Allow negative variables.

This commit is contained in:
projectmoon 2020-10-22 20:47:20 +00:00
parent 0c394d0f79
commit c10ee5c0f3
1 changed files with 34 additions and 5 deletions

View File

@ -1,6 +1,6 @@
use crate::error::BotError;
use combine::parser::char::{digit, letter, spaces};
use combine::{many1, Parser};
use combine::parser::char::{char, digit, letter, spaces};
use combine::{many1, optional, Parser};
use thiserror::Error;
enum ParsedValue {
@ -20,11 +20,21 @@ pub enum VariableParsingError {
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 maybe_minus = optional(char('-')).map(|value: Option<char>| match value {
Some(minus_sign) => String::from(minus_sign),
_ => "".to_owned(),
});
let value = maybe_minus
.and(many1(digit()))
.map(|value: (String, String)| {
let number = format!("{}{}", value.0, value.1);
match number.parse::<i32>() {
Ok(num) => ParsedValue::Valid(num),
_ => ParsedValue::Invalid,
}
});
let mut parser = name.skip(spaces().silent()).and(value);
let (result, rest) = parser.parse(input)?;
@ -41,3 +51,22 @@ pub fn parse_set_variable(input: &str) -> Result<(String, i32), BotError> {
))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn parse_postive_number() {
let result = parse_set_variable("myvar 5");
assert!(result.is_ok());
assert_eq!(("myvar".to_string(), 5), result.unwrap());
}
#[test]
fn parse_negative_number() {
let result = parse_set_variable("myvar -5");
assert!(result.is_ok());
assert_eq!(("myvar".to_string(), -5), result.unwrap());
}
}