1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
//! This example shows you how to define ops in Rust and then call them from
//! JavaScript.
use deno_core::op;
use deno_core::Extension;
use deno_core::JsRuntime;
use deno_core::OpState;
use deno_core::RuntimeOptions;
// This is a hack to make the `#[op]` macro work with
// deno_core examples.
// You can remove this:
use deno_core::*;
#[op]
fn op_sum(
_state: &mut OpState,
nums: Vec<f64>,
_: (),
) -> Result<f64, deno_core::error::AnyError> {
// Sum inputs
let sum = nums.iter().fold(0.0, |a, v| a + v);
// return as a Result<f64, AnyError>
Ok(sum)
}
fn main() {
// Build a deno_core::Extension providing custom ops
let ext = Extension::builder()
.ops(vec![
// An op for summing an array of numbers
// The op-layer automatically deserializes inputs
// and serializes the returned Result & value
op_sum::decl(),
])
.build();
// Initialize a runtime instance
let mut runtime = JsRuntime::new(RuntimeOptions {
extensions: vec![ext],
..Default::default()
});
// Now we see how to invoke the op we just defined. The runtime automatically
// contains a Deno.core object with several functions for interacting with it.
// You can find its definition in core.js.
runtime
.execute_script(
"<usage>",
r#"
// Print helper function, calling Deno.core.print()
function print(value) {
Deno.core.print(value.toString()+"\n");
}
const arr = [1, 2, 3];
print("The sum of");
print(arr);
print("is");
print(Deno.core.opSync('op_sum', arr));
// And incorrect usage
try {
print(Deno.core.opSync('op_sum', 0));
} catch(e) {
print('Exception:');
print(e);
}
"#,
)
.unwrap();
}
|
