Package software.amazon.smithy.rulesengine.language.syntax.expressions.functions

Class Ite

java.lang.Object

software.amazon.smithy.rulesengine.language.syntax.SyntaxElement

software.amazon.smithy.rulesengine.language.syntax.expressions.Expression

software.amazon.smithy.rulesengine.language.syntax.expressions.functions.LibraryFunction

software.amazon.smithy.rulesengine.language.syntax.expressions.functions.Ite

All Implemented Interfaces:

FromSourceLocation, ToNode, TypeCheck, ToCondition, ToExpression

public final class Ite
extends LibraryFunction

An if-then-else (ITE) function that returns one of two values based on a boolean condition.

This function is critical for avoiding SSA (Static Single Assignment) fragmentation in BDD compilation. By computing conditional values atomically without branching, it prevents the graph explosion that occurs when boolean flags like UseFips or UseDualStack create divergent paths with distinct variable identities.

Semantics: ite(condition, trueValue, falseValue)

• If condition is true, returns trueValue
• If condition is false, returns falseValue
• The condition must be a non-optional boolean (use coalesce to provide a default if needed)

Type checking rules (least upper bound of nullability):

• ite(Boolean, T, T) => T - both non-optional, result is non-optional
• ite(Boolean, T, Optional<T>) => Optional<T> - any optional makes result optional
• ite(Boolean, Optional<T>, T) => Optional<T> - any optional makes result optional
• ite(Boolean, Optional<T>, Optional<T>) => Optional<T> - both optional, result is optional

Available since: rules engine 1.1.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	Ite.Definition	A FunctionDefinition for the Ite function.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ID

Fields inherited from class software.amazon.smithy.rulesengine.language.syntax.expressions.functions.LibraryFunction

definition, functionNode

Method Summary

Modifier and Type	Method	Description
<R> R	accept(ExpressionVisitor<R> visitor)	Invoke the ExpressionVisitor functions for this expression.
RulesVersion	availableSince()	Get the rules engine version that this syntax element is available since.
static Ite.Definition	getDefinition()	Gets the FunctionDefinition implementation.
static Ite	ofExpressions(ToExpression condition, ToExpression trueValue, ToExpression falseValue)	Creates a Ite function from the given expressions.
static Ite	ofStrings(ToExpression conditionRef, String trueValue, String falseValue)	Creates a Ite function with a reference condition and string values.
protected Type	typeCheckLocal(Scope<Type> scope)

Methods inherited from class software.amazon.smithy.rulesengine.language.syntax.expressions.functions.LibraryFunction

calculateReferences, canonicalize, equals, expectOneArgument, getArguments, getFunctionDefinition, getName, getSourceLocation, hashCode, shouldSwapArgs, toConditionBuilder, toNode, toString

Methods inherited from class software.amazon.smithy.rulesengine.language.syntax.expressions.Expression

fromNode, getLiteral, getReference, getReference, getReference, getReferences, of, of, of, parseShortform, toExpression, type, typeCheck

Methods inherited from class software.amazon.smithy.rulesengine.language.syntax.SyntaxElement

booleanEqual, getAttr, getAttr, isSet, isValidHostLabel, not, parseUrl, stringEqual, substring, template

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface software.amazon.smithy.rulesengine.language.syntax.ToCondition

toCondition, toCondition

Field Details

ID

public static final String ID

See Also:

• Constant Field Values

Method Details

getDefinition

public static Ite.Definition getDefinition()

Gets the FunctionDefinition implementation.

Returns:

the function definition.

ofExpressions

public static Ite ofExpressions(ToExpression condition,
 ToExpression trueValue,
 ToExpression falseValue)

Creates a Ite function from the given expressions.

Parameters:

condition - the boolean condition to evaluate

trueValue - the value to return if condition is true

falseValue - the value to return if condition is false

Returns:

The resulting Ite function.

ofStrings

public static Ite ofStrings(ToExpression conditionRef,
 String trueValue,
 String falseValue)

Creates a Ite function with a reference condition and string values.

Parameters:

conditionRef - the reference to a boolean parameter

trueValue - the string value if condition is true

falseValue - the string value if condition is false

Returns:

The resulting Ite function.

availableSince

public RulesVersion availableSince()

Description copied from class: SyntaxElement

Get the rules engine version that this syntax element is available since.

Overrides:

availableSince in class SyntaxElement

Returns:

the version this is available since.

accept

public <R> R accept(ExpressionVisitor<R> visitor)

Description copied from class: Expression

Invoke the ExpressionVisitor functions for this expression.

Specified by:

accept in class Expression

Type Parameters:

R - the visitor return type.

Parameters:

visitor - the visitor to be invoked.

Returns:

the return value of the visitor.

typeCheckLocal

protected Type typeCheckLocal(Scope<Type> scope)
                       throws InnerParseError

Overrides:

typeCheckLocal in class LibraryFunction

Throws:

InnerParseError