Package eu.bandm.tools.d2d2.base

Class CharacterParser

java.lang.Object

eu.bandm.tools.d2d2.model.MATCH_ONLY_00

eu.bandm.tools.d2d2.model.SinglePhase

eu.bandm.tools.d2d2.base.CharacterParser

public class CharacterParser
extends SinglePhase

Realizes the fine granular d2d character level parsing. Usage: call constructor, then parse(eu.bandm.tools.d2d2.base.MemScanner<java.lang.String>,eu.bandm.tools.d2d2.model.CharsRegExp,eu.bandm.tools.d2d2.rt.ResultingStructure). The parsing is nondeterministically (implemented as parallel search) and delivers one of the resulting interpretations which consume most input characters.
Character based parsing is conceptually AFTER the elimination of comments, and AFTER the translation of closing parenthesis characters into close tags.
It is NOT AFTER the translation of numeric input character entities.
The standard command character "#" in a parser definition is matched to the actual current command character in the input text.
FIXME Kommentare werden übersprungen ABER NICHT aus den Resultaten gestrichen.
For these translation purposes there are dedicated consumer methods with the word "_filtered_", MemScanner.accept_greedy_filtered_chars(CharSet), MemScanner.accept_one_filtered_char(CharSet), MemScanner.accept_blanks_filtered(), MemScanner.accept_string_w_o_lineswitch(String).
EXCPTION ONE: String constants (by a parser definition like
... ~ "ABC" ~ ...
are only acceptes when outside of comments, i.e. the characters of a String constant parser may not be interrupted by comment insertions.
EXCPTION TWO: Charater sets with a star- or plus operator are interpreted in a GREEDY way, not non-deterministically: ('a'..'z')~* ~ ('a'..'z')
will never match anything!

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	CharacterParser.ParseResult	A simple wrapper for one (of the many parallel) parsing situations; wraps MemScanner as the next input situation and ResultingStructures as collected so far.

Field Summary

Fields

Modifier and Type	Field	Description
protected final Navigate.CharSetCalc	charSetCalc
protected final boolean	doTrace
protected Set<CharacterParser.ParseResult>	hypotheses	Set of alive parsing situations: is input before visiting a grammar sub-expression and output after parsing.
protected final MessageReceiver<SimpleMessage<XMLDocumentIdentifier>>	msg

Fields inherited from class eu.bandm.tools.d2d2.model.MATCH_ONLY_00

_visitor_debug_stream, partial

Constructor Summary

Constructors

Constructor	Description
CharacterParser(Navigate.CharSetCalc charSetCalc, MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> msg, boolean doTrace)	Only constructor.

Method Summary

Modifier and Type	Method	Description
protected void	acceptCharRep(CharSet cset, boolean isstar, boolean istight)	Provides special treatment (implemented directly in the scanner), including different semantics (greedy, not non-determinstically !) for character set expressions.
protected void	acceptRep(GrUnary expr, boolean isstar)
void	action(Alt expr)
void	action(CharBinary expr)
void	action(CharExpr expr)
void	action(CharsRegExp def)
void	action(Enumeration enumeration)	treat enumeration as parser and create a special resulting structure.
void	action(Greedy greedy)	Only the longest matches for each incoming hypotheses are recognized.
void	action(ImportItem def)
void	action(Insertion insertion)	Special case of insertion, namely the reference to an enumeration, can survive the rewriting process: (@ ref).
void	action(Opt expr)
void	action(ParseParticle pp)
void	action(Perm permutation)
void	action(Plus expr)
void	action(Reference ref)
void	action(Seq expr)
void	action(Star expr)
void	action(StringConst expr)
void	action(TagsRegExp def)
protected void	copyContentsFromTo(CharacterParser.ParseResult from, MemScanner<String> startpos, ResultingStructure to)	If "from" has structured contents, then add this into "to", as a sequence and per assoc.
protected void	flattened_consumption_of_enum(Enumeration enumeration)	when called from an insertion: treat an enumeration as mere collection of string constants, i.e.
@Opt ResultingStructure	parse(MemScanner<String> scanner, CharsRegExp parser, ResultingStructure result)	Central executive method.
protected void	subElement(Definition def, Expression rule)	Called when reaching a ParseParticle, a CharsRegExp or an Enumeration, which all lead to wrapping the parsing result into a Result object with this definition as its tag.
protected void	trace(@Opt Location<XMLDocumentIdentifier> loc, String s)
protected void	trace(String s)
protected void	typingError(Location<XMLDocumentIdentifier> loc)

Methods inherited from class eu.bandm.tools.d2d2.model.SinglePhase

action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, action, follow_definitions, follow_defInstances, follow_docu, follow_firsts, follow_globalSubsts, follow_imports, follow_itemDocu, follow_localdefs, follow_localSubsts, follow_modules, follow_namespaces, follow_obligates, follow_on, follow_rawModules, follow_text, follow_weakfirsts, follow_xattributes

Methods inherited from class eu.bandm.tools.d2d2.model.MATCH_ONLY_00

_visitor_trace, action, action, action, action, action, compile, followAll_definitions, followAll_defInstances, followAll_docu, followAll_firsts, followAll_globalSubsts, followAll_imports, followAll_itemDocu, followAll_localdefs, followAll_localSubsts, followAll_modules, followAll_namespaces, followAll_obligates, followAll_on, followAll_rawModules, followAll_text, followAll_weakfirsts, followAll_xattributes, foreignObject, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, match, nomatch

Methods inherited from class java.lang.Object

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

Field Details

msg

protected final MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> msg

charSetCalc

protected final Navigate.CharSetCalc charSetCalc

doTrace

protected final boolean doTrace

hypotheses

protected Set<CharacterParser.ParseResult> hypotheses

Set of alive parsing situations: is input before visiting a grammar sub-expression and output after parsing.

Constructor Details

CharacterParser

public CharacterParser(Navigate.CharSetCalc charSetCalc,
 MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> msg,
 boolean doTrace)

Only constructor. "charSetCalc" is meant as a cache and should be the same for every construction. (Reusage of instances would be possible, but the only current caller=Text2Udom does not.)

Method Details

parse

@Opt
public @Opt ResultingStructure parse(MemScanner<String> scanner,
 CharsRegExp parser,
 ResultingStructure result)

Central executive method. It gets a particular CharsRegExp definition and tries to match the character input (given by the MemScanner) by a non-deterministic, parallel breadth-first execution.
Maintains a set of CharacterParser.ParseResult objects combining parser state and the ResultingStructure, as constructed so far.
In case of success, it returns one (randomly chosen) of the matches which consume most input characters and adjusts "scanner" accordingly. (So "scanner is both an input and an output argument.
In case of failure, it returns null and does not advance the input pointer in "scanner".

copyContentsFromTo

protected void copyContentsFromTo(CharacterParser.ParseResult from,
 MemScanner<String> startpos,
 ResultingStructure to)

If "from" has structured contents, then add this into "to", as a sequence and per assoc. Otherwise copy the characters from "startpos" upto the current(=accepting) input pointer pos in "from". ***

typingError

protected void typingError(Location<XMLDocumentIdentifier> loc)

trace

protected void trace(String s)

trace

protected void trace(@Opt
 @Opt Location<XMLDocumentIdentifier> loc,
 String s)

action

public void action(Insertion insertion)

Special case of insertion, namely the reference to an enumeration, can survive the rewriting process: (@ ref). It means a flattened acceptance of one of the enumeration's string values.
Also INFINITE CYCLES of insertions of CharsRegExp may survive. NOT YET SUPPORTED FIXME.

Overrides:

action in class SinglePhase

action

public void action(Perm permutation)

Overrides:

action in class SinglePhase

action

public void action(Reference ref)

Overrides:

action in class SinglePhase

flattened_consumption_of_enum

protected void flattened_consumption_of_enum(Enumeration enumeration)

when called from an insertion: treat an enumeration as mere collection of string constants, i.e. consume one of them and do NOT create any corresponding element.

action

public void action(Enumeration enumeration)

treat enumeration as parser and create a special resulting structure.

Overrides:

action in class SinglePhase

subElement

protected void subElement(Definition def,
 Expression rule)

Called when reaching a ParseParticle, a CharsRegExp or an Enumeration, which all lead to wrapping the parsing result into a Result object with this definition as its tag. All cases can lead to character data only; the first two cases can also lead to sub-result-objects (structured contents) instead. All results must be wrapped explicitly.

action

public void action(CharsRegExp def)

Overrides:

action in class SinglePhase

action

public void action(ParseParticle pp)

Overrides:

action in class SinglePhase

action

public void action(TagsRegExp def)

Overrides:

action in class SinglePhase

action

public void action(ImportItem def)

Overrides:

action in class SinglePhase

acceptCharRep

protected void acceptCharRep(CharSet cset,
 boolean isstar,
 boolean istight)

Provides special treatment (implemented directly in the scanner), including different semantics (greedy, not non-determinstically !) for character set expressions.

acceptRep

protected void acceptRep(GrUnary expr,
 boolean isstar)

action

public void action(Star expr)

Overrides:

action in class SinglePhase

action

public void action(Plus expr)

Overrides:

action in class SinglePhase

action

public void action(Greedy greedy)

Only the longest matches for each incoming hypotheses are recognized.

Overrides:

action in class SinglePhase

action

public void action(Opt expr)

Overrides:

action in class SinglePhase

action

public void action(Alt expr)

Overrides:

action in class SinglePhase

action

public void action(Seq expr)

Overrides:

action in class SinglePhase

action

public void action(CharBinary expr)

Overrides:

action in class SinglePhase

action

public void action(CharExpr expr)

Overrides:

action in class SinglePhase

action

public void action(StringConst expr)

Overrides:

action in class SinglePhase