ASDParser

java.lang.Object
- asd.ASDParser

All Implemented Interfaces:

ASDSemantics
```
public class ASDParser
extends java.lang.Object
implements ASDSemantics
```
Instances are parsers that can load an ASDGrammar from a specified file and use it to parse given utterances.

Author:

James A. Mason

Field Summary

Fields
Modifier and Type	Field and Description
`java.lang.String`	`ANYTHING` The string used to match anything at all in a given phrase or phrase structure.
`java.lang.String`	`CLOSEQUOTE` The lexical token which is to be recognized as ending a quoted string.
`java.lang.String`	`DUMMYWORD` The string recognized as representing a dummy node/instance in a grammar.
`java.lang.String`	`NO` Abbreviation for NOADVANCE
`java.lang.String`	`NOADVANCE` A possible value returned by the advance() method.
`java.lang.String`	`NUMBER` The string used to stand in for numeric values in a grammar lexicon.
`java.lang.String`	`OPENQUOTE` The lexical token which is to be recognized as beginning a quoted string.
`java.lang.String`	`QUIT` A possible value returned by the advance() method.
`java.lang.String`	`SPACECHARS` Whitespace characters which are to be recognized as delimiters for lexical tokens but not as lexical tokens themselves.
`java.lang.String`	`SPECIALCHARS` Characters which are to be recognized as individual lexical tokens by the segment method.
`java.lang.String`	`STRING` The string used to stand in for quoted strings in a grammar lexicon.
`java.lang.String`	`SUCCEED` A possible value returned by the advance() method.
`static java.lang.String`	`UNKNOWN` The string used to stand in for lexical tokens which are not found in a given grammar lexicon.

Constructor Summary

Constructors
Constructor and Description
`ASDParser()` Initializes an ASDParser with no semantics or application.
`ASDParser(java.lang.Object app)` Initializes an instance with the ASDParser itself to interpret semantic actions and semantic values in the grammar, and with application-specific messages to be sent to the specified application.
`ASDParser(java.lang.Object app, ASDSemantics semanticsInstance)` Initializes an ASDParser instance with a reference to a given application to which application-specific messages are to be sent, and a given instance of a class that implements the ASDSemantics interface.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`java.lang.String`	`advance()` Attempts to advance the parse state one step.
`boolean`	`backup()` Attempts to backtrack the parse state to the most recent place where a local ambiguity occurred -- that is, where there was more than one choice for advancing.
`java.lang.String`	`bracketPhrase()`
`java.lang.String`	`bracketPhrase(ASDPhraseNode p)`
`ASDPhraseNode`	`currentNode()`
`boolean`	`done()` Tests whether or not a parse has been completed successfully.
`java.util.ArrayList<java.lang.String>`	`expectedTypes()`
`java.util.HashMap<java.lang.String,java.lang.Object>`	`features()`
`java.lang.Object`	`get(java.lang.String featureName)` Returns the value of 'feature' with specified name.
`void`	`initialize(java.lang.String aString, java.util.ArrayList<java.lang.String> expected)` Initialize the ASDParser instance for parsing a given string as one of a list of expected phrase types.
`ASDGrammar`	`lexicon()`
`boolean`	`parse()` Attempts to find next parse of current phrase structure.
`int`	`parse(int maxSteps)` Attempts to find next parse of current phrase structure in a specified maximum number of advance steps.
`int`	`parseStepNumber()`
`ASDPhraseNode`	`phraseStructure()`
`void`	`raiseFeatures()` Copies the feature-value pairs from the current node value (which must be a Map) to the current top level of the phrase structure being parsed.
`java.lang.String`	`raiseFeaturesChecking()` Copies the feature-value pairs from the current node value (which must be a Map) to the current top level of the phrase structure being parsed, provided they are compatible with feature values already assigned.
`ASDPhraseNode`	`segment(java.lang.String aString)` Creates a phrase structure, a chain of ASDPhraseNodes, each containing one word, number, punctuation mark, or quoted string from the given String, with a dummy header node at the beginning of the chain.
`java.lang.String`	`semanticAction(java.lang.String action)` Evaluates a string from a "semantic action" field in an ASDGrammar, by invoking the corresponding method of the application object.
`java.lang.Object`	`semanticValue(java.lang.String value)` Evaluates a string from a "semantic value" field in an ASDGrammar, as a long integer number, a quoted string, or by invoking the method of the application object which is named by the semantic value field.
`void`	`set(java.lang.String featureName, java.lang.Object value)` Sets contents of a 'feature' with the specified name to the specified value.
`void`	`setANYTHING(java.lang.String newValue)` Resets the string which is used to match anything at all in a given phrase or phrase structure.
`void`	`setCLOSEQUOTE(java.lang.String newValue)` Resets the lexical token which is to be recognized as ending a quoted string.
`void`	`setDUMMYWORD(java.lang.String newValue)` Resets the string which is recognized by the ASDParser as representing a "dummy" word in the grammar -- used in the labels on dummy nodes.
`void`	`setNOADVANCE(java.lang.String newValue)` Sets the NOADVANCE (== NO) value which may be returned by the advance method to a new value preferred by the client.
`void`	`setNUMBER(java.lang.String newValue)` Resets the string used to stand in for numeric values in a grammar lexicon.
`void`	`setOPENQUOTE(java.lang.String newValue)` Resets the lexical token which is to be recognized as beginning a quoted string.
`void`	`setQUIT(java.lang.String newValue)` Sets the QUIT value which may be returned by the advance method to a new value preferred by the client.
`void`	`setSaveUniquelyParsedSubphrases(boolean save)` Tells the ASDParser instance whether or not to retain uniquely-parsed subphrases when it backtracks.
`void`	`setSPACECHARS(java.lang.String newValue)` Resets the string of characters which are to be recognized as delimiters for lexical tokens but not as lexical tokens themselves.
`void`	`setSPECIALCHARS(java.lang.String newValue)` Resets the string of characters which are to be recognized as individual lexical tokens by the segment method.
`void`	`setSTRING(java.lang.String newValue)` Resets the string used to stand in for quoted strings in a grammar lexicon.
`void`	`setSUCCEED(java.lang.String newValue)` Sets the SUCCEED value which may be returned by the advance method to a new value preferred by the client.
`void`	`setUNKNOWN(java.lang.String newValue)` Resets the string used to stand in for words which are not found in a given grammar lexicon.
`void`	`showTree()` Displays the current parse tree to the console, with a -> pointer to the current node at the top level
`void`	`stepParse(int maxSteps)` Attempts to find next parse of current phrase structure in a specified maximum number of advance steps; displays the parse tree to System.out after each step.
`boolean`	`useGrammar(ASDGrammar grammar)` Sets the ASDParser instance to use a given ASDGrammar.
`boolean`	`useGrammar(java.lang.String fileName)` Sets the ASDParser instance to use an ASDGrammar loaded from a specified file.
`java.lang.Object`	`valueOf(java.lang.String featureName)` Returns the value of 'feature' with specified name.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ANYTHING
```
public java.lang.String ANYTHING
```
    The string used to match anything at all in a given phrase or phrase structure. By default it is equal to "ANYTHING".
  - CLOSEQUOTE
```
public java.lang.String CLOSEQUOTE
```
    The lexical token which is to be recognized as ending a quoted string. The default is ".
  - DUMMYWORD
```
public java.lang.String DUMMYWORD
```
    The string recognized as representing a dummy node/instance in a grammar. By default it is equal to ASDGrammar.DUMMYWORD.
  - NOADVANCE
```
public java.lang.String NOADVANCE
```
    A possible value returned by the advance() method. It indicates that an attempt to advance the parse one step has failed, and backup should be performed if possible.
  - NO
```
public java.lang.String NO
```
    Abbreviation for NOADVANCE
  - NUMBER
```
public java.lang.String NUMBER
```
    The string used to stand in for numeric values in a grammar lexicon. By default it is equal to "NUMBER".
  - OPENQUOTE
```
public java.lang.String OPENQUOTE
```
    The lexical token which is to be recognized as beginning a quoted string. The default is ".
  - QUIT
```
public java.lang.String QUIT
```
    A possible value returned by the advance() method. It indicates that the parse cannot succeed and should be terminated with failure.
  - SPACECHARS
```
public java.lang.String SPACECHARS
```
    Whitespace characters which are to be recognized as delimiters for lexical tokens but not as lexical tokens themselves. Note: Other Unicode whitespace characters are NOT recognized as delimiters but ARE trimmed from the beginnings and ends of lexical tokens, if present.
  - SPECIALCHARS
```
public java.lang.String SPECIALCHARS
```
    Characters which are to be recognized as individual lexical tokens by the segment method. The default value is ",.;:?!$@#%&*()[]{}+=<>/~\\".
  - STRING
```
public java.lang.String STRING
```
    The string used to stand in for quoted strings in a grammar lexicon. By default it is equal to "STRING".
  - SUCCEED
```
public java.lang.String SUCCEED
```
    A possible value returned by the advance() method. It indicates that an attempt to advance the parse one step has been successful.
  - UNKNOWN
```
public static java.lang.String UNKNOWN
```
    The string used to stand in for lexical tokens which are not found in a given grammar lexicon. By default it is equal to "UNKNOWN".
- Constructor Detail
  - ASDParser
```
public ASDParser()
```
    Initializes an ASDParser with no semantics or application. By default it saves uniquely parsed subphrases when it backtracks.
  - ASDParser
```
public ASDParser(java.lang.Object app)
```
    Initializes an instance with the ASDParser itself to interpret semantic actions and semantic values in the grammar, and with application-specific messages to be sent to the specified application. By default the ASDParser instance saves uniquely parsed subphrases when it backtracks.
    
    Parameters:
    
    app - the target for application-specific messages
  - ASDParser
```
public ASDParser(java.lang.Object app,
                 ASDSemantics semanticsInstance)
```
    Initializes an ASDParser instance with a reference to a given application to which application-specific messages are to be sent, and a given instance of a class that implements the ASDSemantics interface. By default the ASDParser instance saves uniquely parsed subphrases when it backtracks.
    
    Parameters:
    
    app - the target for application-specific messages
    
    semanticsInstance - instance of a class that implements ASDSemantics (null if none)
- Method Detail
  - currentNode
```
public ASDPhraseNode currentNode()
```
    Returns:
    
    the current Node at the top level in the phrase structure.
  - expectedTypes
```
public java.util.ArrayList<java.lang.String> expectedTypes()
```
    Returns:
    
    the parser's current list of expected phrase types for the top level of a parse.
  - features
```
public java.util.HashMap<java.lang.String,java.lang.Object> features()
```
    Returns:
    
    the feature-value pairs for the current top level of the phrase structure.
  - get
```
public java.lang.Object get(java.lang.String featureName)
```
    Returns the value of 'feature' with specified name. Same as the valueOf method.
    
    Parameters:
    
    featureName - the feature whose value is to be obtained
    
    Returns:
    
    the value of the feature; null if none
  - lexicon
```
public ASDGrammar lexicon()
```
    Returns:
    
    the ASDGrammar which is currently being used by the parser.
  - phraseStructure
```
public ASDPhraseNode phraseStructure()
```
    Returns:
    
    the header node of the current phrase structure.
  - parseStepNumber
```
public int parseStepNumber()
```
    Returns:
    
    the number of the current step in a parse.
  - set
```
public void set(java.lang.String featureName,
                java.lang.Object value)
```
    Sets contents of a 'feature' with the specified name to the specified value.
    
    Parameters:
    
    featureName - the feature whose value is to be set
    
    value - the value to be assigned to featureName
  - valueOf
```
public java.lang.Object valueOf(java.lang.String featureName)
```
    Returns the value of 'feature' with specified name. Same as the get method.
    
    Parameters:
    
    featureName - the feature whose value is to be obtained
    
    Returns:
    
    the value of the feature; null if none
  - initialize
```
public void initialize(java.lang.String aString,
                       java.util.ArrayList<java.lang.String> expected)
```
    Initialize the ASDParser instance for parsing a given string as one of a list of expected phrase types.
    
    Parameters:
    
    aString - the string to be parsed
    
    expected - an ArrayList of strings, each the name of one of the expected phrase types.
  - advance
```
public java.lang.String advance()
```
    Attempts to advance the parse state one step.
    
    Returns:
    
    SUCCEED if successful, NOADVANCE if unsuccessful but parse should continue after backup, QUIT if parse should quit.
  - backup
```
public boolean backup()
```
    Attempts to backtrack the parse state to the most recent place where a local ambiguity occurred -- that is, where there was more than one choice for advancing.
    
    Returns:
    
    true if backtrack is successful, false if there was no step in the parse to which to backtrack
  - bracketPhrase
```
public java.lang.String bracketPhrase()
```
    Returns:
    
    a string showing the current utterance string with parentheses around each subphrase of more than one non-dummy word.
  - bracketPhrase
```
public java.lang.String bracketPhrase(ASDPhraseNode p)
```
    Parameters:
    
    p - an ASDPhraseNode in a phrase structure
    
    Returns:
    
    a string with parentheses around each subphrase of p with length > 1.
  - done
```
public boolean done()
```
    Tests whether or not a parse has been completed successfully.
    
    Returns:
    
    true if successful, false if not.
  - parse
```
public boolean parse()
```
    Attempts to find next parse of current phrase structure.
    
    Returns:
    
    true if successful, false if unsuccessful
  - parse
```
public int parse(int maxSteps)
```
    Attempts to find next parse of current phrase structure in a specified maximum number of advance steps.
    
    Parameters:
    
    maxSteps - the maximum number of steps permitted
    
    Returns:
    
    positive number of steps required if successful, negative number of steps performed if unsuccessful
  - raiseFeatures
```
public void raiseFeatures()
```
    Copies the feature-value pairs from the current node value (which must be a Map) to the current top level of the phrase structure being parsed.
  - raiseFeaturesChecking
```
public java.lang.String raiseFeaturesChecking()
```
    Copies the feature-value pairs from the current node value (which must be a Map) to the current top level of the phrase structure being parsed, provided they are compatible with feature values already assigned.
    
    Returns:
    
    SUCCEED if they are, NOADVANCE if they are not compatible. Return QUIT if the current node value is not a Map.
  - segment
```
public ASDPhraseNode segment(java.lang.String aString)
```
    Creates a phrase structure, a chain of ASDPhraseNodes, each containing one word, number, punctuation mark, or quoted string from the given String, with a dummy header node at the beginning of the chain.
    
    Parameters:
    
    aString - a string to be parsed
    
    Returns:
    
    the first (dummy) ASDPhraseNode
  - semanticAction
```
public java.lang.String semanticAction(java.lang.String action)
```
    Evaluates a string from a "semantic action" field in an ASDGrammar, by invoking the corresponding method of the application object.
    
    Specified by:
    
    semanticAction in interface ASDSemantics
    
    Parameters:
    
    action - the semantic action string to be evaluated; the name of a public method in the application class, one with no parameters that returns a String.
    
    Returns:
    
    the String returned by the method invoked in the application class; possibly the NOADVANCE or QUIT string.
  - semanticValue
```
public java.lang.Object semanticValue(java.lang.String value)
```
    Evaluates a string from a "semantic value" field in an ASDGrammar, as a long integer number, a quoted string, or by invoking the method of the application object which is named by the semantic value field.
    
    Specified by:
    
    semanticValue in interface ASDSemantics
    
    Parameters:
    
    value - the semantic value string to be evaluated, an integer, a string surrounded by double quotes, or the name of a public method in the application class, one with no parameters that returns a String.
    
    Returns:
    
    the Object returned by the method invoked in the application class; possibly the NOADVANCE or QUIT string.
  - setANYTHING
```
public void setANYTHING(java.lang.String newValue)
```
    Resets the string which is used to match anything at all in a given phrase or phrase structure.
    
    Parameters:
    
    newValue - is the new value used to match anything
  - setCLOSEQUOTE
```
public void setCLOSEQUOTE(java.lang.String newValue)
```
    Resets the lexical token which is to be recognized as ending a quoted string.
    
    Parameters:
    
    newValue - is the new value used to end a quoted string
  - setNOADVANCE
```
public void setNOADVANCE(java.lang.String newValue)
```
    Sets the NOADVANCE (== NO) value which may be returned by the advance method to a new value preferred by the client.
    
    Parameters:
    
    newValue - is the new value to be returned when no advance was possible for the parser
  - setDUMMYWORD
```
public void setDUMMYWORD(java.lang.String newValue)
```
    Resets the string which is recognized by the ASDParser as representing a "dummy" word in the grammar -- used in the labels on dummy nodes.
    
    Parameters:
    
    newValue - is the new value which represents a dummy word
  - setNUMBER
```
public void setNUMBER(java.lang.String newValue)
```
    Resets the string used to stand in for numeric values in a grammar lexicon.
    
    Parameters:
    
    newValue - is the new value which stands for a numeric value
  - setOPENQUOTE
```
public void setOPENQUOTE(java.lang.String newValue)
```
    Resets the lexical token which is to be recognized as beginning a quoted string.
    
    Parameters:
    
    newValue - is the new value which represents an open quote
  - setQUIT
```
public void setQUIT(java.lang.String newValue)
```
    Sets the QUIT value which may be returned by the advance method to a new value preferred by the client.
    
    Parameters:
    
    newValue - is the new value which is returned when parser quits
  - setSaveUniquelyParsedSubphrases
```
public void setSaveUniquelyParsedSubphrases(boolean save)
```
    Tells the ASDParser instance whether or not to retain uniquely-parsed subphrases when it backtracks.
    
    Parameters:
    
    save - when true tells the parser to save uniquely-parsed subphrases
  - setSPACECHARS
```
public void setSPACECHARS(java.lang.String newValue)
```
    Resets the string of characters which are to be recognized as delimiters for lexical tokens but not as lexical tokens themselves. For the initialize method to work properly, these should all be Unicode whitespace characters.
    
    Parameters:
    
    newValue - is the string of characters to be used as delimiters
  - setSPECIALCHARS
```
public void setSPECIALCHARS(java.lang.String newValue)
```
    Resets the string of characters which are to be recognized as individual lexical tokens by the segment method.
    
    Parameters:
    
    newValue - is the string of characters to be recognized as individual tokens
  - setSTRING
```
public void setSTRING(java.lang.String newValue)
```
    Resets the string used to stand in for quoted strings in a grammar lexicon.
    
    Parameters:
    
    newValue - is the string to stand for a quoted string
  - setSUCCEED
```
public void setSUCCEED(java.lang.String newValue)
```
    Sets the SUCCEED value which may be returned by the advance method to a new value preferred by the client.
    
    Parameters:
    
    newValue - is the string to be returned when the parser succeeds in completing a parse
  - setUNKNOWN
```
public void setUNKNOWN(java.lang.String newValue)
```
    Resets the string used to stand in for words which are not found in a given grammar lexicon.
    
    Parameters:
    
    newValue - is the string to represent an unknown word
  - showTree
```
public void showTree()
```
    Displays the current parse tree to the console, with a -> pointer to the current node at the top level
  - stepParse
```
public void stepParse(int maxSteps)
```
    Attempts to find next parse of current phrase structure in a specified maximum number of advance steps; displays the parse tree to System.out after each step.
    
    Parameters:
    
    maxSteps - the maximum number of steps permitted
  - useGrammar
```
public boolean useGrammar(ASDGrammar grammar)
```
    Sets the ASDParser instance to use a given ASDGrammar.
    
    Parameters:
    
    grammar - the grammar to be used.
    
    Returns:
    
    true if grammar is not null, false if grammar is null.
  - useGrammar
```
public boolean useGrammar(java.lang.String fileName)
```
    Sets the ASDParser instance to use an ASDGrammar loaded from a specified file.
    
    Parameters:
    
    fileName - the name of the file containing the grammar.
    
    Returns:
    
    true if successful, false if the grammar cannot be loaded successfully from the file.

Class ASDParser

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ANYTHING

CLOSEQUOTE

DUMMYWORD

NOADVANCE

NO

NUMBER

OPENQUOTE

QUIT

SPACECHARS

SPECIALCHARS

STRING

SUCCEED

UNKNOWN

Constructor Detail

ASDParser

ASDParser

ASDParser

Method Detail

currentNode

expectedTypes

features

get

lexicon

phraseStructure

parseStepNumber

set

valueOf

initialize

advance

backup

bracketPhrase

bracketPhrase

done

parse

parse

raiseFeatures

raiseFeaturesChecking

segment

semanticAction

semanticValue

setANYTHING

setCLOSEQUOTE

setNOADVANCE

setDUMMYWORD

setNUMBER

setOPENQUOTE

setQUIT

setSaveUniquelyParsedSubphrases

setSPACECHARS

setSPECIALCHARS

setSTRING

setSUCCEED

setUNKNOWN

showTree

stepParse

useGrammar

useGrammar