Add functionality to specify a source range

Now a range can be specified to pick random numbers from:
`!roll 1d{0,9}`, `!roll 2d{3,7}`, `!roll 3d{-5,-1}`.

README.md

@@ -1,9 +1,15 @@
 # dice
+
 A [maubot](https://github.com/maubot/maubot) that rolls dice. Has built-in calculator.
 
 ## Usage
-The base command is `!roll`. To roll dice, pass `XdY` as an argument, where `X`
-is the number of dice (optional) and `Y` is the number of sides in each dice.
+
+The base command is `!roll`.
+
+To roll a dice, pass `XdY` as an argument, where `X` is the number of dice
+(optional) and `Y` is the number of sides in each dice. `Y` can be passed as a
+specific range as well (for example: `{0,9}`, `{-5,-1}`).
+
 Most Python math and bitwise operators and basic `math` module functions are
 also supported, which means you can roll different kinds of dice and combine
 the results however you like.

dice.py

@@ -13,7 +13,7 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-from typing import Match, Union, Any, Type
+from typing import Match, Optional, Tuple, Union, Any, Type
 import operator
 import random
 import math
@@ -24,7 +24,10 @@
 from maubot import Plugin, MessageEvent
 from maubot.handlers import command
 
-pattern_regex = re.compile("([0-9]{0,9})[dD]([0-9]{1,9})")
+pattern_regex = re.compile(
+    r"(\d{0,9})d((?:\d|(\{(-?\d), *(-?\d)\})){1,9})",
+    re.IGNORECASE
+)
 
 _OP_MAP = {
     ast.Add: operator.add,
@@ -206,37 +209,58 @@ async def roll(self, evt: MessageEvent, pattern: str) -> None:
 
         individual_rolls = [] if self.show_rolls else None
 
-        def randomize(number: int, size: int) -> int:
-            if size < 0 or number < 0:
+        def randomize(number: int, size: Union[int, Tuple[int, int]]) -> int:
+            size_is_int: bool = isinstance(size, int)
+            choices_range: Tuple[int, int] = (
+                size if isinstance(size, tuple) else (1, size)
+            )
+            if not choices_range[0] <= choices_range[1]:
+                raise ValueError(
+                    "The range's first element must not be greater than the second"
+                )
+            largest: int = choices_range[1]
+            if size_is_int and largest < 0 or number < 0:
                 raise ValueError("randomize() only accepts non-negative values")
-            if size == 0 or number == 0:
+            if size_is_int and largest == 0 or number == 0:
                 return 0
-            elif size == 1:
+            elif size_is_int and largest == 1:
                 return number
             _result = 0
             if number < self.gauss_limit:
                 individual = [] if self.show_rolls and number < self.show_rolls_limit else None
-                for i in range(number):
-                    roll = random.randint(1, size)
+                for _ in range(number):
+                    roll = random.randint(*choices_range)
                     if individual is not None:
                         individual.append(roll)
                     _result += roll
-                if individual:
-                    individual_rolls.append((number, size, individual))
+                if individual and individual_rolls is not None:
+                    individual_rolls.append(
+                        (
+                            number,
+                            largest
+                            if size_is_int
+                            else "{" + ", ".join(str(i) for i in choices_range) + "}",
+                            individual
+                        )
+                    )
             else:
-                mean = number * (size + 1) / 2
-                variance = number * (size ** 2 - 1) / 12
-                while _result < number or _result > number * size:
+                mean = number * (largest + 1) / 2
+                variance = number * (largest ** 2 - 1) / 12
+                while _result < number or _result > number * largest:
                     _result = int(random.gauss(mean, math.sqrt(variance)))
             return _result
 
         def replacer(match: Match) -> str:
-            number = int(match.group(1) or "1")
-            size = int(match.group(2))
+            number: int = int(match.group(1) or "1")
+            range: Optional[str] = match.group(3)
+            size: Union[int, Tuple[int, int]] = (
+                int(match.group(2))
+                if not range
+                else (int(match.group(4)), int(match.group(5)))
+            )
             return str(randomize(number, size))
-
-        pattern = pattern_regex.sub(replacer, pattern)
         try:
+            pattern = pattern_regex.sub(replacer, pattern)
             result = Calc.evaluate(pattern)
             if self.round_decimals >= 0:
                 result = round(result, self.round_decimals)
@@ -263,7 +287,8 @@ async def help(self, evt: MessageEvent) -> None:
             "The base command is `!roll`. \\\n"
             "To roll a dice, pass `XdY` as an argument, where `X` is the "
             "number of dices (optional) and `Y` is the number of sides on "
-            "each dice. \\\n"
+            "each dice. `Y` can be passed as a specific range as well "
+            "(for example: `{0,9}`, `{-5,-1}`). \\\n"
             "Most Python math and bitwise operators and basic `math` module "
             "functions are also supported, which means you can roll different "
             "kinds of dice and combine the results however you like."

maubot.yaml

@@ -1,6 +1,6 @@
 maubot: 0.1.0
 id: xyz.maubot.dice
-version: 1.1.0
+version: 1.2.0
 license: AGPL-3.0-or-later
 modules:
 - dice