always)]
fn check_data_size(&self, _value: &Dynamic) -> Result<(), Box<EvalAltResult>> {
Ok(())
}
#[cfg(not(feature = "unchecked"))]
fn check_data_size(&self, value: &Dynamic) -> Result<(), Box<EvalAltResult>> {
// Recursively calculate the size of a value (especially `Array` and `Map`)
fn calc_size(value: &Dynamic) -> (usize, usize, usize) {
match value.0 {
#[cfg(not(feature = "no_index"))]
Union::Array(ref arr, _, _) => {
arr.iter()
.fold((0, 0, 0), |(arrays, maps, strings), value| match value.0 {
Union::Array(_, _, _) => {
let (a, m, s) = calc_size(value);
(arrays + a + 1, maps + m, strings + s)
}
Union::Blob(ref a, _, _) => (arrays + 1 + a.len(), maps, strings),
#[cfg(not(feature = "no_object"))]
Union::Map(_, _, _) => {
let (a, m, s) = calc_size(value);
(arrays + a + 1, maps + m, strings + s)
}
Union::Str(ref s, _, _) => (arrays + 1, maps, strings + s.len()),
_ => (arrays + 1, maps, strings),
})
}
#[cfg(not(feature = "no_index"))]
Union::Blob(ref arr, _, _) => (arr.len(), 0, 0),
#[cfg(not(feature = "no_object"))]
Union::Map(ref map, _, _) => {
map.values()
.fold((0, 0, 0), |(arrays, maps, strings), value| match value.0 {
#[cfg(not(feature = "no_index"))]
Union::Array(_, _, _) => {
let (a, m, s) = calc_size(value);
(arrays + a, maps + m + 1, strings + s)
}
#[cfg(not(feature = "no_index"))]
Union::Blob(ref a, _, _) => (arrays + a.len(), maps, strings),
Union::Map(_, _, _) => {
let (a, m, s) = calc_size(value);
(arrays + a, maps + m + 1, strings + s)
}
Union::Str(ref s, _, _) => (arrays, maps + 1, strings + s.len()),
_ => (arrays, maps + 1, strings),
})
}
Union::Str(ref s, _, _) => (0, 0, s.len()),
_ => (0, 0, 0),
}
}
// 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 Ok(());
}
let (_arr, _map, s) = calc_size(value);
if s > self
.limits
.max_string_size
.map_or(usize::MAX, NonZeroUsize::get)
{
return Err(EvalAltResult::ErrorDataTooLarge(
"Length of string".to_string(),
Position::NONE,
)
.into());
}
#[cfg(not(feature = "no_index"))]
if _arr
> self
.limits
.max_array_size
.map_or(usize::MAX, NonZeroUsize::get)
{
return Err(EvalAltResult::ErrorDataTooLarge(
"Size of array".to_string(),
Position::NONE,
)
.into());
}
#[cfg(not(feature = "no_object"))]
if _map
> self
.limits
.max_map_size
.map_or(usize::MAX, NonZeroUsize::get)
{
return Err(EvalAltResult::ErrorDataTooLarge(
"Size of object map".to_string(),
Position::NONE,
)
.into());
}
Ok(())
}
/// Check if the number of operations stay within limit.
#[cfg(not(feature = "unchecked"))]
pub(crate) fn inc_operations(
&self,
num_operations: &mut u64,
pos: Position,
) -> Result<(), Box<EvalAltResult>> {
*num_operations += 1;
// Guard against too many operations
if self.max_operations() > 0 && *num_operations > self.max_operations() {
return Err(EvalAltResult::ErrorTooManyOperations(pos).into());
}
// Report progress - only in steps
if let Some(ref progress) = self.progress {
if let Some(token) = progress(*num_operations) {
// Terminate script if progress returns a termination token
return Err(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]
#[must_use]
pub fn map_type_name<'a>(&'a self, name: &'a str) -> &'a str {
self.type_names
.get(name)
.map(|s| s.as_str())
.unwrap_or_else(|| map_std_type_name(name))
}
/// Make a `Box<`[`EvalAltResult<ErrorMismatchDataType>`][EvalAltResult::ErrorMismatchDataType]`>`.
#[inline]
#[must_use]
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()
}
}
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