Package eu.bandm.tools.util2

Class TunableParser<D>

java.lang.Object
eu.bandm.tools.util2.TunableParser<D>
Direct Known Subclasses:
TunableParserForXml
public abstract class TunableParser<D> extends Object
Parser skeleton for explicit lexical decoding and recursive descent ("hand-coded") parsing of idiosyncratic grammars. It is prepared for use as a base class for TunedDTDParser (in fact, it is an extraction from the original code.) Therefore it is prepared for "external entity expansion", which is "file inclusion" in a more general way of talking. This is maintained by IncludingCharBuf, to which all character read, buffer insertion and buffer restore is delegated.
The interface methods fall in different categories:
  • boolean lookahead (...) yields whether the current input does match.
  • void match (...) consumes specified input. MUST match, otherwise calls "fatalError()"
  • boolean matchahead (...) combination of both: consumes specified input iff possible.
Beside these basic interfaces there are some more specialized:
  • matchUpTo(..) and skipUpTo(..) consumes as long as the specified prefix is NOT reached (or end of input is reached).
  • eof(..) matches iff end of input is reached.

  • Field Details

    • in

      protected IncludingCharBuf<D> in
      The current input.

    • topleveldocumentid

      protected D topleveldocumentid
      Id for generating locations in messages.

    • base

      @Opt protected @Opt URL base
      Basis for resolving include directives.

    • messageReceiver

      protected MessageReceiver<? super SimpleMessage<D>> messageReceiver

  • Constructor Details

    • TunableParser

      protected TunableParser(Reader in, D id, MessageReceiver<? super SimpleMessage<D>> msg)
      Constructor.
      Parameters:
      in - source to parse
      id - id of toplevel document, for locations in messages
      msg - message channel

  • Method Details

    • setBase

      public void setBase(@Opt @Opt URL base)
      set base for resolving include directives.

    • setMessageReceiver

      public void setMessageReceiver(MessageReceiver<? super SimpleMessage<D>> rec)

    • getMessageReceiver

      public MessageReceiver<? super SimpleMessage<D>> getMessageReceiver()

    • error

      protected void error(String msg)

    • failure

      protected void failure(String msg)

    • warning

      protected void warning(String msg)

    • fatalError

      protected abstract void fatalError(String s)
      Signals parsing errors, must be re-defined by derived class.

    • readExternal

      @Opt public @Opt String readExternal(String systemID)
      Read a file relative to the current base and return its contents. Is based on URLs to allow include of RELATIVELY given files for files in the file system as well as files given as resource/via class loader.
      Parameters:
      systemID - a "system identifier", which is an URI according to [xml1.0]

    • lookahead

      protected final boolean lookahead(char c)
      Returns whether the next character to read is equal to the parameter.

    • lookahead

      protected final boolean lookahead(int k, char c)
      Returns whether the next character after (k-1) consumptions would be equal to the parameter.

    • lookahead

      protected final boolean lookahead(String prefix)
      Returns whether the current input is prefixed by the string parameter.

    • lookahead

      protected final boolean lookahead(TunableParser.CharSet s)
      Returns whether the next character to read is contained in the parameter.

    • lookahead

      protected final boolean lookahead(int k, TunableParser.CharSet s)
      Returns whether the next character after (k-1) consumptions would be contained in the parameter.

    • matchahead

      protected final boolean matchahead(char c)
      Like lookahead(char), and then consume() if success.

    • matchahead

      protected final boolean matchahead(String prefix)
      Like lookahead(String), and then consume() if success.

    • matchahead

      protected final boolean matchahead(TunableParser.CharSet s)
      Like lookahead(CharSet), and then consume() if success.

    • match

      protected final void match(char c)
      Call to lookahead(char),must succeed, then consume(). Calls fatalError(String) if not.

    • match

      protected final void match(String prefix)
      Call to lookahead(String),must succeed, then consume(). Calls fatalError(String) if not.

    • match

      protected final char match(TunableParser.CharSet s)
      Call to lookahead(CharSet),must succeed, then consume().
      Calls fatalError(String) if not.

    • match

      protected final char match()
      Consumes any character and returns it.

    • matchUpto

      protected String matchUpto(char end)
      Consumes all characters upto (excluding) the given delimiter and returns them.
      Calls fatalError(String) if reading beyond end of input.

    • matchUpto

      protected String matchUpto(String end)
      Consumes all characters upto (excluding) the given delimiter and returns them.
      Calls fatalError(String) if reading beyond end of input.

    • skipUpto

      protected void skipUpto(String end)
      Consumes all characters upto (excluding) the given delimiter and discard them.
      Calls fatalError(String) if reading beyond end of input.

    • consume

      protected void consume()
      Advance input by one character position.

    • eof

      protected void eof()
      Assume end of input reached. Call fatalError(String) if not.

    • lookahead_eof

      protected boolean lookahead_eof()
      Report whether end of input reached.

    • word

      protected String word(TunableParser.CharSet alphabet)
      Accept any sequence of characters from the given set, including the empty word, and return it.