Package com.singularsys.extensions.lambda

Class BracketedRangeSequenceGrammarMatcher

java.lang.Object

com.singularsys.extensions.lambda.BracketedRangeSequenceGrammarMatcher

All Implemented Interfaces:

GrammarMatcher, java.io.Serializable

public class BracketedRangeSequenceGrammarMatcher
extends java.lang.Object
implements GrammarMatcher

A GrammarMatcher which matches lists of items with the syntax [a..b], or a simple list [1,2,3,4]. Differs from ListOrRangeGrammarMatcher as both the sequence operator and range operator are parsed using the standard parser. So 1,2,3,4 is parsed as a single subexpression rather than as four subexpressions.

The precedence of operator should be: ...; Or "||"; Range ".."; Ternary "?:"; Lambda "=>"; Equals "="; Sequence ","

A typical setup might be:

                OperatorTable2 ot = new StandardOperatorTable2();
                Operator rangeOp = new RangeOperator("..", "[", "]", new Range(), Operator.BINARY);
                Operator seqOp = new Operator(",", null, Operator.BINARY+Operator.RIGHT);
                Operator lambdaOp = new Operator("=>", new LambdaFunGenerator(), Operator.BINARY);
                TernaryOperator ternOp = new TernaryOperator("cond", "?", ":", 
                                new TernaryConditional(), 
                                Operator.TERNARY+Operator.NARY+Operator.LEFT);
                                
                ot.insertOperator(new OperatorKey() {}, rangeOp, ot.getAssign());
                ot.insertOperator(new OperatorKey() {}, ternOp,ot.getAssign());
                ot.insertOperator(new OperatorKey() {}, lambdaOp, ot.getAssign());
                ot.appendOperator(new OperatorKey() {}, seqOp, ot.getAssign());

                ConfigurableParser cp = new ConfigurableParser();
        cp.addHashComments();
        cp.addSlashComments();
        cp.addSingleQuoteStrings();
        cp.addDoubleQuoteStrings();
        cp.addWhiteSpace();
        cp.addExponentNumbers();
        cp.addSymbols("(",")","[","]"); 
        cp.setImplicitMultiplicationSymbols("(","["); 
        cp.addOperatorTokenMatcher();
        cp.addIdentifiers();
        cp.addSemiColonTerminator();
        cp.addWhiteSpaceCommentFilter();
        cp.addBracketMatcher("(",")"); 
        cp.addGrammarMatcher(new FunctionSequenceGrammarMatcher(
                        cp.getSymbolToken("("),
                        cp.getSymbolToken(")"),
                        seqOp));
        cp.addGrammarMatcher(new BracketedRangeSequenceGrammarMatcher(
                        cp.getSymbolToken("["),
                        cp.getSymbolToken("]"),
                        rangeOp,seqOp
                        )); 
        cp.addArrayAccessMatcher("[","]"); //$NON-NLS-1$ //$NON-NLS-2$

        lp = new StandardListProcessor();
                jep = new Jep(ot,cp, lp);
 

See Also:

LambdaFunSeqTest, Serialized Form

Constructor Summary

Constructors

Constructor	Description
BracketedRangeSequenceGrammarMatcher(Token open, Token close, Operator rangeOp, Operator seqOp)	Create a ListGrammarMatcher

Method Summary

Modifier and Type	Method	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)	Test whether the input matches this pattern.

Methods inherited from class java.lang.Object

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

Constructor Detail

BracketedRangeSequenceGrammarMatcher

public BracketedRangeSequenceGrammarMatcher(Token open,
                                            Token close,
                                            Operator rangeOp,
                                            Operator seqOp)

Create a ListGrammarMatcher

Parameters:

open - token representing an opening bracket

close - token representing a closing bracket

rangeOp - operator representing the range

seqOp - operator representing sequences

Method Detail

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.

match

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

Description copied from interface: GrammarMatcher

Test whether the input matches this pattern.

Specified by:

match in interface GrammarMatcher

Parameters:

it - An iterator inspecting the input

parser - the parser to use when evaluating sub expressions

Returns:

if matched returns a node representing the content, return null is does not match

Throws:

ParseException - if there is a syntactical error in the input.