70 lines
1.9 KiB
Rust
70 lines
1.9 KiB
Rust
//! This example shows an example of how to parse an escaped string. The
|
|
//! rules for the string are similar to JSON and rust. A string is:
|
|
//!
|
|
//! - Enclosed by double quotes
|
|
//! - Can contain any raw unescaped code point besides \ and "
|
|
//! - Matches the following escape sequences: \b, \f, \n, \r, \t, \", \\, \/
|
|
//! - Matches code points like Rust: \u{XXXX}, where XXXX can be up to 6
|
|
//! hex characters
|
|
//! - an escape followed by whitespace consumes all whitespace between the
|
|
//! escape and the next non-whitespace character
|
|
|
|
#![cfg(feature = "alloc")]
|
|
|
|
mod parser;
|
|
|
|
use winnow::prelude::*;
|
|
|
|
fn main() -> Result<(), lexopt::Error> {
|
|
let args = Args::parse()?;
|
|
|
|
let data = args.input.as_deref().unwrap_or("\"abc\"");
|
|
let result = parser::parse_string::<()>.parse(data);
|
|
match result {
|
|
Ok(data) => println!("{data}"),
|
|
Err(err) => println!("{err:?}"),
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
#[derive(Default)]
|
|
struct Args {
|
|
input: Option<String>,
|
|
}
|
|
|
|
impl Args {
|
|
fn parse() -> Result<Self, lexopt::Error> {
|
|
use lexopt::prelude::*;
|
|
|
|
let mut res = Args::default();
|
|
|
|
let mut args = lexopt::Parser::from_env();
|
|
while let Some(arg) = args.next()? {
|
|
match arg {
|
|
Value(input) => {
|
|
res.input = Some(input.string()?);
|
|
}
|
|
_ => return Err(arg.unexpected()),
|
|
}
|
|
}
|
|
Ok(res)
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn simple() {
|
|
let data = "\"abc\"";
|
|
let result = parser::parse_string::<()>.parse(data);
|
|
assert_eq!(result, Ok(String::from("abc")));
|
|
}
|
|
|
|
#[test]
|
|
fn escaped() {
|
|
let data = "\"tab:\\tafter tab, newline:\\nnew line, quote: \\\", emoji: \\u{1F602}, newline:\\nescaped whitespace: \\ abc\"";
|
|
let result = parser::parse_string::<()>.parse(data);
|
|
assert_eq!(
|
|
result,
|
|
Ok(String::from("tab:\tafter tab, newline:\nnew line, quote: \", emoji: 😂, newline:\nescaped whitespace: abc"))
|
|
);
|
|
}
|