Crate critfail

Expand description

Evaluation and rolling of D&D 5e die roll expressions.

The RollExpression trait provides methods for dealing with the various kinds of rolls. Roll provides the simplest text-in, text-out interface for rolling expressions an printing the result regardless of the type of roll.

use critfail::{RollExpression, Roll};

let check = Roll::new("r-3").unwrap();
let check_outcome = check.roll();
print!("{}", check_outcome); // eg. "11"
print!("{:?}", check_outcome); // eg. "(14)-3"

let damage = Roll::new("2d8+6").unwrap();
let damage_outcome = damage.roll();
print!("{}", damage_outcome); // eg. "13"
print!("{:?}", damage_outcome); // eg. "[2+5]+6"

let attack = Roll::new("r+1?2d6+4").unwrap();
let attack_outcome = attack.roll();
print!("{}", attack_outcome); // eg. "10 ? 16"
print!("{:?}", attack_outcome); // eg. "(9)+1 ? [6+6]+4"

In order to handle the outcome of a Roll programatically, roll expressions are split into Check rolls, Damage rolls, and Attack rolls, each with their own outcome type which provides methods for determining the score and makeup of the results for each.

§Features

wasm-bindgen: Enable this when compiling for wasm32 targets, or random number generation won’t work.

Structs§

Attack: An attack roll consisting of a check and a damage roll.
AttackOutcome: The outcome of an attack roll.
AttackOutcomeBuilder: This is used to create a ‘fudged’ AttackOutcome without actually randomly generating anything.
Check: An ability check - roll a d20, potentially with modifiers or advantage.
CheckOutcome: The outcome of a check roll.
CheckOutcomeBuilder: This is used to create a ‘fudged’ CheckOutcome without actually randomly generating anything.
Damage: A list of dice to roll and modifiers to add, usually used for damage.
DamageOutcome: The outcome of a check roll.
DamageOutcomeBuilder: This is used to create a ‘fudged’ DamageOutcome without actually randomly generating anything.
ParseError: Represents an error parsing a roll expression.

Enums§

AdvState: The advantage state of an ability check.
CritScore: The score of a roll that could be a critical hit/failure
OutcomePart: Enum representing the different kinds of values that can be returned for damage or the modifier on a check.
Roll: Any kind of roll—either a check, damage, or attack roll.
RollOutcome: The outcome of rolling a check, damage, or attack roll.

Traits§

RollExpression: Used for structs defining a set of dice that can be rolled.

Type Aliases§