Package software.amazon.smithy.rulesengine.language.evaluation

Class RuleEvaluator

java.lang.Object

software.amazon.smithy.rulesengine.language.evaluation.RuleEvaluator

All Implemented Interfaces:

ExpressionVisitor<Value>

public class RuleEvaluator
extends java.lang.Object
implements ExpressionVisitor<Value>

A runtime implementation of a rule-set evaluation engine.

Nested Class Summary

Nested classes/interfaces inherited from interface software.amazon.smithy.rulesengine.language.syntax.expressions.ExpressionVisitor

ExpressionVisitor.Default<R>

Constructor Summary

Constructors

Constructor	Description
RuleEvaluator()

Method Summary

Modifier and Type	Method	Description
static Value	evaluate(EndpointRuleSet ruleset, java.util.Map<Identifier,Value> parameterArguments)	Initializes a new RuleEvaluator instances, and evaluates the provided ruleset and parameter arguments.
Value	evaluateCondition(Condition condition)	Evaluates the given condition in the current scope.
Value	evaluateRuleSet(EndpointRuleSet ruleset, java.util.Map<Identifier,Value> parameterArguments)	Evaluate the provided ruleset and parameter arguments.
Value	visitBoolEquals(Expression left, Expression right)	Does a boolean equality check.
Value	visitGetAttr(GetAttr getAttr)	Visits a GetAttr function.
Value	visitIsSet(Expression fn)	Visits an isSet function.
Value	visitLibraryFunction(FunctionDefinition definition, java.util.List<Expression> arguments)	Visits a library function.
Value	visitLiteral(Literal literal)	Visits a literal.
Value	visitNot(Expression not)	Visits a not function.
Value	visitRef(Reference reference)	Visits a reference.
Value	visitStringEquals(Expression left, Expression right)	Does a string equality check.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RuleEvaluator

public RuleEvaluator()

Method Detail

evaluate

public static Value evaluate(EndpointRuleSet ruleset,
                             java.util.Map<Identifier,Value> parameterArguments)

Initializes a new RuleEvaluator instances, and evaluates the provided ruleset and parameter arguments.

Parameters:

ruleset - The endpoint ruleset.

parameterArguments - The rule-set parameter identifiers and values to evaluate the rule-set against.

Returns:

The resulting value from the final matched rule.

evaluateRuleSet

public Value evaluateRuleSet(EndpointRuleSet ruleset,
                             java.util.Map<Identifier,Value> parameterArguments)

Evaluate the provided ruleset and parameter arguments.

Parameters:

ruleset - The endpoint ruleset.

parameterArguments - The rule-set parameter identifiers and values to evaluate the rule-set against.

Returns:

The resulting value from the final matched rule.

evaluateCondition

public Value evaluateCondition(Condition condition)

Evaluates the given condition in the current scope.

Parameters:

condition - the condition to evaluate.

Returns:

the value returned by the condition.

visitLiteral

public Value visitLiteral(Literal literal)

Description copied from interface: ExpressionVisitor

Visits a literal.

Specified by:

visitLiteral in interface ExpressionVisitor<Value>

Parameters:

literal - the literal to visit.

Returns:

the value from the visitor.

visitRef

public Value visitRef(Reference reference)

Description copied from interface: ExpressionVisitor

Visits a reference.

Specified by:

visitRef in interface ExpressionVisitor<Value>

Parameters:

reference - the reference to visit.

Returns:

the value from the visitor.

visitIsSet

public Value visitIsSet(Expression fn)

Description copied from interface: ExpressionVisitor

Visits an isSet function.

Specified by:

visitIsSet in interface ExpressionVisitor<Value>

Parameters:

fn - the isSet function to visit.

Returns:

the value from the visitor.

visitNot

public Value visitNot(Expression not)

Description copied from interface: ExpressionVisitor

Visits a not function.

Specified by:

visitNot in interface ExpressionVisitor<Value>

Parameters:

not - the not function to visit.

Returns:

the value from the visitor.

visitBoolEquals

public Value visitBoolEquals(Expression left,
                             Expression right)

Description copied from interface: ExpressionVisitor

Does a boolean equality check.

Specified by:

visitBoolEquals in interface ExpressionVisitor<Value>

Parameters:

left - the first value to compare.

right - the second value to compare.

Returns:

the value from the visitor.

visitStringEquals

public Value visitStringEquals(Expression left,
                               Expression right)

Description copied from interface: ExpressionVisitor

Does a string equality check.

Specified by:

visitStringEquals in interface ExpressionVisitor<Value>

Parameters:

left - the first value to compare.

right - the second value to compare.

Returns:

the value from the visitor.

visitGetAttr

public Value visitGetAttr(GetAttr getAttr)

Description copied from interface: ExpressionVisitor

Visits a GetAttr function.

Specified by:

visitGetAttr in interface ExpressionVisitor<Value>

Parameters:

getAttr - the GetAttr function to visit.

Returns:

the value from the visitor.

visitLibraryFunction

public Value visitLibraryFunction(FunctionDefinition definition,
                                  java.util.List<Expression> arguments)

Description copied from interface: ExpressionVisitor

Visits a library function.

Specified by:

visitLibraryFunction in interface ExpressionVisitor<Value>

Parameters:

definition - the library function to visit.

arguments - the arguments to the function being visited.

Returns:

the value from the visitor.