YAYparser
Derek Jones edited this page Jul 5, 2012
·
12 revisions
YAYparser is a regular expression driven YAML parser that is aimed to be small and easy to use.
It is still very new, so it may have some errors or missing features.
Forum Thread: CodeIgniter Forum
- Supports anchors (to keep your YAML DRY)
- Supports multiple documents in the same string
- Supports keys and sequences
- Supports [short, list, format]
- Supports: | multiline text
- Good performance (a bit faster than Spyc)
- Does not support tags, currently
- Does not support spaces in keys
- Does not support unicode (as far as I know)
- May trim multiline entries too much
- No escaping of characters
- Due to the usage of regular expressions, errors in YAML will not be detected
Copy and paste the code below into a new file called yayparser_helper.php in your helpers dir.
Just load the YAYparser helper, then you can use the yayparser() function to parse YAML strings into PHP arrays:
$this->load->helper('yayparser');
$data = yayparser($text);
print_r($data);<?php
/*
* Created on 2008 May 31
* by Martin Wernstahl <m4rw3r at gmail dot com>
*/
/*
* Copyright (c) 2008, Martin Wernstahl
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * The name of Martin Wernstahl may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Martin Wernstahl ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL Martin Wernstahl BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
if(!function_exists('YAYPARSER_parse')){
/**
* YAYParser - Parser function.
*
* @param $str The string to be processed
*
* @return An array which contains data built from the string
*/
function YAYPARSER_parse($str){
$ret = array();
if(!strlen($str))
return $ret;
$num = preg_match_all(
// ONE REGEX TO RULE THEM ALL
'@(?:^|\n)([^\S\n]*)(?:((?:\?\s*)?(\S*)\s*(?:#.*)?(?:\n[^\S\n]*#[^\n]*)*(?:\n[^\S\n]*)?:(?:[^\S\n]*)?)|(-(?:[^\S\n]*)?))(?:(?:\&(\S*))(?:[^\S\n]*)?|(?:\*(\S*))(?:[^\S\n]*)?)?(?:((?:[^\|>\'"\n]*)?(?:\n(?:(?:(?:\1)(?:[^\n\S]+)[^\n]*)|(?:[^\n\S]*#[^\n]*)|(?:[^\n\S]*(?=\n))))+)|(?:(\||>).*\n((?:[^\n\S]*\n)*(?:(?:\1)([^\n\S]+)[^\n]*)(?:(?:\n(?:\1)(?:[^\n\S]+?)[^\n]*)|(?:\n[^\n\S]*(?=\n)))*))|(?:("|\')([\w\W]*?)\11)|(?:\{([\w\W]*?)\})|(?:\[([\w\W]*?)\])|(?:([^#\n\s][^#\n]*))?)(?:#[^\n]*)?@'
,$str,$matches,PREG_SET_ORDER);
foreach($matches as $match){
// value:
$data = array();
if(isset($match[9]) && strlen($match[9])){
// multiline
$s = explode("\n",$match[9]);
$indent_len = strlen($match[1]) + strlen($match[10]);
array_walk($s,'YAYPARSER_substr',$indent_len);
array_walk($s,'YAYPARSER_trim');
if($match[8] == '|'){ // "|" preserves newlines
$data = implode("\n",$s);
}
else{
$data = implode(' ',$s);
}
}
elseif(isset($match[7]) && strlen($match[7])){
// block
if(isset($match[4]) && strlen($match[4]))
$match[7] = str_repeat(' ',strlen($match[4]) + strlen($match[1])) . $match[7];
elseif(isset($match[2]) && strlen($match[2]))
$match[7] = str_repeat(' ',strlen($match[2]) + strlen($match[1])) . $match[7];
$data = YAYPARSER_parse($match[7]);
}
elseif(isset($match[12]) && strlen($match[12])){
// flow scalar
$arr = explode("\n",$match[12]);
array_walk($arr,'YAYPARSER_trim');
$data = trim(implode("\n",$arr));
}
elseif(isset($match[13]) && strlen($match[13])){
// flow node with key/value
$list = explode(',',$match[13]);
array_walk($list,'YAYPARSER_trim');
foreach($list as $l){
$data = array_merge($data,(Array)YAYPARSER_parse($l));
}
}
elseif(isset($match[14]) && strlen($match[14])){
$data = explode(',',$match[14]);
array_walk($data,'YAYPARSER_trim');
}
elseif(isset($match[15])){
// value
$data = $match[15];
}
// create anchor
if(isset($match[5]) && strlen($match[5]))
$GLOBALS['YAYPARSER_anchors'][$match[5]] = $data;
// load anchor
if(isset($match[6]) && strlen($match[6])){
if(isset($GLOBALS['YAYPARSER_anchors'][$match[6]]))
$data = $GLOBALS['YAYPARSER_anchors'][$match[6]];
else
log_message('warning','yayparser: The anchor '.$match[6].' was not found.');
}
// key / list saving
if(isset($match[3]) && strlen($match[3])){
$ret[$match[3]] = $data;
}
elseif(isset($match[4]) && strlen($match[4])){
// list
$ret[] = $data;
}
}
if($num)
return $ret;
// a block without any tags/lists is regarded as a string (newline = space)
$arr = explode("\n",$str);
array_walk($arr,'YAYPARSER_trim');
return trim(implode(' ',$arr));
}
}
if(!function_exists('yayparser')){
/**
* YAYParser - Yet Anoter Yaml Parser.
*
* @param $str The string to be processed
*
* @return An array which contains data built from the string
*/
function yayparser($str){
if(!strlen($str))
return array();
$ret = array();
// split the string into many documents according to the YAML standard
preg_match_all('@(?:(?:^|\n)-{3}([\w\W]*?)(?:\n\.{3}(?:[\w\W]*?)(?=(?:\n-{3})|$))?(?=(?:\n-{3})|(?:$)))@',
"---\n".$str, // make $str an explicit document by adding a --- in the beginning
$matches,PREG_SET_ORDER);
foreach($matches as $match){
$GLOBALS['YAYPARSER_anchors'] = array();
if(isset($match[1]) && strlen(trim($match[1]))){
if(count($data = YAYPARSER_parse($match[1])))
$ret[] = $data;
}
}
if(count($ret) == 1)
$ret = $ret[0];
return $ret;
}
}
if(!function_exists('YAYPARSER_substr')){
/**
* A substr wrapper for use with array_walk().
*/
function YAYPARSER_substr(&$value,&$key,&$len){
$value = substr($value,$len);
}
}
if(!function_exists('YAYPARSER_trim')){
/**
* A trim wrapper for use with array_walk().
*/
function YAYPARSER_trim(&$value,&$key){
$value = trim($value);
}
}
?>