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RiveScript-1.19
River stage zero No dependents
3 ++
/ RiveScript

NAME

RiveScript - Rendering Intelligence Very Easily

SYNOPSIS

  use RiveScript;

  # Create a new RiveScript interpreter.
  my $rs = new RiveScript;

  # Load a directory of replies.
  $rs->loadDirectory ("./replies");

  # Load another file.
  $rs->loadFile ("./more_replies.rs");

  # Stream in some RiveScript code.
  $rs->stream (q~
    + hello bot
    - Hello, human.
  ~);

  # Sort all the loaded replies.
  $rs->sortReplies;

  # Chat with the bot.
  while (1) {
    print "You> ";
    chomp (my $msg = <STDIN>);
    my $reply = $rs->reply ('localuser',$msg);
    print "Bot> $reply\n";
  }

DESCRIPTION

RiveScript is a simple trigger/response language primarily used for the creation of chatting robots. It's designed to have an easy-to-learn syntax but provide a lot of power and flexibility. For more information, visit http://www.rivescript.com/

METHODS

GENERAL

new (ARGS)

Create a new instance of a RiveScript interpreter. The instance will become its own "chatterbot," with its own set of responses and user variables. You can pass in any global variables here. The two standard variables are:

  debug     - Turns on debug mode (a LOT of information will be printed to the
              terminal!). Default is 0 (disabled).
  verbose   - When debug mode is on, all debug output will be printed to the
              terminal if 'verbose' is also true. The default value is 1.
  debugfile - Optional: paired with debug mode, all debug output is also written
              to this file name. Since debug mode prints such a large amount of
              data, it is often more practical to have the output go to an
              external file for later review. Default is '' (no file).
  depth     - Determines the recursion depth limit when following a trail of replies
              that point to other replies. Default is 50.

It's recommended that if you set any other global variables that you do so by calling setGlobal or defining it within the RiveScript code. This will avoid the possibility of overriding reserved globals. Currently, these variable names are reserved:

  topics   sorted  sortsthat  sortedthat  thats
  arrays   subs    person     client      bot
  objects  syntax  sortlist   reserved    debugopts
  frozen   globals handlers   objlangs

Note: the options "verbose" and "debugfile", when provided, are noted and then deleted from the root object space, so that if your RiveScript code uses variables by the same values it won't conflict with the values that you passed here.

LOADING AND PARSING

loadDirectory ($PATH[,@EXTS])

Load a directory full of RiveScript documents. $PATH must be a path to a directory. @EXTS is optionally an array containing file extensions, including the dot. By default @EXTS is ('.rs').

Returns true on success, false on failure.

loadFile ($PATH)

Load a single RiveScript document. $PATH should be the path to a valid RiveScript file. Returns true on success; false otherwise.

stream ($CODE)

Stream RiveScript code directly into the module. This is for providing RS code from within the Perl script instead of from an external file. Returns true on success.

sortReplies

Call this method after loading replies to create an internal sort buffer. This is necessary for trigger matching purposes. If you fail to call this method yourself, RiveScript will call it once when you request a reply. However, it will complain loudly about it.

CONFIGURATION

setHandler ($LANGUAGE => $CODEREF, ...)

Define some code to handle objects of a particular programming language. If the coderef is undef, it will delete the handler.

The code receives the variables $rs, $action, $name, and $data. These variables are described here:

  $rs     = Reference to Perl RiveScript object.
  $action = "load" during the parsing phase when an >object is found.
            "call" when provoked via a <call> tag for a reply
  $name   = The name of the object.
  $data   = The source of the object during the parsing phase, or an array
            reference of arguments when provoked via a <call> tag.

There is a default handler set up that handles Perl objects. The source code of this object is as follows, for your reference:

  $self->setHandler (perl => sub {
    my ($rs,$action,$name,$data) = @_;

    # $action will be "load" during the parsing phase, or "call"
    # when called via <call>.

    # Loading
    if ($action eq "load") {
      # Create a dynamic Perl subroutine.
      my $code = "sub RSOBJ_$name {\n"
        . $data
        . "}";

      # Evaluate it.
      eval ($code);
      if ($@) {
        $rs->issue("Perl object $name creation failed: $@");
      }
      else {
        # Load it.
        $rs->setSubroutine($name => \&{"RSOBJ_$name"});
      }
    }

    # Calling
    elsif ($action eq "call") {
      # Make sure the object exists.
      if (exists $rs->{objects}->{$name}) {
        # Call it.
        my @args = @{$data};
        my $return = &{ $rs->{objects}->{$name} } ($rs,@args);
        return $return;
      }
      else {
        return "[ERR: Object Not Found]";
      }
    }
  });

If you want to block Perl objects from being loaded, you can just set it to be undef, and its handler will be deleted and Perl objects will be skipped over:

  $rs->setHandler (perl => undef);

The rationale behind this "pluggable" object interface is that it makes RiveScript more flexible given certain environments. For instance, if you use RiveScript on the web where the user chats with your bot using CGI, you might define a handler so that JavaScript objects can be loaded and called. Perl itself can't execute JavaScript, but the user's web browser can.

Here's an example of defining a handler for JavaScript objects:

  my $scripts = {}; # Place to store JS code.

  $rs->setHandler (javascript => sub {
    my ($self,$action,$name,$data) = @_;

    # Loading the object.
    if ($action eq "load") {
      # Just store the code.
      $scripts->{$name} = $data;
    }
    else {
      # Turn the args into a JavaScript array.
      my $code = "var fields = new Array();\n";
      for (my $i = 0; $i < scalar @{$data}; $i++) {
        $code .= "fields[$i] = \"$data->[$i]\";\n";
      }

      # Come up with code for the web browser.
      $code .= "function rsobject (args) {\n"
             . "$scripts->{$name}\n"
             . "}"
             . "document.writeln( rsobject(fields) );\n";
      return "<script type=\"text/javascript\">\n"
        . $code
        . "</script>";
    }
  });

So, the above example just loads the JavaScript source code into a hash reference named $scripts, and then when called it creates some JavaScript code to put the call's arguments into an array, creates a function that accepts the args, then calls this function in a document.writeln. Here's an example of how this would be used in the RiveScript code:

  // Define an object to encode text into rot13 to be executed by the web browser
  > object rot13 javascript
    var txt = args.join(" "); // Turn the args array into a string
    var result = "";

    for (var i = 0; i < txt.length; i++) {
      var b = txt.charCodeAt(i);

      // 65 = A    97 = a
      // 77 = M   109 = m
      // 78 = N   110 = n
      // 90 = Z   122 = z

      var isLetter = 0;

      if (b >= 65 && b <= 77) {
        isLetter = 1;
        b += 13;
      }
      else if (b >= 97 && b <= 109) {
        isLetter = 1;
        b += 13;
      }
      else if (b >= 78 && b <= 90) {
        isLetter = 1;
        b -= 13;
      }
      else if (b >= 110 && b <= 122) {
        isLetter = 1;
        b -= 13;
      }

      if (isLetter) {
        result += String.fromCharCode(b);
      }
      else {
        result += String.fromCharCode(b);
      }
    }

    return result;
  < object

  // Use the object
  + say * in rot13
  - "<star>" in rot13 is: <call>rot13 <star></call>.

Now, when the user at the web browser provokes this reply, it will get back a bunch of JavaScript code as part of the response. It might be like this:

  <b>User:</b> say hello world in rot13<br>
  <b>Bot:</b> "hello world" in rot13 is: <script type="text/javascript">
  var fields = new Array();
  fields[0] = "hello";
  fields[1] = "world";
  function rsobject (args) {
    var txt = args.join(" "); // Turn the args array into a string
    var result = "";

    for (var i = 0; i < txt.length; i++) {
      var b = txt.charCodeAt(i);

      // 65 = A    97 = a
      // 77 = M   109 = m
      // 78 = N   110 = n
      // 90 = Z   122 = z

      var isLetter = 0;

      if (b >= 65 && b <= 77) {
        isLetter = 1;
        b += 13;
      }
      else if (b >= 97 && b <= 109) {
        isLetter = 1;
        b += 13;
      }
      else if (b >= 78 && b <= 90) {
        isLetter = 1;
        b -= 13;
      }
      else if (b >= 110 && b <= 122) {
        isLetter = 1;
        b -= 13;
      }

      if (isLetter) {
        result += String.fromCharCode(b);
      }
      else {
        result += String.fromCharCode(b);
      }
    }

    return result;
  }
  document.writeln(rsobject(fields));
  </script>.

And so, the JavaScript gets executed inside the bot's response by the web browser.

In this case, Perl itself can't handle JavaScript code, but considering the environment the bot is running in (CGI served to a web browser), the web browser is capable of executing JavaScript. So, we set up a custom object handler so that JavaScript objects are given directly to the browser to be executed there.

setSubroutine ($NAME, $CODEREF)

Manually create a RiveScript object (a dynamic bit of Perl code that can be provoked in a RiveScript response). $NAME should be a single-word, alphanumeric string. $CODEREF should be a pointer to a subroutine or an anonymous sub.

setGlobal (%DATA)

Set one or more global variables, in hash form, where the keys are the variable names and the values are their value. This subroutine will make sure that you don't override any reserved global variables, and warn if that happens.

This is equivalent to ! global in RiveScript code.

To delete a global, set its value to undef or "<undef>". This is true for variables, substitutions, person, and uservars.

setVariable (%DATA)

Set one or more bot variables (things that describe your bot's personality).

This is equivalent to ! var in RiveScript code.

setSubstitution (%DATA)

Set one or more substitution patterns. The keys should be the original word, and the value should be the word to substitute with it.

  $rs->setSubstitution (
    q{what's}  => 'what is',
    q{what're} => 'what are',
  );

This is equivalent to ! sub in RiveScript code.

setPerson (%DATA)

Set a person substitution. This is equivalent to ! person in RiveScript code.

setUservar ($USER,%DATA)

Set a variable for a user. $USER should be their User ID, and %DATA is a hash containing variable/value pairs.

This is like <set> for a specific user.

getUservar ($USER, $VAR)

This is an alias for getUservars, and is here because it makes more grammatical sense.

getUservars ([$USER][, $VAR])

Get all the variables about a user. If a username is provided, returns a hash reference containing that user's information. Else, a hash reference of all the users and their information is returned.

You can optionally pass a second argument, $VAR, to get a specific variable that belongs to the user. For instance, getUservars ("soandso", "age").

This is like <get> for a specific user or for all users.

clearUservars ([$USER])

Clears all variables about $USER. If no $USER is provided, clears all variables about all users.

freezeUservars ($USER)

Freeze the current state of variables for user $USER. This will back up the user's current state (their variables and reply history). This won't statically prevent the user's state from changing; it merely saves its current state. Then use thawUservars() to revert back to this previous state.

thawUservars ($USER[, %OPTIONS])

If the variables for $USER were previously frozen, this method will restore them to the state they were in when they were last frozen. It will then delete the stored cache by default. The following options are accepted as an additional hash of parameters (these options are mutually exclusive and you shouldn't use both of them at the same time. If you do, "discard" will win.):

  discard: Don't restore the user's state from the frozen copy, just delete the
           frozen copy.
  keep:    Keep the frozen copy even after restoring the user's state. With this
           you can repeatedly thawUservars on the same user to revert their state
           without having to keep freezing them again. On the next freeze, the
           last frozen state will be replaced with the new current state.

Examples:

  # Delete the frozen cache but don't modify the user's variables.
  $rs->thawUservars ("soandso", discard => 1);

  # Restore the user's state from cache, but don't delete the cache.
  $rs->thawUservars ("soandso", keep => 1);
lastMatch ($USER)

After fetching a reply for user $USER, the lastMatch method will return the raw text of the trigger that the user has matched with their reply. This function may return undef in the event that the user did not match any trigger at all (likely the last reply was "ERR: No Reply Matched" as well).

INTERACTION

reply ($USER,$MESSAGE)

Fetch a response to $MESSAGE from user $USER. RiveScript will take care of lowercasing, running substitutions, and removing punctuation from the message.

Returns a response from the RiveScript brain.

INTERNAL

debug ($MESSAGE) *Internal

Prints a debug message to the terminal. Called from within in debug mode.

issue ($MESSAGE) *Internal

Called internally to report an issue (similar to a warning). If debug mode is active, it will print the issue to STDOUT with a # sign prepended. Otherwise, the issue is sent to STDERR via warn.

parse ($FILENAME, $CODE) *Internal

This method is called internally to parse a file or streamed RiveScript code. $FILENAME is only there so it can keep internal track of files and line numbers, in case syntax errors appear.

sortThatTriggers *Internal

This method sorts all the +Trigger lines that are paired with a common %Previous line. This is necessary for when one question by the bot could have multiple replies. I found a bug with the following RS code:

  + how [are] you [doing]
  - I'm doing great, how are you?
  - Good -- how are you?
  - Fine, how are you?

  + [*] @good [*]
  % * how are you
  - That's good. :-)

  + [*] @bad [*]
  % * how are you
  - Aww. :-( What's the matter?

  + *
  % * how are you
  - I see...

The effective trigger order was "[*] @good [*]", "*", "[*] @bad [*]", because there was no sort buffer and it was relying on Perl's hash sorting. This method was introduced to fix that problem and sort these triggers too.

You don't need to call this method yourself; it is called automatically on a sortReplies() request.

sortList ($NAME,@LIST) *Internal

This is used internally to sort arrays (namely, person and substitution pattern arrays). Sets $rs-{sortlist}->{$NAME}> to an array reference of the sorted values in @LIST. The values are sorted by number of words from greatest to smallest, with each group of same-word-count items sorted by length amongst themselves.

_getreply ($USER,$MSG,%TAGS) *Internal

Do NOT call this method yourself. This method assumes a few things about the user's input that is taken care of by reply(). There is no reason to call this method manually.

_reply_regexp ($USER,$TRIGGER) *Internal

This method takes a raw trigger $TRIGGER and formats it for a matching attempt in a regular expression. It removes {weight} tags, processes arrays, processes bot variables and other tags, and returns something ready for the regular expression engine.

processTags ($USER,$MSG,$REPLY,$STARS,$BOTSTARS) *Internal

Process tags in the bot's response. $USER and $MSG are the values originally passed to the reply engine. $REPLY is the bot's raw response. $STARS and $BOTSTARS are array references containing any wildcards matched in a trigger or %Previous command, respectively. Returns a reply with all the tags processed.

_formatMessage ($STRING) *Internal

Formats a message to prepare it for reply matching. Lowercases the string, runs substitutions, and sanitizes what's left.

_stringUtil ($TYPE,$STRING) *Internal

Runs string modifiers on $STRING (uppercase, lowercase, sentence, formal).

_personSub ($STRING) *Internal

Runs person substitutions on $STRING.

RIVESCRIPT

This interpreter tries its best to follow RiveScript standards. Currently it supports RiveScript 2.0 documents. A current copy of the RiveScript working draft is included with this package: see RiveScript::WD.

ERROR MESSAGES

Most of the Perl warnings that the module will emit are self-explanatory, and when parsing RiveScript files, file names and line numbers will be given. This section of the manpage instead outlines error strings that may turn up in responses to the bot's queries.

ERR: Deep Recursion Detected!

The deep recursion depth limit has been reached (a response redirected to a different trigger, which redirected somewhere else, etc.).

How to fix: override the global variable depth. This can be done via setGlobal or in the RiveScript code:

  ! global depth = 100

ERR: No Reply Matched

No match was found for the client's message.

How to fix: create a catch-all trigger of just *.

  + *
  - I don't know how to reply to that.

ERR: No Reply Found

A match to the client's message was found, but no response to it was found. This might mean you had a set of conditionals after it, and no -Reply to fall back on, and every conditional returned false.

How to fix: make sure you have at least one -Reply to every +Trigger, even if you don't expect that the -Reply will ever be used.

[ERR: Can't Modify Non-Numeric Variable $var]

You called a math tag on a variable, and the current value of the variable contains something that isn't a number.

How to fix: verify that the variable you're working with is a number. If necessary, reset the variable via <set>.

[ERR: Math Can't "add" Non-Numeric Value $value]

("add" may also be sub, mult, or div). You tried to run a math function on a variable, but the value you used wasn't a number.

How to fix: verify that you're adding, subtracting, multiplying, or dividing using numbers.

[ERR: Can't Divide By Zero]

A <div> tag was found that attempted to divide a variable by zero.

How to fix: make sure your division isn't dividing by zero. If you're using a variable to provide the divisor, validate that the variable isn't zero by using a conditional.

  * <get divisor> == 0 => The divisor is zero so I can't do that.
  - <div myvar=<get divisor>>I divided the variable by <get divisor>.

[ERR: Object Not Found]

RiveScript attempted to call an object that doesn't exist. This may be because a syntax error in the object prevented Perl from evaluating it, or the object was written in a different programming language.

How to fix: verify that the called object was loaded properly. You will receive notifications on the terminal if the object failed to load for any reason.

SEE ALSO

RiveScript::WD - A current snapshot of the Working Draft that defines the standards of RiveScript.

http://www.rivescript.com/ - The official homepage of RiveScript.

CHANGES

  1.19  Apr 12 2009
  - Added support for defining custom object handlers for non-Perl programming
    languages.
  - All the methods like setGlobal, setVariable, setUservar, etc. will now
    accept undef or "<undef>" as values - this will delete the variables.
  - There are no reserved global variable names anymore. Now, if a variable name
    would conflict with a reserved name, it is put into a "protected" space
    elsewhere in the object. Still take note of which names are reserved though.

  1.18  Dec 31 2008
  - Added support for topics to inherit their triggers from other topics.
    e.g. > topic alpha inherits beta
  - Fixed some bugs related to !array with ^continue's, and expanded its
    functionality therein.
  - Updated the getUservars() function to optionally be able to get just a specific
    variable from the user's data. Added getUservar() as a grammatically correct
    alias to this new functionality.
  - Added the functions freezeUservars() and thawUservars() to back up and
    restore a user's variables.
  - Added the function lastMatch(), which returns the text of the trigger that
    matched the user's last message.
  - The # command for RiveScript comments has been deprecated in revision 7 of
    the RiveScript Working Draft. The Perl module will now emit warnings each
    time the # comments are processed.
  - Modified a couple of triggers in the default Eliza brain to improve matching
    issues therein.
  - +Triggers can contain user <get> tags now.
  - Updated the RiveScript Working Draft.

  1.17  Sep 15 2008
  - Updated the rsdemo tool to be more flexible as a general debugging and
    developing program. Also updated rsdemo and rsup to include POD documentation
    that can be read via `perldoc`.
  - Added a global variable $RiveScript::basedir which is the the path to your
    Perl lib/RiveScript folder. This is used by `rsdemo` as its default location
    to search for replies.
  - Tweak: Triggers of only # and _ can exist now alongside the old single-wildcard
    trigger of *.
  - Bugfix: The lookahead code would throw Perl warnings if the following line
    had a single space in it, but was otherwise empty.
  - Bugfix: Inline comment removing has been fixed.
  - Bugfix: In conditionals, any blank side of the equality will get a default
    value of "undefined". This way you can use a matching array inside an optional
    and check if that <star> tag is defined.
    + i am wearing a [(@colors)] shirt
    * <star> ne undefined => Why are you wearing a <star> shirt?
    - What color is it?
  - Updated the RiveScript Working Draft.

  1.16  Jul 22 2008
  - New options to the constructor: 'verbose' and 'debugfile'. See the new()
    constructor for details.
  - Added new wildcard variants:
    * matches anything (previous behavior)
    # matches only numbers
    _ matches only letters
    So you can have a trigger like "+ i am # years old" and "+ i am * years old",
    with the latter trigger telling them to try that again and use a NUMBER this
    time. :)
  - Bugfix: when there were multiple +trigger's that had a common %previous,
    there was no internal sort buffer for those +trigger's. As a result, matching
    wasn't very efficient. Added the method sortThatTriggers() to fix this.
  - Bugfix: tags weren't being processed in @Redirects when they really
    should've!
  - Bugfix: The ^Continue lookahead code wouldn't work if the next line began
    with a tab. Fixed!
  - Updated the RiveScript Working Draft.

  1.15  Jun 19 2008
  - Person substitutions support multiple-word patterns now.
  - Message substititons also support multiple-word patterns now.
  - Added syntax tracking, so Deep Recursion errors can give you a filename and
    line number where the problem occurred.
  - Added a handler for detecting when a user was put into an empty topic.
  - Rearranged tag priority.
  - Updated the RiveScript Working Draft.

  1.14  Apr  2 2008
  - Bugfix: If a BEGIN/request trigger didn't exist, RiveScript would not fetch
    any replies for the client's message. Fixed.
  - Bugfix: Tags weren't being re-processed for the text of the BEGIN statement,
    so i.e. {uppercase}{ok}{/uppercase} wasn't working as expected. Fixed.
  - Bugfix: RiveScript wasn't parsing out inline comments properly.
  - Rearranged tag priorities.
  - Optimization: When substituting <star>s in, an added bit of code will insert
    '' (nothing) if the variable is undefined. This prevents Perl warnings that
    occurred frequently with the Eliza brain.
  - Updated the RiveScript Working Draft.

  1.13  Mar 18 2008
  - Included an "rsup" script for upgrading old RiveScript code.
  - Attempted to fix the package for CPAN (1.12 was a broken upload).
  - Bugfix: <bot> didn't have higher priority than <set>, so
    i.e. <set name=<bot name>> wouldn't work as expected. Fixed.

  1.12  Mar 16 2008
  - Initial beta release for a RiveScript 2.00 parser.

AUTHOR

  Casey Kirsle, http://www.cuvou.com/

KEYWORDS

bot, chatbot, chatterbot, chatter bot, reply, replies, script, aiml, alpha

COPYRIGHT AND LICENSE

  RiveScript - Rendering Intelligence Very Easily
  Copyright (C) 2008  Casey Kirsle

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA