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#![forbid(unsafe_code)]
use rand::Rng;
mod error;
pub use error::Error;
use error::MyResult;
mod post;
use post::{EResult, EvaluatedTerm, RolledDie, TResult};
pub use post::{ExpressionResult, FormatOptions};
mod expose;
#[cfg(not(target_arch = "wasm32"))]
pub use expose::{roll_tuples, tuple_vec};
mod parse;
use parse::{Die, Expr, Sign, Term};
pub use parse::ParseError;
pub mod builder;
use builder::RollBuilder;
#[cfg(target_arch = "wasm32")]
use wasm_bindgen::prelude::*;
mod display;
pub mod prelude;
pub mod util;
fn roll_die_with<R>(a: &Die, rng: &mut R) -> Result<RolledDie, Error>
where
R: Rng,
{
if a.size == 1 {
Ok(RolledDie {
total: a.number,
parts: (0..a.number).map(|_| 1).collect(),
sign_part: Sign::Positive,
})
} else if a.size < 1 {
Err(Error::InvalidDie)
} else {
let mut total: i64 = 0;
let mut parts = Vec::new();
for _ in 0..a.number {
let random;
if let Some(bound) = a.size.checked_add(1) {
random = rng.gen_range(1, bound);
} else {
random = rng.gen();
}
total = total.checked_add(random).ok_or(Error::OverflowPositive)?;
parts.push(random);
}
Ok(RolledDie {
total,
parts,
sign_part: Sign::Positive,
})
}
}
fn eval_term_with<R>(a: &Expr, rng: &mut R) -> TResult
where
R: Rng,
{
let t = match a.term {
Term::Die(x) => roll_die_with(&x, rng).into(),
Term::Constant(x) => MyResult::Ok(EvaluatedTerm::Constant(x)),
};
(a.sign * t).into()
}
#[cfg(not(target_arch = "wasm32"))]
pub fn roll(input: &str) -> EResult {
Ok(RollBuilder::new().parse(input)?.into_roll()?.roll()?)
}
fn try_roll_expr_iter_with<I, R>(rng: &mut R, input: I) -> EResult
where
I: Iterator<Item = Result<Expr, Error>>,
R: Rng,
{
let mut pairs = Vec::new();
let mut total: i64 = 0;
for x in input {
match x {
Ok(x) => {
let res = eval_term_with(&x, rng)?;
let res_val = res.value();
pairs.push((x, res));
total = total.checked_add(res_val).ok_or(if res_val > 0 {
Error::OverflowPositive
} else {
Error::OverflowNegative
})?;
}
Err(x) => return Err(x),
}
}
Ok(ExpressionResult::new(pairs, total))
}
fn roll_expr_iter_with<I, R>(rng: &mut R, input: I) -> EResult
where
I: Iterator<Item = Expr>,
R: Rng,
{
try_roll_expr_iter_with(rng, input.map(Ok))
}
#[cfg(test)]
mod tests {
use crate::{roll, Die};
#[test]
fn arithmetic() {
assert_eq!(roll("5 + 3").unwrap().total(), 8);
assert_eq!(roll("5 - 3").unwrap().total(), 2);
}
#[test]
fn dice() {
let mut good = true;
match Die::new(0, 0) {
Ok(_) => good = false,
Err(_) => (),
}
if !good {
panic!()
}
}
}