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Day 4 WIP parsing lines

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Tyler Hallada
2018-12-15 17:52:48 -05:00
parent a3abcbf107
commit ac311a1b1c
6 changed files with 296 additions and 0 deletions
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src/day4.rs Normal file
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extern crate chrono;
extern crate regex;
use std::error::Error;
use std::fs::File;
use std::io::{BufRead, BufReader};
use std::fmt;
use std::collections::{HashMap, HashSet};
use std::iter::FromIterator;
use chrono::prelude::*;
use regex::{Regex, Captures};
const INPUT: &str = "inputs/4.txt";
#[derive(Debug, PartialEq)]
enum Record {
Start {
time: NaiveDateTime,
guard_id: u32,
},
Sleep {
time: NaiveDateTime,
},
Wake {
time: NaiveDateTime,
},
}
#[derive(Debug, Clone, PartialEq)]
struct MalformedRecord {
details: String
}
impl MalformedRecord {
fn new(msg: &str) -> MalformedRecord {
MalformedRecord{ details: msg.to_string() }
}
}
impl fmt::Display for MalformedRecord {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.details)
}
}
impl Error for MalformedRecord {
fn description(&self) -> &str {
&self.details
}
}
fn read_records(filename: &str) -> Result<Vec<Record>, Box<Error>> {
let mut records: Vec<Record> = Vec::new();
let record_regex =
Regex::new(r"\[(?P<timestamp>\d{4}-\d{2}-\d{2}\s\d{2}:\d{2})\]\s(?:(?P<start>Guard #(?P<guard_id>\d+) begins shift)|(?P<sleep>falls asleep)|(?P<wake>wakes up))")?;
let file = File::open(filename)?;
for line in BufReader::new(file).lines() {
match record_regex.captures(&line?) {
Some(captures) => {
println!("{:?}", NaiveDateTime::parse_from_str(
&get_captured_field(&captures, "timestamp")?,
"%Y-%m-%d %H:%M")?);
if has_captured_field(&captures, "start")? {
records.push(Record::Start {
time: NaiveDateTime::parse_from_str(
&get_captured_field(&captures, "timestamp")?,
"%Y-%m-%d %H:%M")?,
guard_id: get_captured_field(&captures, "guard_id")?.parse()?,
});
} else if has_captured_field(&captures, "sleep")? {
records.push(Record::Sleep {
time: NaiveDateTime::parse_from_str(
&get_captured_field(&captures, "timestamp")?,
"%Y-%m-%d %H:%M")?,
});
} else {
records.push(Record::Wake {
time: NaiveDateTime::parse_from_str(
&get_captured_field(&captures, "timestamp")?,
"%Y-%m-%d %H:%M")?,
});
}
},
None => return Err(Box::new(MalformedRecord {
details: "Malformed record line, no fields could be found".to_string()
})),
};
}
Ok(records)
}
fn get_captured_field(captures: &Captures, field: &str) -> Result<String, Box<Error>> {
match captures.name(field) {
Some(capture) => Ok(String::from(capture.as_str())),
None => return Err(Box::new(MalformedRecord {
details: format!("Malformed record line, field {} could not be found", field)
}))
}
}
fn has_captured_field(captures: &Captures, field: &str) -> Result<bool, Box<Error>> {
match captures.name(field) {
Some(_) => Ok(true),
None => Ok(false)
}
}
#[cfg(test)]
mod tests {
use super::*;
const TEST_INPUT: &str = "inputs/4_test.txt";
const TEST_INPUT_MALFORMED: &str = "inputs/4_test_malformed.txt";
#[test]
fn reads_records_file() {
assert_eq!(read_records(TEST_INPUT).unwrap(), vec![
Record::Start {
time: NaiveDateTime::parse_from_str(
"1518-11-01 00:00", "%Y-%m-%d %H:%M").unwrap(),
guard_id: 10,
},
Record::Sleep {
time: NaiveDateTime::parse_from_str(
"1518-11-01 00:05", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Wake {
time: NaiveDateTime::parse_from_str(
"1518-11-01 00:25", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Sleep {
time: NaiveDateTime::parse_from_str(
"1518-11-01 00:30", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Wake {
time: NaiveDateTime::parse_from_str(
"1518-11-01 00:55", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Start {
time: NaiveDateTime::parse_from_str(
"1518-11-01 23:58", "%Y-%m-%d %H:%M").unwrap(),
guard_id: 99,
},
Record::Sleep {
time: NaiveDateTime::parse_from_str(
"1518-11-02 00:40", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Wake {
time: NaiveDateTime::parse_from_str(
"1518-11-02 00:50", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Start {
time: NaiveDateTime::parse_from_str(
"1518-11-03 00:05", "%Y-%m-%d %H:%M").unwrap(),
guard_id: 10,
},
Record::Sleep {
time: NaiveDateTime::parse_from_str(
"1518-11-03 00:24", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Wake {
time: NaiveDateTime::parse_from_str(
"1518-11-03 00:29", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Start {
time: NaiveDateTime::parse_from_str(
"1518-11-04 00:02", "%Y-%m-%d %H:%M").unwrap(),
guard_id: 99,
},
Record::Sleep {
time: NaiveDateTime::parse_from_str(
"1518-11-04 00:36", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Wake {
time: NaiveDateTime::parse_from_str(
"1518-11-04 00:46", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Start {
time: NaiveDateTime::parse_from_str(
"1518-11-05 00:03", "%Y-%m-%d %H:%M").unwrap(),
guard_id: 99,
},
Record::Sleep {
time: NaiveDateTime::parse_from_str(
"1518-11-05 00:45", "%Y-%m-%d %H:%M").unwrap(),
},
Record::Wake {
time: NaiveDateTime::parse_from_str(
"1518-11-05 00:55", "%Y-%m-%d %H:%M").unwrap(),
},
]);
}
#[test]
fn errors_on_malformed_records_file() {
match read_records(TEST_INPUT_MALFORMED) {
Ok(_) => assert!(false, "read_records should have returned an error"),
Err(err) => assert_eq!(
(*err).description(),
"Malformed record line, no fields could be found".to_string(),
),
}
}
}