SemanticContext.Empty (ANTLR 4 Runtime 4.13.2 API)

java.lang.Object
- org.antlr.v4.runtime.atn.SemanticContext
- - org.antlr.v4.runtime.atn.SemanticContext.Empty

Enclosing class:: SemanticContext

public static class SemanticContext.Empty
extends SemanticContext

Nested Class Summary
- Nested classes/interfaces inherited from class org.antlr.v4.runtime.atn.SemanticContext
  SemanticContext.AND, SemanticContext.Empty, SemanticContext.Operator, SemanticContext.OR, SemanticContext.PrecedencePredicate, SemanticContext.Predicate

Field Summary

Fields
Modifier and Type Field Description

static SemanticContext.Empty Instance
The default SemanticContext, which is semantically equivalent to a predicate of the form {true}?.

Constructor Summary

Constructors
Constructor Description

Empty()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`eval(Recognizer<?,?> parser, RuleContext parserCallStack)`	For context independent predicates, we evaluate them without a local context (i.e., null context).

Methods inherited from class org.antlr.v4.runtime.atn.SemanticContext
and, evalPrecedence, or

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - Instance
```
public static final SemanticContext.Empty Instance
```
    The default SemanticContext, which is semantically equivalent to a predicate of the form {true}?.
- Constructor Detail
  - Empty
```
public Empty()
```
- Method Detail
  - eval
```
public boolean eval(Recognizer<?,?> parser,
                    RuleContext parserCallStack)
```
    Description copied from class: SemanticContext
    
    For context independent predicates, we evaluate them without a local context (i.e., null context). That way, we can evaluate them without having to create proper rule-specific context during prediction (as opposed to the parser, which creates them naturally). In a practical sense, this avoids a cast exception from RuleContext to myruleContext.
    For context dependent predicates, we must pass in a local context so that references such as $arg evaluate properly as _localctx.arg. We only capture context dependent predicates in the context in which we begin prediction, so we passed in the outer context here in case of context dependent predicate evaluation.
    
    Specified by:
    
    eval in class SemanticContext