noope.input
Class BlockReader

java.lang.Object
  |
  +--noope.input.BlockReader

Direct Known Subclasses:

ArrayBlockReader, StringBlockReader

public abstract class BlockReader

extends java.lang.Object

This is an abstract class used for reading in the law and entity definitions. This might be from a file, but is abstract, so it could be from anything, for example, a GUI editor program. This is a generic class, could be used for anything using this block format. (This is the syntax accepted by StringBlockReader.)

#any whitespace seperates tokens
#string values can use double quote marks to delimit
#use \" to put a quote mark inside a string
#comments start with a # symbol and extend until end of line
#[] denotes optional

header [parameter]
{
key1 value1  # this is an entry
key2 value2
key3 value3
...
keyN valueN
subheader1 [subparameter1]	# this is a block
{
subkey1 subvalue1
...
subsubheader1 [subsubparameter1]
{
...
}
}
header2 [subparameter2]
{
...
}
}

The format used for reading in a Physics object is as follows.

 
# this file is case sensitive
# comments start with hash

physics
{
laws
{
law 
{
[name "string"]
constant1 
constant2 
...
}
}
entities
{
entity []
{
[name "string"]
position 
velocity 
inertialMass 
}

Law1 
{
...
}
Law2
{
...
}
}
}

Here is an example of using the file format:

physics
{
laws
{
law Gravity
{
name "Gravity"
G 6.67e-23
}
}
entities
{
entity
{
# defaults to Entity class
name "Electron" position (0.5,54.5,45.1)
velocity 0	  # promotes to (0,0,0)
inertialMass 9.1e-31

Gravity
{
mass 9.1e-31
}
Electric
{
charge -1.6e-19
}
}
}
}

Version:

Miklos Reiter 19-May-2001: updated javadoc comments Modified by Miklos Reiter 21-Mar-2001: added peekNextEntry and peekNextBlock methods. Modified again by Paul Evans 27-Apr-2001: added toString

Author:

Paul Evans

Constructor Summary

BlockReader()

Method Summary

void	assertEmpty() Throws exception unless BlockReader is empty.
abstract BlockReaderLocation	getBlockLocation() Similar to getEntryLocation
abstract BlockReaderContext	getContext(BlockReaderLocation loc) Converts a Location into a fully-qualified Context object.
abstract BlockReaderLocation	getEntryLocation() Returns a BlockReaderLocation object describing the current Entry location.
abstract java.lang.String	getHeader() Returns the header of this block.
abstract BlockReader	getNextBlock() Returns the next subblock, which is an instance of BlockReader.
abstract java.lang.String[]	getNextEntry() Returns the next Entry, as a string array.
abstract java.lang.String	getParameter() Returns the parameter of this block.
abstract boolean	hasMoreBlocks() Returns TRUE if this block has more Blocks after the one that was last returned
abstract boolean	hasMoreEntries() Returns TRUE if this block has more Entries after the one that was last returned
abstract BlockReader	peekNextBlock() This method acts as getNextBlock() but does not advance position
abstract java.lang.String[]	peekNextEntry() This method acts as getNextEntry() but does not advance position
abstract void	seekFirstBlock() Resets the subblock position to the beginning, so that the next call to getNextBlock() will return the first subblock (unless there are no subblocks, in which case an exception is thrown, of course.
abstract void	seekFirstEntry() Moves the "entry pointer" back to the first Entry, so that the next call to getNextEntry() will return the first one in the block

Methods inherited from class java.lang.Object

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

Constructor Detail

BlockReader

public BlockReader()

Method Detail

getHeader

public abstract java.lang.String getHeader()
                                    throws BlockReaderException

Returns the header of this block. This is in some sense its "title".

getParameter

public abstract java.lang.String getParameter()
                                       throws BlockReaderException

Returns the parameter of this block.

hasMoreEntries

public abstract boolean hasMoreEntries()
                                throws BlockReaderException

Returns TRUE if this block has more Entries after the one that was last returned

getNextEntry

public abstract java.lang.String[] getNextEntry()
                                         throws BlockReaderException

Returns the next Entry, as a string array.

peekNextEntry

public abstract java.lang.String[] peekNextEntry()
                                          throws BlockReaderException

This method acts as getNextEntry() but does not advance position

seekFirstEntry

public abstract void seekFirstEntry()
                             throws BlockReaderException

Moves the "entry pointer" back to the first Entry, so that the next call to getNextEntry() will return the first one in the block

getEntryLocation

public abstract BlockReaderLocation getEntryLocation()
                                              throws BlockReaderException

Returns a BlockReaderLocation object describing the current Entry location. A BlockReaderLocation does not make sense to anyone, except this BlockReader and its parents.

hasMoreBlocks

public abstract boolean hasMoreBlocks()
                               throws BlockReaderException

Returns TRUE if this block has more Blocks after the one that was last returned

getNextBlock

public abstract BlockReader getNextBlock()
                                  throws BlockReaderException

Returns the next subblock, which is an instance of BlockReader. The first time called, it returns the first entry, and thereafter, returns successively later entries. If no more exist, it will throw an exception.

peekNextBlock

public abstract BlockReader peekNextBlock()
                                   throws BlockReaderException

This method acts as getNextBlock() but does not advance position

seekFirstBlock

public abstract void seekFirstBlock()
                             throws BlockReaderException

Resets the subblock position to the beginning, so that the next call to getNextBlock() will return the first subblock (unless there are no subblocks, in which case an exception is thrown, of course.

getBlockLocation

public abstract BlockReaderLocation getBlockLocation()
                                              throws BlockReaderException

Similar to getEntryLocation

getContext

public abstract BlockReaderContext getContext(BlockReaderLocation loc)
                                       throws BlockReaderException

Converts a Location into a fully-qualified Context object. This means that error messages, reports, etc... can be generated.

assertEmpty

public void assertEmpty()
                 throws BRLoadingException

Throws exception unless BlockReader is empty.