Conversion Module

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This XQuery Module contains functions to convert data between different formats.

Contents

[edit] Conventions

Updated with Version 9.0:

All functions and errors in this module are assigned to the http://basex.org/modules/convert namespace, which is statically bound to the convert prefix.

[edit] Strings

[edit] convert:binary-to-string

Signatures convert:binary-to-string($bytes as xs:anyAtomicType) as xs:string
convert:binary-to-string($bytes as xs:anyAtomicType, $encoding as xs:string) as xs:string
convert:binary-to-string($bytes as xs:anyAtomicType, $encoding as xs:string, $fallback as xs:boolean) as xs:string
Summary Converts the specifed $bytes (xs:base64Binary, xs:hexBinary) to a string:
  • The UTF-8 default encoding can be overwritten with the optional $encoding argument.
  • By default, invalid characters will be rejected. If $fallback is set to true, these characters will be replaced with the Unicode replacement character FFFD (�).
Errors string: The input is an invalid XML string, or the wrong encoding has been specified.
BXCO0002: The specified encoding is invalid or not supported.
Examples
  • convert:binary-to-string(xs:hexBinary('48656c6c6f576f726c64')) yields HelloWorld.

[edit] convert:string-to-base64

Signatures convert:string-to-base64($string as xs:string) as xs:base64Binary
convert:string-to-base64($string as xs:string, $encoding as xs:string) as xs:base64Binary
Summary Converts the specified $string to an xs:base64Binary item. If the default encoding is chosen, conversion will be cheap, as strings and binaries are both internally represented as byte arrays.
The UTF-8 default encoding can be overwritten with the optional $encoding argument.
Errors binary: The input cannot be represented in the specified encoding.
encoding: The specified encoding is invalid or not supported.
Examples
  • string(convert:string-to-base64('HelloWorld')) yields SGVsbG9Xb3JsZA==.

[edit] convert:string-to-hex

Signatures convert:string-to-hex($string as xs:string) as xs:hexBinary
convert:string-to-hex($string as xs:string, $encoding as xs:string) as xs:hexBinary
Summary Converts the specified $string to an xs:hexBinary item. If the default encoding is chosen, conversion will be cheap, as strings and binaries are both internally represented as byte arrays.
The UTF-8 default encoding can be overwritten with the optional $encoding argument.
Errors binary: The input cannot be represented in the specified encoding.
encoding: The specified encoding is invalid or not supported.
Examples
  • string(convert:string-to-hex('HelloWorld')) yields 48656C6C6F576F726C64.

[edit] Binary Data

[edit] convert:integers-to-base64

Updated with Version 9.0: Renamed from convert:bytes-to-base64; argument type relaxed from xs:byte to xs:integer.

Signatures convert:integers-to-base64($integers as xs:integer*) as xs:base64Binary
Summary Converts the specified $integers to an item of type xs:base64Binary:
  • Only the first 8 bits of the supplied integers will be considered.
  • Conversion of byte sequences is particularly cheap, as items of binary type are internally represented as byte arrays.

[edit] convert:integers-to-hex

Updated with Version 9.0: Renamed from convert:bytes-to-base64; argument type relaxed from xs:byte to xs:integer.

Signatures convert:integers-to-hex($integers as xs:integer*) as xs:hexBinary
Summary Converts the specified $integers to an item of type xs:hexBinary:
  • Only the first 8 bits of the supplied integers will be considered.
  • Conversion of byte sequences is particularly cheap, as items of binary type are internally represented as byte arrays.

[edit] convert:binary-to-integers

Introduced with Version 9.0:

Signatures convert:binary-to-integer($binary as xs:anyAtomicType) as xs:integer*
Summary Returns the specified $binary (xs:base64Binary, xs:hexBinary) as a sequence of unsigned integers (octets).
Examples
  • convert:binary-to-integer(xs:hexBinary('FF')) yields 255.

[edit] convert:binary-to-bytes

Signatures convert:binary-to-bytes($binary as xs:anyAtomicType) as xs:byte*
Summary Returns the specified $binary (xs:base64Binary, xs:hexBinary) as a sequence of bytes. The conversion is very cheap and takes no additional memory, as items of binary type are internally represented as byte arrays.
Examples
  • convert:binary-to-bytes(xs:base64Binary('QmFzZVggaXMgY29vbA==')) yields the sequence (66, 97, 115, 101, 88, 32, 105, 115, 32, 99, 111, 111, 108).
  • convert:binary-to-bytes(xs:hexBinary("4261736558")) yields the sequence (66 97 115 101 88).

[edit] Numbers

[edit] convert:integer-to-base

Signatures convert:integer-to-base($number as xs:integer, $base as xs:integer) as xs:string
Summary Converts $number to a string, using the specified $base, interpreting it as a 64-bit unsigned integer.
The first base elements of the sequence '0',..,'9','a',..,'z' are used as digits.
Valid bases are 2, .., 36.
Errors base: The specified base is not in the range 2-36.
Examples
  • convert:integer-to-base(-1, 16) yields 'ffffffffffffffff'.
  • convert:integer-to-base(22, 5) yields '42'.

[edit] convert:integer-from-base

Signatures convert:integer-from-base($string as xs:string, $base as xs:integer) as xs:integer
Summary Decodes an integer from $string, using the specified $base.
The first base elements of the sequence '0',..,'9','a',..,'z' are allowed as digits; case does not matter.
Valid bases are 2 - 36.
If the supplied string contains more than 64 bits of information, the result will be truncated.
Errors base: The specified base is not in the range 2-36.
integer: The specified digit is not valid for the given range.
Examples
  • convert:integer-from-base('ffffffffffffffff', 16) yields -1.
  • convert:integer-from-base('CAFEBABE', 16) yields 3405691582.
  • convert:integer-from-base('42', 5) yields 22.
  • convert:integer-from-base(convert:integer-to-base(123, 7), 7) yields 123.

[edit] Dates and Durations

[edit] convert:integer-to-dateTime

Signatures convert:integer-to-dateTime($milliseconds as xs:integer) as xs:dateTime
Summary Converts the specified number of $milliseconds since 1 Jan 1970 to an item of type xs:dateTime.
Examples
  • convert:integer-to-dateTime(0) yields 1970-01-01T00:00:00Z.
  • convert:integer-to-dateTime(1234567890123) yields 2009-02-13T23:31:30.123Z.
  • convert:integer-to-dateTime(prof:current-ms()) returns the current miliseconds in the xs:dateTime format.

[edit] convert:dateTime-to-integer

Signatures convert:dateTime-to-integer($dateTime as xs:dateTime) as xs:integer
Summary Converts the specified $dateTime item to the number of milliseconds since 1 Jan 1970.
Examples
  • convert:dateTime-to-integer(xs:dateTime('1970-01-01T00:00:00Z')) yields 0.

[edit] convert:integer-to-dayTime

Signatures convert:integer-to-dayTime($milliseconds as xs:integer) as xs:dayTimeDuration
Summary Converts the specified number of $milliseconds to an item of type xs:dayTimeDuration.
Examples
  • convert:integer-to-dayTime(1234) yields PT1.234S.

[edit] convert:dayTime-to-integer

Signatures convert:dayTime-to-integer($dayTime as xs:dayTimeDuration) as xs:integer
Summary Converts the specified $dayTime duration to milliseconds represented by an integer.
Examples
  • convert:dayTime-to-integer(xs:dayTimeDuration('PT1S')) yields 1000.

[edit] Errors

Updated with Version 9.0:

Code Description
base The specified base is not in the range 2-36.
binary The input cannot be converted to a binary representation.
encoding The specified encoding is invalid or not supported.
integer The specified digit is not valid for the given range.
string The input is an invalid XML string, or the wrong encoding has been specified.

[edit] Changelog

Version 9.0
Version 8.5
Version 7.5

The module was introduced with Version 7.3. Some of the functions have been adopted from the obsolete Utility Module.

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