New function to combine dice, and use this function for hit dice.

Fixes: https://github.com/canismarko/dungeon-sheets/issues/84

dungeonsheets/character.py

@@ -24,6 +24,7 @@ from dungeonsheets import (
 from dungeonsheets.content_registry import find_content
 from dungeonsheets.weapons import Weapon
 from dungeonsheets.content import Creature
+from dungeonsheets.dice import combine_dice
 
 
 dice_re = re.compile(r"(\d+)d(\d+)")
@@ -789,9 +790,11 @@ class Character(Creature):
     @property
     def hit_dice(self):
         """What type and how many dice to use for re-gaining hit points.
-
+        
         To change, set hit_dice_num and hit_dice_faces."""
-        return " + ".join([f"{c.level}d{c.hit_dice_faces}" for c in self.class_list])
+        dice_s = " + ".join([f"{c.level}d{c.hit_dice_faces}" for c in self.class_list])
+        dice_s = combine_dice(dice_s)
+        return dice_s
 
     @property
     def hit_dice_faces(self):

dungeonsheets/dice.py

@@ -1,10 +1,12 @@
 import random
 import re
 from collections import namedtuple
+from itertools import groupby
 
 from dungeonsheets.exceptions import DiceError
 
 dice_re = re.compile(r"(\d+)d(\d+)", flags=re.I)
+dice_part_re = re.compile(r"[0-9d]+", flags=re.I)
 Dice = namedtuple("Dice", ("num", "faces"))
 
 
@@ -25,6 +27,36 @@ def read_dice_str(dice_str):
     return dice
 
 
+def combine_dice(dice_str):
+    """Condense a dice string into its simplest representation.
+
+    For example: "1d8 + 5 + 2d8 + 2" would be reduced to "3d8 + 7".
+
+    Returns
+    =======
+    new_dice_str
+      A new, condensed string for the given dice.
+    
+    """
+    dice = []
+    bonuses = 0
+    # Sort out each portion of the dice string
+    for part in dice_part_re.findall(dice_str):
+        try:
+            dice.append(read_dice_str(part))
+        except DiceError:
+            bonuses += int(part)
+    # Recombine the dice into a more concise string
+    new_parts = []
+    dice = sorted(dice, key=lambda x: x.faces)
+    for faces, grp in groupby(dice, key=lambda x: x.faces):
+        new_parts.append(f"{sum([d.num for d in grp])}d{faces}")
+    if bonuses > 0:
+        new_parts.append(str(bonuses))
+    new_dice_str = " + ".join(new_parts)
+    return new_dice_str
+
+
 def roll(a, b=None):
     """roll(20) means roll 1d20, roll(2, 6) means roll 2d6"""
     if b is None:

tests/test_dice.py

@@ -19,6 +19,11 @@ class TestDice(TestCase):
         with self.assertRaises(DiceError):
             dice.read_dice_str("Ed15")
 
+    def test_combine_dice(self):
+        self.assertEqual(dice.combine_dice("1d8 + 6 + 2d8 + 12"), "3d8 + 18")
+        self.assertEqual(dice.combine_dice("1d8 + 1d5 + 2d8 + 1d5"), "2d5 + 3d8")
+        
+
     def test_simple_rolling(self):
         num_tests = 100
         for _ in range(num_tests):