ContextTracker Class Reference

Tracks user interaction and context. More...

#include <contextTracker.h>

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List of all members.

Public Member Functions

 ContextTracker (Configuration *config, PredictorRegistry *predictorRegistry, PresageCallback *callback, const char[]=DEFAULT_WORD_CHARS, const char[]=DEFAULT_SEPARATOR_CHARS, const char[]=DEFAULT_BLANKSPACE_CHARS, const char[]=DEFAULT_CONTROL_CHARS)
 ~ContextTracker ()
const PresageCallbackcallback (const PresageCallback *callback)
bool contextChange ()
std::string getPrefix () const
std::string getToken (const int) const
std::string getExtraTokenToLearn (const int index, const std::vector< std::string > &change) const
std::string getFutureStream () const
std::string getPastStream () const
bool isCompletionValid (const std::string &) const
std::string getWordChars () const
std::string getSeparatorChars () const
std::string getBlankspaceChars () const
std::string getControlChars () const
std::string toString () const
void update ()
void learn (const std::string &text) const
 Learn from text.
virtual void update (const Observable *variable)
void set_logger (const std::string &value)
void set_sliding_window_size (const std::string &value)
void set_lowercase_mode (const std::string &value)

Static Public Attributes

static const char * LOGGER = "Presage.ContextTracker.LOGGER"
static const char * SLIDING_WINDOW_SIZE = "Presage.ContextTracker.SLIDING_WINDOW_SIZE"
static const char * LOWERCASE_MODE = "Presage.ContextTracker.LOWERCASE_MODE"

Private Member Functions

bool isWordChar (const char) const
bool isSeparatorChar (const char) const
bool isControlChar (const char) const
bool isBlankspaceChar (const char) const

Private Attributes

std::string wordChars
std::string separatorChars
std::string blankspaceChars
std::string controlChars
bool lowercase_mode
const PresageCallbackcontext_tracker_callback
PredictorRegistrypredictorRegistry
ContextChangeDetectorcontextChangeDetector
Logger< char > logger
Dispatcher< ContextTrackerdispatcher

Detailed Description

Tracks user interaction and context.

ContextTracker job is to track the history of user input and track context changes.

History is the sequence of characters input by the user. Context is defined by the token the system is attempting to predict. Context changes occur when certain characters are input.

Tracking user input history and context changes can be trickier than one would think. To ease this operation, characters are classified into these categories:

word characters blankspace characters separator characters control characters

Word characters become part of the current prefix. Word characters do not trigger a change in context.

Blankspace and separator characters trigger a context change and mark the end of the current prediction token.

Control characters are non-printable characters such up, down, left, right arrows and function keys.

Use-cases:

Full sentence: Yesterday I went to the market to buy an apple.

History:Yesterday I went to the| wi-2 "went" wi-1 "to" prefix "" postfix ""

: 'SPC' (space) History:Yesterday I went to the| wi-2 "to" wi-1 "the" prefix "" postfix ""

: 'm' History:Yesterday I went to the m| wi-2 "to" wi-1 "the" prefix "m" postfix ""

: 'a' History:Yesterday I went to the ma| wi-2 "to" wi-1 "the" prefix "ma" postfix ""

: 'rket' History:Yesterday I went to the market| wi-2 "to" wi-1 "the" prefix "market" postfix ""

: 'SPC' History:Yesterday I went to the market | wi-2 "the" wi-1 "market" prefix "" postfix ""

: 't' History:Yesterday I went to the market t| wi-2 "the" wi-1 "market" prefix "t" postfix ""

: 'LEFT_ARROW' History:Yesterday I went to the market |t wi-2 "the" wi-1 "market" prefix "" postfix ""

: 'LEFT_ARROW' History:Yesterday I went to the market| t wi-2 "to" wi-1 "the" prefix "market" postfix ""

: 's' History:Yesterday I went to the markets| t wi-2 "to" wi-1 "the" prefix "markets" postfix ""

Definition at line 155 of file contextTracker.h.


Constructor & Destructor Documentation

ContextTracker::ContextTracker ( Configuration config,
PredictorRegistry predictorRegistry,
PresageCallback callback,
const char  wChars[] = DEFAULT_WORD_CHARS,
const char  tChars[] = DEFAULT_SEPARATOR_CHARS,
const char  bChars[] = DEFAULT_BLANKSPACE_CHARS,
const char  cChars[] = DEFAULT_CONTROL_CHARS 
)
ContextTracker::~ContextTracker (  ) 

Definition at line 78 of file contextTracker.cpp.

References contextChangeDetector.


Member Function Documentation

const PresageCallback * ContextTracker::callback ( const PresageCallback callback  ) 

Definition at line 101 of file contextTracker.cpp.

References context_tracker_callback.

bool ContextTracker::contextChange (  ) 

Returns true if a context change occured.

Definition at line 113 of file contextTracker.cpp.

References ContextChangeDetector::context_change(), contextChangeDetector, and getPastStream().

Referenced by Presage::context_change(), Selector::select(), and Selector::update().

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std::string ContextTracker::getBlankspaceChars (  )  const

Definition at line 313 of file contextTracker.cpp.

References blankspaceChars.

std::string ContextTracker::getControlChars (  )  const

Definition at line 318 of file contextTracker.cpp.

References controlChars.

std::string ContextTracker::getExtraTokenToLearn ( const int  index,
const std::vector< std::string > &  change 
) const

Definition at line 218 of file contextTracker.cpp.

References getToken().

Referenced by SmoothedNgramPredictor::learn().

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std::string ContextTracker::getFutureStream (  )  const

Definition at line 247 of file contextTracker.cpp.

References context_tracker_callback, and PresageCallback::get_future_stream().

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std::string ContextTracker::getPastStream (  )  const

Definition at line 252 of file contextTracker.cpp.

References context_tracker_callback, and PresageCallback::get_past_stream().

Referenced by Presage::context(), contextChange(), and update().

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std::string ContextTracker::getPrefix (  )  const

Definition at line 173 of file contextTracker.cpp.

References getToken().

Referenced by isCompletionValid(), RecencyPredictor::predict(), DictionaryPredictor::predict(), DejavuPredictor::predict(), AbbreviationExpansionPredictor::predict(), Presage::prefix(), Selector::Selector(), and Selector::thresholdFilter().

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std::string ContextTracker::getSeparatorChars (  )  const

Definition at line 308 of file contextTracker.cpp.

References separatorChars.

std::string ContextTracker::getToken ( const int  index  )  const
std::string ContextTracker::getWordChars (  )  const

Definition at line 303 of file contextTracker.cpp.

References wordChars.

bool ContextTracker::isBlankspaceChar ( const char  c  )  const [private]

Definition at line 287 of file contextTracker.cpp.

References blankspaceChars.

bool ContextTracker::isCompletionValid ( const std::string &  completion  )  const

Definition at line 258 of file contextTracker.cpp.

References getPrefix(), and Utility::strtolower().

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bool ContextTracker::isControlChar ( const char  c  )  const [private]

Definition at line 295 of file contextTracker.cpp.

References controlChars.

bool ContextTracker::isSeparatorChar ( const char  c  )  const [private]

Definition at line 279 of file contextTracker.cpp.

References separatorChars.

bool ContextTracker::isWordChar ( const char  c  )  const [private]

Definition at line 271 of file contextTracker.cpp.

References wordChars.

void ContextTracker::learn ( const std::string &  text  )  const

Learn from text.

Train the predictors on

Parameters:
text. Each active predictor will apply their machine learning algorithm to learn from the
text. 

Definition at line 130 of file contextTracker.cpp.

References blankspaceChars, endl(), ForwardTokenizer::hasMoreTokens(), PredictorRegistry::Iterator::hasNext(), PredictorRegistry::iterator(), Predictor::learn(), logger, lowercase_mode, Tokenizer::lowercaseMode(), PredictorRegistry::Iterator::next(), ForwardTokenizer::nextToken(), predictorRegistry, and separatorChars.

Referenced by update().

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void ContextTracker::set_logger ( const std::string &  value  ) 

Definition at line 83 of file contextTracker.cpp.

References endl(), logger, and setlevel().

Referenced by ContextTracker().

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void ContextTracker::set_lowercase_mode ( const std::string &  value  ) 

Definition at line 95 of file contextTracker.cpp.

References endl(), Utility::isYes(), logger, and lowercase_mode.

Referenced by ContextTracker().

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void ContextTracker::set_sliding_window_size ( const std::string &  value  ) 

Definition at line 89 of file contextTracker.cpp.

References contextChangeDetector, endl(), logger, and ContextChangeDetector::set_sliding_window_size().

Referenced by ContextTracker().

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std::string ContextTracker::toString (  )  const

Definition at line 323 of file contextTracker.cpp.

References context_tracker_callback, PresageCallback::get_future_stream(), and PresageCallback::get_past_stream().

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void ContextTracker::update ( const Observable variable  )  [virtual]

Implements Observer.

Definition at line 328 of file contextTracker.cpp.

References Dispatcher< class_t >::dispatch(), dispatcher, endl(), Observable::get_name(), Observable::get_value(), and logger.

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void ContextTracker::update (  ) 

Definition at line 118 of file contextTracker.cpp.

References ContextChangeDetector::change(), contextChangeDetector, getPastStream(), learn(), and ContextChangeDetector::update_sliding_window().

Referenced by Presage::predict().

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Member Data Documentation

std::string ContextTracker::blankspaceChars [private]
std::string ContextTracker::controlChars [private]

Definition at line 214 of file contextTracker.h.

Referenced by ContextTracker(), getControlChars(), and isControlChar().

Definition at line 233 of file contextTracker.h.

Referenced by ContextTracker(), and update().

Logger<char> ContextTracker::logger [private]
const char * ContextTracker::LOGGER = "Presage.ContextTracker.LOGGER" [static]

Definition at line 206 of file contextTracker.h.

Referenced by ContextTracker().

Definition at line 216 of file contextTracker.h.

Referenced by ContextTracker(), getToken(), learn(), and set_lowercase_mode().

const char * ContextTracker::LOWERCASE_MODE = "Presage.ContextTracker.LOWERCASE_MODE" [static]

Definition at line 208 of file contextTracker.h.

Referenced by ContextTracker().

Definition at line 229 of file contextTracker.h.

Referenced by ContextTracker(), and learn().

std::string ContextTracker::separatorChars [private]

Definition at line 212 of file contextTracker.h.

Referenced by ContextTracker(), getSeparatorChars(), getToken(), isSeparatorChar(), and learn().

const char * ContextTracker::SLIDING_WINDOW_SIZE = "Presage.ContextTracker.SLIDING_WINDOW_SIZE" [static]

Definition at line 207 of file contextTracker.h.

Referenced by ContextTracker().

std::string ContextTracker::wordChars [private]

Definition at line 211 of file contextTracker.h.

Referenced by ContextTracker(), getWordChars(), and isWordChar().


The documentation for this class was generated from the following files:

Generated on 9 Feb 2015 for presage by  doxygen 1.6.1