Discordian date: Difference between revisions

=={{header|Rust}}==

'''Compiler:''' [[Rust]] (1.21.0)

[[Category:Rust]]

{{libheader|chrono}}

{{libheader|ddate}}

This example is taken in large part from the ddate crate and used with the

permission of the author.

<lang rust>extern crate chrono;

use chrono::NaiveDate;

use std::str::FromStr;

fn main() {

let date = std::env::args().nth(1).expect("Please provide a YYYY-MM-DD date.");

println!("{} is {}", date, NaiveDate::from_str(&date).unwrap().to_poee());

}

// The necessary constants for the seasons, weekdays, and holydays.

const APOSTLES: [&str; 5] = ["Mungday", "Mojoday", "Syaday", "Zaraday", "Maladay"];

const HOLYDAYS: [&str; 5] = ["Chaoflux", "Discoflux", "Confuflux", "Bureflux", "Afflux"];

const SEASONS: [&str; 5] = ["Chaos", "Discord", "Confusion", "Bureaucracy", "The Aftermath"];

const WEEKDAYS: [&str; 5] = ["Sweetmorn", "Boomtime", "Pungenday", "Prickle-Prickle", "Setting Orange"];

// The necessary constants for the conversion.

const APOSTLE_HOLYDAY: usize = 5;

const CURSE_OF_GREYFACE: i32 = 1166;

const SEASON_DAYS: usize = 73;

const SEASON_HOLYDAY: usize = 50;

const ST_TIBS_DAY: usize = 59;

const WEEK_DAYS: usize = 5;

// This extends the `Datelike` trait of Rust's Chrono crate with a method that

// prints any Datelike type as a String.

impl<T: Datelike> DiscordianDate for T {}

pub trait DiscordianDate: Datelike {

fn to_poee(&self) -> String {

let day = self.ordinal0() as usize;

let leap = self.year() % 4 == 0 && self.year() % 100 != 0 || self.year() % 400 == 0;

let year = self.year() + CURSE_OF_GREYFACE;

if leap && day == ST_TIBS_DAY { return format!("St. Tib's Day, in the YOLD {}", year); }

let day_offset = if leap && day > ST_TIBS_DAY { day - 1 } else { day };

let day_of_season = day_offset % SEASON_DAYS + 1;

let season = SEASONS[day_offset / SEASON_DAYS];

let weekday = WEEKDAYS[day_offset % WEEK_DAYS];

let holiday = if day_of_season == APOSTLE_HOLYDAY {

format!("\nCelebrate {}", APOSTLES[day_offset / SEASON_DAYS])

} else if day_of_season == SEASON_HOLYDAY {

format!("\nCelebrate {}", HOLYDAYS[day_offset / SEASON_DAYS])

} else {

String::with_capacity(0)

};

format!("{}, the {} day of {} in the YOLD {}{}",

weekday, ordinalize(day_of_season), season, year, holiday)

}

}

/// A helper function to ordinalize a numeral.

fn ordinalize(num: usize) -> String {

let s = format!("{}", num);

let suffix = if s.ends_with('1') && !s.ends_with("11") {

"st"

} else if s.ends_with('2') && !s.ends_with("12") {

"nd"

} else if s.ends_with('3') && !s.ends_with("13") {

"rd"

} else {

"th"

};

format!("{}{}", s, suffix)

}

</lang>

{{Out}}<pre>$ ./ddate -1166-1-1

-1166-1-1 is Sweetmorn, the 1st day of Chaos in the YOLD 0

$ ./ddate 2000-2-28

2000-2-28 is Prickle-Prickle, the 59th day of Chaos in the YOLD 3166

$ ./ddate -4004-2-29

-4004-2-29 is St. Tib's Day, in the YOLD -2838

$ ./ddate 1066-2-28

1066-2-28 is Prickle-Prickle, the 59th day of Chaos in the YOLD 2232

$ ./ddate 1492-3-1

1492-3-1 is Setting Orange, the 60th day of Chaos in the YOLD 2658

$ ./ddate 1492-9-26

1492-9-26 is Prickle-Prickle, the 50th day of Bureaucracy in the YOLD 2658

Celebrate Bureflux

$ ./ddate 2012-10-24

2012-10-24 is Boomtime, the 5th day of The Aftermath in the YOLD 3178

Celebrate Maladay

$

</pre>