Module io.github.brantunger.unruly.core

Package io.github.brantunger.unruly.api.exception

@NullMarked package io.github.brantunger.unruly.api.exception

The exceptions the engine throws, all unchecked and all extending UnrulyException.

• RulesEngine.load(java.util.List) throws RuleCompilationException, whose failures() lists each problem it found.
• RulesEngine.run(io.github.brantunger.unruly.api.FactStore) throws RuleExecutionException, for a failure inside a rule or one that belongs to no rule, such as a stopped run.
• An expression language's compiler throws InvalidExpressionException to reject an expression; load() reports it as the cause of a RuleCompilationException that names the rule.
• Misuse throws IllegalStateException (running before load(), or on a closed engine) or IllegalArgumentException (a fact name rules can't use, or a fact that doesn't match its declaration). A run also throws IllegalStateException when, while borrowing a copy of the rules, it found the same rule list closed each time it read the engine's rules again, many times in a row, which means an engine invariant has broken rather than that the call was wrong; a reload in between starts the count again.

On either engine exception, getRuleName() names the failing rule, or is null for a failure that isn't about one rule; getExpressionKind() says whether its condition or its action failed; and issues() on a RuleCompilationException says where the language found each problem.

Types in this package are non-null unless annotated Nullable.

See Also:

• Exceptions by method

Related Packages

Package	Description
io.github.brantunger.unruly.api	The engine's public API: build an engine, give it rules, run it against facts, and observe its runs.
io.github.brantunger.unruly.api.language	The interfaces an expression language implements, so rule conditions and actions can be compiled and run, and the ones the engine passes to it.

Class	Description
ExpressionKind	Which part of a rule an expression is.
InvalidExpressionException	Thrown by an ExpressionCompiler to reject an expression: one that breaks a rule the engine enforces, such as a condition that assigns to a fact, or one with an error the language can point to, such as a syntax error.
InvalidExpressionException.Issue	One problem a language found in an expression.
InvalidExpressionException.Issue.Severity	Whether an issue stops an expression compiling.
RuleCompilationException	Exception thrown when a rule fails to compile, or when several do.
RuleExecutionException	Thrown by run() when a run fails: because a rule's condition or action failed, or because something outside any rule did.
UnrulyException	The base runtime exception for the Unruly engine.