public Class ParserRuleContext

If we are debugging or building a parse tree for a visitor, we need to track all of the tokens and rule invocations associated with this rule's context. This is empty for parsing w/o tree constr. operation because we don't the need to track the details about how we parse this rule.

The exception that forced this rule to return. If the rule successfully completed, this is null.

For debugging/tracing purposes, we want to track all of the nodes in the ATN traversed by the parser for a particular rule. This list indicates the sequence of ATN nodes used to match the elements of the children list. This list does not include ATN nodes and other rules used to match rule invocations. It traces the rule invocation node itself but nothing inside that other rule's ATN submachine. There is NOT a one-to-one correspondence between the children and states list. There are typically many nodes in the ATN traversed for each element in the children list. For example, for a rule invocation there is the invoking state and the following state. The parser setState() method updates field s and adds it to this list if we are debugging/tracing. This does not trace states visited during prediction.

For debugging/tracing purposes, we want to track all of the nodes in the ATN traversed by the parser for a particular rule. This list indicates the sequence of ATN nodes used to match the elements of the children list. This list does not include ATN nodes and other rules used to match rule invocations. It traces the rule invocation node itself but nothing inside that other rule's ATN submachine. There is NOT a one-to-one correspondence between the children and states list. There are typically many nodes in the ATN traversed for each element in the children list. For example, for a rule invocation there is the invoking state and the following state. The parser setState() method updates field s and adds it to this list if we are debugging/tracing. This does not trace states visited during prediction.

Add a parse tree node to this as a child. Works for internal and leaf nodes. Does not set parent link; other add methods must do that. Other addChild methods call this. We cannot set the parent pointer of the incoming node because the existing interfaces do not have a setParent() method and I don't want to break backward compatibility for this.

Since

4.7

Add a token leaf node child and force its parent to be this node.

Add a child to this node based upon matchedToken. It creates a TerminalNodeImpl rather than using Parser#createTerminalNode(ParserRuleContext, Token). I'm leaving this in for compatibility but the parser doesn't use this anymore.

Annotations

@Deprecated

Add an error node child and force its parent to be this node.

Since

4.7

Add a child to this node based upon badToken. It creates a ErrorNodeImpl rather than using Parser#createErrorNode(ParserRuleContext, Token). I'm leaving this in for compatibility but the parser doesn't use this anymore.

Annotations

@Deprecated

COPY a ctx (I'm deliberately not using copy constructor) to avoid confusion with creating node with parent. Does not copy children (except error leaves). This is used in the generated parser code to flip a generic XContext node for rule X to a YContext for alt label Y. In that sense, it is not really a generic copy function. If we do an error sync() at start of a rule, we might add error nodes to the generic XContext so this function must copy those nodes to the YContext as well else they are lost!

Overrides org.antlr.v4.runtime.RuleContext.getChild.

Implements org.antlr.v4.runtime.tree.ParseTree.getChild.

Doc from org.antlr.v4.runtime.tree.Tree.getChild.

If there are children, get the ith value indexed from 0.

Annotations

@Override

Overrides org.antlr.v4.runtime.RuleContext.getChildCount.

Implements org.antlr.v4.runtime.tree.Tree.getChildCount.

Doc from org.antlr.v4.runtime.tree.Tree.getChildCount.

How many children are there? If there is none, then this node represents a leaf node.

Annotations

@Override

Overrides org.antlr.v4.runtime.RuleContext.getParent.

Implements org.antlr.v4.runtime.tree.ParseTree.getParent.

Doc from org.antlr.v4.runtime.tree.Tree.getParent.

The parent of this node. If the return value is null, then this node is the root of the tree.

Annotations

@Override

Overrides org.antlr.v4.runtime.RuleContext.getSourceInterval.

Implements org.antlr.v4.runtime.tree.SyntaxTree.getSourceInterval.

Doc from org.antlr.v4.runtime.tree.SyntaxTree.getSourceInterval.

Return an Interval indicating the index in the TokenStream of the first and last token associated with this subtree. If this node is a leaf, then the interval represents a single token and has interval i..i for token index i.

An interval of i..i-1 indicates an empty interval at position i in the input stream, where 0 <= i <= the size of the input token stream. Currently, the code base can only have i=0..n-1 but in concept one could have an empty interval after EOF.

If source interval is unknown, this returns Interval#INVALID.

As a weird special case, the source interval for rules matched after EOF is unspecified.

Annotations

@Override

Get the initial token in this context. Note that the range from start to stop is inclusive, so for rules that do not consume anything (for example, zero length or error productions) this token may exceed stop.

Get the final token in this context. Note that the range from start to stop is inclusive, so for rules that do not consume anything (for example, zero length or error productions) this token may precede start.

Used by enterOuterAlt to toss out a RuleContext previously added as we entered a rule. If we have # label, we will need to remove generic ruleContext object.

Used for rule context info debugging during parse-time, not so much for ATN debugging