Expression

Package: com.hypixel.hytale.server.npc.util.expression

public class Expression

Entry point for the NPC expression evaluator. An Expression instance owns a CompileContext and an ExecutionContext and provides methods to compile expression strings into instruction lists, execute pre-compiled instructions, or evaluate an expression in a single call. The compile step uses a Lexer<Token> shared across all instances.

Fields

Modifier	Type	Name	Description
private static final	Lexer<Token>	lexer	Shared lexer instance for tokenizing expression strings.
@Nonnull private final	ExecutionContext	executionContext	Execution context obtained from the compile context.
@Nonnull private final	CompileContext	compileContext	Compile context for parsing and type-checking expressions.

Constructors

Signature
public Expression()

Methods

Modifier	Return Type	Signature
public	ValueType	compile(@Nonnull String expression, Scope scope, @Nonnull List<ExecutionContext.Instruction> instructions, boolean fullResolve)
public	ValueType	compile(@Nonnull String expression, Scope compileScope, @Nonnull List<ExecutionContext.Instruction> instructions)
@Nonnull public	ExecutionContext	execute(@Nonnull List<ExecutionContext.Instruction> instructions, Scope scope)
@Nonnull public	ExecutionContext	execute(@Nonnull ExecutionContext.Instruction[] instructions, Scope scope)
@Nonnull public	ExecutionContext	evaluate(@Nonnull String expression, Scope scope)
public static	ValueType	compileStatic(@Nonnull String expression, Scope scope, @Nonnull List<ExecutionContext.Instruction> instructions)
@Nonnull public static	Lexer<Token>	getLexerInstance()

Usage

compile() parses an expression string into a list of ExecutionContext.Instruction objects and returns the result type. execute() runs a pre-compiled instruction list against a Scope. evaluate() combines both steps for one-shot evaluation. The fullResolve parameter in the four-argument compile overload controls whether the compiler resolves all symbols at compile time.

Related Types

• ExecutionContext — the stack VM that runs compiled instructions
• Scope — provides variable bindings and functions
• ValueType — result type discriminant