blob: 6cdd672e3f3b12ee9466b86528e7cdbdcd980077 (
plain) (
blame)
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
|
//! Example: Using the `group!()` Macro to Register Outside Types
//!
//! This example demonstrates how to use the `group!()` macro to make outside
//! types (from `std` or other crates) recognizable by the Mingling framework,
//! without modifying the original type definition.
//!
//! Run:
//! ```bash
//! cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- parse 42
//! cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- parse hello
//! ```
//!
//! Output:
//! ```plaintext
//! Parsed number: 42
//! Parse error: invalid digit found in string
//! ```
use mingling::{macros::group, prelude::*};
use std::num::ParseIntError;
dispatcher!("parse");
// --------- IMPORTANT ---------
// You can directly use the `group!` macro to define outside types as types
// recognizable by Mingling
// _____________ from std::num::ParseIntError
// /
// vvvvvvvvvvvvv
group!(ParseIntError);
// --------- IMPORTANT ---------
pack!(ParsedNumber = i32);
/// Parse the first argument as an `i32`
///
/// On success, routes to `render_number`.
/// On failure, routes to `render_parse_error` via the registered outside type.
#[chain]
fn parse_number(args: EntryParse) -> Next {
let input = args.inner.first().cloned().unwrap_or_default();
match input.parse::<i32>() {
Ok(num) => ParsedNumber::new(num).to_chain(),
Err(e) => e.to_chain(),
}
}
/// Renderer for successful parse — displays the parsed integer.
// _____________ Using std::num::ParseIntError as a chain input
// /
#[renderer] // vvvvvvvvvvvv
fn render_number(num: ParsedNumber) {
r_println!("Parsed number: {}", *num);
}
/// Renderer for parse errors — using the outside `ParseIntError` type.
///
/// The `ParseIntError` type is registered via `group!` above, so it implements
/// `Groupped<ThisProgram>` and can be used directly in a `#[renderer]` function.
#[renderer]
fn render_parse_error(err: ParseIntError) {
r_println!("Parse error: {}", err);
}
fn main() {
let mut program = ThisProgram::new();
program.with_dispatcher(CMDParse);
program.exec_and_exit();
}
gen_program!();
|
