Pandorabots had inevitably to add some features to AIML that were not part of the AIML specification. The following code fragment demonstrates some of these new features. Pandorabots provides the unique ability to run AIML templates inside the HTML that will appear on the client’s browser. This very feature, the ability to process AIML templates inside the browser HTML, is itself an example of Pandorabot’s embrace and extend approach to AIML.
One useful set of AIML templates displays history of the last four exchanges with the client, a dialogue history, updated every time the client says something and the bot responds. Such a set of templates is easy to program in Pandorabots AIML. But as we shall see, it makes use of almost every feature of Pandorabots “embraced and extended” AIML.
Human inputs are displayed with a prefix prompt “Human:” and bot responses are displayed with the bot’s name followed by a “:” If there have been fewer than four exchanges, the screen should appear blank rather than show unfilled lines with prompts.
<i><b>Human:</b></i> <request index="3"/><br/>
<i><b><bot name="name"/>:</b></i> <response index="3"/><br/>
<i><b>Human:</b></i> <request index="2"/><br/>
<i><b><bot name="name"/>:</b></i> <response index="2"/><br/>
<i><b>Human:</b></i> <request index="1"/><br/>
<i><b><bot name="name"/>:</b></i> <response index="1"/><br/>
Pandorabots has adopted a boundary condition in AIML where the list item in the condition tag has a value equal to the wild card “*”. In this example the <set> operation sets the AIML predicate “_history” to the value of <request index=”1”/>. If <request index=”1”/> has not been set, then it cannot match any value, including “*”. Using this bit of AIML trickery, Pandorabots says that the AIML code inside the <li value=”*”> will not be executed because “_history” is set to “undefined”. I am as much in favor of the undefined as the next person, but this is not standard AIML.
This example doesn’t show it, but Pandorabots also allows wildcards in some AIML tag indexes. For example, the tag
indicates the set of input sentences included in <that index=”1,1”/>…<that index=”1,N”/>.
Here is a general problem of mathematical reference that appears in AIML. You might call it, the problem of “multiline response”. Consider a dialogue between two individuals. One of them, B, asks, or says, something, that begins and ends with a sentence. It consists of several sentences. What B says is, as we say, “multiline”. The respondent, A, next utters his or her own reply to what he or she has heard. What A says is also multiline.
And so what B says next. Sometimes, of course, the multiline utterances consist of just one line, but in general a script consists of sequences of such back-and-forth, multiline responses.
At the lowest level AIML provides for processing individual input sentences. One AIML pattern matches one input sentence. The next level of context is usually provided by the <that> variable. Most of the time, AIML has no way to distinguish whether inputs came from multiline input sequences, or from individual inputs, which may help explain some bizarre constructions that emerge from unpredictable multiline input queries.
The AIML specification provides for indexed <input/> and <that/> tags to store the values of previous input values and robot replies. The <input index=”X”/> tag is one dimensional but the <that index=”X,Y”/> tag is already two dimensional, owing to the fact that the Xth previous input can have Y sentences in it’s reply. We see here that AIML makes no distinction for input sentences that come from multiline inputs, or one shots, so to speak, because doing so would add another needless indexing dimension to <input/> and <that/>.
The typical AIML interpreter master loop is to append all of the output sentences together into a single output paragraph for the bot output. If the program keeps a history of these outputs and the associated multiline inputs, then it has created something very similar to the Pandorabots <request/> and <response/> tags.
Getting back to the example, <request/> and <response/> are the indexed history tags of the entire multiline input and output of the human and bot, respectively.
Pandorabots supports three extension attributes to the date element in templates:
timzeone should be an integer number of hours +/- from GMT and that locale is the iso language/country code pair e.g., en_US, ja_JP. Locale defaults to en_US. The set of supported locales are:
af_ZA ar_OM da_DK en_HK es_CO es_PY fr_CA is_IS mt_MT sh_YU vi_VN
ar_AE ar_QA de_AT en_IE es_CR es_SV fr_CH it_CH nb_NO sk_SK zh_CN
ar_BH ar_SA de_BE en_IN es_DO es_US fr_FR it_IT nl_BE sl_SI zh_HK
ar_DZ ar_SD de_CH en_NZ es_EC es_UY fr_LU ja_JP nl_NL sq_AL zh_SG
ar_EG ar_SY de_DE en_PH es_ES es_VE ga_IE kl_GL nn_NO sr_YU zh_TW
ar_IN ar_TN de_LU en_SG es_GT et_EE gl_ES ko_KR no_NO sv_FI
ar_IQ ar_YE el_GR en_US es_HN eu_ES gv_GB kw_GB pl_PL sv_SE
ar_JO be_BY en_AU en_ZA es_MX fa_IN he_IL lt_LT pt_BR ta_IN
ar_KW bg_BG en_BE en_ZW es_NI fa_IR hi_IN lv_LV pt_PT te_IN
ar_LB bn_IN en_BW es_AR es_PA fi_FI hr_HR mk_MK ro_RO th_TH
ar_LY ca_ES en_CA es_BO es_PE fo_FO hu_HU mr_IN ru_RU tr_TR
ar_MA cs_CZ en_GB es_CL es_PR fr_BE id_ID ms_MY ru_UA uk_UA
format is a format string as given to the Unix strftime function:
You can include your own message in the format string, along with one or more format control strings. These format control strings tell the date function whether to print the date or time, whether to use AM or PM, a 24 hour clock or a 12 hour, abbreviate the day of the week or not, and so on. Some of the supported format control strings include:
%a Abbreviated weekday name
%A Full weekday name
%b Abbreviated month name
%B Full month name
%c Date and time representation appropriate for locale
%d Day of month as decimal number (01 – 31)
%H Hour in 24-hour format (00 – 23)
%I Hour in 12-hour format (01 – 12)
%j Day of year as decimal number (001 – 366)
%m Month as decimal number (01 – 12)
%M Minute as decimal number (00 – 59)
%p Current locale’s A.M./P.M. indicator for 12-hour clock
%S Second as decimal number (00 – 59)
%U Week of year as decimal number, with Sunday as first day of week (00 – 53)
%w Weekday as decimal number (0 – 6; Sunday is 0)
%W Week of year as decimal number, with Monday as first day of week (00 – 53)
%x Date representation for current locale
%X Time representation for current locale
%y Year without century, as decimal number (00 – 99)
%Y Year with century, as decimal number
%Z Time-zone name or abbreviation; no characters if time zone is unknown
%% Percent sign
If you don't specify a format you'll just get the date using the default format for the particular locale.
timezone is the time zone expressed as the number of hours west of GMT.
If any of the attributes are invalid, it will fall back to the default
behavior of <date/> (i.e. with no attributes specified)
To display the date and time in French using Central European time you would use:
<date locale="fr_FR" timezone="-1" format="%c"/>
You can also improve the specificity of common certain time and date related inquiries to the ALICE bot, as illustrated by the following dialogue fragment.
what day is it
Human: what month is it
Human: what year is this
Human: what is the date
ALICE: Thursday, December 02, 2004.
Although we saw in a previous section how to set predicate defaults in Pandorabots with AIML, most other AIML interpreters support predicate defaults in different way, using a startup data file. Similarly, Pandorabots lacks botmaster control over a variety of functions that are pretty much closed or hard-wired, at least for the time being, in Pandorabots.
· Deperiodization – Removing ambiguous punctuation like “Dr.” and “St”, and also applying heuristic rules to determine what makes a sentence a sentence. This feature is hard wired in Pandorabots.
· Normalization – Expanding contractions, removing all remaining punctuation, repairing many spelling errors. This feature is hard wired in Pandorabots.
· Predicate defaults – AIML predicates have a default value for <get/>. You can only set one global <get/> value in Pandorabots. In this book, under the section on custom HTML, we showed a trick using embedded HTML-side AIML (another non-standard, embrace-and-extend feature) to set the default value of predicates.
· Predicate <set/> returns – Some predicates return the predicate name, such as pronouns, and some return the set values. These choices are hard wired in Pandorabots.