com.singularsys.extensions.structure

Class SequenceRule

java.lang.Object

com.singularsys.extensions.structure.SequenceRule

All Implemented Interfaces:

GrammaticalRuleI, GrammarMatcher, java.io.Serializable

Direct Known Subclasses:

SequenceSeparatorRule

public class SequenceRule
extends java.lang.Object
implements GrammaticalRuleI

Parses a sequence of statements

 <SequenceRule> ::=
        (<statement>)*
 

A successful parses will return a SequenceNode with one child per statement. If there is only one child then just that child will be parsed.

Author:

Richard Morris

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SequenceRule(GrammaticalRuleI statement)

Method Summary

Modifier and Type	Method and Description
void	init(Jep jep) Delayed initialisation, this methods is called whenever components of the jep instance are changed.
Node	match(Lookahead2Iterator<Token> it, GrammarParser parser) Attempt to parse the input using the rule
Node	match(Lookahead2Iterator<Token> it, SymbolToken end, GrammarParser parser) Repeatedly parse statements until end token is encountered or end of input

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SequenceRule

public SequenceRule(GrammaticalRuleI statement)

Parameters:

statement - rule to parse individual statements

Method Detail

match

public Node match(Lookahead2Iterator<Token> it,
                  SymbolToken end,
                  GrammarParser parser)
           throws ParseException

Repeatedly parse statements until end token is encountered or end of input

Parameters:

it - the input list of tokens

end - symbol marking end of sequence

parser - parser to parse individual statements

Returns:

a SequenceNode

Throws:

ParseException - if input cannot be parsed

match

public Node match(Lookahead2Iterator<Token> it,
                  GrammarParser parser)
           throws ParseException

Description copied from interface: GrammaticalRuleI

Attempt to parse the input using the rule

Specified by:

match in interface GrammaticalRuleI

Specified by:

match in interface GrammarMatcher

Parameters:

it - iterator with tokens to parse

parser - the parser to parse any components of the rule

Returns:

successful parses should return a Node, null if unsuccessful

Throws:

ParseException - if there is a syntactical error

init

public void init(Jep jep)

Description copied from interface: GrammarMatcher

Delayed initialisation, this methods is called whenever components of the jep instance are changed.

Specified by:

init in interface GrammarMatcher

Parameters:

jep - the current jep instance.