Difference between revisions of "Conversion Module"

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| '''Errors'''
 
| '''Errors'''
 
|{{Error|BXCO0001|#Errors}} The input is an invalid XML string, or the wrong encoding has been specified.<br/>{{Error|BXCO0002|#Errors}} The specified encoding is invalid or not supported.
 
|{{Error|BXCO0001|#Errors}} The input is an invalid XML string, or the wrong encoding has been specified.<br/>{{Error|BXCO0002|#Errors}} The specified encoding is invalid or not supported.
 +
|-
 +
| '''Examples'''
 +
|
 +
* {{Code|convert:to-string(xs:hexBinary('48656c6c6f576f726c64'))}} returns the string {{Code|HelloWorld}}.
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|}
 +
 +
==convert:to-base64==
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{|
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|-
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| width='90' | '''Signatures'''
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|{{Func|convert:to-base64|$input as xs:string|xs:base64Binary}}<br/>{{Func|convert:to-base64|$input as xs:string, $encoding as xs:string|xs:base64Binary}}
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|-
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| '''Summary'''
 +
|Converts the specified string to a {{Code|xs:base64Binary}}} item. If the default encoding is chosen, conversion will be very cheap in BaseX, as both {{Code|xs:string}} and {{Code|xs:base64Binary}} items are internally mapped to byte arrays.<br/>The UTF-8 default encoding can be overwritten with the optional {{Code|$encoding}} argument.
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|-
 +
| '''Errors'''
 +
|{{Error|BXCO0001|#Errors}} The input cannot be represented in the specified encoding.<br/>{{Error|BXCO0002|#Errors}} The specified encoding is invalid or not supported.
 
|-
 
|-
 
| '''Examples'''
 
| '''Examples'''

Revision as of 16:22, 27 May 2012

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.

Binary Data

convert:to-string

Signatures convert:to-string($bytes as basex:binary) as xs:string
convert:to-string($bytes as basex:binary, $encoding as xs:string) 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.
Errors BXCO0001: 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:to-string(xs:hexBinary('48656c6c6f576f726c64')) returns the string HelloWorld.

convert:to-base64

Signatures convert:to-base64($input as xs:string) as xs:base64Binary
convert:to-base64($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 very cheap in BaseX, as both xs:string and xs:base64Binary items are internally mapped to 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
  • convert:to-string(xs:hexBinary('48656c6c6f576f726c64')) returns the string HelloWorld.

convert:to-bytes

Signatures convert:to-bytes($bin as basex:binary) as xs:byte*
Summary Extracts the bytes from the given binary data $bin.
Examples
  • convert:to-bytes(xs:base64Binary('QmFzZVggaXMgY29vbA==')) returns the sequence (66, 97, 115, 101, 88, 32, 105, 115, 32, 99, 111, 111, 108).
  • convert:to-bytes(xs:hexBinary("4261736558")) returns the sequence (66 97 115 101 88).

Numeric Data

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.
Examples
  • convert:integer-to-base(-1, 16) returns the hexadecimal string 'ffffffffffffffff'.
  • convert:integer-to-base(22, 5) returns '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.
Examples
  • convert:integer-from-base('ffffffffffffffff', 16) returns -1.
  • convert:integer-from-base('CAFEBABE', 16) returns 3405691582.
  • convert:integer-from-base('42', 5) returns 22.
  • convert:integer-from-base(convert:integer-to-base(123, 7), 7) returns 123.

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.

Changelog

The module was introduced with Version 7.3.