dice 1.0.0

dice

Parse and roll dice notation strings in D. It aspires to support everything that Roll20 does (eventually).

Installation

Add the dependency via the usual way with DUB.

The short version is: add dependency "dice" version="~>1.0.0" to your project's dub.sdl or "dependences": { "dice": "~>1.0.0" } to your project's dub.json (depending on which one you have).

Usage

The package has two public functions:

roll(input) -> float

Parse a dice notation string and roll it. The notation supports:

1. Dice rolling

   roll("1d20"); // Rolls a twenty-sided die
   roll("3d6"); // Rolls 3 six-sided dice
   roll("4dF"); // Rolls 4 FATE/FUDGE dice

1. Arithmetic (addition, subtraction, division, and multiplication)

   roll("(3*2)-9/3"); // Performs basic math
   roll("1d20+8-3"); // Performs math after resolving die roll

1. Dropping and keeping

   roll("6d6d3"); // Drops the lowest 3 rolls
   roll("6d6dl3"); // Same as the preceding roll
   roll("6d6k3"); // Keeps the 3 highest rolls
   roll("6d6kh3"); // Same as the preceding roll
   roll("6d6kl3"); // Keeps the 3 lowest rolls
   roll("{3d6,3d6}k1"); // Rolls two groups of 3 six-sided dice and keeps the highest group

1. Exploding dice (rolling the maximum on a die causes another roll)

   roll("3d6!"); // If any of the 3 d6 rolls result in a 6, roll another one

1. Math functions

   roll("ceil(100/75)d6"); // Rounds up to the nearest integer (2) and rolls that many d6 dice
   roll("floor(1/2)"); // Rounds down to the nearest integer (0)
   roll("round(1/2)"); // Rounds down if less than 0.5 and up if 0.5 or more
   roll("abs(1d6-100)"); // Returns the absolute value of the result

1. Success/Failure count

   roll("4d6>3"); // Number of dice rolled that were greater than 3
   roll("4d6f<3"); // Number of dice rolled that were less than 3
   roll("4d6>3f>5"); // Number of dice rolled that were greater than 3 but less than 6
   roll("3d20=11"); // Number of dice rolled that were equal to 11
   roll("3d20f=19"); // Number of dice rolled that were not equal to 19

Order of Operations

Parts of the notation are solved in the following order:

1. Math functions (ceil, floor, round, abs)
2. Notation inside parentheses ((2+2)d6)
3. Multiplication and division (100*2/10)
4. Addition and subtraction (100+10-20)
5. Grouped dice ({2d6,2d6})
6. Success/failure checks (4d6>2)
7. FATE dice (4dF)
8. Drop/keep dice (6d6k3)
9. Exploding dice (4d6!)
10. Regular dice (1d20)

rollDie(sides) -> int

Rolls a die with a number of sides and returns the result

rollDie(20); // Rolls a twenty-sided die
rollDie(6); // Rolls a six-sided die