44 lines
1.2 KiB
Rust
44 lines
1.2 KiB
Rust
use crate::error::BotError;
|
|
use combine::parser::char::{digit, letter, spaces};
|
|
use combine::{many1, Parser};
|
|
use thiserror::Error;
|
|
|
|
enum ParsedValue {
|
|
Valid(i32),
|
|
Invalid,
|
|
}
|
|
|
|
#[derive(Error, Debug)]
|
|
pub enum VariableParsingError {
|
|
#[error("invalid variable value, must be a number")]
|
|
InvalidValue,
|
|
|
|
#[error("unconsumed input")]
|
|
UnconsumedInput,
|
|
}
|
|
|
|
pub fn parse_set_variable(input: &str) -> Result<(String, i32), BotError> {
|
|
let name = many1(letter()).map(|value: String| value);
|
|
|
|
let value = many1(digit()).map(|value: String| match value.parse::<i32>() {
|
|
Ok(num) => ParsedValue::Valid(num),
|
|
_ => ParsedValue::Invalid,
|
|
});
|
|
|
|
let mut parser = name.skip(spaces().silent()).and(value);
|
|
let (result, rest) = parser.parse(input)?;
|
|
|
|
if rest.len() == 0 {
|
|
match result {
|
|
(variable_name, ParsedValue::Valid(value)) => Ok((variable_name, value)),
|
|
_ => Err(BotError::VariableParsingError(
|
|
VariableParsingError::InvalidValue,
|
|
)),
|
|
}
|
|
} else {
|
|
Err(BotError::VariableParsingError(
|
|
VariableParsingError::UnconsumedInput,
|
|
))
|
|
}
|
|
}
|