rhai/examples/definitions/main.rs
2022-09-08 10:53:55 +08:00

71 lines
2.2 KiB
Rust

use rhai::plugin::*;
use rhai::{Engine, EvalAltResult, Scope};
#[export_module]
pub mod general_kenobi {
/// General Kenobi's Constant.
pub const CONSTANT: i64 = 42;
/// Returns a string where "hello there" is repeated `n` times.
pub fn hello_there(n: i64) -> String {
use std::convert::TryInto;
"hello there ".repeat(n.try_into().unwrap())
}
}
fn main() -> Result<(), Box<EvalAltResult>> {
let mut engine = Engine::new();
let mut scope = Scope::new();
// This variable will also show up in the definitions, since it will be part of the scope.
scope.push("hello_there", "hello there");
// This constant will also show up in the definitions, since it will be part of the scope.
scope.push_constant("HELLO", "hello there");
#[cfg(not(feature = "no_module"))]
engine.register_static_module("general_kenobi", exported_module!(general_kenobi).into());
// Custom operators also show up in definitions.
#[cfg(not(feature = "no_custom_syntax"))]
{
engine.register_custom_operator("minus", 100).unwrap();
engine.register_fn("minus", |a: i64, b: i64| a - b);
}
engine.run_with_scope(
&mut scope,
"hello_there = general_kenobi::hello_there(4 minus 2);",
)?;
// Generate definitions for the contents of the engine and the scope.
engine
.definitions_with_scope(&scope)
.write_to_dir("examples/definitions/.rhai/definitions")
.unwrap();
// Alternatively we can write all of the above to a single file.
engine
.definitions_with_scope(&scope)
.write_to_file("examples/definitions/.rhai/all_in_one.d.rhai")
.unwrap();
// Skip standard packages if not needed (e.g. they are provided elsewhere).
engine
.definitions_with_scope(&scope)
.include_standard_packages(false)
.write_to_file("examples/definitions/.rhai/all_in_one_without_standard.d.rhai")
.unwrap();
// Write function definitions as JSON.
let json = engine
.definitions()
.include_standard_packages(false)
.json()
.unwrap();
std::fs::write("examples/definitions/.rhai/defs.json", json).unwrap();
Ok(())
}