-
-                            
fn:string(object)
-                            
-                                Returns the value of $arg represented as a xs:string. If no argument is supplied, the
-                                context item (.) is used as the default argument. The behavior of the function if the
-                                argument is omitted is exactly the same as if the context item had been passed as the
-                                argument.
-
-                                If the context item is undefined, error [err:XPDY0002]XP is raised.
-
-                                If $arg is the empty sequence, the zero-length string is returned.
-
-                                If $arg is a node, the function returns the string-value of the node, as obtained using
-                                the dm:string-value accessor defined in the Section 5.13 string-value AccessorDM.
-
-                                If $arg is an atomic value, then the function returns the same string as is returned by
-                                the expression " $arg cast as xs:string " (see 17 Casting).
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | string- | The object to convert to a string- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | string((1<0))- | false- | 
-                                    
-                                        | string(.11)- | 0.11- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:codepoints-to-string()
-                            
-                                Creates an xs:string from a sequence of The Unicode Standard code points. Returns the
-                                zero-length string if $arg is the empty sequence. If any of the code points in $arg is
-                                not a legal XML character, an error is raised [err:FOCH0001].
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:integer*- | $arg- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | codepoints-to-string((2309, 2358, 2378, 2325))- | अशॊक- | 
-                                    
-                                        | codepoints-to-string((40, 32, 865, 176, 32, 860, 662, 32, 865, 176, 41))
-- | ( ͡° ͜ʖ ͡°)- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:string-to-codepoints()
-                            
-                                Returns the sequence of The Unicode Standard code points that constitute an xs:string.
-                                If $arg is a zero-length string or the empty sequence, the empty sequence is
-                                returned.
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string*- | $arg- | 
-                                
-                                
Return type: xs:integer*
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | string-to-codepoints("Thérèse")- | (84, 104, 233, 114, 232, 115, 101)- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:compare()
-                            
-                                Returns -1, 0, or 1, depending on whether the value of the $comparand1 is respectively
-                                less than, equal to, or greater than the value of $comparand2, according to the rules of
-                                the collation that is used.
-
-                                The collation used by the invocation of this function is determined according to the
-                                rules in 7.3.1 Collations.
-
-                                If either argument is the empty sequence, the result is the empty sequence.
-
-                                This function, invoked with the first signature, backs up the "eq", "ne", "gt", "lt",
-                                "le" and "ge" operators on string values.
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $comparand1- | 
-                                    
-                                        | xs:string?- | $comparand2- | 
-                                    
-                                        | xs:string- | $collation (Optional)- | 
-                                
-                                
Return type: xs:integer*
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | compare('abc', 'abc')- | 0- | 
-                                    
-                                        | compare('abc', 'acc')- | -1- | 
-                                    
-                                        | compare('abc', 'acc')- | 1- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:codepoint-equal()
-                            
-                                Returns true or false depending on whether the value of $comparand1 is equal to the
-                                value of $comparand2, according to the 
Unicode code
-                                    point collation.
-
-                                If either argument is the empty sequence, the result is the empty sequence.
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $comparand1- | 
-                                    
-                                        | xs:string?- | $comparand2- | 
-                                
-                                
Return type: xs:boolean?
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | codepoint-equal("asdf", "asdf")- | true- | 
-                                    
-                                        | codepoint-equal("asdf", "asdf ")- | false- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:concat()
-                            
-                                Accepts two or more xs:anyAtomicType arguments and casts them to xs:string. Returns the
-                                xs:string that is the concatenation of the values of its arguments after conversion. If
-                                any of the arguments is the empty sequence, the argument is treated as the zero-length
-                                string.
-
-                                The fn:concat function is specified to allow two or more arguments, which are
-                                concatenated together. This is the only function specified in this document that allows
-                                a variable number of arguments. This capability is retained for compatibility with [XML
-                                Path Language (XPath) Version 1.0].
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:anyAtomicType?- | $arg1- | 
-                                    
-                                        | xs:anyAtomicType?- | $arg2- | 
-                                    
-                                        | xs:anyAtomicType?- | $arg... (Optional)- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | concat('un', 'grateful')- | ungrateful- | 
-                                    
-                                        | concat('Thy ', (), 'old ', "groans", "", ' ring', ' yet', ' in', ' my', '
-                                            ancient',' ears.')- | Thy old groans ring yet in my ancient ears.- | 
-                                    
-                                        | fn:concat('Ciao!',())- | Ciao!- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:string-join()
-                            
-                                Returns a xs:string created by concatenating the members of the $arg1 sequence using
-                                $arg2 as a separator. If the value of $arg2 is the zero-length string, then the members
-                                of $arg1 are concatenated without a separator.
-
-                                If the value of $arg1 is the empty sequence, the zero-length string is returned.
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string*- | $arg1- | 
-                                    
-                                        | xs:string- | $arg2- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | string-join(('Now', 'is', 'the', 'time', '...'), ' ')- | Now is the time ...- | 
-                                    
-                                        | string-join(('Blow, ', 'blow, ', 'thou ', 'winter ', 'wind!'), '')- | Blow, blow, thou winter wind!- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:substring()
-                            
-                                Returns the portion of the value of $sourceString beginning at the position indicated by
-                                the value of $startingLoc and continuing for the number of characters indicated by the
-                                value of $length. The characters returned do not extend beyond $sourceString. If
-                                $startingLoc is zero or negative, only those characters in positions greater than zero
-                                are returned.
-                                More specifically, the three argument version of the function returns the characters in
-                                $sourceString whose position $p obeys:
-                                
fn:round($startingLoc) <= $p < fn:round($startingLoc) + fn:round($length)
-                                The two argument version of the function assumes that $length is infinite and returns
-                                the characters in $sourceString whose position $p obeys:
-                                
fn:round($startingLoc) <= $p < fn:round(INF)
-                                In the above computations, the rules for op:numeric-less-than() and
-                                op:numeric-greater-than() apply.
-                                If the value of $sourceString is the empty sequence, the zero-length string is
-                                returned.
-
-                                
Note:
-                                The first character of a string is located at position 1, not position 0.
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $sourceString- | 
-                                    
-                                        | xs:double- | $startingLoc- | 
-                                    
-                                        | xs:double- | $length (Optional)- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | substring("motor car", 6)- | " car"- | 
-                                    
-                                        | substring("metadata", 4, 3)- | ada- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:string-length()
-                            
-                                Returns an xs:integer equal to the length in characters of the value of $arg.
-
-                                If the value of $arg is the empty sequence, the xs:integer 0 is returned.
-
-                                If no argument is supplied, $arg defaults to the string value (calculated using
-                                fn:string()) of the context item (.). If no argument is supplied and the context item is
-                                undefined an error is raised: [err:XPDY0002].
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg (Optional)- | 
-                                
-                                
Return type: xs:integer
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | string-length("Harp not on that string, madam; that is past.")- | 45- | 
-                                    
-                                        | string-length(())- | 0- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:normalize-space()
-                            
-                                Returns the value of $arg with whitespace normalized by stripping leading and trailing
-                                whitespace and replacing sequences of one or more than one whitespace character with a
-                                single space, #x20.
-
-                                If the value of $arg is the empty sequence, returns the zero-length string.
-
-                                If no argument is supplied, then $arg defaults to the string value (calculated using
-                                fn:string()) of the context item (.). If no argument is supplied and the context item is
-                                undefined an error is raised: [err:XPDY0002].
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg (Optional)- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | normalize-space(" The wealthy curled darlings of our nation. ")- | The wealthy curled darlings of our nation.- | 
-                                    
-                                        | normalize-space(())- | ""- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:normalize-unicode()
-                            
-                                Returns the value of $arg normalized according to the normalization criteria for a
-                                normalization form identified by the value of $normalizationForm. The effective value of
-                                the $normalizationForm is computed by removing leading and trailing blanks, if present,
-                                and converting to upper case.
-
-                                If the value of $arg is the empty sequence, returns the zero-length string.
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg- | 
-                                    
-                                        | xs:string- | $normalizationForm (Optional)- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | normalize-unicode("test ")- | test- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:upper-case()
-                            
-                                Returns the value of $arg after translating every character to its upper-case
-                                correspondent as defined in the appropriate case mappings section in the Unicode
-                                standard [The Unicode Standard]. For versions of Unicode beginning with the 2.1.8
-                                update, only locale-insensitive case mappings should be applied. Beginning with version
-                                3.2.0 (and likely future versions) of Unicode, precise mappings are described in default
-                                case operations, which are full case mappings in the absence of tailoring for particular
-                                languages and environments. Every lower-case character that does not have an upper-case
-                                correspondent, as well as every upper-case character, is included in the returned value
-                                in its original form.
-
-                                If the value of $arg is the empty sequence, the zero-length string is returned.
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | upper-case("abCd0")- | ABCD0- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:lower-case()
-                            
-                                Returns the value of $arg after translating every character to its lower-case
-                                correspondent as defined in the appropriate case mappings section in the Unicode
-                                standard [The Unicode Standard]. For versions of Unicode beginning with the 2.1.8
-                                update, only locale-insensitive case mappings should be applied. Beginning with version
-                                3.2.0 (and likely future versions) of Unicode, precise mappings are described in default
-                                case operations, which are full case mappings in the absence of tailoring for particular
-                                languages and environments. Every upper-case character that does not have a lower-case
-                                correspondent, as well as every lower-case character, is included in the returned value
-                                in its original form.
-
-                                If the value of $arg is the empty sequence, the zero-length string is returned.
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | lower-case("abCd0")- | abcd0- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:translate()
-                            
-                                Returns the value of $arg modified so that every character in the value of $arg that
-                                occurs at some position N in the value of $mapString has been replaced by the character
-                                that occurs at position N in the value of $transString.
-
-                                If the value of $arg is the empty sequence, the zero-length string is returned.
-
-                                Every character in the value of $arg that does not appear in the value of $mapString is
-                                unchanged.
-
-                                Every character in the value of $arg that appears at some position M in the value of
-                                $mapString, where the value of $transString is less than M characters in length, is
-                                omitted from the returned value. If $mapString is the zero-length string $arg is
-                                returned.
-
-                                If a character occurs more than once in $mapString, then the first occurrence determines
-                                the replacement character. If $transString is longer than $mapString, the excess
-                                characters are ignored.
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg- | 
-                                    
-                                        | xs:string- | $mapString- | 
-                                    
-                                        | xs:string- | $mapString- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | translate("bar","abc","ABC")- | BAr- | 
-                                    
-                                        | translate("--aaa--","abc-","ABC")- | AAA- | 
-                                    
-                                        | translate("abcdabc", "abc", "AB")- | ABdAB- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:encode-for-uri()
-                            
-                                This function encodes reserved characters in an xs:string that is intended to be used in
-                                the path segment of a URI. It is invertible but not idempotent. This function applies
-                                the URI escaping rules defined in section 2 of [RFC 3986] to the xs:string supplied as
-                                $uri-part. The effect of the function is to escape reserved characters. Each such
-                                character in the string is replaced with its percent-encoded form as described in [RFC
-                                3986].
-
-                                If $uri-part is the empty sequence, returns the zero-length string.
-
-                                All characters are escaped except those identified as "unreserved" by [RFC 3986], that
-                                is the upper- and lower-case letters A-Z, the digits 0-9, HYPHEN-MINUS ("-"), LOW LINE
-                                ("_"), FULL STOP ".", and TILDE "~".
-
-                                Note that this function escapes URI delimiters and therefore cannot be used
-                                indiscriminately to encode "invalid" characters in a path segment.
-
-                                Since [RFC 3986] recommends that, for consistency, URI producers and normalizers should
-                                use uppercase hexadecimal digits for all percent-encodings, this function must always
-                                generate hexadecimal values using the upper-case letters A-F.
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $uri-part- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | encode-for-uri("https://www.google.com")- | "https%3A%2F%2Fwww. -google.com"
 | 
-                                    
-                                        | concat("http://www.example.com/", encode-for-uri("~bébé"))- | http://www.example.com/ -~b%C3%A9b%C3%A9
 | 
-                                    
-                                        | concat("http://www.example.com/", encode-for-uri("100% organic"))- | http://www.example.com/ -100%25%20organic
 | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:iri-to-uri()
-                            
-                                This function converts an xs:string containing an IRI into a URI according to the rules
-                                spelled out in Section 3.1 of [RFC 3987]. It is idempotent but not invertible.
-
-                                If $iri contains a character that is invalid in an IRI, such as the space character (see
-                                note below), the invalid character is replaced by its percent-encoded form as described
-                                in [RFC 3986] before the conversion is performed.
-
-                                If $iri is the empty sequence, returns the zero-length string.
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $iri- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | iri-to-uri ("http://www.example.com/00/Weather/CA/Los%20Angeles#ocean")- | "http://www.example.com/00/ -Weather/CA/Los%20Angeles#ocean"
 | 
-                                    
-                                        | iri-to-uri ("http://www.example.com/~bébé")- | http://www.example.com/ -~b%C3%A9b%C3%A9
 | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:escape-html-uri()
-                            
-                                This function escapes all characters except printable characters of the US-ASCII coded
-                                character set, specifically the octets ranging from 32 to 126 (decimal). The effect of
-                                the function is to escape a URI in the manner html user agents handle attribute values
-                                that expect URIs. Each character in $uri to be escaped is replaced by an escape
-                                sequence, which is formed by encoding the character as a sequence of octets in UTF-8,
-                                and then representing each of these octets in the form %HH, where HH is the hexadecimal
-                                representation of the octet. This function must always generate hexadecimal values using
-                                the upper-case letters A-F.
-                                If $uri is the empty sequence, returns the zero-length string.
-
-                                
Note:
-                                The behavior of this function corresponds to the recommended handling of non-ASCII
-                                characters in URI attribute values as described in [HTML 4.0] Appendix B.2.1.
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $uri- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | escape-html-uri("http://www.example.com/00/Weather/CA/Los Angeles#ocean")
-- | http://www.example.com/00/Weather/CA/Los Angeles#ocean- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:contains()
-                            
-                                Returns an xs:boolean indicating whether or not the value of $arg1 contains (at the
-                                beginning, at the end, or anywhere within) at least one sequence of collation units that
-                                provides a minimal match to the collation units in the value of $arg2, according to the
-                                collation that is used.
-
-                                If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable
-                                collation units, it is interpreted as the zero-length string.
-
-                                If the value of $arg2 is the zero-length string, then the function returns true.
-
-                                If the value of $arg1 is the zero-length string, the function returns false.
-
-                                The collation used by the invocation of this function is determined according to the
-                                rules in 7.3.1 Collations. If the specified collation does not support collation units
-                                an error ·may· be raised [err:FOCH0004].
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg1- | 
-                                    
-                                        | xs:string?- | $arg2- | 
-                                    
-                                        | xs:string?- | $collation (Optional)- | 
-                                
-                                
Return type: xs:boolean
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | contains( "tattoo", "tat")- | true- | 
-                                    
-                                        | contains( "tattoo", "ttt")- | false- | 
-                                    
-                                        | contains ( "", ())- | true- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:starts-with()
-                            
-                                Returns an xs:boolean indicating whether or not the value of $arg1 starts with a
-                                sequence of collation units that provides a match to the collation units of $arg2
-                                according to the collation that is used.
-
-                                If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable
-                                collation units, it is interpreted as the zero-length string.
-
-                                If the value of $arg2 is the zero-length string, then the function returns true. If the
-                                value of $arg1 is the zero-length string and the value of $arg2 is not the zero-length
-                                string, then the function returns false.
-
-                                The collation used by the invocation of this function is determined according to the
-                                rules in 7.3.1 Collations. If the specified collation does not support collation units
-                                an error ·may· be raised [err:FOCH0004].
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg1- | 
-                                    
-                                        | xs:string?- | $arg2- | 
-                                    
-                                        | xs:string?- | $collation (Optional)- | 
-                                
-                                
Return type: xs:boolean
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | starts-with( "tattoo", "tat")- | true- | 
-                                    
-                                        | starts-with( "tattoo", "ttt")- | false- | 
-                                    
-                                        | starts-with ( "", ())- | true- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:ends-with()
-                            
-                                Returns an xs:boolean indicating whether or not the value of $arg1 starts with a
-                                sequence of collation units that provides a match to the collation units of $arg2
-                                according to the collation that is used.
-
-                                If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable
-                                collation units, it is interpreted as the zero-length string.
-
-                                If the value of $arg2 is the zero-length string, then the function returns true. If the
-                                value of $arg1 is the zero-length string and the value of $arg2 is not the zero-length
-                                string, then the function returns false.
-
-                                The collation used by the invocation of this function is determined according to the
-                                rules in 7.3.1 Collations. If the specified collation does not support collation units
-                                an error ·may· be raised [err:FOCH0004].
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg1- | 
-                                    
-                                        | xs:string?- | $arg2- | 
-                                    
-                                        | xs:string?- | $collation (Optional)- | 
-                                
-                                
Return type: xs:boolean
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | ends-with( "tattoo", "too")- | true- | 
-                                    
-                                        | ends-with( "tattoo", "tatoo")- | false- | 
-                                    
-                                        | ends-with ((), ())- | true- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:substring-before()
-                            
-                                Returns the substring of the value of $arg1 that precedes in the value of $arg1 the
-                                first occurrence of a sequence of collation units that provides a minimal match to the
-                                collation units of $arg2 according to the collation that is used.
-
-                                If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable
-                                collation units, it is interpreted as the zero-length string.
-
-                                If the value of $arg2 is the zero-length string, then the function returns the
-                                zero-length string.
-
-                                If the value of $arg1 does not contain a string that is equal to the value of $arg2,
-                                then the function returns the zero-length string.
-
-                                The collation used by the invocation of this function is determined according to the
-                                rules in 7.3.1 Collations If the specified collation does not support collation units an
-                                error ·may· be raised [err:FOCH0004].
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg1- | 
-                                    
-                                        | xs:string?- | $arg2- | 
-                                    
-                                        | xs:string?- | $collation (Optional)- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | substring-before( "tattoo", "too")- | tat- | 
-                                    
-                                        | substring-before( "tattoo", "tat")- | <empty string>- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:substring-after()
-                            
-                                Returns the substring of the value of $arg1 that follows in the value of $arg1 the first
-                                occurrence of a sequence of collation units that provides a minimal match to the
-                                collation units of $arg2 according to the collation that is used.
-
-                                If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable
-                                collation units, it is interpreted as the zero-length string.
-
-                                If the value of $arg2 is the zero-length string, then the function returns the value of
-                                $arg1.
-
-                                If the value of $arg1 does not contain a string that is equal to the value of $arg2,
-                                then the function returns the zero-length string.
-
-                                The collation used by the invocation of this function is determined according to the
-                                rules in 7.3.1 Collations If the specified collation does not support collation units an
-                                error ·may· be raised [err:FOCH0004].
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $arg1- | 
-                                    
-                                        | xs:string?- | $arg2- | 
-                                    
-                                        | xs:string?- | $collation (Optional)- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | substring-after( "tattoo", "too")- | <empty string>- | 
-                                    
-                                        | substring-after( "tattoo", "tat")- | too- | 
-                                
-                                
W3C Documentation reference
-                            
-
-
-                            
fn:matches()
-                            
-                                The function returns true if $input matches the regular expression supplied as $pattern
-                                as influenced by the value of $flags, if present; otherwise, it returns false.
-
-                                The effect of calling the first version of this function (omitting the argument $flags)
-                                is the same as the effect of calling the second version with the $flags argument set to
-                                a zero-length string. Flags are defined in 7.6.1.1 Flags.
-
-                                If $input is the empty sequence, it is interpreted as the zero-length string.
-                                Unless the metacharacters ^ and $ are used as anchors, the string is considered to match
-                                the pattern if any substring matches the pattern. But if anchors are used, the anchors
-                                must match the start/end of the string (in string mode), or the start/end of a line (in
-                                multiline mode).
-
-                                An error is raised [err:FORX0002] if the value of $pattern is invalid according to the
-                                rules described in section 7.6.1 Regular Expression Syntax.
-
-                                An error is raised [err:FORX0001] if the value of $flags is invalid according to the
-                                rules described in section 7.6.1 Regular Expression Syntax.
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $input- | 
-                                    
-                                        | xs:string- | $pattern- | 
-                                    
-                                        | xs:string- | $flags (Optional)- | 
-                                
-                                
Return type: xs:boolean
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | matches("abracadabra", "bra")- | true- | 
-                                    
-                                        | matches("abracadabra", "^a.*a$")- | false- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:replace()
-                            
-                                The function returns the xs:string that is obtained by replacing each non-overlapping
-                                substring of $input that matches the given $pattern with an occurrence of the
-                                $replacement string.
-
-                                The effect of calling the first version of this function (omitting the argument $flags)
-                                is the same as the effect of calling the second version with the $flags argument set to
-                                a zero-length string. Flags are defined in 7.6.1.1 Flags.
-
-                                The $flags argument is interpreted in the same manner as for the fn:matches()
-                                function.
-
-                                If $input is the empty sequence, it is interpreted as the zero-length string.
-
-                                If two overlapping substrings of $input both match the $pattern, then only the
 first
-                                one (that is, the one whose first character comes first in the $input string) is
-                                replaced.
-
-                                Within the $replacement string, a variable $N may be used to refer to the substring
-                                captured by the Nth parenthesized sub-expression in the regular expression. For each
-                                match of the pattern, these variables are assigned the value of the content matched by
-                                the relevant sub-expression, and the modified replacement string is then substituted for
-                                the characters in $input that matched the pattern. $0 refers to the substring captured
-                                by the regular expression as a whole.
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $input- | 
-                                    
-                                        | xs:string- | $pattern- | 
-                                    
-                                        | xs:string- | $replacement- | 
-                                    
-                                        | xs:string- | $flags (Optional)- | 
-                                
-                                
Return type: xs:string
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | replace("abracadabra", "bra", "*")- | a*cada*- | 
-                                    
-                                        | replace("abracadabra", "a.*a", "*")- | *- | 
-                                    
-                                        | replace("AAAA", "A+", "b")- | b- | 
-                                
-                                
W3C Documentation reference
-                            
-
-                            
fn:tokenize()
-                            
-                                This function breaks the $input string into a sequence of strings, treating any
-                                substring that matches $pattern as a separator. The separators themselves are not
-                                returned.
-
-                                The effect of calling the first version of this function (omitting the argument $flags)
-                                is the same as the effect of calling the second version with the $flags argument set to
-                                a zero-length string. Flags are defined in 7.6.1.1 Flags.
-
-                                The $flags argument is interpreted in the same way as for the fn:matches() function.
-
-                                If $input is the empty sequence, or if $input is the zero-length string, the result is
-                                the empty sequence.
-
-                                If the supplied $pattern matches a zero-length string, that is, if fn:matches("",
-                                $pattern, $flags) returns true, then an error is raised: [err:FORX0003].
-
-                                If a separator occurs at the start of the $input string, the result sequence will start
-                                with a zero-length string. Zero-length strings will also occur in the result sequence if
-                                a separator occurs at the end of the $input string, or if two adjacent substrings match
-                                the supplied $pattern.
-
-
-                                
Arguments and return type:
-                                
-                                    
-                                        | Type- | Description- | 
-                                    
-                                        | xs:string?- | $input- | 
-                                    
-                                        | xs:string- | $pattern- | 
-                                    
-                                        | xs:string- | $flags (Optional)- | 
-                                
-                                
Return type: xs:string*
-                                
Examples: 
-                                
-                                    
-                                        | Expression- | Result- | 
-                                    
-                                        | tokenize("The cat sat on the mat", "\s+")- | ("The", "cat", "sat", "on", "the", "mat")- | 
-                                    
-                                        | tokenize("1, 15, 24, 50", ",\s*")- | ("1", "15", "24", "50")- | 
-                                    
-                                        | tokenize("1,15,,24,50,", ",")- | ("1", "15", "", "24", "50", "")- | 
-                                
-                                
W3C Documentation reference
-                            
-
-