Merge pull request #5 from jhwgh1968/rhai_plugin

Added basic Plugin trait and test
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Stephen Chung 2020-04-26 12:20:25 +08:00 committed by GitHub
commit 976f22d613
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3 changed files with 62 additions and 0 deletions

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@ -22,6 +22,7 @@ num-traits = { version = "0.2.11", default-features = false }
[features]
#default = ["no_stdlib", "no_function", "no_index", "no_object", "no_float", "only_i32", "unchecked", "no_optimize", "sync"]
default = []
plugins = []
unchecked = [] # unchecked arithmetic
no_index = [] # no arrays and indexing
no_float = [] # no floating-point

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@ -9,6 +9,49 @@ use crate::token::Position;
use crate::stdlib::{any::TypeId, boxed::Box, string::ToString};
/// A trait to register custom plugins with the `Engine`.
///
/// A plugin consists of a number of functions. All functions will be registered with the engine.
#[cfg(feature = "plugins")]
pub trait RegisterPlugin<PL: Plugin> {
/// Register a custom function with the `Engine`.
///
/// # Example
///
/// ```
/// use rhai::{Dynamic, Engine, INT, Plugin, RegisterDynamicFn, RegisterPlugin};
///
/// // A simple custom plugin type. This should not usually be done with hand-written code.
/// struct AddOffsetPlugin(INT);
/// impl AddOffsetPlugin {
/// fn add_offset(&self, x: INT) -> Dynamic {
/// Dynamic::from(x + self.0)
/// }
/// }
/// impl Plugin for AddOffsetPlugin {
/// fn name(&self) -> &str {
/// "My Plugin"
/// }
/// fn register_contents(self, engine: &mut Engine) {
/// let add_offset_fn: Box<dyn Fn(INT) -> Dynamic> = {
/// Box::new(move |x| self.add_offset(x))
/// };
/// engine.register_dynamic_fn("add_offset", add_offset_fn);
/// }
/// }
///
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
///
/// let mut engine = Engine::new();
/// engine.register_plugin(AddOffsetPlugin(50));
///
/// assert_eq!(engine.eval::<i64>("add_offset(42)")?, 92);
/// # Ok(())
/// # }
/// ```
fn register_plugin(&mut self, plugin: PL);
}
/// A trait to register custom functions with the `Engine`.
pub trait RegisterFn<FN, ARGS, RET> {
/// Register a custom function with the `Engine`.
@ -98,6 +141,15 @@ pub trait RegisterResultFn<FN, ARGS, RET> {
fn register_result_fn(&mut self, name: &str, f: FN);
}
/// Represents an externally-written plugin for the Rhai interpreter.
///
/// This should not be used directly. Use the `plugin_module!` macro instead.
#[cfg(feature = "plugins")]
pub trait Plugin {
fn register_contents(self, engine: &mut Engine);
fn name(&self) -> &str;
}
// These types are used to build a unique _marker_ tuple type for each combination
// of function parameter types in order to make each trait implementation unique.
// That is because stable Rust currently does not allow distinguishing implementations
@ -127,6 +179,13 @@ pub fn cloned<T: Clone>(data: &mut T) -> T {
data.clone()
}
#[cfg(feature = "plugins")]
impl<PL: Plugin> RegisterPlugin<PL> for Engine {
fn register_plugin(&mut self, plugin: PL) {
plugin.register_contents(self)
}
}
/// This macro counts the number of arguments via recursion.
macro_rules! count_args {
() => { 0_usize };

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@ -89,6 +89,8 @@ pub use engine::{calc_fn_spec as calc_fn_hash, Engine};
pub use error::{ParseError, ParseErrorType};
pub use fn_call::FuncArgs;
pub use fn_register::{RegisterDynamicFn, RegisterFn, RegisterResultFn};
#[cfg(feature = "plugins")]
pub use fn_register::{Plugin, RegisterPlugin};
pub use parser::{AST, INT};
pub use result::EvalAltResult;
pub use scope::Scope;