Conversion Module

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

Conventions

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

Strings

convert:binary-to-string

Updated with Version 8.5: $fallback argument added.

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 binary data (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 BXCO0001: The input is an invalid XML string, or the wrong encoding has been specified. Invalid XML characters will be ignored if the CHECKSTRINGS option is turned off.
BXCO0002: The specified encoding is invalid or not supported.
Examples
  • convert:binary-to-string(xs:hexBinary('48656c6c6f576f726c64')) yields HelloWorld.

convert:string-to-base64

Signatures convert:string-to-base64($input as xs:string) as xs:base64Binary
convert:string-to-base64($input as xs:string, $encoding as xs:string) as xs:base64Binary
Summary Converts the specified string to a xs:base64Binary item. If the default encoding is chosen, conversion will be cheap, as both xs:string and xs:base64Binary items are internally represented as byte arrays.
The UTF-8 default encoding can be overwritten with the optional $encoding argument.
Errors BXCO0001: The input cannot be represented in the specified encoding.
BXCO0002: The specified encoding is invalid or not supported.
Examples
  • string(convert:string-to-base64('HelloWorld')) yields SGVsbG9Xb3JsZA==.

convert:string-to-hex

Signatures convert:string-to-hex($input as xs:string) as xs:hexBinary
convert:string-to-hex($input as xs:string, $encoding as xs:string) as xs:hexBinary
Summary Converts the specified string to a xs:hexBinary item. If the default encoding is chosen, conversion will be cheap, as both xs:string and xs:hexBinary items are internally represented as byte arrays.
The UTF-8 default encoding can be overwritten with the optional $encoding argument.
Errors BXCO0001: The input cannot be represented in the specified encoding.
BXCO0002: The specified encoding is invalid or not supported.
Examples
  • string(convert:string-to-hex('HelloWorld')) yields 48656C6C6F576F726C64.

Binary Data

convert:bytes-to-base64

Signatures convert:bytes-to-base64($input as xs:byte*) as xs:base64Binary
Summary Converts the specified byte sequence to a xs:base64Binary item. Conversion is cheap, as xs:base64Binary items are internally represented as byte arrays.
Errors BXCO0001: The input cannot be represented in the specified encoding.
BXCO0002: The specified encoding is invalid or not supported.
Examples
  • string(convert:string-to-base64('HelloWorld')) yields SGVsbG9Xb3JsZA==.

convert:bytes-to-hex

Signatures convert:bytes-to-hex($input as xs:byte*) as xs:hexBinary
Summary Converts the specified byte sequence to a xs:hexBinary item. Conversion is cheap, as xs:hexBinary items are internally represented as byte arrays.

convert:binary-to-bytes

Signatures convert:binary-to-bytes($bin as xs:anyAtomicType) as xs:byte*
Summary Returns the specified binary data (xs:base64Binary, xs:hexBinary) as a sequence of bytes.
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).

Numbers

convert:integer-to-base

Signatures convert:integer-to-base($num as xs:integer, $base as xs:integer) as xs:string
Summary Converts $num to base $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 BXCO0004: 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'.

convert:integer-from-base

Signatures convert:integer-from-base($str as xs:string, $base as xs:integer) as xs:integer
Summary Decodes an xs:integer from $str, assuming that it's encoded in base $base.
The first $base elements of the sequence '0',..,'9','a',..,'z' are allowed as digits, case doesn't matter.
Valid bases are 2 - 36.
If $str contains more than 64 bits of information, the result is truncated arbitarily.
Errors BXCO0004: The specified base is not in the range 2-36.
BXCO0005: 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.

Dates and Durations

convert:integer-to-dateTime

Signatures convert:integer-to-dateTime($ms 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:dateTime-to-integer

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

convert:integer-to-dayTime

Signatures convert:integer-to-dayTime($ms 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.

convert:dayTime-to-integer

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

Errors

Code Description
BXCO0001 The input is an invalid XML string, or the wrong encoding has been specified.
BXCO0002 The specified encoding is invalid or not supported.
BXCO0003 The specified base is not in the range 2-36.
BXCO0004 The specified encoding is invalid or not supported.
BXCO0005 The specified digit is not valid for the given range.

Changelog

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.