eu.bandm.tscore.base

Class Translet.State<R>

java.lang.Object

eu.bandm.tscore.base.Translet.State<R>

Enclosing class:

Translet

public static class Translet.State<R>
extends Object

Central data type for parser operation. Combines input situation, currently applied Translet.Parser, delivered Result, and the preceding state, thus forming a kind of parse tree in post order notation:

                                _______/ ----------- Parser(SEQU)
       ________________________/  ______/                 ^
     Parser                  Parser                       |
       ^                      ^                           |
       |                      |.parser                    |
   +------------+  .pre     +------------+   .pre    +------------+              
   | State      | <----     | State      |  <-----   | State      | 
   +------------+           +------------+           +------------+              
                                |.s |.pos
                                v   v
                            "toConsume"
  

State objects are added (a) when input characters are consumed, (b) when functions are applied for further result generation, or (c) when a storage action must be memorized for later execution.

".s" is constant and always simply copied, to be accessible by the terminal symbol parsing functions; ".pos" is advancing and reflects the situation AFTER ".parser" has consumed.

Parsing is executed in a breadth-first search, so that finally different successful parsing trees can coexist. All STORING operations are not yet performed but done ex-parte-post, after one of these solutions has been selected.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int	depth FIXME ????
static Predicate<Translet.State>	p_atEnd
(package private) Translet.Parser<R>	parser The translet parser which has consumed to produce this state.
(package private) int	pos The position after parsing.
(package private) @Opt Translet.State<?>	pre The preceding state.
(package private) R	result
(package private) String	s The input data on which all parsers operate.

Method Summary

Modifier and Type	Method and Description
boolean	atEnd() Return whether parsing has reached the end of the input string.
String	consumed() Returns the character input consumed DIRECTLY by the parser of this state, i.e.
void	executeStoring(Event e, Location<XMLDocumentIdentifier> loc, MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> msg) Step back through the chain of parser states and execute all store operation.
static Translet.State<Object>	initState(String s, int pos) Create an initial state with only the input data, no parser or result yet.
String	lookingAt() Return the current rest of the input string.
String	simpleString() Deliver printable representation only of this state.
<N,M extends N> Translet.State<N>	succ(Translet.Parser<N> parser, int pos, M result) Return a new State, which is successor of "this", and in which "parser" has delivered "result" and consumed input up to "pos".
<N,M extends N> Translet.State<N>	succ(Translet.Parser<N> parser, M result) Return a new State, which is successor of "this", and in which "parser" has delivered "result", but no input has been consumed.
String	toString() Deliver printable representation of the whole chain of states ending here.

Methods inherited from class java.lang.Object

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

Field Detail

parser

final Translet.Parser<R> parser

The translet parser which has consumed to produce this state.

pre

@Opt
final @Opt Translet.State<?> pre

The preceding state. Only == null for the very first state.

s

final String s

The input data on which all parsers operate.

pos

final int pos

The position after parsing.

depth

final int depth

FIXME ????

result

@Opt
final R result

p_atEnd

public static final Predicate<Translet.State> p_atEnd

Method Detail

initState

public static Translet.State<Object> initState(String s,
                                               int pos)

Create an initial state with only the input data, no parser or result yet.

succ

public <N,M extends N> Translet.State<N> succ(Translet.Parser<N> parser,
                                              M result)

Return a new State, which is successor of "this", and in which "parser" has delivered "result", but no input has been consumed.

succ

public <N,M extends N> Translet.State<N> succ(Translet.Parser<N> parser,
                                              int pos,
                                              M result)

Return a new State, which is successor of "this", and in which "parser" has delivered "result" and consumed input up to "pos".

executeStoring

public void executeStoring(Event e,
                           Location<XMLDocumentIdentifier> loc,
                           MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> msg)

Step back through the chain of parser states and execute all store operation. This is delegated to Translet.Parser.executeStoring(Translet.State,Event,Location,MessageReceiver). Only the instances of some dedicated parser classes really execute storing.

Parameters:

e - the event which is used as key for all the data maps

loc - the location of the whole expression, used in all error messages generated by storing.

msg - drain of error messages.

atEnd

public boolean atEnd()

Return whether parsing has reached the end of the input string.

consumed

public String consumed()

Returns the character input consumed DIRECTLY by the parser of this state, i.e. iff it is a terminal symbol. Both ".pos" and ".pre.pos" must be considered.

lookingAt

public String lookingAt()

Return the current rest of the input string.

simpleString

public String simpleString()

Deliver printable representation only of this state.

toString

public String toString()

Deliver printable representation of the whole chain of states ending here.

Overrides:

toString in class Object