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rhai/src/api.rs
Stephen Chung 92ba7b42d5 Implement namespaces chain.
2020-10-20 10:54:32 +08:00

1827 lines
59 KiB
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//! Module that defines the extern API of `Engine`.
use crate::any::{Dynamic, Variant};
use crate::engine::{Engine, EvalContext, Imports, State};
use crate::error::ParseError;
use crate::fn_native::{FnCallArgs, NativeCallContext, SendSync};
use crate::optimize::OptimizationLevel;
use crate::parser::AST;
use crate::result::EvalAltResult;
use crate::scope::Scope;
use crate::token::Position;
#[cfg(not(feature = "no_index"))]
use crate::{
engine::{Array, FN_IDX_GET, FN_IDX_SET},
utils::ImmutableString,
};
#[cfg(not(feature = "no_object"))]
use crate::{
engine::{make_getter, make_setter, Map},
error::ParseErrorType,
token::Token,
};
#[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
use crate::fn_register::{RegisterFn, RegisterResultFn};
#[cfg(not(feature = "no_function"))]
use crate::{fn_args::FuncArgs, fn_call::ensure_no_data_race, module::Module, StaticVec};
#[cfg(not(feature = "no_optimize"))]
use crate::optimize::optimize_into_ast;
use crate::stdlib::{
any::{type_name, TypeId},
boxed::Box,
string::String,
};
#[cfg(not(feature = "no_optimize"))]
use crate::stdlib::mem;
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
use crate::stdlib::{fs::File, io::prelude::*, path::PathBuf};
/// Engine public API
impl Engine {
/// Register a function of the `Engine`.
///
/// ## WARNING - Low Level API
///
/// This function is very low level. It takes a list of `TypeId`'s indicating the actual types of the parameters.
///
/// Arguments are simply passed in as a mutable array of `&mut Dynamic`,
/// The arguments are guaranteed to be of the correct types matching the `TypeId`'s.
///
/// To access a primary parameter value (i.e. cloning is cheap), use: `args[n].clone().cast::<T>()`
///
/// To access a parameter value and avoid cloning, use `std::mem::take(args[n]).cast::<T>()`.
/// Notice that this will _consume_ the argument, replacing it with `()`.
///
/// To access the first mutable parameter, use `args.get_mut(0).unwrap()`
#[deprecated(note = "this function is volatile and may change")]
#[inline(always)]
pub fn register_raw_fn<T: Variant + Clone>(
&mut self,
name: &str,
arg_types: &[TypeId],
func: impl Fn(NativeCallContext, &mut FnCallArgs) -> Result<T, Box<EvalAltResult>>
+ SendSync
+ 'static,
) -> &mut Self {
self.global_module.set_raw_fn(name, arg_types, func);
self
}
/// Register a custom type for use with the `Engine`.
/// The type must implement `Clone`.
///
/// # Example
///
/// ```
/// #[derive(Debug, Clone, Eq, PartialEq)]
/// struct TestStruct {
/// field: i64
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { field: 1 } }
/// fn update(&mut self, offset: i64) { self.field += offset; }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Use `register_fn` to register methods on the type.
/// engine.register_fn("update", TestStruct::update);
///
/// assert_eq!(
/// engine.eval::<TestStruct>("let x = new_ts(); x.update(41); x")?,
/// TestStruct { field: 42 }
/// );
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn register_type<T: Variant + Clone>(&mut self) -> &mut Self {
self.register_type_with_name::<T>(type_name::<T>())
}
/// Register a custom type for use with the `Engine`, with a pretty-print name
/// for the `type_of` function. The type must implement `Clone`.
///
/// # Example
///
/// ```
/// #[derive(Clone)]
/// struct TestStruct {
/// field: i64
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { field: 1 } }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// assert_eq!(
/// engine.eval::<String>("let x = new_ts(); type_of(x)")?,
/// "rust_out::TestStruct"
/// );
///
/// // Register the custom type with a name.
/// engine.register_type_with_name::<TestStruct>("Hello");
///
/// // Register methods on the type.
/// engine.register_fn("new_ts", TestStruct::new);
///
/// assert_eq!(
/// engine.eval::<String>("let x = new_ts(); type_of(x)")?,
/// "Hello"
/// );
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn register_type_with_name<T: Variant + Clone>(&mut self, name: &str) -> &mut Self {
if self.type_names.is_none() {
self.type_names = Some(Default::default());
}
// Add the pretty-print type name into the map
self.type_names
.as_mut()
.unwrap()
.insert(type_name::<T>().into(), name.into());
self
}
/// Register an iterator adapter for an iterable type with the `Engine`.
/// This is an advanced feature.
#[inline(always)]
pub fn register_iterator<T>(&mut self) -> &mut Self
where
T: Variant + Clone + Iterator,
<T as Iterator>::Item: Variant + Clone,
{
self.global_module.set_iterable::<T>();
self
}
/// Register a getter function for a member of a registered type with the `Engine`.
///
/// The function signature must start with `&mut self` and not `&self`.
///
/// # Example
///
/// ```
/// #[derive(Clone)]
/// struct TestStruct {
/// field: i64
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { field: 1 } }
/// // Even a getter must start with `&mut self` and not `&self`.
/// fn get_field(&mut self) -> i64 { self.field }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register a getter on a property (notice it doesn't have to be the same name).
/// engine.register_get("xyz", TestStruct::get_field);
///
/// assert_eq!(engine.eval::<i64>("let a = new_ts(); a.xyz")?, 1);
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn register_get<T, U>(
&mut self,
name: &str,
callback: impl Fn(&mut T) -> U + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
{
self.register_fn(&make_getter(name), callback)
}
/// Register a getter function for a member of a registered type with the `Engine`.
/// Returns `Result<Dynamic, Box<EvalAltResult>>`.
///
/// The function signature must start with `&mut self` and not `&self`.
///
/// # Example
///
/// ```
/// use rhai::{Engine, Dynamic, EvalAltResult, RegisterFn};
///
/// #[derive(Clone)]
/// struct TestStruct {
/// field: i64
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { field: 1 } }
/// // Even a getter must start with `&mut self` and not `&self`.
/// fn get_field(&mut self) -> Result<Dynamic, Box<EvalAltResult>> {
/// Ok(self.field.into())
/// }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register a getter on a property (notice it doesn't have to be the same name).
/// engine.register_get_result("xyz", TestStruct::get_field);
///
/// assert_eq!(engine.eval::<i64>("let a = new_ts(); a.xyz")?, 1);
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn register_get_result<T: Variant + Clone>(
&mut self,
name: &str,
callback: impl Fn(&mut T) -> Result<Dynamic, Box<EvalAltResult>> + SendSync + 'static,
) -> &mut Self {
self.register_result_fn(&make_getter(name), callback)
}
/// Register a setter function for a member of a registered type with the `Engine`.
///
/// # Example
///
/// ```
/// #[derive(Debug, Clone, Eq, PartialEq)]
/// struct TestStruct {
/// field: i64
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { field: 1 } }
/// fn set_field(&mut self, new_val: i64) { self.field = new_val; }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register a setter on a property (notice it doesn't have to be the same name)
/// engine.register_set("xyz", TestStruct::set_field);
///
/// // Notice that, with a getter, there is no way to get the property value
/// assert_eq!(
/// engine.eval::<TestStruct>("let a = new_ts(); a.xyz = 42; a")?,
/// TestStruct { field: 42 }
/// );
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn register_set<T, U>(
&mut self,
name: &str,
callback: impl Fn(&mut T, U) + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
{
self.register_fn(&make_setter(name), callback)
}
/// Register a setter function for a member of a registered type with the `Engine`.
/// Returns `Result<(), Box<EvalAltResult>>`.
///
/// # Example
///
/// ```
/// use rhai::{Engine, Dynamic, EvalAltResult, RegisterFn};
///
/// #[derive(Debug, Clone, Eq, PartialEq)]
/// struct TestStruct {
/// field: i64
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { field: 1 } }
/// fn set_field(&mut self, new_val: i64) -> Result<(), Box<EvalAltResult>> {
/// self.field = new_val;
/// Ok(())
/// }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register a setter on a property (notice it doesn't have to be the same name)
/// engine.register_set_result("xyz", TestStruct::set_field);
///
/// // Notice that, with a getter, there is no way to get the property value
/// assert_eq!(
/// engine.eval::<TestStruct>("let a = new_ts(); a.xyz = 42; a")?,
/// TestStruct { field: 42 }
/// );
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn register_set_result<T, U>(
&mut self,
name: &str,
callback: impl Fn(&mut T, U) -> Result<(), Box<EvalAltResult>> + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
{
self.register_result_fn(&make_setter(name), move |obj: &mut T, value: U| {
callback(obj, value).map(Into::into)
})
}
/// Short-hand for registering both getter and setter functions
/// of a registered type with the `Engine`.
///
/// All function signatures must start with `&mut self` and not `&self`.
///
/// # Example
///
/// ```
/// #[derive(Clone)]
/// struct TestStruct {
/// field: i64
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { field: 1 } }
/// // Even a getter must start with `&mut self` and not `&self`.
/// fn get_field(&mut self) -> i64 { self.field }
/// fn set_field(&mut self, new_val: i64) { self.field = new_val; }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register a getter and a setter on a property
/// // (notice it doesn't have to be the same name)
/// engine.register_get_set("xyz", TestStruct::get_field, TestStruct::set_field);
///
/// assert_eq!(engine.eval::<i64>("let a = new_ts(); a.xyz = 42; a.xyz")?, 42);
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn register_get_set<T, U>(
&mut self,
name: &str,
get_fn: impl Fn(&mut T) -> U + SendSync + 'static,
set_fn: impl Fn(&mut T, U) + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
{
self.register_get(name, get_fn).register_set(name, set_fn)
}
/// Register an index getter for a custom type with the `Engine`.
///
/// The function signature must start with `&mut self` and not `&self`.
///
/// # Panics
///
/// Panics if the type is `Array` or `Map`.
/// Indexers for arrays, object maps and strings cannot be registered.
///
/// # Example
///
/// ```
/// #[derive(Clone)]
/// struct TestStruct {
/// fields: Vec<i64>
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { fields: vec![1, 2, 3, 4, 5] } }
/// // Even a getter must start with `&mut self` and not `&self`.
/// fn get_field(&mut self, index: i64) -> i64 { self.fields[index as usize] }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// # #[cfg(not(feature = "no_object"))]
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register an indexer.
/// engine.register_indexer_get(TestStruct::get_field);
///
/// assert_eq!(engine.eval::<i64>("let a = new_ts(); a[2]")?, 3);
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn register_indexer_get<T, X, U>(
&mut self,
callback: impl Fn(&mut T, X) -> U + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
X: Variant + Clone,
{
if TypeId::of::<T>() == TypeId::of::<Array>() {
panic!("Cannot register indexer for arrays.");
}
#[cfg(not(feature = "no_object"))]
if TypeId::of::<T>() == TypeId::of::<Map>() {
panic!("Cannot register indexer for object maps.");
}
if TypeId::of::<T>() == TypeId::of::<String>()
|| TypeId::of::<T>() == TypeId::of::<&str>()
|| TypeId::of::<T>() == TypeId::of::<ImmutableString>()
{
panic!("Cannot register indexer for strings.");
}
self.register_fn(FN_IDX_GET, callback)
}
/// Register an index getter for a custom type with the `Engine`.
/// Returns `Result<Dynamic, Box<EvalAltResult>>`.
///
/// The function signature must start with `&mut self` and not `&self`.
///
/// # Panics
///
/// Panics if the type is `Array` or `Map`.
/// Indexers for arrays, object maps and strings cannot be registered.
///
/// # Example
///
/// ```
/// use rhai::{Engine, Dynamic, EvalAltResult, RegisterFn};
///
/// #[derive(Clone)]
/// struct TestStruct {
/// fields: Vec<i64>
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { fields: vec![1, 2, 3, 4, 5] } }
/// // Even a getter must start with `&mut self` and not `&self`.
/// fn get_field(&mut self, index: i64) -> Result<Dynamic, Box<EvalAltResult>> {
/// Ok(self.fields[index as usize].into())
/// }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// # #[cfg(not(feature = "no_object"))]
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register an indexer.
/// engine.register_indexer_get_result(TestStruct::get_field);
///
/// assert_eq!(engine.eval::<i64>("let a = new_ts(); a[2]")?, 3);
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn register_indexer_get_result<T, X>(
&mut self,
callback: impl Fn(&mut T, X) -> Result<Dynamic, Box<EvalAltResult>> + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
X: Variant + Clone,
{
if TypeId::of::<T>() == TypeId::of::<Array>() {
panic!("Cannot register indexer for arrays.");
}
#[cfg(not(feature = "no_object"))]
if TypeId::of::<T>() == TypeId::of::<Map>() {
panic!("Cannot register indexer for object maps.");
}
if TypeId::of::<T>() == TypeId::of::<String>()
|| TypeId::of::<T>() == TypeId::of::<&str>()
|| TypeId::of::<T>() == TypeId::of::<ImmutableString>()
{
panic!("Cannot register indexer for strings.");
}
self.register_result_fn(FN_IDX_GET, callback)
}
/// Register an index setter for a custom type with the `Engine`.
///
/// # Panics
///
/// Panics if the type is `Array` or `Map`.
/// Indexers for arrays, object maps and strings cannot be registered.
///
/// # Example
///
/// ```
/// #[derive(Clone)]
/// struct TestStruct {
/// fields: Vec<i64>
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { fields: vec![1, 2, 3, 4, 5] } }
/// fn set_field(&mut self, index: i64, value: i64) { self.fields[index as usize] = value; }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// # #[cfg(not(feature = "no_object"))]
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register an indexer.
/// engine.register_indexer_set(TestStruct::set_field);
///
/// assert_eq!(
/// engine.eval::<TestStruct>("let a = new_ts(); a[2] = 42; a")?.fields[2],
/// 42
/// );
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn register_indexer_set<T, X, U>(
&mut self,
callback: impl Fn(&mut T, X, U) + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
X: Variant + Clone,
{
if TypeId::of::<T>() == TypeId::of::<Array>() {
panic!("Cannot register indexer for arrays.");
}
#[cfg(not(feature = "no_object"))]
if TypeId::of::<T>() == TypeId::of::<Map>() {
panic!("Cannot register indexer for object maps.");
}
if TypeId::of::<T>() == TypeId::of::<String>()
|| TypeId::of::<T>() == TypeId::of::<&str>()
|| TypeId::of::<T>() == TypeId::of::<ImmutableString>()
{
panic!("Cannot register indexer for strings.");
}
self.register_fn(FN_IDX_SET, callback)
}
/// Register an index setter for a custom type with the `Engine`.
/// Returns `Result<(), Box<EvalAltResult>>`.
///
/// # Panics
///
/// Panics if the type is `Array` or `Map`.
/// Indexers for arrays, object maps and strings cannot be registered.
///
/// # Example
///
/// ```
/// use rhai::{Engine, Dynamic, EvalAltResult, RegisterFn};
///
/// #[derive(Clone)]
/// struct TestStruct {
/// fields: Vec<i64>
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { fields: vec![1, 2, 3, 4, 5] } }
/// fn set_field(&mut self, index: i64, value: i64) -> Result<(), Box<EvalAltResult>> {
/// self.fields[index as usize] = value;
/// Ok(())
/// }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// # #[cfg(not(feature = "no_object"))]
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register an indexer.
/// engine.register_indexer_set_result(TestStruct::set_field);
///
/// assert_eq!(
/// engine.eval::<TestStruct>("let a = new_ts(); a[2] = 42; a")?.fields[2],
/// 42
/// );
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn register_indexer_set_result<T, X, U>(
&mut self,
callback: impl Fn(&mut T, X, U) -> Result<(), Box<EvalAltResult>> + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
X: Variant + Clone,
{
if TypeId::of::<T>() == TypeId::of::<Array>() {
panic!("Cannot register indexer for arrays.");
}
#[cfg(not(feature = "no_object"))]
if TypeId::of::<T>() == TypeId::of::<Map>() {
panic!("Cannot register indexer for object maps.");
}
if TypeId::of::<T>() == TypeId::of::<String>()
|| TypeId::of::<T>() == TypeId::of::<&str>()
|| TypeId::of::<T>() == TypeId::of::<ImmutableString>()
{
panic!("Cannot register indexer for strings.");
}
self.register_result_fn(FN_IDX_SET, move |obj: &mut T, index: X, value: U| {
callback(obj, index, value).map(Into::into)
})
}
/// Short-hand for register both index getter and setter functions for a custom type with the `Engine`.
///
/// # Panics
///
/// Panics if the type is `Array` or `Map`.
/// Indexers for arrays, object maps and strings cannot be registered.
///
/// # Example
///
/// ```
/// #[derive(Clone)]
/// struct TestStruct {
/// fields: Vec<i64>
/// }
///
/// impl TestStruct {
/// fn new() -> Self { Self { fields: vec![1, 2, 3, 4, 5] } }
/// // Even a getter must start with `&mut self` and not `&self`.
/// fn get_field(&mut self, index: i64) -> i64 { self.fields[index as usize] }
/// fn set_field(&mut self, index: i64, value: i64) { self.fields[index as usize] = value; }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register the custom type.
/// # #[cfg(not(feature = "no_object"))]
/// engine.register_type::<TestStruct>();
///
/// engine.register_fn("new_ts", TestStruct::new);
///
/// // Register an indexer.
/// engine.register_indexer_get_set(TestStruct::get_field, TestStruct::set_field);
///
/// assert_eq!(engine.eval::<i64>("let a = new_ts(); a[2] = 42; a[2]")?, 42);
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn register_indexer_get_set<T, X, U>(
&mut self,
getter: impl Fn(&mut T, X) -> U + SendSync + 'static,
setter: impl Fn(&mut T, X, U) -> () + SendSync + 'static,
) -> &mut Self
where
T: Variant + Clone,
U: Variant + Clone,
X: Variant + Clone,
{
self.register_indexer_get(getter)
.register_indexer_set(setter)
}
/// Compile a string into an `AST`, which can be used later for evaluation.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// // Compile a script to an AST and store it for later evaluation
/// let ast = engine.compile("40 + 2")?;
///
/// for _ in 0..42 {
/// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
/// }
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn compile(&self, script: &str) -> Result<AST, ParseError> {
self.compile_with_scope(&Default::default(), script)
}
/// Compile a string into an `AST` using own scope, which can be used later for evaluation.
///
/// The scope is useful for passing constants into the script for optimization
/// when using `OptimizationLevel::Full`.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # #[cfg(not(feature = "no_optimize"))]
/// # {
/// use rhai::{Engine, Scope, OptimizationLevel};
///
/// let mut engine = Engine::new();
///
/// // Set optimization level to 'Full' so the Engine can fold constants
/// // into function calls and operators.
/// engine.set_optimization_level(OptimizationLevel::Full);
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push_constant("x", 42_i64); // 'x' is a constant
///
/// // Compile a script to an AST and store it for later evaluation.
/// // Notice that `Full` optimization is on, so constants are folded
/// // into function calls and operators.
/// let ast = engine.compile_with_scope(&mut scope,
/// "if x > 40 { x } else { 0 }" // all 'x' are replaced with 42
/// )?;
///
/// // Normally this would have failed because no scope is passed into the 'eval_ast'
/// // call and so the variable 'x' does not exist. Here, it passes because the script
/// // has been optimized and all references to 'x' are already gone.
/// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
/// # }
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn compile_with_scope(&self, scope: &Scope, script: &str) -> Result<AST, ParseError> {
self.compile_scripts_with_scope(scope, &[script])
}
/// When passed a list of strings, first join the strings into one large script,
/// and then compile them into an `AST` using own scope, which can be used later for evaluation.
///
/// The scope is useful for passing constants into the script for optimization
/// when using `OptimizationLevel::Full`.
///
/// ## Note
///
/// All strings are simply parsed one after another with nothing inserted in between, not even
/// a newline or space.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # #[cfg(not(feature = "no_optimize"))]
/// # {
/// use rhai::{Engine, Scope, OptimizationLevel};
///
/// let mut engine = Engine::new();
///
/// // Set optimization level to 'Full' so the Engine can fold constants
/// // into function calls and operators.
/// engine.set_optimization_level(OptimizationLevel::Full);
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push_constant("x", 42_i64); // 'x' is a constant
///
/// // Compile a script made up of script segments to an AST and store it for later evaluation.
/// // Notice that `Full` optimization is on, so constants are folded
/// // into function calls and operators.
/// let ast = engine.compile_scripts_with_scope(&mut scope, &[
/// "if x > 40", // all 'x' are replaced with 42
/// "{ x } el",
/// "se { 0 }" // segments do not need to be valid scripts!
/// ])?;
///
/// // Normally this would have failed because no scope is passed into the 'eval_ast'
/// // call and so the variable 'x' does not exist. Here, it passes because the script
/// // has been optimized and all references to 'x' are already gone.
/// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
/// # }
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn compile_scripts_with_scope(
&self,
scope: &Scope,
scripts: &[&str],
) -> Result<AST, ParseError> {
self.compile_with_scope_and_optimization_level(scope, scripts, self.optimization_level)
}
/// Join a list of strings and compile into an `AST` using own scope at a specific optimization level.
#[inline(always)]
pub(crate) fn compile_with_scope_and_optimization_level(
&self,
scope: &Scope,
scripts: &[&str],
optimization_level: OptimizationLevel,
) -> Result<AST, ParseError> {
let stream = self.lex(scripts, None);
self.parse(&mut stream.peekable(), scope, optimization_level)
}
/// Read the contents of a file into a string.
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
#[inline]
fn read_file(path: PathBuf) -> Result<String, Box<EvalAltResult>> {
let mut f = File::open(path.clone()).map_err(|err| {
EvalAltResult::ErrorSystem(
format!("Cannot open script file '{}'", path.to_string_lossy()),
err.into(),
)
})?;
let mut contents = String::new();
f.read_to_string(&mut contents).map_err(|err| {
EvalAltResult::ErrorSystem(
format!("Cannot read script file '{}'", path.to_string_lossy()),
err.into(),
)
})?;
Ok(contents)
}
/// Compile a script file into an `AST`, which can be used later for evaluation.
///
/// # Example
///
/// ```no_run
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// // Compile a script file to an AST and store it for later evaluation.
/// // Notice that a PathBuf is required which can easily be constructed from a string.
/// let ast = engine.compile_file("script.rhai".into())?;
///
/// for _ in 0..42 {
/// engine.eval_ast::<i64>(&ast)?;
/// }
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
#[inline(always)]
pub fn compile_file(&self, path: PathBuf) -> Result<AST, Box<EvalAltResult>> {
self.compile_file_with_scope(&Default::default(), path)
}
/// Compile a script file into an `AST` using own scope, which can be used later for evaluation.
///
/// The scope is useful for passing constants into the script for optimization
/// when using `OptimizationLevel::Full`.
///
/// # Example
///
/// ```no_run
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # #[cfg(not(feature = "no_optimize"))]
/// # {
/// use rhai::{Engine, Scope, OptimizationLevel};
///
/// let mut engine = Engine::new();
///
/// // Set optimization level to 'Full' so the Engine can fold constants.
/// engine.set_optimization_level(OptimizationLevel::Full);
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push_constant("x", 42_i64); // 'x' is a constant
///
/// // Compile a script to an AST and store it for later evaluation.
/// // Notice that a PathBuf is required which can easily be constructed from a string.
/// let ast = engine.compile_file_with_scope(&mut scope, "script.rhai".into())?;
///
/// let result = engine.eval_ast::<i64>(&ast)?;
/// # }
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
#[inline(always)]
pub fn compile_file_with_scope(
&self,
scope: &Scope,
path: PathBuf,
) -> Result<AST, Box<EvalAltResult>> {
Self::read_file(path).and_then(|contents| Ok(self.compile_with_scope(scope, &contents)?))
}
/// Parse a JSON string into a map.
///
/// The JSON string must be an object hash. It cannot be a simple JavaScript primitive.
///
/// Set `has_null` to `true` in order to map `null` values to `()`.
/// Setting it to `false` will cause a _variable not found_ error during parsing.
///
/// # JSON With Sub-Objects
///
/// This method assumes no sub-objects in the JSON string. That is because the syntax
/// of a JSON sub-object (or object hash), `{ .. }`, is different from Rhai's syntax, `#{ .. }`.
/// Parsing a JSON string with sub-objects will cause a syntax error.
///
/// If it is certain that the character `{` never appears in any text string within the JSON object,
/// then globally replace `{` with `#{` before calling this method.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, Map};
///
/// let engine = Engine::new();
///
/// let map = engine.parse_json(
/// r#"{"a":123, "b":42, "c":{"x":false, "y":true}, "d":null}"#
/// .replace("{", "#{").as_str(), true)?;
///
/// assert_eq!(map.len(), 4);
/// assert_eq!(map["a"].as_int().unwrap(), 123);
/// assert_eq!(map["b"].as_int().unwrap(), 42);
/// assert!(map["d"].is::<()>());
///
/// let c = map["c"].read_lock::<Map>().unwrap();
/// assert_eq!(c["x"].as_bool().unwrap(), false);
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_object"))]
pub fn parse_json(&self, json: &str, has_null: bool) -> Result<Map, Box<EvalAltResult>> {
let mut scope = Default::default();
// Trims the JSON string and add a '#' in front
let json_text = json.trim_start();
let scripts = if json_text.starts_with(Token::MapStart.syntax().as_ref()) {
[json_text, ""]
} else if json_text.starts_with(Token::LeftBrace.syntax().as_ref()) {
["#", json_text]
} else {
return Err(ParseErrorType::MissingToken(
Token::LeftBrace.syntax().into(),
"to start a JSON object hash".into(),
)
.into_err(Position::new(1, (json.len() - json_text.len() + 1) as u16))
.into());
};
let stream = self.lex(
&scripts,
if has_null {
Some(Box::new(|token| match token {
// If `null` is present, make sure `null` is treated as a variable
Token::Reserved(s) if s == "null" => Token::Identifier(s),
_ => token,
}))
} else {
None
},
);
let ast =
self.parse_global_expr(&mut stream.peekable(), &scope, OptimizationLevel::None)?;
// Handle null - map to ()
if has_null {
scope.push_constant("null", ());
}
self.eval_ast_with_scope(&mut scope, &ast)
}
/// Compile a string containing an expression into an `AST`,
/// which can be used later for evaluation.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// // Compile a script to an AST and store it for later evaluation
/// let ast = engine.compile_expression("40 + 2")?;
///
/// for _ in 0..42 {
/// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
/// }
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn compile_expression(&self, script: &str) -> Result<AST, ParseError> {
self.compile_expression_with_scope(&Default::default(), script)
}
/// Compile a string containing an expression into an `AST` using own scope,
/// which can be used later for evaluation.
///
/// The scope is useful for passing constants into the script for optimization
/// when using `OptimizationLevel::Full`.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # #[cfg(not(feature = "no_optimize"))]
/// # {
/// use rhai::{Engine, Scope, OptimizationLevel};
///
/// let mut engine = Engine::new();
///
/// // Set optimization level to 'Full' so the Engine can fold constants
/// // into function calls and operators.
/// engine.set_optimization_level(OptimizationLevel::Full);
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push_constant("x", 10_i64); // 'x' is a constant
///
/// // Compile a script to an AST and store it for later evaluation.
/// // Notice that `Full` optimization is on, so constants are folded
/// // into function calls and operators.
/// let ast = engine.compile_expression_with_scope(&mut scope,
/// "2 + (x + x) * 2" // all 'x' are replaced with 10
/// )?;
///
/// // Normally this would have failed because no scope is passed into the 'eval_ast'
/// // call and so the variable 'x' does not exist. Here, it passes because the script
/// // has been optimized and all references to 'x' are already gone.
/// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
/// # }
/// # Ok(())
/// # }
/// ```
#[inline]
pub fn compile_expression_with_scope(
&self,
scope: &Scope,
script: &str,
) -> Result<AST, ParseError> {
let scripts = [script];
let stream = self.lex(&scripts, None);
{
let mut peekable = stream.peekable();
self.parse_global_expr(&mut peekable, scope, self.optimization_level)
}
}
/// Evaluate a script file.
///
/// # Example
///
/// ```no_run
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// // Notice that a PathBuf is required which can easily be constructed from a string.
/// let result = engine.eval_file::<i64>("script.rhai".into())?;
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
#[inline(always)]
pub fn eval_file<T: Variant + Clone>(&self, path: PathBuf) -> Result<T, Box<EvalAltResult>> {
Self::read_file(path).and_then(|contents| self.eval::<T>(&contents))
}
/// Evaluate a script file with own scope.
///
/// # Example
///
/// ```no_run
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, Scope};
///
/// let engine = Engine::new();
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push("x", 42_i64);
///
/// // Notice that a PathBuf is required which can easily be constructed from a string.
/// let result = engine.eval_file_with_scope::<i64>(&mut scope, "script.rhai".into())?;
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
#[inline(always)]
pub fn eval_file_with_scope<T: Variant + Clone>(
&self,
scope: &mut Scope,
path: PathBuf,
) -> Result<T, Box<EvalAltResult>> {
Self::read_file(path).and_then(|contents| self.eval_with_scope::<T>(scope, &contents))
}
/// Evaluate a string.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// assert_eq!(engine.eval::<i64>("40 + 2")?, 42);
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn eval<T: Variant + Clone>(&self, script: &str) -> Result<T, Box<EvalAltResult>> {
self.eval_with_scope(&mut Default::default(), script)
}
/// Evaluate a string with own scope.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, Scope};
///
/// let engine = Engine::new();
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push("x", 40_i64);
///
/// assert_eq!(engine.eval_with_scope::<i64>(&mut scope, "x += 2; x")?, 42);
/// assert_eq!(engine.eval_with_scope::<i64>(&mut scope, "x += 2; x")?, 44);
///
/// // The variable in the scope is modified
/// assert_eq!(scope.get_value::<i64>("x").expect("variable x should exist"), 44);
/// # Ok(())
/// # }
/// ```
#[inline]
pub fn eval_with_scope<T: Variant + Clone>(
&self,
scope: &mut Scope,
script: &str,
) -> Result<T, Box<EvalAltResult>> {
let ast = self.compile_with_scope_and_optimization_level(
scope,
&[script],
self.optimization_level,
)?;
self.eval_ast_with_scope(scope, &ast)
}
/// Evaluate a string containing an expression.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// assert_eq!(engine.eval_expression::<i64>("40 + 2")?, 42);
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn eval_expression<T: Variant + Clone>(
&self,
script: &str,
) -> Result<T, Box<EvalAltResult>> {
self.eval_expression_with_scope(&mut Default::default(), script)
}
/// Evaluate a string containing an expression with own scope.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, Scope};
///
/// let engine = Engine::new();
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push("x", 40_i64);
///
/// assert_eq!(engine.eval_expression_with_scope::<i64>(&mut scope, "x + 2")?, 42);
/// # Ok(())
/// # }
/// ```
#[inline]
pub fn eval_expression_with_scope<T: Variant + Clone>(
&self,
scope: &mut Scope,
script: &str,
) -> Result<T, Box<EvalAltResult>> {
let scripts = [script];
let stream = self.lex(&scripts, None);
// No need to optimize a lone expression
let ast = self.parse_global_expr(&mut stream.peekable(), scope, OptimizationLevel::None)?;
self.eval_ast_with_scope(scope, &ast)
}
/// Evaluate an `AST`.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::Engine;
///
/// let engine = Engine::new();
///
/// // Compile a script to an AST and store it for later evaluation
/// let ast = engine.compile("40 + 2")?;
///
/// // Evaluate it
/// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn eval_ast<T: Variant + Clone>(&self, ast: &AST) -> Result<T, Box<EvalAltResult>> {
self.eval_ast_with_scope(&mut Default::default(), ast)
}
/// Evaluate an `AST` with own scope.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, Scope};
///
/// let engine = Engine::new();
///
/// // Compile a script to an AST and store it for later evaluation
/// let ast = engine.compile("x + 2")?;
///
/// // Create initialized scope
/// let mut scope = Scope::new();
/// scope.push("x", 40_i64);
///
/// // Compile a script to an AST and store it for later evaluation
/// let ast = engine.compile("x += 2; x")?;
///
/// // Evaluate it
/// assert_eq!(engine.eval_ast_with_scope::<i64>(&mut scope, &ast)?, 42);
/// assert_eq!(engine.eval_ast_with_scope::<i64>(&mut scope, &ast)?, 44);
///
/// // The variable in the scope is modified
/// assert_eq!(scope.get_value::<i64>("x").expect("variable x should exist"), 44);
/// # Ok(())
/// # }
/// ```
#[inline]
pub fn eval_ast_with_scope<T: Variant + Clone>(
&self,
scope: &mut Scope,
ast: &AST,
) -> Result<T, Box<EvalAltResult>> {
let mut mods = Default::default();
let (result, _) = self.eval_ast_with_scope_raw(scope, &mut mods, ast)?;
let typ = self.map_type_name(result.type_name());
return result.try_cast::<T>().ok_or_else(|| {
EvalAltResult::ErrorMismatchOutputType(
self.map_type_name(type_name::<T>()).into(),
typ.into(),
Position::none(),
)
.into()
});
}
/// Evaluate an `AST` with own scope.
#[inline(always)]
pub(crate) fn eval_ast_with_scope_raw<'a>(
&self,
scope: &mut Scope,
mods: &mut Imports,
ast: &'a AST,
) -> Result<(Dynamic, u64), Box<EvalAltResult>> {
self.eval_statements(scope, mods, ast.statements(), &[ast.lib()])
}
/// Evaluate a file, but throw away the result and only return error (if any).
/// Useful for when you don't need the result, but still need to keep track of possible errors.
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
#[inline(always)]
pub fn consume_file(&self, path: PathBuf) -> Result<(), Box<EvalAltResult>> {
Self::read_file(path).and_then(|contents| self.consume(&contents))
}
/// Evaluate a file with own scope, but throw away the result and only return error (if any).
/// Useful for when you don't need the result, but still need to keep track of possible errors.
#[cfg(not(feature = "no_std"))]
#[cfg(not(target_arch = "wasm32"))]
#[inline(always)]
pub fn consume_file_with_scope(
&self,
scope: &mut Scope,
path: PathBuf,
) -> Result<(), Box<EvalAltResult>> {
Self::read_file(path).and_then(|contents| self.consume_with_scope(scope, &contents))
}
/// Evaluate a string, but throw away the result and only return error (if any).
/// Useful for when you don't need the result, but still need to keep track of possible errors.
#[inline(always)]
pub fn consume(&self, script: &str) -> Result<(), Box<EvalAltResult>> {
self.consume_with_scope(&mut Default::default(), script)
}
/// Evaluate a string with own scope, but throw away the result and only return error (if any).
/// Useful for when you don't need the result, but still need to keep track of possible errors.
#[inline]
pub fn consume_with_scope(
&self,
scope: &mut Scope,
script: &str,
) -> Result<(), Box<EvalAltResult>> {
let scripts = [script];
let stream = self.lex(&scripts, None);
let ast = self.parse(&mut stream.peekable(), scope, self.optimization_level)?;
self.consume_ast_with_scope(scope, &ast)
}
/// Evaluate an AST, but throw away the result and only return error (if any).
/// Useful for when you don't need the result, but still need to keep track of possible errors.
#[inline(always)]
pub fn consume_ast(&self, ast: &AST) -> Result<(), Box<EvalAltResult>> {
self.consume_ast_with_scope(&mut Default::default(), ast)
}
/// Evaluate an `AST` with own scope, but throw away the result and only return error (if any).
/// Useful for when you don't need the result, but still need to keep track of possible errors.
#[inline(always)]
pub fn consume_ast_with_scope(
&self,
scope: &mut Scope,
ast: &AST,
) -> Result<(), Box<EvalAltResult>> {
let mut mods = Default::default();
self.eval_statements(scope, &mut mods, ast.statements(), &[ast.lib()])
.map(|_| ())
}
/// Call a script function defined in an `AST` with multiple arguments.
/// Arguments are passed as a tuple.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # #[cfg(not(feature = "no_function"))]
/// # {
/// use rhai::{Engine, Scope};
///
/// let engine = Engine::new();
///
/// let ast = engine.compile(r"
/// fn add(x, y) { len(x) + y + foo }
/// fn add1(x) { len(x) + 1 + foo }
/// fn bar() { foo/2 }
/// ")?;
///
/// let mut scope = Scope::new();
/// scope.push("foo", 42_i64);
///
/// // Call the script-defined function
/// let result: i64 = engine.call_fn(&mut scope, &ast, "add", ( String::from("abc"), 123_i64 ) )?;
/// assert_eq!(result, 168);
///
/// let result: i64 = engine.call_fn(&mut scope, &ast, "add1", ( String::from("abc"), ) )?;
/// // ^^^^^^^^^^^^^^^^^^^^^^^^ tuple of one
/// assert_eq!(result, 46);
///
/// let result: i64 = engine.call_fn(&mut scope, &ast, "bar", () )?;
/// assert_eq!(result, 21);
/// # }
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_function"))]
#[inline]
pub fn call_fn<A: FuncArgs, T: Variant + Clone>(
&self,
scope: &mut Scope,
ast: &AST,
name: &str,
args: A,
) -> Result<T, Box<EvalAltResult>> {
let mut arg_values = args.into_vec();
let mut args: StaticVec<_> = arg_values.as_mut().iter_mut().collect();
let result = self.call_fn_dynamic_raw(scope, ast.lib(), name, &mut None, args.as_mut())?;
let typ = self.map_type_name(result.type_name());
return result.try_cast().ok_or_else(|| {
EvalAltResult::ErrorMismatchOutputType(
self.map_type_name(type_name::<T>()).into(),
typ.into(),
Position::none(),
)
.into()
});
}
/// Call a script function defined in an `AST` with multiple `Dynamic` arguments
/// and optionally a value for binding to the 'this' pointer.
///
/// ## WARNING
///
/// All the arguments are _consumed_, meaning that they're replaced by `()`.
/// This is to avoid unnecessarily cloning the arguments.
/// Do not use the arguments after this call. If they are needed afterwards,
/// clone them _before_ calling this function.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # #[cfg(not(feature = "no_function"))]
/// # {
/// use rhai::{Engine, Scope, Dynamic};
///
/// let engine = Engine::new();
///
/// let ast = engine.compile(r"
/// fn add(x, y) { len(x) + y + foo }
/// fn add1(x) { len(x) + 1 + foo }
/// fn bar() { foo/2 }
/// fn action(x) { this += x; } // function using 'this' pointer
/// ")?;
///
/// let mut scope = Scope::new();
/// scope.push("foo", 42_i64);
///
/// // Call the script-defined function
/// let result = engine.call_fn_dynamic(&mut scope, &ast, "add", None, [ String::from("abc").into(), 123_i64.into() ])?;
/// // ^^^^ no 'this' pointer
/// assert_eq!(result.cast::<i64>(), 168);
///
/// let result = engine.call_fn_dynamic(&mut scope, &ast, "add1", None, [ String::from("abc").into() ])?;
/// assert_eq!(result.cast::<i64>(), 46);
///
/// let result = engine.call_fn_dynamic(&mut scope, &ast, "bar", None, [])?;
/// assert_eq!(result.cast::<i64>(), 21);
///
/// let mut value: Dynamic = 1_i64.into();
/// let result = engine.call_fn_dynamic(&mut scope, &ast, "action", Some(&mut value), [ 41_i64.into() ])?;
/// // ^^^^^^^^^^^^^^^^ binding the 'this' pointer
/// assert_eq!(value.as_int().unwrap(), 42);
/// # }
/// # Ok(())
/// # }
/// ```
#[cfg(not(feature = "no_function"))]
#[inline(always)]
pub fn call_fn_dynamic(
&self,
scope: &mut Scope,
lib: impl AsRef<Module>,
name: &str,
mut this_ptr: Option<&mut Dynamic>,
mut arg_values: impl AsMut<[Dynamic]>,
) -> Result<Dynamic, Box<EvalAltResult>> {
let mut args: StaticVec<_> = arg_values.as_mut().iter_mut().collect();
self.call_fn_dynamic_raw(scope, lib.as_ref(), name, &mut this_ptr, args.as_mut())
}
/// Call a script function defined in an `AST` with multiple `Dynamic` arguments.
///
/// ## WARNING
///
/// All the arguments are _consumed_, meaning that they're replaced by `()`.
/// This is to avoid unnecessarily cloning the arguments.
/// Do not use the arguments after this call. If they are needed afterwards,
/// clone them _before_ calling this function.
#[cfg(not(feature = "no_function"))]
#[inline]
pub(crate) fn call_fn_dynamic_raw(
&self,
scope: &mut Scope,
lib: &Module,
name: &str,
this_ptr: &mut Option<&mut Dynamic>,
args: &mut FnCallArgs,
) -> Result<Dynamic, Box<EvalAltResult>> {
let fn_def = lib
.get_script_fn(name, args.len(), true)
.ok_or_else(|| EvalAltResult::ErrorFunctionNotFound(name.into(), Position::none()))?;
let mut state = State::new();
let mut mods = Default::default();
// Check for data race.
if cfg!(not(feature = "no_closure")) {
ensure_no_data_race(name, args, false)?;
}
self.call_script_fn(
scope,
&mut mods,
&mut state,
&[lib],
this_ptr,
fn_def,
args,
0,
)
}
/// Optimize the `AST` with constants defined in an external Scope.
/// An optimized copy of the `AST` is returned while the original `AST` is consumed.
///
/// Although optimization is performed by default during compilation, sometimes it is necessary to
/// _re_-optimize an AST. For example, when working with constants that are passed in via an
/// external scope, it will be more efficient to optimize the `AST` once again to take advantage
/// of the new constants.
///
/// With this method, it is no longer necessary to recompile a large script. The script `AST` can be
/// compiled just once. Before evaluation, constants are passed into the `Engine` via an external scope
/// (i.e. with `scope.push_constant(...)`). Then, the `AST is cloned and the copy re-optimized before running.
#[cfg(not(feature = "no_optimize"))]
#[inline]
pub fn optimize_ast(
&self,
scope: &Scope,
mut ast: AST,
optimization_level: OptimizationLevel,
) -> AST {
let lib = if cfg!(not(feature = "no_function")) {
ast.lib()
.iter_fn()
.filter(|(_, _, _, _, f)| f.is_script())
.map(|(_, _, _, _, f)| f.get_fn_def().clone())
.collect()
} else {
Default::default()
};
let stmt = mem::take(ast.statements_mut());
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, &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.
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # use std::sync::RwLock;
/// # use std::sync::Arc;
/// use rhai::Engine;
///
/// let result = Arc::new(RwLock::new(0_u64));
/// let logger = result.clone();
///
/// let mut engine = Engine::new();
///
/// engine.on_progress(move |&ops| {
/// if ops > 10000 {
/// false
/// } else if ops % 800 == 0 {
/// *logger.write().unwrap() = ops;
/// true
/// } else {
/// true
/// }
/// });
///
/// engine.consume("for x in range(0, 50000) {}")
/// .expect_err("should error");
///
/// assert_eq!(*result.read().unwrap(), 9600);
///
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn on_progress(
&mut self,
callback: impl Fn(&u64) -> bool + SendSync + 'static,
) -> &mut Self {
self.progress = Some(Box::new(callback));
self
}
/// Override default action of `print` (print to stdout using `println!`)
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # use std::sync::RwLock;
/// # use std::sync::Arc;
/// use rhai::Engine;
///
/// let result = Arc::new(RwLock::new(String::from("")));
///
/// let mut engine = Engine::new();
///
/// // Override action of 'print' function
/// let logger = result.clone();
/// engine.on_print(move |s| logger.write().unwrap().push_str(s));
///
/// engine.consume("print(40 + 2);")?;
///
/// assert_eq!(*result.read().unwrap(), "42");
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn on_print(&mut self, callback: impl Fn(&str) + SendSync + 'static) -> &mut Self {
self.print = Box::new(callback);
self
}
/// Override default action of `debug` (print to stdout using `println!`)
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// # use std::sync::RwLock;
/// # use std::sync::Arc;
/// use rhai::Engine;
///
/// let result = Arc::new(RwLock::new(String::from("")));
///
/// let mut engine = Engine::new();
///
/// // Override action of 'print' function
/// let logger = result.clone();
/// engine.on_debug(move |s| logger.write().unwrap().push_str(s));
///
/// engine.consume(r#"debug("hello");"#)?;
///
/// assert_eq!(*result.read().unwrap(), r#""hello""#);
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn on_debug(&mut self, callback: impl Fn(&str) + SendSync + 'static) -> &mut Self {
self.debug = Box::new(callback);
self
}
}
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