Patterns now have priority

rocketbot/cogs/patterncog.py

@@ -77,7 +77,7 @@ class PatternCog(BaseCog, name='Pattern Matching'):
 			return
 
 		patterns = self.__get_patterns(message.guild)
-		for statement in patterns.values():
+		for statement in sorted(patterns.values(), key=lambda s : s.priority, reverse=True):
 			if statement.expression.matches(message):
 				await self.__trigger_actions(message, statement)
 				break
@@ -231,5 +231,28 @@ class PatternCog(BaseCog, name='Pattern Matching'):
 			return
 		msg = ''
 		for name, statement in sorted(patterns.items()):
-			msg += f'Pattern `{name}`:\n```\n{statement.original}\n```\n'
+			msg += f'Pattern `{name}` (priority={statement.priority}):\n```\n{statement.original}\n```\n'
 		await context.message.reply(msg, mention_author=False)
+
+	@pattern.command(
+		brief='Sets a pattern\'s priority level',
+		description='Sets the priority for a pattern. Messages are checked ' +
+			'against patterns with the highest priority first. Patterns with ' +
+			'the same priority may be checked in arbitrary order. Default ' +
+			'priority is 100.',
+	)
+	async def setpriority(self, context: commands.Context, name: str, priority: int) -> None:
+		'Command handler'
+		patterns = self.__get_patterns(context.guild)
+		statement = patterns.get(name)
+		if statement is None:
+			await context.message.reply(
+				f'{CONFIG["failure_emoji"]} No such pattern `{name}`',
+				mention_author=False)
+			return
+		statement.priority = priority
+		self.__save_patterns(context.guild, patterns)
+		await context.message.reply(
+			f'{CONFIG["success_emoji"]} Priority for pattern `{name}` ' + \
+			f'updated to `{priority}`.',
+			mention_author=False)

rocketbot/pattern.py

@@ -143,15 +143,20 @@ class PatternStatement:
 	A full message match statement. If a message matches the given expression,
 	the given actions should be performed.
 	"""
+
+	DEFAULT_PRIORITY = 100
+
 	def __init__(self,
 			name: str,
 			actions: list[PatternAction],
 			expression: PatternExpression,
-			original: str):
+			original: str,
+			priority: int = DEFAULT_PRIORITY):
 		self.name = name
 		self.actions = list(actions)  # PatternAction[]
 		self.expression = expression
 		self.original = original
+		self.priority = priority
 
 	def check_deprecations(self) -> None:
 		"""
@@ -177,6 +182,7 @@ class PatternStatement:
 		"""
 		return {
 			'name': self.name,
+			'priority': self.priority,
 			'statement': self.original,
 		}
 
@@ -185,7 +191,9 @@ class PatternStatement:
 		"""
 		Gets a PatternStatement from its JSON representation.
 		"""
-		return PatternCompiler.parse_statement(json['name'], json['statement'])
+		ps = PatternCompiler.parse_statement(json['name'], json['statement'])
+		ps.priority = json.get('priority', cls.DEFAULT_PRIORITY)
+		return ps
 
 class PatternCompiler:
 	"""