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Merge pull request #254 from schungx/master

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Added variable resolver.
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Stephen Chung 2020-10-11 22:51:19 +08:00 committed by GitHub
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25 changed files with 645 additions and 278 deletions
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3
RELEASES.md
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@ -15,10 +15,13 @@ Breaking changes
* The following `EvalAltResult` variants are removed and merged into `EvalAltResult::ErrorMismatchDataType`: `ErrorCharMismatch`, `ErrorNumericIndexExpr`, `ErrorStringIndexExpr`, `ErrorImportExpr`, `ErrorLogicGuard`, `ErrorBooleanArgMismatch` * The following `EvalAltResult` variants are removed and merged into `EvalAltResult::ErrorMismatchDataType`: `ErrorCharMismatch`, `ErrorNumericIndexExpr`, `ErrorStringIndexExpr`, `ErrorImportExpr`, `ErrorLogicGuard`, `ErrorBooleanArgMismatch`
* `Scope::iter_raw` returns an iterator with an additional field indicating whether the variable is constant or not. * `Scope::iter_raw` returns an iterator with an additional field indicating whether the variable is constant or not.
* `rhai::ser` and `rhai::de` namespaces are merged into `rhai::serde`. * `rhai::ser` and `rhai::de` namespaces are merged into `rhai::serde`.
* New reserved symbols: `++`, `--`, `..`, `...`.
* Callback signature for custom syntax implementation function is changed to allow for more flexibility.
New features New features
------------ ------------
* New `Engine::on_var` to register a _variable resolver_.
* `const` statements can now take any expression (or none at all) instead of only constant values. * `const` statements can now take any expression (or none at all) instead of only constant values.
* `OptimizationLevel::Simple` now eagerly evaluates built-in binary operators of primary types (if not overloaded). * `OptimizationLevel::Simple` now eagerly evaluates built-in binary operators of primary types (if not overloaded).
* Added `is_def_var()` to detect if variable is defined, and `is_def_fn()` to detect if script function is defined. * Added `is_def_var()` to detect if variable is defined, and `is_def_fn()` to detect if script function is defined.

6
doc/src/SUMMARY.md
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@ -121,14 +121,16 @@ The Rhai Scripting Language
5. [Multi-Layer Functions](patterns/multi-layer.md) 5. [Multi-Layer Functions](patterns/multi-layer.md)
6. [One Engine Instance Per Call](patterns/parallel.md) 6. [One Engine Instance Per Call](patterns/parallel.md)
7. [Scriptable Event Handler with State](patterns/events.md) 7. [Scriptable Event Handler with State](patterns/events.md)
8. [Dynamic Constants Provider](patterns/dynamic-const.md)
9. [Advanced Topics](advanced.md) 9. [Advanced Topics](advanced.md)
1. [Capture Scope for Function Call](language/fn-capture.md) 1. [Capture Scope for Function Call](language/fn-capture.md)
2. [Low-Level API](rust/register-raw.md) 2. [Low-Level API](rust/register-raw.md)
3. [Use as DSL](engine/dsl.md) 3. [Variable Resolver](engine/var.md)
4. [Use as DSL](engine/dsl.md)
1. [Disable Keywords and/or Operators](engine/disable.md) 1. [Disable Keywords and/or Operators](engine/disable.md)
2. [Custom Operators](engine/custom-op.md) 2. [Custom Operators](engine/custom-op.md)
3. [Extending with Custom Syntax](engine/custom-syntax.md) 3. [Extending with Custom Syntax](engine/custom-syntax.md)
4. [Multiple Instantiation](patterns/multiple.md) 5. [Multiple Instantiation](patterns/multiple.md)
10. [Appendix](appendix/index.md) 10. [Appendix](appendix/index.md)
1. [Keywords](appendix/keywords.md) 1. [Keywords](appendix/keywords.md)
2. [Operators and Symbols](appendix/operators.md) 2. [Operators and Symbols](appendix/operators.md)

12
doc/src/advanced.md
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@ -3,14 +3,4 @@ Advanced Topics
{{#include links.md}} {{#include links.md}}
This section covers advanced features such as: This section covers advanced features of the Rhai [`Engine`].
* [Advanced patterns]({{rootUrl}}/patterns/index.md) in using Rhai.
* [Capture the calling scope]({{rootUrl}}/language/fn-capture.md) in a function call.
* [`serde`] integration.
* Low-level [function registration API]({{rootUrl}}/rust/register-raw.md)
* [Domain-Specific Languages][DSL].

4
doc/src/appendix/operators.md
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@ -56,6 +56,10 @@ Symbols and Patterns
| `/*` .. `*/` | comment | block comment | | `/*` .. `*/` | comment | block comment |
| `(*` .. `*)` | comment | _reserved_ | | `(*` .. `*)` | comment | _reserved_ |
| `<` .. `>` | angular brackets | _reserved_ | | `<` .. `>` | angular brackets | _reserved_ |
| `++` | increment | _reserved_ |
| `--` | decrement | _reserved_ |
| `..` | range | _reserved_ |
| `...` | range | _reserved_ |
| `#` | hash | _reserved_ | | `#` | hash | _reserved_ |
| `@` | at | _reserved_ | | `@` | at | _reserved_ |
| `$` | dollar | _reserved_ | | `$` | dollar | _reserved_ |

39
doc/src/engine/custom-syntax.md
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@ -114,13 +114,17 @@ Any custom syntax must include an _implementation_ of it.
The function signature of an implementation is: The function signature of an implementation is:
> `Fn(engine: &Engine, context: &mut EvalContext, scope: &mut Scope, inputs: &[Expression]) -> Result<Dynamic, Box<EvalAltResult>>` > `Fn(scope: &mut Scope, context: &mut EvalContext, inputs: &[Expression]) -> Result<Dynamic, Box<EvalAltResult>>`
where: where:
* `engine: &Engine` - reference to the current [`Engine`].
* `context: &mut EvalContext` - mutable reference to the current evaluation _context_; **do not touch**.
* `scope: &mut Scope` - mutable reference to the current [`Scope`]; variables can be added to it. * `scope: &mut Scope` - mutable reference to the current [`Scope`]; variables can be added to it.
* `context: &mut EvalContext` - mutable reference to the current evaluation _context_ (**do not touch**) which exposes the following fields:
* `context.engine(): &Engine` - reference to the current [`Engine`].
* `context.namespace(): &Module` - reference to the current _global namespace_ (as a [module]) containing all script-defined functions.
* `context.call_level(): usize` - the current nesting level of function calls.
* `inputs: &[Expression]` - a list of input expression trees. * `inputs: &[Expression]` - a list of input expression trees.
#### WARNING - Lark's Vomit #### WARNING - Lark's Vomit
@ -143,11 +147,12 @@ To access a particular argument, use the following patterns:
### Evaluate an Expression Tree ### Evaluate an Expression Tree
Use the `engine::eval_expression_tree` method to evaluate an expression tree. Use the `EvalContext::eval_expression_tree` method to evaluate an arbitrary expression tree
within the current evaluation context.
```rust ```rust
let expr = inputs.get(0).unwrap(); let expr = inputs.get(0).unwrap();
let result = engine.eval_expression_tree(context, scope, expr)?; let result = context.eval_expression_tree(scope, expr)?;
``` ```
### Declare Variables ### Declare Variables
@ -157,15 +162,15 @@ New variables maybe declared (usually with a variable name that is passed in via
It can simply be pushed into the [`Scope`]. It can simply be pushed into the [`Scope`].
However, beware that all new variables must be declared _prior_ to evaluating any expression tree. However, beware that all new variables must be declared _prior_ to evaluating any expression tree.
In other words, any `Scope::push` calls must come _before_ any `Engine::eval_expression_tree` calls. In other words, any `Scope::push` calls must come _before_ any `EvalContext::eval_expression_tree` calls.
```rust ```rust
let var_name = inputs[0].get_variable_name().unwrap().to_string(); let var_name = inputs[0].get_variable_name().unwrap().to_string();
let expr = inputs.get(1).unwrap(); let expr = inputs.get(1).unwrap();
scope.push(var_name, 0 as INT); // do this BEFORE 'engine.eval_expression_tree'! scope.push(var_name, 0 as INT); // do this BEFORE 'context.eval_expression_tree'!
let result = engine.eval_expression_tree(context, scope, expr)?; let result = context.eval_expression_tree(context, scope, expr)?;
``` ```
@ -182,27 +187,29 @@ The syntax is passed simply as a slice of `&str`.
```rust ```rust
// Custom syntax implementation // Custom syntax implementation
fn implementation_func( fn implementation_func(
engine: &Engine,
context: &mut EvalContext,
scope: &mut Scope, scope: &mut Scope,
context: &mut EvalContext,
inputs: &[Expression] inputs: &[Expression]
) -> Result<Dynamic, Box<EvalAltResult>> { ) -> Result<Dynamic, Box<EvalAltResult>> {
let var_name = inputs[0].get_variable_name().unwrap().to_string(); let var_name = inputs[0].get_variable_name().unwrap().to_string();
let stmt = inputs.get(1).unwrap(); let stmt = inputs.get(1).unwrap();
let condition = inputs.get(2).unwrap(); let condition = inputs.get(2).unwrap();
// Push one new variable into the 'scope' BEFORE 'eval_expression_tree' // Push one new variable into the 'scope' BEFORE 'context.eval_expression_tree'
scope.push(var_name, 0 as INT); scope.push(var_name, 0 as INT);
loop { loop {
// Evaluate the statement block // Evaluate the statement block
engine.eval_expression_tree(context, scope, stmt)?; context.eval_expression_tree(scope, stmt)?;
// Evaluate the condition expression // Evaluate the condition expression
let stop = !engine.eval_expression_tree(context, scope, condition)? let stop = !context.eval_expression_tree(scope, condition)?
.as_bool() .as_bool().map_err(|err| Box::new(
.map_err(|_| EvalAltResult::ErrorBooleanArgMismatch( EvalAltResult::ErrorMismatchDataType(
"do-while".into(), expr.position() "bool".to_string(),
err.to_string(),
condition.position(),
)
))?; ))?;
if stop { if stop {

8
doc/src/engine/raw.md
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@ -18,11 +18,11 @@ Built-in Operators
------------------ ------------------
| Operators | Assignment operators | Supported for types (see [standard types]) | | Operators | Assignment operators | Supported for types (see [standard types]) |
| ------------------------ | ---------------------------- | ----------------------------------------------------------------------------- | | ------------------------- | ---------------------------- | ----------------------------------------------------------------------------- |
| `+`, | `+=` | `INT`, `FLOAT` (if not [`no_float`]), `ImmutableString` | | `+`, | `+=` | `INT`, `FLOAT` (if not [`no_float`]), `char`, `ImmutableString` |
| `-`, `*`, `/`, `%`, `~`, | `-=`, `*=`, `/=`, `%=`, `~=` | `INT`, `FLOAT` (if not [`no_float`]) | | `-`, `*`, `/`, `%`, `~`, | `-=`, `*=`, `/=`, `%=`, `~=` | `INT`, `FLOAT` (if not [`no_float`]) |
| `<<`, `>>`, `^`, | `<<=`, `>>=`, `^=` | `INT` | | `<<`, `>>` | `<<=`, `>>=` | `INT` |
| `&`, <code>\|</code>, | `&=`, <code>\|=</code> | `INT`, `bool` | | `&`, <code>\|</code>, `^` | `&=`, <code>\|=</code>, `^=` | `INT`, `bool` |
| `&&`, <code>\|\|</code> | | `bool` | | `&&`, <code>\|\|</code> | | `bool` |
| `==`, `!=` | | `INT`, `FLOAT` (if not [`no_float`]), `bool`, `char`, `()`, `ImmutableString` | | `==`, `!=` | | `INT`, `FLOAT` (if not [`no_float`]), `bool`, `char`, `()`, `ImmutableString` |
| `>`, `>=`, `<`, `<=` | | `INT`, `FLOAT` (if not [`no_float`]), `char`, `()`, `ImmutableString` | | `>`, `>=`, `<`, `<=` | | `INT`, `FLOAT` (if not [`no_float`]), `char`, `()`, `ImmutableString` |

72
doc/src/engine/var.md Normal file
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@ -0,0 +1,72 @@
Variable Resolver
=================
{{#include ../links.md}}
By default, Rhai looks up access to variables from the enclosing block scope,
working its way outwards until it reaches the top (global) level, then it
searches the [`Scope`] that is passed into the `Engine::eval` call.
There is a built-in facility for advanced users to _hook_ into the variable
resolution service and to override its default behavior.
To do so, provide a closure to the [`Engine`] via the [`Engine::on_var`] method:
```rust
let mut engine = Engine::new();
// Register a variable resolver.
engine.on_var(|name, index, scope, context| {
match name {
"MYSTIC_NUMBER" => Ok(Some((42 as INT).into())),
// Override a variable - make it not found even if it exists!
"DO_NOT_USE" => Err(Box::new(
EvalAltResult::ErrorVariableNotFound(name.to_string(), Position::none())
)),
// Silently maps 'chameleon' into 'innocent'.
"chameleon" => scope.get_value("innocent").map(Some).ok_or_else(|| Box::new(
EvalAltResult::ErrorVariableNotFound(name.to_string(), Position::none())
)),
// Return Ok(None) to continue with the normal variable resolution process.
_ => Ok(None)
}
});
```
Returned Values are Constants
----------------------------
Variable values, if any returned, are treated as _constants_ by the script and cannot be assigned to.
This is to avoid needing a mutable reference to the underlying data provider which may not be possible to obtain.
In order to change these variables, it is best to push them into a custom [`Scope`] instead of using
a variable resolver. Then these variables can be assigned to and their updated values read back after
the script is evaluated.
Function Signature
------------------
The function signature passed to `Engine::on_var` takes the following form:
> `Fn(name: &str, index: usize, scope: &Scope, context: &EvalContext) -> Result<Option<Dynamic>, Box<EvalAltResult>> + 'static`
where:
* `name: &str` - variable name.
* `index: usize` - an offset from the bottom of the current [`Scope`] that the variable is supposed to reside.
Offsets start from 1, with 1 meaning the last variable in the current [`Scope`]. Essentially the correct variable is at position `scope.len() - index`.
If `index` is zero, then there is no pre-calculated offset position and a search through the current [`Scope`] must be performed.
* `scope : &Scope` - reference to the current [`Scope`] containing all variables up to the current evaluation position.
* `context: &EvalContext` - reference to the current evaluation _context_, which exposes the following fields:
* `context.engine(): &Engine` - reference to the current [`Engine`].
* `context.namespace(): &Module` - reference to the current _global namespace_ (as a [module]) containing all script-defined functions.
* `context.call_level(): usize` - the current nesting level of function calls.
The return value is `Result<Option<Dynamic>, Box<EvalAltResult>>` where `Ok(None)` indicates that the normal
variable resolution process should continue.

1
doc/src/links.md
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@ -106,6 +106,7 @@
[module]: {{rootUrl}}/rust/modules/index.md [module]: {{rootUrl}}/rust/modules/index.md
[modules]: {{rootUrl}}/rust/modules/index.md [modules]: {{rootUrl}}/rust/modules/index.md
[module resolver]: {{rootUrl}}/rust/modules/resolvers.md [module resolver]: {{rootUrl}}/rust/modules/resolvers.md
[variable resolver]: {{rootUrl}}/engine/var.md
[`export`]: {{rootUrl}}/language/modules/export.md [`export`]: {{rootUrl}}/language/modules/export.md
[`import`]: {{rootUrl}}/language/modules/import.md [`import`]: {{rootUrl}}/language/modules/import.md

56
doc/src/patterns/dynamic-const.md Normal file
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@ -0,0 +1,56 @@
Dynamic Constants Provider
=========================
{{#include ../links.md}}
Usage Scenario
--------------
* A system has a _large_ number of constants, but only a minor set will be used by any script.
* The system constants are expensive to load.
* The system constants set is too massive to push into a custom [`Scope`].
* The values of system constants are volatile and call-dependent.
Key Concepts
------------
* Use a [variable resolver] to intercept variable access.
* Only load a variable when it is being used.
* Perform a lookup based on variable name, and provide the correct data value.
* May even perform back-end network access or look up the latest value from a database.
Implementation
--------------
```rust
let mut engine = Engine::new();
// Create shared data provider.
// Assume that Provider::get(&str) -> Option<value> gets a system constant.
let provider: Arc<Provider> = get_data_provider();
// Clone the shared provider
let db = provider.clone();
// Register a variable resolver.
// Move the shared provider into the closure.
engine.on_var(move |name, _, _, _| Ok(db.get(name).map(Dynamic::from)));
```
Values are Constants
--------------------
All values provided by a [variable resolver] are _constants_ due to their dynamic nature.
They cannot be assigned to.
In order to change values in an external system, register a dedicated API for that purpose.

14
doc/src/rust/print-custom.md
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@ -8,10 +8,10 @@ it is necessary that the following functions be registered (assuming the custom
is `T : Display + Debug`): is `T : Display + Debug`):
| Function | Signature | Typical implementation | Usage | | Function | Signature | Typical implementation | Usage |
| ----------- | ------------------------------------------------------------- | ------------------------------------- | ---------------------------------------------------------------------------------------- | | ----------- | ---------------------------------------------- | ---------------------------- | -------------------------------------------------------------------- |
| `to_string` | <code>\|s: &mut T\| -> ImmutableString</code> | `s.to_string().into()` | converts the custom type into a [string] | | `to_string` | <code>\|x: &mut T\| -> String</code> | `x.to_string()` | converts the custom type into a [string] |
| `print` | <code>\|s: &mut T\| -> ImmutableString</code> | `s.to_string().into()` | converts the custom type into a [string] for the [`print`] statement | | `print` | <code>\|x: &mut T\| -> String</code> | `x.to_string()` | converts the custom type into a [string] for the [`print`] statement |
| `debug` | <code>\|s: &mut T\| -> ImmutableString</code> | `format!("{:?}", s).into()` | converts the custom type into a [string] for the [`debug`] statement | | `debug` | <code>\|x: &mut T\| -> String</code> | `format!("{:?}", x)` | converts the custom type into a [string] for the [`debug`] statement |
| `+` | <code>\|s1: ImmutableString, s: T\| -> ImmutableString</code> | `s1 + s` | appends the custom type to another [string], for `print("Answer: " + type);` usage | | `+` | <code>\|s: &str, x: T\| -> String</code> | `format!("{}{}", s, x)` | concatenates the custom type with another [string] |
| `+` | <code>\|s: T, s2: ImmutableString\| -> ImmutableString</code> | `s.to_string().push_str(&s2).into();` | appends another [string] to the custom type, for `print(type + " is the answer");` usage | | `+` | <code>\|x: &mut T, s: &str\| -> String</code> | `x.to_string().push_str(s);` | concatenates another [string] with the custom type |
| `+=` | <code>\|s1: &mut ImmutableString, s: T\|</code> | `s1 += s.to_string()` | appends the custom type to an existing [string], for `s += type;` usage | | `+=` | <code>\|s: &mut ImmutableString, x: T\|</code> | `s += x.to_string()` | appends the custom type to an existing [string] |

1
doc/src/safety/max-operations.md
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@ -3,6 +3,7 @@ Maximum Number of Operations
{{#include ../links.md}} {{#include ../links.md}}
Limit How Long a Script Can Run Limit How Long a Script Can Run
------------------------------ ------------------------------

3
doc/src/safety/progress.md
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@ -7,7 +7,8 @@ It is impossible to know when, or even whether, a script run will end
(a.k.a. the [Halting Problem](http://en.wikipedia.org/wiki/Halting_problem)). (a.k.a. the [Halting Problem](http://en.wikipedia.org/wiki/Halting_problem)).
When dealing with third-party untrusted scripts that may be malicious, to track evaluation progress and When dealing with third-party untrusted scripts that may be malicious, to track evaluation progress and
to force-terminate a script prematurely (for any reason), provide a closure to the `Engine::on_progress` method: to force-terminate a script prematurely (for any reason), provide a closure to the [`Engine`] via
the `Engine::on_progress` method:
```rust ```rust
let mut engine = Engine::new(); let mut engine = Engine::new();

45
src/api.rs
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@ -1,7 +1,7 @@
//! Module that defines the extern API of `Engine`. //! Module that defines the extern API of `Engine`.
use crate::any::{Dynamic, Variant}; use crate::any::{Dynamic, Variant};
use crate::engine::{Engine, Imports, State}; use crate::engine::{Engine, EvalContext, Imports, State};
use crate::error::ParseError; use crate::error::ParseError;
use crate::fn_native::{IteratorFn, SendSync}; use crate::fn_native::{IteratorFn, SendSync};
use crate::module::{FuncReturn, Module}; use crate::module::{FuncReturn, Module};
@ -1686,6 +1686,49 @@ impl Engine {
optimize_into_ast(self, scope, stmt, lib, optimization_level) optimize_into_ast(self, scope, stmt, lib, optimization_level)
} }
/// Provide a callback that will be invoked before each variable access.
///
/// ## Return Value of Callback
///
/// Return `Ok(None)` to continue with normal variable access.
/// Return `Ok(Some(Dynamic))` as the variable's value.
///
/// ## Errors in Callback
///
/// Return `Err(...)` if there is an error.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let mut engine = Engine::new();
///
/// // Register a variable resolver.
/// engine.on_var(|name, _, _, _| {
/// match name {
/// "MYSTIC_NUMBER" => Ok(Some(42_i64.into())),
/// _ => Ok(None)
/// }
/// });
///
/// engine.eval::<i64>("MYSTIC_NUMBER")?;
///
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn on_var(
&mut self,
callback: impl Fn(&str, usize, &Scope, &EvalContext) -> Result<Option<Dynamic>, Box<EvalAltResult>>
+ SendSync
+ 'static,
) -> &mut Self {
self.resolve_var = Some(Box::new(callback));
self
}
/// Register a callback for script evaluation progress. /// Register a callback for script evaluation progress.
/// ///
/// # Example /// # Example

346
src/engine.rs
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@ -2,7 +2,7 @@
use crate::any::{map_std_type_name, Dynamic, Union}; use crate::any::{map_std_type_name, Dynamic, Union};
use crate::fn_call::run_builtin_op_assignment; use crate::fn_call::run_builtin_op_assignment;
use crate::fn_native::{Callback, FnPtr}; use crate::fn_native::{Callback, FnPtr, OnVarCallback};
use crate::module::{Module, ModuleRef}; use crate::module::{Module, ModuleRef};
use crate::optimize::OptimizationLevel; use crate::optimize::OptimizationLevel;
use crate::packages::{Package, PackagesCollection, StandardPackage}; use crate::packages::{Package, PackagesCollection, StandardPackage};
@ -10,7 +10,7 @@ use crate::parser::{Expr, ReturnType, Stmt, INT};
use crate::r#unsafe::unsafe_cast_var_name_to_lifetime; use crate::r#unsafe::unsafe_cast_var_name_to_lifetime;
use crate::result::EvalAltResult; use crate::result::EvalAltResult;
use crate::scope::{EntryType as ScopeEntryType, Scope}; use crate::scope::{EntryType as ScopeEntryType, Scope};
use crate::syntax::{CustomSyntax, EvalContext}; use crate::syntax::CustomSyntax;
use crate::token::Position; use crate::token::Position;
use crate::{calc_fn_hash, StaticVec}; use crate::{calc_fn_hash, StaticVec};
@ -148,7 +148,7 @@ pub enum Target<'a> {
} }
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))] #[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
impl Target<'_> { impl<'a> Target<'a> {
/// Is the `Target` a reference pointing to other data? /// Is the `Target` a reference pointing to other data?
#[allow(dead_code)] #[allow(dead_code)]
#[inline(always)] #[inline(always)]
@ -207,7 +207,7 @@ impl Target<'_> {
} }
/// Get the value of the `Target` as a `Dynamic`, cloning a referenced value if necessary. /// Get the value of the `Target` as a `Dynamic`, cloning a referenced value if necessary.
#[inline(always)] #[inline(always)]
pub fn clone_into_dynamic(self) -> Dynamic { pub fn take_or_clone(self) -> Dynamic {
match self { match self {
Self::Ref(r) => r.clone(), // Referenced value is cloned Self::Ref(r) => r.clone(), // Referenced value is cloned
#[cfg(not(feature = "no_closure"))] #[cfg(not(feature = "no_closure"))]
@ -218,6 +218,14 @@ impl Target<'_> {
Self::StringChar(_, _, ch) => ch, // Character is taken 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,
}
}
/// Get a mutable reference from the `Target`. /// Get a mutable reference from the `Target`.
#[inline(always)] #[inline(always)]
pub fn as_mut(&mut self) -> &mut Dynamic { pub fn as_mut(&mut self) -> &mut Dynamic {
@ -374,6 +382,39 @@ pub struct Limits {
pub max_map_size: usize, pub max_map_size: usize,
} }
/// Context of a script evaluation process.
#[derive(Debug)]
pub struct EvalContext<'e, 'a, 's, 'm, 't, 'd: 't> {
pub(crate) engine: &'e Engine,
pub(crate) mods: &'a mut Imports,
pub(crate) state: &'s mut State,
pub(crate) lib: &'m Module,
pub(crate) this_ptr: &'t mut Option<&'d mut Dynamic>,
pub(crate) level: usize,
}
impl<'e, 'a, 's, 'm, 't, 'd> EvalContext<'e, 'a, 's, 'm, 't, 'd> {
/// The current `Engine`.
pub fn engine(&self) -> &'e Engine {
self.engine
}
/// _[INTERNALS]_ The current set of modules imported via `import` statements.
/// Available under the `internals` feature only.
#[cfg(feature = "internals")]
#[cfg(not(feature = "no_modules"))]
pub fn imports(&self) -> &'a Imports {
self.mods
}
/// The global namespace containing definition of all script-defined functions.
pub fn namespace(&self) -> &'m Module {
self.lib
}
/// The current nesting level of function calls.
pub fn call_level(&self) -> usize {
self.level
}
}
/// Rhai main scripting engine. /// Rhai main scripting engine.
/// ///
/// ``` /// ```
@ -412,6 +453,8 @@ pub struct Engine {
pub(crate) custom_keywords: Option<HashMap<String, u8>>, pub(crate) custom_keywords: Option<HashMap<String, u8>>,
/// Custom syntax. /// Custom syntax.
pub(crate) custom_syntax: Option<HashMap<String, CustomSyntax>>, pub(crate) custom_syntax: Option<HashMap<String, CustomSyntax>>,
/// Callback closure for resolving variable access.
pub(crate) resolve_var: Option<OnVarCallback>,
/// Callback closure for implementing the `print` command. /// Callback closure for implementing the `print` command.
pub(crate) print: Callback<str, ()>, pub(crate) print: Callback<str, ()>,
@ -522,88 +565,6 @@ pub fn search_imports_mut<'s>(
}) })
} }
/// Search for a variable within the scope or within imports,
/// depending on whether the variable name is qualified.
pub fn search_namespace<'s, 'a>(
scope: &'s mut Scope,
mods: &'s mut Imports,
state: &mut State,
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &'a Expr,
) -> Result<(&'s mut Dynamic, &'a str, ScopeEntryType, Position), Box<EvalAltResult>> {
match expr {
Expr::Variable(v) => match v.as_ref() {
// Qualified variable
((name, pos), Some(modules), hash_var, _) => {
let module = search_imports_mut(mods, state, modules)?;
let target = module
.get_qualified_var_mut(*hash_var)
.map_err(|err| match *err {
EvalAltResult::ErrorVariableNotFound(_, _) => {
EvalAltResult::ErrorVariableNotFound(
format!("{}{}", modules, name),
*pos,
)
.into()
}
_ => err.new_position(*pos),
})?;
// Module variables are constant
Ok((target, name, ScopeEntryType::Constant, *pos))
}
// Normal variable access
_ => search_scope_only(scope, state, this_ptr, expr),
},
_ => unreachable!(),
}
}
/// Search for a variable within the scope
pub fn search_scope_only<'s, 'a>(
scope: &'s mut Scope,
state: &mut State,
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &'a Expr,
) -> Result<(&'s mut Dynamic, &'a str, ScopeEntryType, Position), Box<EvalAltResult>> {
let ((name, pos), _, _, index) = match expr {
Expr::Variable(v) => v.as_ref(),
_ => unreachable!(),
};
// Check if the variable is `this`
if name == KEYWORD_THIS {
if let Some(val) = this_ptr {
return Ok(((*val).into(), KEYWORD_THIS, ScopeEntryType::Normal, *pos));
} else {
return EvalAltResult::ErrorUnboundThis(*pos).into();
}
}
// Check if it is directly indexed
let index = if state.always_search { None } else { *index };
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.into(), *pos))?
.0
};
let (val, typ) = scope.get_mut(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, name, typ, *pos))
}
impl Engine { impl Engine {
/// Create a new `Engine` /// Create a new `Engine`
#[inline(always)] #[inline(always)]
@ -628,6 +589,9 @@ impl Engine {
custom_keywords: None, custom_keywords: None,
custom_syntax: None, custom_syntax: None,
// variable resolver
resolve_var: None,
// default print/debug implementations // default print/debug implementations
print: Box::new(default_print), print: Box::new(default_print),
debug: Box::new(default_print), debug: Box::new(default_print),
@ -678,6 +642,8 @@ impl Engine {
custom_keywords: None, custom_keywords: None,
custom_syntax: None, custom_syntax: None,
resolve_var: None,
print: Box::new(|_| {}), print: Box::new(|_| {}),
debug: Box::new(|_| {}), debug: Box::new(|_| {}),
progress: None, progress: None,
@ -702,6 +668,111 @@ impl Engine {
} }
} }
/// Search for a variable within the scope or within imports,
/// depending on whether the variable name is qualified.
pub(crate) fn search_namespace<'s, 'a>(
&self,
scope: &'s mut Scope,
mods: &'s mut Imports,
state: &mut State,
lib: &Module,
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &'a Expr,
) -> Result<(Target<'s>, &'a str, ScopeEntryType, Position), Box<EvalAltResult>> {
match expr {
Expr::Variable(v) => match v.as_ref() {
// Qualified variable
((name, pos), Some(modules), hash_var, _) => {
let module = search_imports_mut(mods, state, modules)?;
let target =
module
.get_qualified_var_mut(*hash_var)
.map_err(|err| match *err {
EvalAltResult::ErrorVariableNotFound(_, _) => {
EvalAltResult::ErrorVariableNotFound(
format!("{}{}", modules, name),
*pos,
)
.into()
}
_ => err.fill_position(*pos),
})?;
// Module variables are constant
Ok((target.into(), name, ScopeEntryType::Constant, *pos))
}
// Normal variable access
_ => self.search_scope_only(scope, mods, state, lib, this_ptr, expr),
},
_ => unreachable!(),
}
}
/// Search for a variable within the scope
pub(crate) fn search_scope_only<'s, 'a>(
&self,
scope: &'s mut Scope,
mods: &mut Imports,
state: &mut State,
lib: &Module,
this_ptr: &'s mut Option<&mut Dynamic>,
expr: &'a Expr,
) -> Result<(Target<'s>, &'a str, ScopeEntryType, Position), Box<EvalAltResult>> {
let ((name, pos), _, _, index) = match expr {
Expr::Variable(v) => v.as_ref(),
_ => unreachable!(),
};
// Check if the variable is `this`
if name == KEYWORD_THIS {
if let Some(val) = this_ptr {
return Ok(((*val).into(), KEYWORD_THIS, ScopeEntryType::Normal, *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 context = EvalContext {
engine: self,
mods,
state,
lib,
this_ptr,
level: 0,
};
if let Some(result) = resolve_var(name, index.map_or(0, |v| v.get()), scope, &context)
.map_err(|err| err.fill_position(*pos))?
{
return Ok((result.into(), name, ScopeEntryType::Constant, *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.into(), *pos))?
.0
};
let (val, typ) = scope.get_mut(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(), name, typ, *pos))
}
/// Chain-evaluate a dot/index chain. /// Chain-evaluate a dot/index chain.
/// Position in `EvalAltResult` is `None` and must be set afterwards. /// Position in `EvalAltResult` is `None` and must be set afterwards.
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))] #[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
@ -750,7 +821,7 @@ impl Engine {
state, lib, this_ptr, obj_ptr, expr, idx_values, next_chain, level, state, lib, this_ptr, obj_ptr, expr, idx_values, next_chain, level,
new_val, new_val,
) )
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
// xxx[rhs] = new_val // xxx[rhs] = new_val
_ if new_val.is_some() => { _ if new_val.is_some() => {
@ -800,7 +871,7 @@ impl Engine {
// xxx[rhs] // xxx[rhs]
_ => self _ => self
.get_indexed_mut(state, lib, target, idx_val, pos, false, true, level) .get_indexed_mut(state, lib, target, idx_val, pos, false, true, level)
.map(|v| (v.clone_into_dynamic(), false)), .map(|v| (v.take_or_clone(), false)),
} }
} }
@ -815,7 +886,7 @@ impl Engine {
state, lib, name, *hash, target, idx_val, &def_val, *native, false, state, lib, name, *hash, target, idx_val, &def_val, *native, false,
level, level,
) )
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
// xxx.module::fn_name(...) - syntax error // xxx.module::fn_name(...) - syntax error
Expr::FnCall(_) => unreachable!(), Expr::FnCall(_) => unreachable!(),
@ -837,7 +908,7 @@ impl Engine {
state, lib, target, index, *pos, false, false, level, state, lib, target, index, *pos, false, false, level,
)?; )?;
Ok((val.clone_into_dynamic(), false)) Ok((val.take_or_clone(), false))
} }
// xxx.id = ??? // xxx.id = ???
Expr::Property(x) if new_val.is_some() => { Expr::Property(x) if new_val.is_some() => {
@ -849,7 +920,7 @@ impl Engine {
level, level,
) )
.map(|(v, _)| (v, true)) .map(|(v, _)| (v, true))
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
// xxx.id // xxx.id
Expr::Property(x) => { Expr::Property(x) => {
@ -860,7 +931,7 @@ impl Engine {
level, level,
) )
.map(|(v, _)| (v, false)) .map(|(v, _)| (v, false))
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
// {xxx:map}.sub_lhs[expr] | {xxx:map}.sub_lhs.expr // {xxx:map}.sub_lhs[expr] | {xxx:map}.sub_lhs.expr
Expr::Index(x) | Expr::Dot(x) if target.is::<Map>() => { Expr::Index(x) | Expr::Dot(x) if target.is::<Map>() => {
@ -883,7 +954,7 @@ impl Engine {
state, lib, name, *hash, target, idx_val, &def_val, state, lib, name, *hash, target, idx_val, &def_val,
*native, false, level, *native, false, level,
) )
.map_err(|err| err.new_position(*pos))?; .map_err(|err| err.fill_position(*pos))?;
val.into() val.into()
} }
// {xxx:map}.module::fn_name(...) - syntax error // {xxx:map}.module::fn_name(...) - syntax error
@ -896,7 +967,7 @@ impl Engine {
state, lib, this_ptr, &mut val, expr, idx_values, next_chain, level, state, lib, this_ptr, &mut val, expr, idx_values, next_chain, level,
new_val, new_val,
) )
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
// xxx.sub_lhs[expr] | xxx.sub_lhs.expr // xxx.sub_lhs[expr] | xxx.sub_lhs.expr
Expr::Index(x) | Expr::Dot(x) => { Expr::Index(x) | Expr::Dot(x) => {
@ -913,7 +984,7 @@ impl Engine {
state, lib, getter, 0, args, is_ref, true, false, None, state, lib, getter, 0, args, is_ref, true, false, None,
&None, level, &None, level,
) )
.map_err(|err| err.new_position(*pos))?; .map_err(|err| err.fill_position(*pos))?;
let val = &mut val; let val = &mut val;
@ -929,7 +1000,7 @@ impl Engine {
level, level,
new_val, new_val,
) )
.map_err(|err| err.new_position(*pos))?; .map_err(|err| err.fill_position(*pos))?;
// Feed the value back via a setter just in case it has been updated // Feed the value back via a setter just in case it has been updated
if updated || may_be_changed { if updated || may_be_changed {
@ -945,7 +1016,7 @@ impl Engine {
EvalAltResult::ErrorDotExpr(_, _) => { EvalAltResult::ErrorDotExpr(_, _) => {
Ok(Default::default()) Ok(Default::default())
} }
_ => Err(err.new_position(*pos)), _ => Err(err.fill_position(*pos)),
}, },
)?; )?;
} }
@ -961,7 +1032,7 @@ impl Engine {
state, lib, name, *hash, target, idx_val, &def_val, state, lib, name, *hash, target, idx_val, &def_val,
*native, false, level, *native, false, level,
) )
.map_err(|err| err.new_position(*pos))?; .map_err(|err| err.fill_position(*pos))?;
let val = &mut val; let val = &mut val;
let target = &mut val.into(); let target = &mut val.into();
@ -969,7 +1040,7 @@ impl Engine {
state, lib, this_ptr, target, expr, idx_values, next_chain, state, lib, this_ptr, target, expr, idx_values, next_chain,
level, new_val, level, new_val,
) )
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
// xxx.module::fn_name(...) - syntax error // xxx.module::fn_name(...) - syntax error
Expr::FnCall(_) => unreachable!(), Expr::FnCall(_) => unreachable!(),
@ -1017,10 +1088,10 @@ impl Engine {
let (var_name, var_pos) = &x.0; let (var_name, var_pos) = &x.0;
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(*var_pos))?; .map_err(|err| err.fill_position(*var_pos))?;
let (target, _, typ, pos) = let (target, _, typ, pos) =
search_namespace(scope, mods, state, this_ptr, dot_lhs)?; self.search_namespace(scope, mods, state, lib, this_ptr, dot_lhs)?;
// Constants cannot be modified // Constants cannot be modified
match typ { match typ {
@ -1036,7 +1107,7 @@ impl Engine {
state, lib, &mut None, obj_ptr, dot_rhs, idx_values, chain_type, level, new_val, state, lib, &mut None, obj_ptr, dot_rhs, idx_values, chain_type, level, new_val,
) )
.map(|(v, _)| v) .map(|(v, _)| v)
.map_err(|err| err.new_position(*op_pos)) .map_err(|err| err.fill_position(*op_pos))
} }
// {expr}.??? = ??? or {expr}[???] = ??? // {expr}.??? = ??? or {expr}[???] = ???
expr if new_val.is_some() => { expr if new_val.is_some() => {
@ -1050,7 +1121,7 @@ impl Engine {
state, lib, this_ptr, obj_ptr, dot_rhs, idx_values, chain_type, level, new_val, state, lib, this_ptr, obj_ptr, dot_rhs, idx_values, chain_type, level, new_val,
) )
.map(|(v, _)| v) .map(|(v, _)| v)
.map_err(|err| err.new_position(*op_pos)) .map_err(|err| err.fill_position(*op_pos))
} }
} }
} }
@ -1075,7 +1146,7 @@ impl Engine {
level: usize, level: usize,
) -> Result<(), Box<EvalAltResult>> { ) -> Result<(), Box<EvalAltResult>> {
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(expr.position()))?; .map_err(|err| err.fill_position(expr.position()))?;
match expr { match expr {
Expr::FnCall(x) if x.1.is_none() => { Expr::FnCall(x) if x.1.is_none() => {
@ -1248,7 +1319,7 @@ impl Engine {
level: usize, level: usize,
) -> Result<Dynamic, Box<EvalAltResult>> { ) -> Result<Dynamic, Box<EvalAltResult>> {
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(rhs.position()))?; .map_err(|err| err.fill_position(rhs.position()))?;
let lhs_value = self.eval_expr(scope, mods, state, lib, this_ptr, lhs, level)?; let lhs_value = self.eval_expr(scope, mods, state, lib, this_ptr, lhs, level)?;
let rhs_value = self.eval_expr(scope, mods, state, lib, this_ptr, rhs, level)?; let rhs_value = self.eval_expr(scope, mods, state, lib, this_ptr, rhs, level)?;
@ -1270,7 +1341,7 @@ impl Engine {
if self if self
.call_native_fn(state, lib, op, hash, args, false, false, &def_value) .call_native_fn(state, lib, op, hash, args, false, false, &def_value)
.map_err(|err| err.new_position(rhs.position()))? .map_err(|err| err.fill_position(rhs.position()))?
.0 .0
.as_bool() .as_bool()
.unwrap_or(false) .unwrap_or(false)
@ -1310,7 +1381,7 @@ impl Engine {
level: usize, level: usize,
) -> Result<Dynamic, Box<EvalAltResult>> { ) -> Result<Dynamic, Box<EvalAltResult>> {
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(expr.position()))?; .map_err(|err| err.fill_position(expr.position()))?;
let result = match expr { let result = match expr {
Expr::Expr(x) => self.eval_expr(scope, mods, state, lib, this_ptr, x.as_ref(), level), Expr::Expr(x) => self.eval_expr(scope, mods, state, lib, this_ptr, x.as_ref(), level),
@ -1329,8 +1400,9 @@ impl Engine {
} }
} }
Expr::Variable(_) => { Expr::Variable(_) => {
let (val, _, _, _) = search_namespace(scope, mods, state, this_ptr, expr)?; let (val, _, _, _) =
Ok(val.clone()) self.search_namespace(scope, mods, state, lib, this_ptr, expr)?;
Ok(val.take_or_clone())
} }
Expr::Property(_) => unreachable!(), Expr::Property(_) => unreachable!(),
@ -1340,12 +1412,18 @@ impl Engine {
// var op= rhs // var op= rhs
Expr::Assignment(x) if matches!(x.0, Expr::Variable(_)) => { Expr::Assignment(x) if matches!(x.0, Expr::Variable(_)) => {
let (lhs_expr, op, rhs_expr, op_pos) = x.as_ref(); let (lhs_expr, op, rhs_expr, op_pos) = x.as_ref();
let mut rhs_val = let mut rhs_val = self
self.eval_expr(scope, mods, state, lib, this_ptr, rhs_expr, level)?; .eval_expr(scope, mods, state, lib, this_ptr, rhs_expr, level)?
let (lhs_ptr, name, typ, pos) = .flatten();
search_namespace(scope, mods, state, this_ptr, lhs_expr)?; let (mut lhs_ptr, name, typ, pos) =
self.search_namespace(scope, mods, state, lib, this_ptr, lhs_expr)?;
if !lhs_ptr.is_ref() {
return EvalAltResult::ErrorAssignmentToConstant(name.to_string(), pos).into();
}
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(pos))?; .map_err(|err| err.fill_position(pos))?;
match typ { match typ {
// Assignment to constant variable // Assignment to constant variable
@ -1354,11 +1432,10 @@ impl Engine {
)), )),
// Normal assignment // Normal assignment
ScopeEntryType::Normal if op.is_empty() => { ScopeEntryType::Normal if op.is_empty() => {
let value = rhs_val.flatten();
if cfg!(not(feature = "no_closure")) && lhs_ptr.is_shared() { if cfg!(not(feature = "no_closure")) && lhs_ptr.is_shared() {
*lhs_ptr.write_lock::<Dynamic>().unwrap() = value; *lhs_ptr.as_mut().write_lock::<Dynamic>().unwrap() = rhs_val;
} else { } else {
*lhs_ptr = value; *lhs_ptr.as_mut() = rhs_val;
} }
Ok(Default::default()) Ok(Default::default())
} }
@ -1369,7 +1446,8 @@ impl Engine {
// 3) Map to `var = var op rhs` // 3) Map to `var = var op rhs`
// Qualifiers (none) + function name + number of arguments + argument `TypeId`'s. // Qualifiers (none) + function name + number of arguments + argument `TypeId`'s.
let arg_types = once(lhs_ptr.type_id()).chain(once(rhs_val.type_id())); let arg_types =
once(lhs_ptr.as_mut().type_id()).chain(once(rhs_val.type_id()));
let hash_fn = calc_fn_hash(empty(), op, 2, arg_types); let hash_fn = calc_fn_hash(empty(), op, 2, arg_types);
match self match self
@ -1383,10 +1461,10 @@ impl Engine {
let lhs_ptr_inner; let lhs_ptr_inner;
if cfg!(not(feature = "no_closure")) && lhs_ptr.is_shared() { if cfg!(not(feature = "no_closure")) && lhs_ptr.is_shared() {
lock_guard = lhs_ptr.write_lock::<Dynamic>().unwrap(); lock_guard = lhs_ptr.as_mut().write_lock::<Dynamic>().unwrap();
lhs_ptr_inner = lock_guard.deref_mut(); lhs_ptr_inner = lock_guard.deref_mut();
} else { } else {
lhs_ptr_inner = lhs_ptr; lhs_ptr_inner = lhs_ptr.as_mut();
} }
let args = &mut [lhs_ptr_inner, &mut rhs_val]; let args = &mut [lhs_ptr_inner, &mut rhs_val];
@ -1399,13 +1477,14 @@ impl Engine {
} }
} }
// Built-in op-assignment function // Built-in op-assignment function
_ if run_builtin_op_assignment(op, lhs_ptr, &rhs_val)?.is_some() => {} _ if run_builtin_op_assignment(op, lhs_ptr.as_mut(), &rhs_val)?
.is_some() => {}
// Not built-in: expand to `var = var op rhs` // Not built-in: expand to `var = var op rhs`
_ => { _ => {
let op = &op[..op.len() - 1]; // extract operator without = let op = &op[..op.len() - 1]; // extract operator without =
// Clone the LHS value // Clone the LHS value
let args = &mut [&mut lhs_ptr.clone(), &mut rhs_val]; let args = &mut [&mut lhs_ptr.as_mut().clone(), &mut rhs_val];
// Run function // Run function
let (value, _) = self let (value, _) = self
@ -1413,14 +1492,14 @@ impl Engine {
state, lib, op, 0, args, false, false, false, None, &None, state, lib, op, 0, args, false, false, false, None, &None,
level, level,
) )
.map_err(|err| err.new_position(*op_pos))?; .map_err(|err| err.fill_position(*op_pos))?;
let value = value.flatten(); let value = value.flatten();
if cfg!(not(feature = "no_closure")) && lhs_ptr.is_shared() { if cfg!(not(feature = "no_closure")) && lhs_ptr.is_shared() {
*lhs_ptr.write_lock::<Dynamic>().unwrap() = value; *lhs_ptr.as_mut().write_lock::<Dynamic>().unwrap() = value;
} else { } else {
*lhs_ptr = value; *lhs_ptr.as_mut() = value;
} }
} }
} }
@ -1451,7 +1530,7 @@ impl Engine {
state, lib, op, 0, args, false, false, false, None, &None, level, state, lib, op, 0, args, false, false, false, None, &None, level,
) )
.map(|(v, _)| v) .map(|(v, _)| v)
.map_err(|err| err.new_position(*op_pos))?; .map_err(|err| err.fill_position(*op_pos))?;
Some((result, rhs_expr.position())) Some((result, rhs_expr.position()))
}; };
@ -1520,7 +1599,7 @@ impl Engine {
scope, mods, state, lib, this_ptr, name, args_expr, &def_val, *hash, *native, scope, mods, state, lib, this_ptr, name, args_expr, &def_val, *hash, *native,
false, *capture, level, false, *capture, level,
) )
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
// Module-qualified function call // Module-qualified function call
@ -1530,7 +1609,7 @@ impl Engine {
scope, mods, state, lib, this_ptr, modules, name, args_expr, *def_val, *hash, scope, mods, state, lib, this_ptr, modules, name, args_expr, *def_val, *hash,
*capture, level, *capture, level,
) )
.map_err(|err| err.new_position(*pos)) .map_err(|err| err.fill_position(*pos))
} }
Expr::In(x) => self.eval_in_expr(scope, mods, state, lib, this_ptr, &x.0, &x.1, level), Expr::In(x) => self.eval_in_expr(scope, mods, state, lib, this_ptr, &x.0, &x.1, level),
@ -1571,20 +1650,21 @@ impl Engine {
let func = (x.0).1.as_ref(); let func = (x.0).1.as_ref();
let ep = (x.0).0.iter().map(|e| e.into()).collect::<StaticVec<_>>(); let ep = (x.0).0.iter().map(|e| e.into()).collect::<StaticVec<_>>();
let mut context = EvalContext { let mut context = EvalContext {
engine: self,
mods, mods,
state, state,
lib, lib,
this_ptr, this_ptr,
level, level,
}; };
func(self, &mut context, scope, ep.as_ref()) func(scope, &mut context, ep.as_ref())
} }
_ => unreachable!(), _ => unreachable!(),
}; };
self.check_data_size(result) self.check_data_size(result)
.map_err(|err| err.new_position(expr.position())) .map_err(|err| err.fill_position(expr.position()))
} }
/// Evaluate a statement /// Evaluate a statement
@ -1605,7 +1685,7 @@ impl Engine {
level: usize, level: usize,
) -> Result<Dynamic, Box<EvalAltResult>> { ) -> Result<Dynamic, Box<EvalAltResult>> {
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(stmt.position()))?; .map_err(|err| err.fill_position(stmt.position()))?;
let result = match stmt { let result = match stmt {
// No-op // No-op
@ -1720,7 +1800,7 @@ impl Engine {
} }
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(stmt.position()))?; .map_err(|err| err.fill_position(stmt.position()))?;
match self.eval_stmt(scope, mods, state, lib, this_ptr, stmt, level) { match self.eval_stmt(scope, mods, state, lib, this_ptr, stmt, level) {
Ok(_) => (), Ok(_) => (),
@ -1872,7 +1952,7 @@ impl Engine {
}; };
self.check_data_size(result) self.check_data_size(result)
.map_err(|err| err.new_position(stmt.position())) .map_err(|err| err.fill_position(stmt.position()))
} }
/// Check a result to ensure that the data size is within allowable limit. /// Check a result to ensure that the data size is within allowable limit.

84
src/fn_call.rs
View File

@ -2,9 +2,9 @@
use crate::any::Dynamic; use crate::any::Dynamic;
use crate::engine::{ use crate::engine::{
search_imports, search_namespace, search_scope_only, Engine, Imports, State, KEYWORD_DEBUG, search_imports, Engine, Imports, State, KEYWORD_DEBUG, KEYWORD_EVAL, KEYWORD_FN_PTR,
KEYWORD_EVAL, KEYWORD_FN_PTR, KEYWORD_FN_PTR_CALL, KEYWORD_FN_PTR_CURRY, KEYWORD_IS_DEF_FN, KEYWORD_FN_PTR_CALL, KEYWORD_FN_PTR_CURRY, KEYWORD_IS_DEF_FN, KEYWORD_IS_DEF_VAR,
KEYWORD_IS_DEF_VAR, KEYWORD_PRINT, KEYWORD_TYPE_OF, KEYWORD_PRINT, KEYWORD_TYPE_OF,
}; };
use crate::error::ParseErrorType; use crate::error::ParseErrorType;
use crate::fn_native::{FnCallArgs, FnPtr}; use crate::fn_native::{FnCallArgs, FnPtr};
@ -861,7 +861,7 @@ impl Engine {
}) })
.and_then(|s| FnPtr::try_from(s)) .and_then(|s| FnPtr::try_from(s))
.map(Into::<Dynamic>::into) .map(Into::<Dynamic>::into)
.map_err(|err| err.new_position(expr.position())); .map_err(|err| err.fill_position(expr.position()));
} }
} }
@ -1000,7 +1000,7 @@ impl Engine {
})?; })?;
let result = if !script.is_empty() { let result = if !script.is_empty() {
self.eval_script_expr(scope, mods, state, lib, script, level + 1) self.eval_script_expr(scope, mods, state, lib, script, level + 1)
.map_err(|err| err.new_position(expr.position())) .map_err(|err| err.fill_position(expr.position()))
} else { } else {
Ok(().into()) Ok(().into())
}; };
@ -1040,18 +1040,21 @@ impl Engine {
.map(|expr| self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)) .map(|expr| self.eval_expr(scope, mods, state, lib, this_ptr, expr, level))
.collect::<Result<_, _>>()?; .collect::<Result<_, _>>()?;
let (target, _, _, pos) = search_namespace(scope, mods, state, this_ptr, lhs)?; let (target, _, _, pos) =
self.search_namespace(scope, mods, state, lib, this_ptr, lhs)?;
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(pos))?; .map_err(|err| err.fill_position(pos))?;
args = if target.is_shared() { args = if target.is_shared() || target.is_value() {
arg_values.insert(0, target.flatten_clone()); arg_values.insert(0, target.take_or_clone().flatten());
arg_values.iter_mut().collect() arg_values.iter_mut().collect()
} else { } else {
// Turn it into a method call only if the object is not shared // Turn it into a method call only if the object is not shared and not a simple value
is_ref = true; is_ref = true;
once(target).chain(arg_values.iter_mut()).collect() once(target.take_ref().unwrap())
.chain(arg_values.iter_mut())
.collect()
}; };
} }
// func(..., ...) // func(..., ...)
@ -1121,16 +1124,23 @@ impl Engine {
.collect::<Result<_, _>>()?; .collect::<Result<_, _>>()?;
// Get target reference to first argument // Get target reference to first argument
let var_expr = args_expr.get(0).unwrap();
let (target, _, _, pos) = let (target, _, _, pos) =
search_scope_only(scope, state, this_ptr, args_expr.get(0).unwrap())?; self.search_scope_only(scope, mods, state, lib, this_ptr, var_expr)?;
self.inc_operations(state) self.inc_operations(state)
.map_err(|err| err.new_position(pos))?; .map_err(|err| err.fill_position(pos))?;
if target.is_shared() || target.is_value() {
arg_values[0] = target.take_or_clone().flatten();
args = arg_values.iter_mut().collect();
} else {
let (first, rest) = arg_values.split_first_mut().unwrap(); let (first, rest) = arg_values.split_first_mut().unwrap();
first_arg_value = Some(first); first_arg_value = Some(first);
args = once(target.take_ref().unwrap())
args = once(target).chain(rest.iter_mut()).collect(); .chain(rest.iter_mut())
.collect();
}
} }
// func(..., ...) or func(mod::x, ...) // func(..., ...) or func(mod::x, ...)
_ => { _ => {
@ -1239,8 +1249,28 @@ pub fn run_builtin_binary_op(
use crate::packages::arithmetic::arith_basic::INT::functions::*; use crate::packages::arithmetic::arith_basic::INT::functions::*;
let args_type = x.type_id(); let args_type = x.type_id();
let second_type = y.type_id();
if y.type_id() != args_type { if second_type != args_type {
if args_type == TypeId::of::<char>() && second_type == TypeId::of::<ImmutableString>() {
let x = x.clone().cast::<char>();
let y = &*y.read_lock::<ImmutableString>().unwrap();
match op {
"+" => return Ok(Some(format!("{}{}", x, y).into())),
_ => (),
}
} else if args_type == TypeId::of::<ImmutableString>()
&& second_type == TypeId::of::<char>()
{
let x = &*x.read_lock::<ImmutableString>().unwrap();
let y = y.clone().cast::<char>();
match op {
"+" => return Ok(Some((x + y).into())),
_ => (),
}
}
return Ok(None); return Ok(None);
} }
@ -1317,6 +1347,7 @@ pub fn run_builtin_binary_op(
let y = y.clone().cast::<char>(); let y = y.clone().cast::<char>();
match op { match op {
"+" => return Ok(Some(format!("{}{}", x, y).into())),
"==" => return Ok(Some((x == y).into())), "==" => return Ok(Some((x == y).into())),
"!=" => return Ok(Some((x != y).into())), "!=" => return Ok(Some((x != y).into())),
">" => return Ok(Some((x > y).into())), ">" => return Ok(Some((x > y).into())),
@ -1367,8 +1398,19 @@ pub fn run_builtin_op_assignment(
use crate::packages::arithmetic::arith_basic::INT::functions::*; use crate::packages::arithmetic::arith_basic::INT::functions::*;
let args_type = x.type_id(); let args_type = x.type_id();
let second_type = y.type_id();
if second_type != args_type {
if args_type == TypeId::of::<ImmutableString>() && second_type == TypeId::of::<char>() {
let y = y.read_lock::<char>().unwrap().deref().clone();
let mut x = x.write_lock::<ImmutableString>().unwrap();
match op {
"+=" => return Ok(Some(*x += y)),
_ => (),
}
}
if y.type_id() != args_type {
return Ok(None); return Ok(None);
} }
@ -1417,6 +1459,14 @@ pub fn run_builtin_op_assignment(
"|=" => return Ok(Some(*x = *x || y)), "|=" => return Ok(Some(*x = *x || y)),
_ => (), _ => (),
} }
} else if args_type == TypeId::of::<char>() {
let y = y.read_lock::<char>().unwrap().deref().clone();
let mut x = x.write_lock::<Dynamic>().unwrap();
match op {
"+=" => return Ok(Some(*x = format!("{}{}", *x, y).into())),
_ => (),
}
} else if args_type == TypeId::of::<ImmutableString>() { } else if args_type == TypeId::of::<ImmutableString>() {
let y = y.read_lock::<ImmutableString>().unwrap().deref().clone(); let y = y.read_lock::<ImmutableString>().unwrap().deref().clone();
let mut x = x.write_lock::<ImmutableString>().unwrap(); let mut x = x.write_lock::<ImmutableString>().unwrap();

18
src/fn_native.rs
View File

@ -1,11 +1,12 @@
//! Module defining interfaces to native-Rust functions. //! Module defining interfaces to native-Rust functions.
use crate::any::Dynamic; use crate::any::Dynamic;
use crate::engine::Engine; use crate::engine::{Engine, EvalContext};
use crate::module::Module; use crate::module::Module;
use crate::parser::{FnAccess, ScriptFnDef}; use crate::parser::{FnAccess, ScriptFnDef};
use crate::plugin::PluginFunction; use crate::plugin::PluginFunction;
use crate::result::EvalAltResult; use crate::result::EvalAltResult;
use crate::scope::Scope;
use crate::token::{is_valid_identifier, Position}; use crate::token::{is_valid_identifier, Position};
use crate::utils::ImmutableString; use crate::utils::ImmutableString;
@ -220,6 +221,21 @@ pub type Callback<T, R> = Box<dyn Fn(&T) -> R + 'static>;
#[cfg(feature = "sync")] #[cfg(feature = "sync")]
pub type Callback<T, R> = Box<dyn Fn(&T) -> R + Send + Sync + 'static>; pub type Callback<T, R> = Box<dyn Fn(&T) -> R + Send + Sync + 'static>;
/// A standard callback function.
#[cfg(not(feature = "sync"))]
pub type OnVarCallback = Box<
dyn Fn(&str, usize, &Scope, &EvalContext) -> Result<Option<Dynamic>, Box<EvalAltResult>>
+ 'static,
>;
/// A standard callback function.
#[cfg(feature = "sync")]
pub type OnVarCallback = Box<
dyn Fn(&str, usize, &Scope, &EvalContext) -> Result<Option<Dynamic>, Box<EvalAltResult>>
+ Send
+ Sync
+ 'static,
>;
/// A type encapsulating a function callable by Rhai. /// A type encapsulating a function callable by Rhai.
#[derive(Clone)] #[derive(Clone)]
pub enum CallableFunction { pub enum CallableFunction {

4
src/lib.rs
View File

@ -83,7 +83,7 @@ mod r#unsafe;
mod utils; mod utils;
pub use any::Dynamic; pub use any::Dynamic;
pub use engine::Engine; pub use engine::{Engine, EvalContext};
pub use error::{ParseError, ParseErrorType}; pub use error::{ParseError, ParseErrorType};
pub use fn_native::{FnPtr, IteratorFn}; pub use fn_native::{FnPtr, IteratorFn};
pub use fn_register::{RegisterFn, RegisterResultFn}; pub use fn_register::{RegisterFn, RegisterResultFn};
@ -91,7 +91,7 @@ pub use module::Module;
pub use parser::{ImmutableString, AST, INT}; pub use parser::{ImmutableString, AST, INT};
pub use result::EvalAltResult; pub use result::EvalAltResult;
pub use scope::Scope; pub use scope::Scope;
pub use syntax::{EvalContext, Expression}; pub use syntax::Expression;
pub use token::Position; pub use token::Position;
#[cfg(feature = "internals")] #[cfg(feature = "internals")]

5
src/module/mod.rs
View File

@ -1430,11 +1430,12 @@ impl Module {
) )
.map_err(|err| { .map_err(|err| {
// Wrap the error in a module-error // Wrap the error in a module-error
Box::new(EvalAltResult::ErrorInModule( EvalAltResult::ErrorInModule(
"".to_string(), "".to_string(),
err, err,
Position::none(), Position::none(),
)) )
.into()
}) })
}, },
); );

11
src/packages/string_more.rs
View File

@ -43,7 +43,7 @@ macro_rules! reg_functions {
} }
def_package!(crate:MoreStringPackage:"Additional string utilities, including string building.", lib, { def_package!(crate:MoreStringPackage:"Additional string utilities, including string building.", lib, {
reg_functions!(lib += basic; INT, bool, char, FnPtr); reg_functions!(lib += basic; INT, bool, FnPtr);
#[cfg(not(feature = "only_i32"))] #[cfg(not(feature = "only_i32"))]
#[cfg(not(feature = "only_i64"))] #[cfg(not(feature = "only_i64"))]
@ -139,15 +139,6 @@ mod string_functions {
s s
} }
#[rhai_fn(name = "+=")]
pub fn append_char(s: &mut ImmutableString, ch: char) {
*s += ch;
}
#[rhai_fn(name = "+=")]
pub fn append_string(s: &mut ImmutableString, add: ImmutableString) {
*s += &add;
}
#[rhai_fn(name = "len", get = "len")] #[rhai_fn(name = "len", get = "len")]
pub fn len(s: &str) -> INT { pub fn len(s: &str) -> INT {
s.chars().count() as INT s.chars().count() as INT

2
src/result.rs
View File

@ -339,7 +339,7 @@ impl EvalAltResult {
/// Consume the current `EvalAltResult` and return a new one with the specified `Position` /// Consume the current `EvalAltResult` and return a new one with the specified `Position`
/// if the current position is `Position::None`. /// if the current position is `Position::None`.
#[inline(always)] #[inline(always)]
pub(crate) fn new_position(mut self: Box<Self>, new_position: Position) -> Box<Self> { pub(crate) fn fill_position(mut self: Box<Self>, new_position: Position) -> Box<Self> {
if self.position().is_none() { if self.position().is_none() {
self.set_position(new_position); self.set_position(new_position);
} }

86
src/syntax.rs
View File

@ -1,10 +1,9 @@
//! Module implementing custom syntax for `Engine`. //! Module implementing custom syntax for `Engine`.
use crate::any::Dynamic; use crate::any::Dynamic;
use crate::engine::{Engine, Imports, State, MARKER_BLOCK, MARKER_EXPR, MARKER_IDENT}; use crate::engine::{Engine, EvalContext, MARKER_BLOCK, MARKER_EXPR, MARKER_IDENT};
use crate::error::{LexError, ParseError}; use crate::error::{LexError, ParseError};
use crate::fn_native::{SendSync, Shared}; use crate::fn_native::{SendSync, Shared};
use crate::module::Module;
use crate::parser::Expr; use crate::parser::Expr;
use crate::result::EvalAltResult; use crate::result::EvalAltResult;
use crate::scope::Scope; use crate::scope::Scope;
@ -19,15 +18,11 @@ use crate::stdlib::{
/// A general expression evaluation trait object. /// A general expression evaluation trait object.
#[cfg(not(feature = "sync"))] #[cfg(not(feature = "sync"))]
pub type FnCustomSyntaxEval = dyn Fn( pub type FnCustomSyntaxEval =
&Engine, dyn Fn(&mut Scope, &mut EvalContext, &[Expression]) -> Result<Dynamic, Box<EvalAltResult>>;
&mut EvalContext,
&mut Scope,
&[Expression],
) -> Result<Dynamic, Box<EvalAltResult>>;
/// A general expression evaluation trait object. /// A general expression evaluation trait object.
#[cfg(feature = "sync")] #[cfg(feature = "sync")]
pub type FnCustomSyntaxEval = dyn Fn(&Engine, &mut EvalContext, &mut Scope, &[Expression]) -> Result<Dynamic, Box<EvalAltResult>> pub type FnCustomSyntaxEval = dyn Fn(&mut Scope, &mut EvalContext, &[Expression]) -> Result<Dynamic, Box<EvalAltResult>>
+ Send + Send
+ Sync; + Sync;
@ -63,6 +58,30 @@ impl Expression<'_> {
} }
} }
impl EvalContext<'_, '_, '_, '_, '_, '_> {
/// Evaluate an expression tree.
///
/// ## WARNING - Low Level API
///
/// This function is very low level. It evaluates an expression from an AST.
#[inline(always)]
pub fn eval_expression_tree(
&mut self,
scope: &mut Scope,
expr: &Expression,
) -> Result<Dynamic, Box<EvalAltResult>> {
self.engine.eval_expr(
scope,
self.mods,
self.state,
self.lib,
self.this_ptr,
expr.expr(),
self.level,
)
}
}
#[derive(Clone)] #[derive(Clone)]
pub struct CustomSyntax { pub struct CustomSyntax {
pub segments: StaticVec<String>, pub segments: StaticVec<String>,
@ -77,27 +96,17 @@ impl fmt::Debug for CustomSyntax {
} }
} }
/// Context of a script evaluation process.
#[derive(Debug)]
pub struct EvalContext<'a, 's, 'm, 't, 'd: 't> {
pub(crate) mods: &'a mut Imports,
pub(crate) state: &'s mut State,
pub(crate) lib: &'m Module,
pub(crate) this_ptr: &'t mut Option<&'d mut Dynamic>,
pub(crate) level: usize,
}
impl Engine { impl Engine {
/// Register a custom syntax with the `Engine`.
///
/// * `keywords` holds a slice of strings that define the custom syntax.
/// * `new_vars` is the number of new variables declared by this custom syntax, or the number of variables removed (if negative).
/// * `func` is the implementation function.
pub fn register_custom_syntax<S: AsRef<str> + ToString>( pub fn register_custom_syntax<S: AsRef<str> + ToString>(
&mut self, &mut self,
keywords: &[S], keywords: &[S],
scope_delta: isize, new_vars: isize,
func: impl Fn( func: impl Fn(&mut Scope, &mut EvalContext, &[Expression]) -> Result<Dynamic, Box<EvalAltResult>>
&Engine,
&mut EvalContext,
&mut Scope,
&[Expression],
) -> Result<Dynamic, Box<EvalAltResult>>
+ SendSync + SendSync
+ 'static, + 'static,
) -> Result<&mut Self, ParseError> { ) -> Result<&mut Self, ParseError> {
@ -176,7 +185,7 @@ impl Engine {
let syntax = CustomSyntax { let syntax = CustomSyntax {
segments, segments,
func: (Box::new(func) as Box<FnCustomSyntaxEval>).into(), func: (Box::new(func) as Box<FnCustomSyntaxEval>).into(),
scope_delta, scope_delta: new_vars,
}; };
if self.custom_syntax.is_none() { if self.custom_syntax.is_none() {
@ -190,27 +199,4 @@ impl Engine {
Ok(self) Ok(self)
} }
/// Evaluate an expression tree.
///
/// ## WARNING - Low Level API
///
/// This function is very low level. It evaluates an expression from an AST.
#[inline(always)]
pub fn eval_expression_tree(
&self,
context: &mut EvalContext,
scope: &mut Scope,
expr: &Expression,
) -> Result<Dynamic, Box<EvalAltResult>> {
self.eval_expr(
scope,
context.mods,
context.state,
context.lib,
context.this_ptr,
expr.expr(),
context.level,
)
}
} }

20
src/token.rs
View File

@ -1205,6 +1205,10 @@ fn get_next_token_inner(
eat_next(stream, pos); eat_next(stream, pos);
return Some((Token::PlusAssign, start_pos)); return Some((Token::PlusAssign, start_pos));
} }
('+', '+') => {
eat_next(stream, pos);
return Some((Token::Reserved("++".into()), start_pos));
}
('+', _) if !state.non_unary => return Some((Token::UnaryPlus, start_pos)), ('+', _) if !state.non_unary => return Some((Token::UnaryPlus, start_pos)),
('+', _) => return Some((Token::Plus, start_pos)), ('+', _) => return Some((Token::Plus, start_pos)),
@ -1218,6 +1222,10 @@ fn get_next_token_inner(
eat_next(stream, pos); eat_next(stream, pos);
return Some((Token::Reserved("->".into()), start_pos)); return Some((Token::Reserved("->".into()), start_pos));
} }
('-', '-') => {
eat_next(stream, pos);
return Some((Token::Reserved("--".into()), start_pos));
}
('-', _) if !state.non_unary => return Some((Token::UnaryMinus, start_pos)), ('-', _) if !state.non_unary => return Some((Token::UnaryMinus, start_pos)),
('-', _) => return Some((Token::Minus, start_pos)), ('-', _) => return Some((Token::Minus, start_pos)),
@ -1282,12 +1290,22 @@ fn get_next_token_inner(
(';', _) => return Some((Token::SemiColon, start_pos)), (';', _) => return Some((Token::SemiColon, start_pos)),
(',', _) => return Some((Token::Comma, start_pos)), (',', _) => return Some((Token::Comma, start_pos)),
('.', '.') => {
eat_next(stream, pos);
if stream.peek_next() == Some('.') {
eat_next(stream, pos);
return Some((Token::Reserved("...".into()), start_pos));
} else {
return Some((Token::Reserved("..".into()), start_pos));
}
}
('.', _) => return Some((Token::Period, start_pos)), ('.', _) => return Some((Token::Period, start_pos)),
('=', '=') => { ('=', '=') => {
eat_next(stream, pos); eat_next(stream, pos);
// Warn against `===`
if stream.peek_next() == Some('=') { if stream.peek_next() == Some('=') {
eat_next(stream, pos); eat_next(stream, pos);
return Some((Token::Reserved("===".into()), start_pos)); return Some((Token::Reserved("===".into()), start_pos));

23
tests/syntax.rs
View File

@ -22,21 +22,28 @@ fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
"do", "|", "$ident$", "|", "->", "$block$", "while", "$expr$", "do", "|", "$ident$", "|", "->", "$block$", "while", "$expr$",
], ],
1, 1,
|engine: &Engine, context: &mut EvalContext, scope: &mut Scope, inputs: &[Expression]| { |scope: &mut Scope, context: &mut EvalContext, inputs: &[Expression]| {
let var_name = inputs[0].get_variable_name().unwrap().to_string(); let var_name = inputs[0].get_variable_name().unwrap().to_string();
let stmt = inputs.get(1).unwrap(); let stmt = inputs.get(1).unwrap();
let expr = inputs.get(2).unwrap(); let condition = inputs.get(2).unwrap();
scope.push(var_name, 0 as INT); scope.push(var_name, 0 as INT);
loop { loop {
engine.eval_expression_tree(context, scope, stmt)?; context.eval_expression_tree(scope, stmt)?;
if !engine let stop = !context
.eval_expression_tree(context, scope, expr)? .eval_expression_tree(scope, condition)?
.as_bool() .as_bool()
.map_err(|err| engine.make_type_mismatch_err::<bool>(err, expr.position()))? .map_err(|err| {
{ Box::new(EvalAltResult::ErrorMismatchDataType(
"bool".to_string(),
err.to_string(),
condition.position(),
))
})?;
if stop {
break; break;
} }
} }
@ -61,7 +68,7 @@ fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
// The first symbol must be an identifier // The first symbol must be an identifier
assert_eq!( assert_eq!(
*engine *engine
.register_custom_syntax(&["!"], 0, |_, _, _, _| Ok(().into())) .register_custom_syntax(&["!"], 0, |_, _, _| Ok(().into()))
.expect_err("should error") .expect_err("should error")
.0, .0,
ParseErrorType::BadInput("Improper symbol for custom syntax: '!'".to_string()) ParseErrorType::BadInput("Improper symbol for custom syntax: '!'".to_string())

2
tests/unary_minus.rs
View File

@ -9,7 +9,7 @@ fn test_unary_minus() -> Result<(), Box<EvalAltResult>> {
#[cfg(not(feature = "no_function"))] #[cfg(not(feature = "no_function"))]
assert_eq!(engine.eval::<INT>("fn neg(x) { -x } neg(5)")?, -5); assert_eq!(engine.eval::<INT>("fn neg(x) { -x } neg(5)")?, -5);
assert_eq!(engine.eval::<INT>("5 - -+++--+-5")?, 0); assert_eq!(engine.eval::<INT>("5 - -+ + + - -+-5")?, 0);
Ok(()) Ok(())
} }

40
tests/var_scope.rs
View File

@ -1,4 +1,4 @@
use rhai::{Engine, EvalAltResult, Scope, INT}; use rhai::{Engine, EvalAltResult, Position, Scope, INT};
#[test] #[test]
fn test_var_scope() -> Result<(), Box<EvalAltResult>> { fn test_var_scope() -> Result<(), Box<EvalAltResult>> {
@ -52,3 +52,41 @@ fn test_scope_eval() -> Result<(), Box<EvalAltResult>> {
Ok(()) Ok(())
} }
#[test]
fn test_var_resolver() -> Result<(), Box<EvalAltResult>> {
let mut engine = Engine::new();
let mut scope = Scope::new();
scope.push("innocent", 1 as INT);
scope.push("chameleon", 123 as INT);
scope.push("DO_NOT_USE", 999 as INT);
engine.on_var(|name, _, scope, _| {
match name {
"MYSTIC_NUMBER" => Ok(Some((42 as INT).into())),
// Override a variable - make it not found even if it exists!
"DO_NOT_USE" => {
Err(EvalAltResult::ErrorVariableNotFound(name.to_string(), Position::none()).into())
}
// Silently maps 'chameleon' into 'innocent'.
"chameleon" => scope.get_value("innocent").map(Some).ok_or_else(|| {
EvalAltResult::ErrorVariableNotFound(name.to_string(), Position::none()).into()
}),
// Return Ok(None) to continue with the normal variable resolution process.
_ => Ok(None),
}
});
assert_eq!(
engine.eval_with_scope::<INT>(&mut scope, "MYSTIC_NUMBER")?,
42
);
assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "chameleon")?, 1);
assert!(
matches!(*engine.eval_with_scope::<INT>(&mut scope, "DO_NOT_USE").expect_err("should error"),
EvalAltResult::ErrorVariableNotFound(n, _) if n == "DO_NOT_USE")
);
Ok(())
}