att.grappa
Class Parser

java.lang.Object
  java_cup.runtime.lr_parser
      att.grappa.Parser

public class Parser
extends lr_parser

This class provides a parser for the dot graph representation format. It is used in conjunction with JavaCup, a yacc-like parser generator originally by:

Scott E. Hudson
Graphics Visualization and Usability Center
Georgia Institute of Technology

and more recently modified and maintained by a number of people at Princeton University.

Version:

1.2, 21 Aug 2005; Copyright 1996 - 2005 by AT&T Corp.

Author:

John Mocenigo, Research @ AT&T Labs

Field Summary

protected static short[][]	_action_table Parse-action table.
protected static short[][]	_production_table Production table.
protected static short[][]	_reduce_table reduce_goto table.
protected CUP$Parser$actions	action_obj Instance of action encapsulation class.
private int	debugLevel
private java.io.PrintWriter	errWriter
private Lexer	lexer
private Graph	theGraph

Fields inherited from class java_cup.runtime.lr_parser

_done_parsing, _error_sync_size, action_tab, cur_token, lookahead, lookahead_pos, production_tab, reduce_tab, stack, tos

Constructor Summary

Parser()
Default constructor.

Parser(java.io.InputStream inputStream)
A convenience constructor equivalent to Parser(inputStream,null,null).

Parser(java.io.InputStream inputStream, java.io.OutputStream errorStream)
A convenience constructor equivalent to Parser(inputStream,errorStream,null).

Parser(java.io.InputStream inputStream, java.io.OutputStream errorStream, Graph graph)
Create an instance of Parser with input, error output and a supplied Graph object.

Parser(java.io.Reader inputReader)
A convenience constructor equivalent to Parser(inputReader,null,null).

Parser(java.io.Reader inputReader, java.io.PrintWriter errorWriter)
A convenience constructor equivalent to Parser(inputReader,errorWriter,null).

Parser(java.io.Reader inputReader, java.io.PrintWriter errorWriter, Graph graph)
Create an instance of Parser with input, error output and a supplied Graph object.

Parser(Scanner s)
Constructor which sets the default scanner.

Method Summary

short[][]	action_table() Access to parse-action table.
void	debug_message(int level, java.lang.String message) Write a debugging message to the error stream.
void	debug_message(java.lang.String message) Write a debugging message to the error stream.
Symbol	debug_parse(int debug) Invokes the parser in debug mode.
Symbol	do_action(int act_num, lr_parser parser, java.util.Stack stack, int top) Invoke a user supplied parse action.
int	EOF_sym() EOF Symbol index.
int	error_sym() error Symbol index.
(package private) CUP$Parser$actions	getActionObject()
int	getDebugLevel() Get the debug level for this parser.
java.io.PrintWriter	getErrorWriter() Get the error writer, if any, for this parser.
Graph	getGraph() Get the graph resulting from the parsing operations.
Lexer	getLexer() Get the Lexer object associated with this parser.
protected void	init_actions() Action encapsulation object initializer.
short[][]	production_table() Access to production table.
short[][]	reduce_table() Access to reduce_goto table.
void	report_error(java.lang.String message, java.lang.Object info) Report a fatal error.
void	report_warning(java.lang.String message, java.lang.Object info) Report a non-fatal error.
Symbol	scan() Scan to get the next Symbol.
int	start_production() Indicates start production.
int	start_state() Indicates start state.
void	user_init() User initialization code.

Methods inherited from class java_cup.runtime.lr_parser

advance_lookahead, cur_err_token, debug_parse, debug_reduce, debug_shift, debug_stack, done_parsing, dump_stack, error_recovery, error_sync_size, find_recovery_config, get_action, get_reduce, getScanner, parse_lookahead, parse, read_lookahead, report_fatal_error, restart_lookahead, setScanner, shift_under_error, syntax_error, try_parse_ahead, unpackFromStrings, unrecovered_syntax_error

Methods inherited from class java.lang.Object

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

Field Detail

_production_table

protected static final short[][] _production_table

Production table.

_action_table

protected static final short[][] _action_table

Parse-action table.

_reduce_table

protected static final short[][] _reduce_table

reduce_goto table.

action_obj

protected CUP$Parser$actions action_obj

Instance of action encapsulation class.

theGraph

private Graph theGraph

errWriter

private java.io.PrintWriter errWriter

lexer

private Lexer lexer

debugLevel

private int debugLevel

Constructor Detail

Parser

public Parser()

Default constructor.

Parser

public Parser(Scanner s)

Constructor which sets the default scanner.

Parser

public Parser(java.io.Reader inputReader,
              java.io.PrintWriter errorWriter,
              Graph graph)

Create an instance of Parser with input, error output and a supplied Graph object. The graph object is cleared (reset) before new graph components are added to it by this parsing operation.

Parameters:

inputReader - input Reader object

errorWriter - error output Writer object (or null to suppress error output)

graph - Graph object for storing parsed graph information (or null to create a new object)

Parser

public Parser(java.io.Reader inputReader,
              java.io.PrintWriter errorWriter)

A convenience constructor equivalent to Parser(inputReader,errorWriter,null).

Parameters:

inputReader - input Reader object

errorWriter - error output Writer object (or null to suppress error output)

Parser

public Parser(java.io.Reader inputReader)

A convenience constructor equivalent to Parser(inputReader,null,null).

Parameters:

inputReader - input Reader object

Parser

public Parser(java.io.InputStream inputStream,
              java.io.OutputStream errorStream,
              Graph graph)

Create an instance of Parser with input, error output and a supplied Graph object. The input stream is converted to a Reader and the error stream is converted to a Writer.

Parameters:

inputStream - input InputStream object

errorStream - error output OutputStream object (or null to suppress error output)

graph - Graph object for storing parsed graph information (or null to create a new object)

Parser

public Parser(java.io.InputStream inputStream,
              java.io.OutputStream errorStream)

A convenience constructor equivalent to Parser(inputStream,errorStream,null).

Parameters:

inputStream - input InputStream object

errorStream - error output OutputStream object

Parser

public Parser(java.io.InputStream inputStream)

A convenience constructor equivalent to Parser(inputStream,null,null).

Parameters:

inputStream - input InputStream object

Method Detail

production_table

public short[][] production_table()

Access to production table.

Specified by:

production_table in class lr_parser

action_table

public short[][] action_table()

Access to parse-action table.

Specified by:

action_table in class lr_parser

See Also:

lr_parser.get_action(int, int)

reduce_table

public short[][] reduce_table()

Access to reduce_goto table.

Specified by:

reduce_table in class lr_parser

See Also:

lr_parser.get_reduce(int, int)

init_actions

protected void init_actions()

Action encapsulation object initializer.

Specified by:

init_actions in class lr_parser

do_action

public Symbol do_action(int act_num,
                        lr_parser parser,
                        java.util.Stack stack,
                        int top)
                 throws java.lang.Exception

Invoke a user supplied parse action.

Specified by:

do_action in class lr_parser

Parameters:

act_num - the internal index of the action to be performed.

parser - the parser object we are acting for.

stack - the parse stack of that object.

top - the index of the top element of the parse stack.

Throws:

java.lang.Exception

start_state

public int start_state()

Indicates start state.

Specified by:

start_state in class lr_parser

start_production

public int start_production()

Indicates start production.

Specified by:

start_production in class lr_parser

EOF_sym

public int EOF_sym()

EOF Symbol index.

Specified by:

EOF_sym in class lr_parser

error_sym

public int error_sym()

error Symbol index.

Specified by:

error_sym in class lr_parser

user_init

public void user_init()
               throws java.lang.Exception

User initialization code.

Overrides:

user_init in class lr_parser

Throws:

java.lang.Exception

scan

public Symbol scan()
            throws java.lang.Exception

Scan to get the next Symbol.

Overrides:

scan in class lr_parser

Throws:

java.lang.Exception

getLexer

public Lexer getLexer()

Get the Lexer object associated with this parser.

Returns:

the associated lexical analyzer.

getErrorWriter

public java.io.PrintWriter getErrorWriter()

Get the error writer, if any, for this parser.

Returns:

the error writer for this parser.

getDebugLevel

public int getDebugLevel()

Get the debug level for this parser. The debug level is set to a non-zero value by calling debug_parse.

Returns:

the debug level of this parser.

See Also:

debug_parse(int)

report_error

public void report_error(java.lang.String message,
                         java.lang.Object info)
                  throws GraphParserException

Report a fatal error. Calling this method will throw a GraphParserException.

Overrides:

report_error in class lr_parser

Parameters:

message - the error message to send to the error stream and include in the thrown exception

info - not used

Throws:

GraphParserException - whenver this method is called

report_warning

public void report_warning(java.lang.String message,
                           java.lang.Object info)

Report a non-fatal error.

Parameters:

message - the warning message to send to the error stream, if the stream non-null.

info - not used

debug_message

public void debug_message(java.lang.String message)

Write a debugging message to the error stream. The debug level of the message is 5.

Overrides:

debug_message in class lr_parser

Parameters:

message - the debug message to send to the error stream, if the stream non-null.

See Also:

debug_message(int,String)

debug_message

public void debug_message(int level,
                          java.lang.String message)

Write a debugging message to the error stream. A message is written only if the error stream is not null and the debug level of the message is greater than or equal to the debugging level of the parser.

Parameters:

level - the level of the message

message - the debug message to send to the error stream, if the stream non-null.

See Also:

getDebugLevel()

debug_parse

public Symbol debug_parse(int debug)
                   throws java.lang.Exception

Invokes the parser in debug mode. The lowering the debug level reduces the amount of debugging output. A level of 0 inhibits all debugging messages, generally a level of 10 will let all messages get through.

Parameters:

debug - the debug level to use for filtering debug messages based on priority.

Throws:

java.lang.Exception - if parse() does

getActionObject

CUP$Parser$actions getActionObject()

getGraph

public Graph getGraph()

Get the graph resulting from the parsing operations.

Returns:

the graph generated from the input.