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Tamino text retrieval operations consider text as sequences of words. A word is a sequence of characters that is delimited by characters such as whitespace or punctuation characters. The process of analyzing text and determining words and delimiters is called tokenization. Depending on the language, there are different tokenizers available in Tamino. The default, so-called "white space-separated" tokenizer is suitable for most letter-based languages. However, ideographic languages such as Chinese, Japanese or Korean (often referred together as CJK languages) have a totally different concept of segmenting a sequence of ideographs into "word" tokens. Tamino offers a special tokenizer for Japanese.

Tokens are categorized into character classes such as "character", "delimiter" or "number". You can find detailed information about this topic in the section Implications Concerning Text Retrieval in Unicode and Text Retrieval.

For the purpose of doing text retrieval in XQuery, it is sufficient to think of full text in terms of words and delimiters. In this context, "words" are referred to as word tokens, regardless of whether a tokenizer analyzed a series of letters or of ideographs.

This document covers the following topics:

• Simple Text Search

• Context Operations

• Highlighting Retrieval Results

• Phonetic Searches

• Stemming

• Rules for Searches Using Phonetic Values and Stemming

• Thesaurus

• Pattern Matching

Simple Text Search

There are two possibilities to search nodes in XML documents for some text: You can either use an exact search or search for word tokens. Let us look for divers among the patients in our hospital database. We know that there is someone who is a "professional diver":

for    $a in input()/patient
where  $a/occupation = "Professional Diver"
return <divers level="professional">{ $a/name }</divers>

And Tamino will return Mr. Atkins as the only representative of the hospital's professional divers. To find all divers, professional or not, you are inclined to ask:

for    $a in input()/patient
where  $a/occupation = "diver"
return <divers>{ $a/name }</divers>

The result is an empty sequence, so we lost even the professional diver. The where clause contains an equality expression that is true if the text contents of the node read exactly "diver". Since the occupation element in Mr. Atkin's reads "Professional Diver", the result is false and no divers are returned. However, using the function tf:containsText you can search for the word "diver" somewhere in the node occupation and without looking at the case:

for    $a in input()/patient
where  tf:containsText($a/occupation, "diver")
return <divers>{ $a/name }</divers>

Now Tamino returns Mr. Atkins in the diver list, since the tokenizer identifies "Diver" as a word, delimited on the left by a space character. After applying lower case as standard tokenizer rule the token "diver" is found and the function tf:containsText returns true. Please note that this function looks for word tokens, so using tf:containsText($a/occupation, "dive") would yield false, since "dive" is not a token that can be found in any of the occupation nodes. Similarly, a query using tf:containsText($a/occupation, "professional diver") returns true, since the two word tokens are found in that order in the occupation node. However, tf:containsText($a/occupation, "diver professional") returns false: Although both tokens are found, they are not in the specified order.

Context Operations

With context operations you can search for expressions that consist of one or more words which do not necessarily follow after one another. For example, you can search for variants of the expression "text retrieval" such as "retrieval of text" or in "text storage and retrieval". In Tamino, there are functions that let you specify the following context operations (here, "#" stands for one token):

• Maximum word distance
  "text # # retrieval" matches "text retrieval" and "text storage and retrieval"

• Word order
  If word order is not significant, "text retrieval" matches "text retrieval" and "retrieval of text"

The functions tf:containsAdjacentText and tf:containsNearText both expect a maximum word distance as second argument. Consider the following query:

let $text := text{"One, Two, Three, Four, Can I have a little more?"}
return tf:containsAdjacentText($text, 9, "one", "more")

This graphics shows you the search string, its tokens and how the query matches the search string:

The function tf:containsAdjacentText returns true if the tokens "one" and "more" are found in that order within a distance of less than nine tokens. Since there are eight unmatched tokens, the function returns true for the above query. Let us slightly change the query expression:

let    $text := text{"One, Two, Three, Four, Can I have a little more?"}
return tf:containsAdjacentText($text, 9, "one", "four", "more")

The function returns true if all the tokens "one", "four" and "more" are found in that order within a distance of less than nine tokens, not including any matched tokens in between such as "four". Since there are seven unmatched tokens, the function returns true for the above query.

Generally, if you use a distance value of "1", it means that the tokens follow immediately one after another. It follows that tf:containsAdjacentText($mynode, 1, "search", "text") is equivalent to tf:containsText($mynode, "search text").

While tf:containsAdjacentText respects the word order, the function tf:containsNearText does not. The following query using tf:containsNearText returns true, using tf:containsAdjacentText it would return false:

let    $text := text{"One, Two, Three, Four, Can I have a little more?"}
return tf:containsNearText($text, 2, "four", "one", "two")

Highlighting Retrieval Results

When retrieving information from some text corpus, it is desirable to visualize the information found. In Tamino XQuery, you can do so by "highlighting" retrieval results. Consider the following query from the Tamino XQuery reference guide which searches in all review nodes for the word "discussion":

for    $a in input()/reviews/entry
let    $ref := tf:createTextReference($a/review, "discussion")
where  $ref
return tf:highlight($a, $ref, "REV_DISC")

A Tamino client application could highlight the results as follows:

<entry>
  <title>Data on the Web</title>
  <price>34.95</price>
  <review>A very good discussion of semi-structured database systems and XML.</review>
</entry>
<entry>
  <title>Advanced Programming in the Unix environment</title>
  <price>65.95</price>
  <review>A clear and detailed discussion of UNIX programming.</review>
</entry>

You can see from the query expression that there are two steps involved when highlighting retrieval results:

1. Generate a reference description to the locations that should be highlighted.

2. Apply highlighting to the document according to the locations.

Generating Reference Descriptions

A reference description is necessary for highlighting later on. It consists of at least the following global information:

• collection

• document type ("doctype")

• document number

• node id

References to text within a node further need to describe the locations of start and end points, the range. You can create reference descriptions by using the following functions: tf:createAdjacentTextReference, tf:createNearTextReference, and tf:createTextReference. These functions work exactly like their tf:containsXXXText counterparts, only that they return reference descriptions of text ranges instead of a Boolean value. There is another function tf:createNodeReference to create reference descriptions of nodes. Let us have a look at the reference descriptions that will be used in our example query:

for $a in input()/reviews/entry
return tf:createTextReference($a/review, "discussion")

Tamino will return these two object descriptions in its response:

The figure below shows you the text ranges for which reference descriptions have been created:

Highlighting Documents

Any location, for which a reference description exists, can be highlighted by using the function tf:highlight. The query performing the highlighting is repeated here for your convenience:

for $a in input()/reviews/entry
let $ref := tf:createTextReference($a/review, "discussion")
where $ref
return tf:highlight($a, $ref, "REV_DISC")

As arguments, the function tf:highlight requires a node, a previously-generated reference description and a marker string. Tamino uses processing instructions (PIs) to indicate the start and end of the range to be highlighted so that a client application receiving the Tamino response document can parse and process them. The marker string is used as the so-called PI target. You can easily identify the highlighted text ranges in the response document for the above query:

<entry>
  <title>Data on the Web</title>
  <price>34.95</price>
  <review>A very good <?REV_DISC + 1 ?>discussion<?REV_DISC - 1 ?> of semi-structured database systems and XML.</review>
</entry>
<entry>
  <title>Advanced Programming in the Unix environment</title>
  <price>65.95</price>
  <review>A clear and detailed <?REV_DISC + 2 ?>discussion<?REV_DISC - 2 ?> of UNIX programming.</review>
</entry>

The start and end of the highlighted text range are indicated by the plus and minus signs in the PI. Furthermore, highlighted ranges are numbered. This is also true when highlighting complete nodes:

for    $a in input()/bib
let    $ref:= tf:createNodeReference($a/book[1])
return tf:highlight($a, $ref, "FIRST")

The resulting document is:

<book year="1994"><?FIRST + 1?>
   <title>TCP/IP Illustrated</title>
   <author><last>Stevens</last><first>W.</first></author>
   <publisher>Addison-Wesley</publisher>
   <price>65.95</price>
 <?FIRST - 1?></book>

Phonetic Searches

A "phonetic search" allows you to search for words that are phonetically equivalent. Linguistically speaking, you are looking for homophones. For example, in English the letters c and s as in "city" and "song" are both pronounced [s], and the words "eight" and "ate" are both pronounced (in square brackets you see the phonetic transcription using the IPA, the International Phonetic Alphabet).

There are many areas where this facility proves valuable: Imagine a patient database having lots of patients with German names. Now you want to retrieve all patients with the name "Maier". In German, it is an everyday surname, just as "Kim", "Smith", and "Andersson" are for Korean, English and Swedish respectively. You can use a query performing a simple text search such as:

for    $a in input()/patient
where  $a/name = "Maier"
return $a/name

or you can use tf:containsText:

for    $a in input()/patient
where  tf:containsText($a/name, "Maier")
return $a/name

Unfortunately, there are at least four variants of the name which are all pronounced : "Maier", "Mayer", "Meier", and "Meyer". Instead of constructing long Boolean expressions that try to cover all existing homophones, you can use tf:phonetic in the scope of one of the search functions:

for    $a in input()/patient
where  tf:containsText($a/name, tf:phonetic("Maier"))
return $a/name

This query will return all patients whose names sound like .

Tamino uses a set of rules to determine phonetic equivalency. There are rules pre-defined, which are explained in more detail in the reference documentation to tf:phonetic. These rules are suitable for German and English, but you can create your own set of rules. See the section Rules for Searches Using Phonetic Values and Stemming below.

Note:
You can not use tf:phonetic standalone, but only in the context of one of the following functions: tf:containsText, tf:containsAdjacentText, tf:containsNearText, tf:createAdjacentTextReference, tf:createNearTextReference, tf:createTextReference. This means that the result of calling this function in another context is unspecified and might change in a future Tamino version.

Stemming

A corpus with text in an inflecting language such as English or German often contains words in inflected forms: nouns are declined and verbs are conjugated: "The nightingales were singing in the trees." If you want to search for all occurrences of the verb "to sing" or of the nouns "nightingale" and "tree", you need to know how these words are inflected and derived. One method is to reduce any inflected form to its word stem. It is the stem to which morphemes are attached to construct a certain grammatical form: So "were" + "sing" + "-ing" indicates the past continuous tense of the verb "to sing".

In Tamino, you can use the function tf:stem to retrieve occurrences of all word forms belonging to the same word stem. Similarly to tf:phonetic, it works only in the scope of one of the search functions:

let $text :=
 <chapter>
  <para>Die Bank eröffnete drei neue Filialen im Verlauf der letzten fünf Jahre.</para>
  <para>Ermüdet von dem Spaziergang setzte sich die alte Dame erleichtert auf die
    gepflegt wirkende Bank mitten im Stadtpark.</para>
  <para>Die aktuelle Bilanz der Bank zeigt einen Anstieg der liquiden Mittel im
    Vergleich zum Vorjahresquartal.</para>
  </chapter>
for    $a in $text//para
let    $check := 
       for    $value in ("Geld", "Bilanz", "Filiale", "monetär", "Aktie")
       return tf:containsNearText($a, 10, tf:stem($value), tf:stem("Bank")) 
where  count($check[. eq true()]) > 0
return $a

This returns all para elements whose text contains at least one word which is related to a specific reading of the German word "Bank". The resulting document contains the first and the third para element, but not the second, since it does not contain any of the words defined in the sequence ("Geld", "Bilanz", "Filiale", "monetär", "Aktie") in a distance of less than ten words from "Bank".

Tamino uses a set of rules to determine whether a word token belongs to some stem. There is a pre-defined rule set that works reasonably well for German. However, you can create your own set of rules. See the section Rules for Searches Using Phonetic Values and Stemming below. You can reach the pre-defined rules set using the following query:

declare namespace ino="http://namespaces.softwareag.com/tamino/response2"
collection("ino:vocabulary")/ino:stemrules

Note:
Do not use tf:stem standalone; use it only in the context of one of the following functions: tf:containsText, tf:containsAdjacentText, tf:containsNearText, tf:createAdjacentTextReference, tf:createNearTextReference, tf:createTextReference. The result of calling this function in any other context is unspecified and might change in a future Tamino version.

Rules for Searches Using Phonetic Values and Stemming

For queries that involve phonetics and stemming, Tamino internally uses the same mechanism, implemented as a finite-state machine, that rewrites the function argument according to a set of rules. These rules are described by XML schemas stored in the collection ino:vocabulary and have the names PHONRULES and STEMRULES:

This is the schema for PHONRULES:

<xs:complexType>
  <xs:sequence>
    <xs:element name="phonrule" minOccurs="1" maxOccurs="unbounded">
      <xs:complexType>
        <xs:attribute name="phonStage" type="xs:integer" use="required" />
        <xs:attribute name="phonType" type="xs:string" use="required" />
        <xs:attribute name="phonReqs" type="xs:integer" use="required" />
        <xs:attribute name="phonMinChars" type="xs:integer" use="required" />
        <xs:attribute name="phonChars" type="xs:string" use="required" />
        <xs:attribute name="phonReplaceChars" type="xs:string" use="required" />
        <xs:attribute name="phonNextStage" type="xs:integer" use="required" />
      </xs:complexType>
    </xs:element>      
  </xs:sequence>    
</xs:complexType>

This is the schema for STEMRULES:

<xs:complexType>
  <xs:sequence>
    <xs:element name="stemrule" minOccurs="1" maxOccurs="unbounded">
      <xs:complexType>
        <xs:attribute name="stemStage" type="xs:integer" use="required" />
        <xs:attribute name="stemType" type="xs:string" use="required" />
        <xs:attribute name="stemReqs" type="xs:integer" use="required" />
        <xs:attribute name="stemMinChars" type="xs:integer" use="required" />
        <xs:attribute name="stemChars" type="xs:string" use="required" />
        <xs:attribute name="stemReplaceChars" type="xs:string" use="required" />
        <xs:attribute name="stemNextStage" type="xs:integer" use="required" />
      </xs:complexType>
    </xs:element>      
  </xs:sequence>    
</xs:complexType>

So a set of rules consists of a series of ino:phonrule or ino:stemrule elements. The semantics of a rule are determined by its attributes, all of which are mandatory:

• Location
  The attributes ino:phonType and ino:stemType define the part of word affected by the rule: This is one of the values "SUFFIX", "INFIX" or "PREFIX"

• Character Substitution
  These attributes define the characters to look for and their replacement:

  • The attributes ino:phonChars and ino:stemChars define the sequence of characters to look for in a string

  • The attributes ino:phonReplaceChars and ino:stemReplaceChars define the substitution string.

• State Machine Control
  These attributes control the way the state machine is treating this rule:

  • The attributes ino:phonStage and ino:stemStage define the state in which the rule will be active. The attribute value is a number from 1 to n. In most of the rules there will be no state change.

  • The attributes ino:phonNextStage and ino:stemNextStage define the next state when the rule has fired. If the value is "0" the machine stops and the result is computed.

• Restrictions
  If a restriction is violated, the rule will not be executed.

  • The attributes ino:phonMinChars and ino:stemMinChars define the minimum length of the word fragment for the rule to be applied.

  • The attributes ino:phonReqs and ino:stemReqs define the minimum number of syllables in the word fragment for the rule to be applied. For ino:phonReqs this is practically always the value "0".

The order of the rules is significant. The following stem rules protect the substitution of "EAR":

<ino:stemrule ino:stemType='SUFFIX' ino:stemStage='2' ino:stemNextStage='0' 
		ino:stemChars='EAR' ino:stemReplaceChars='EAR'	ino:stemReqs='0' ino:stemMinChars='6' />
<ino:stemrule ino:stemType='SUFFIX' ino:stemStage='2' ino:stemNextStage='0'
		ino:stemChars='AR' 	ino:stemReplaceChars=''	   ino:stemReqs='0' ino:stemMinChars='5' />

Thesaurus

A thesaurus is a special kind of dictionary that is ordered by topic or semantic relationships. A regular dictionary uses a lexicographic order: for example, letter-based languages use the language's alphabet; ideographic languages use the base signs and the number of strokes. In contrast, a thesaurus is ordered by meaning: it helps you find words or phrases for general ideas. Semantic relationships let you explore words along two directions: horizontally by looking up variants with the same context of meaning (e.g., synonyms, antonyms) or vertically by finding broader, superordinate terms (hypernyms), and narrower, subordinate terms (hyponyms). In Tamino, this adds another dimension of text retrieval functionality: now you can retrieve contents not only by using the graphemic representation or syntactic variants of the search term, but also by using its semantic properties.

Tamino supports the most important aspects of a thesaurus: synonyms, hypernyms and hyponyms. There is no pre-defined thesaurus, so you can specify one tailored to the special vocabulary of your Tamino application scenario. You can define one or more thesauri in a single database. The collection ino:vocabulary holds thesaurus entries as term elements, each of which is assigned to a single thesaurus using the attribute ino:thesaurus. A term element can contain the following elements:

termName

defines the name of the thesaurus entry (mandatory)

synonym

defines a term which is synonymous to termName

broaderTerm

defines a term which is superordinate to termName (hypernym)

narrowerTerm

defines a term which is subordinate to termName (hyponym)

Example

To create a sample thesaurus with words having to do with animals, load the following data into the collection ino:vocabulary of an existing database. Please refer to the section Loading Data into Tamino for more information about loading data into Tamino.

The example file dog.xml

<?xml version="1.0"?>
<term ino:thesaurus="animals"
      xmlns:ino="http://namespaces.softwareag.com/tamino/response2">
  <ino:termName>dog</ino:termName>
  <ino:synonym>canine</ino:synonym>
  <ino:synonym>pooch</ino:synonym>
  <ino:synonym>doggie</ino:synonym>
  <ino:synonym>bow-wow</ino:synonym>
  <ino:synonym>puppy-dog</ino:synonym>
  <ino:synonym>perp</ino:synonym>
  <ino:synonym>whelp</ino:synonym>
  <ino:broaderTerm>carnivore</ino:broaderTerm>
</term>

The example file carnivore.xml

<?xml version="1.0"?>
<term ino:thesaurus="animals"
      xmlns:ino="http://namespaces.softwareag.com/tamino/response2">
  <ino:termName>carnivore</ino:termName>
  <ino:broaderTerm>mammal</ino:broaderTerm>
</term>

These two files establish the thesaurus "animals" for the given database. In the vertical direction the following hierarchy can be derived: A dog is a carnivore; a carnivore is a mammal. This is because the ino:broaderTerm contents ("carnivore") in the thesaurus entry for "dog" matches the ino:termName of another thesaurus entry, namely "carnivore".

Furthermore synonyms are defined for the entry "dog" that denote a dog using colloquial language, biological terms, pet names, etc.

Examples

Return all paragraphs in the specified document that contain a synonym of "dog":

let $doc := <doc>
  <p>Have you seen the large dog around the corner?</p>
  <p>On the farm nearby, a checkered whelp was playing on the ground with some cats.</p>
  <p>Also, some horses could be seen in the stable.</p>
 </doc>
for    $p in $doc/p
where  tf:containsText($p,tf:synonym("dog"))
return $p

As a result, the first two paragraphs are returned. Strictly speaking, only "whelp" is defined as a proper synonym, but Tamino follows the intuitive assumption that you also expect the term itself to be part of the result set. This holds for other thesaurus functions as well.

The following query returns all superordinate terms of "dog", for which you use the Tamino function tf:broaderTerms:

declare namespace ino="http://namespaces.softwareag.com/tamino/response2"
for    $p in collection("ino:vocabulary")/ino:term
where  tf:containsText($p/ino:termName,tf:broaderTerms("dog"))
return $p/ino:termName

Here, the two ino:termName instances for dog and carnivore are returned.

Pattern Matching

You can conveniently perform text searches with the help of search patterns. Tamino's text retrieval system allows for efficient queries using special characters that match one or more characters in a word. In Tamino XQuery the following functions support text search using pattern matching:

tf:containsText
tf:containsAdjacentText
tf:containsNearText
tf:createTextReference
tf:createAdjacentTextReference
tf:createNearTextReference

The tokenizer that is being used determines the pattern matching facilities that are available. The following table gives an overview of the characters that have a special meaning when used in one of the above functions:

The default tokenizer ("white space-separated") supports all types of special characters, whereas the Japanese tokenizer only supports wildcard characters. The section Wildcard Characters provides details about the peculiarities when using the Japanese tokenizer.

The table above shows the default settings. However, with the white space-separated tokenizer you can use a different character for each of these special characters. If, for example, your data frequently uses the asterisk sign as a regular character, it is more convenient to redefine the wildcard character instead of having to escape the asterisks using the escapecard character every time they occur. See the section Customizing Special Character Settings for information on how to change these settings. The discussion here assumes the default settings as defined in ino:transliteration and, if not stated otherwise, the usage of the standard white space-separated tokenizer.

In the context of pattern matching, a word consists of a non-empty sequence of characters: for example, a wildcard character (default: asterisk) matches zero or more characters in a word, so that a single "*" represents a single word. If the search string contains more than one word, such as in the expression tf:containsText($node, "word1 word2") then it is treated as tf:containsAdjacentText($node, 1, "word1", "word2").

The following sections contain more information about searching with any of these special characters and how to change the default setting:

• The Maskcard Character

• Wildcard Characters

• The Escapecard Character

• Customizing Special Character Settings

The Maskcard Character

The maskcard character, which by default is a question mark "?", stands for a single character in a word. A pattern theat?? thus matches theatre as well as theater, but not theatrical since ?? only match ri and the rest (cal) is not matched.

Consider the following query:

let $text := text{"one two three four five six seven eight nine ten"}
return 
(tf:containsText($text, "??"), tf:containsText($text, "t??"), tf:containsText($text, "two?three"))

The query returns a sequence of three items, each being a Boolean value that indicates whether the specified pattern matches the contents of the text node in $text. Attempting to match the first pattern ?? yields "false", since there are no numerals with only two letters. The second pattern t?? matches all three-letter numerals beginning with t, namely two and ten, so "true" is returned. The last pattern fails again, although the pattern two?three seems to match the value "two three". However, since pattern matching is always performed on the basis of a word, the match does not succeed: the string "two three" is treated as two words delimited by the space character in between.

Note:
Introducing the question mark as a maskcard character also has the effect that it is no longer classified as a delimiter character in the default transliteration.

Wildcard Characters

In contrast to the maskcard character, which matches exactly one character, the wildcard character matches zero or more characters in a word. By default, the wildcard character is an asterisk "*".

Consider the following query:

let    $text := text{"one, two"}
return tf:containsAdjacentText($text, 1, "one", "*", "*")

This query returns false, since tf:containsAdjacentText expects two word tokens adjacent to "one".

If you use the default tokenizer, i.e. the white space-separated tokenizer, then the wildcard character is always the asterisk "*" (Unicode value U+002A).

Using the Japanese Tokenizer

If you use the Japanese tokenizer, all of the following characters are recognized as wildcard characters:

Note:
In contrast to the standard white space-separated tokenizer, this definition of wildcard characters is fixed and cannot be changed.

The Japanese tokenizer does not support wildcard characters in the middle of a word, since there are no explicit delimiter characters. So "疾*患" will be treated as "疾*" adj "患".

The example queries below focus on the contents of the patient/submitted/diagnosis nodes to show the effect of performing search operations with or without wildcard characters on segmentation of Japanese words.

1.

Contents		心臓に問題がある
Translation		problems with the heart
Segmentation	Word Tokens	心臓	ある	問題
	Translation	heart (physical)	has	problem

2.

Contents		心臓麻痺
Translation		heart attack
Segmentation	Word Tokens	心臓	麻痺
	Translation	heart	paralysis

3.

Contents		心臓疾患
Translation		heart disease
Segmentation	Word Tokens	心臓	疾患
	Translation	heart	disease

4.

Contents		心臓血管疾患
Translation		cardiovascular disease
Segmentation	Word Tokens	心臓血管	疾患
	Translation	heart angio (cardiovascular)	disease

The following example queries all use the same query skeleton:

for    $a in input()/patient/submitted/diagnosis
where  <function-call> 
return $a

tf:containsText($a, "心臓")

tf:containsText($a, "心臓病")

tf:containsText($a, "心*")

tf:containsText($a, "心臓*")

tf:containsText($a, "心臓疾患")

tf:containsAdjacentText($a, 1, "心臓", "疾患")

tf:containsNearText($a, 1, "心臓", "問題")

tf:containsNearText($a, 1, "心*", "*患")

The Escapecard Character

With the help of the escapecard character you can negate any special meaning of the following single character. By default, the escapecard character is the backslash character "\". Use it if you want to look for any of the maskcard, escapecard or wildcard characters as literal characters.

Example 1: Escaping an Asterisk

let $text:= text{"** End of code **"}
return tf:containsText($text, "\*\*")

Here, the match succeeds if there is any two-letter word in $text that consists only of asterisks. This is true for the first and last words in $text.

Example 2: Escaping a Backslash

The following checks the path separator character that is used in $path and returns the result as plain text, ordered by platform:

{?serialization method="text" media-type="text/plain"?}
let $path := text{"C:\Program Files\Software AG\Tamino"}
return 
( "Path Separators Used
",
  "DOS/Windows	: ", tf:containsText($path, "*\\*"), "
",
  "UNIX	: ", tf:containsText($path, "*/*"), "
",
  "MacOS	: ", tf:containsText($path, "*:*")
)

In the pattern, the path separator character must be enclosed by the regular wildcard character, since it would not form a word on its own. Provided that the path separator character is defined as a regular character, the query reports for each platform whether its standard path separator character is used, although this example is certainly not a bullet-proof method. However, if the path separator is not defined as a regular character, it will be interpreted as a delimiter. Using the default settings, the pattern in function call tf:containsText($path, "*\\*") will thus be interpreted as if "* *" were used, since the escapecard character tries to mask an invalid character and the text retrieval system uses a delimiter instead. This would yield "true", since there are two occurrences of two adjacent words separated by a space character ("Program Files" and "Software AG"). In cases like these you should ensure that the transliteration is appropriately defined according to what your application expects.

Note:
In contrast to "*", the characters "\" and "?" are normally not classified as regular characters in the collection ino:transliteration. See the section Customizing Transliterations for instructions how to customize this special collection.

Customizing Special Character Settings

If you use the default tokenizer (white space-separated), you can customize the settings for the special characters used in pattern matching. They are declared as attributes to ino:transliteration in the special collection ino:vocabulary:

To change the value of any of these attributes, you can use a query similar to the following, which sets the value of the maskcard character to the default value:

declare namespace ino="http://namespaces.softwareag.com/tamino/response2"
update insert attribute ino:maskchar {"?"}
into input()/ino:transliteration

You can check your changes with the following query:

declare namespace ino="http://namespaces.softwareag.com/tamino/response2"
for $a in input()/ino:transliteration/@*
return $a

Note that only attributes that have been modified are returned.

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