org.javacc.parser
Class Lookahead
java.lang.Object
org.javacc.parser.Expansion
org.javacc.parser.Lookahead
public class Lookahead
- extends Expansion
Describes lookahead rule for a particular expansion or expansion
sequence (See Sequence.java). In case this describes the lookahead
rule for a single expansion unit, then a sequence is created with
this node as the first element, and the expansion unit as the second
and last element.
Field Summary |
java.util.Vector |
action_tokens
Contains the list of tokens that make up the semantic lookahead
if any. |
int |
amount
The lookahead amount. |
boolean |
isExplicit
Is set to true if this is an explicit lookahead specification. |
Expansion |
la_expansion
The expansion used to determine whether or not to choose the
corresponding parse option. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
action_tokens
public java.util.Vector action_tokens
- Contains the list of tokens that make up the semantic lookahead
if any. If this node represents a different kind of lookahead (other
than semantic lookahead), then this vector contains nothing. If
this vector contains something, then it is the boolean expression
that forms the semantic lookahead. In this case, the following
fields "amount" and "la_expansion" are ignored.
amount
public int amount
- The lookahead amount. Its default value essentially gives us
infinite lookahead.
la_expansion
public Expansion la_expansion
- The expansion used to determine whether or not to choose the
corresponding parse option. This expansion is parsed upto
"amount" tokens of lookahead or until a complete match for it
is found. Usually, this is the same as the expansion to be
parsed.
isExplicit
public boolean isExplicit
- Is set to true if this is an explicit lookahead specification.
Lookahead
public Lookahead()