I'm not attempting to solve this puzzle, but, regarding the output from
print_r(), try this for nicely formatted output:
echo "<pre>";
print_r($myarray);
echo "</pre>";
Looks much better.
Monty
> From: [EMAIL PROTECTED] (Peter Harkins)
> Newsgroups: php.general
> Date: Sat, 26 Oct 2002 02:37:51 -0700
> To: [EMAIL PROTECTED]
> Subject: parsing conundrum
>
> If you know what recursion is and like a challege, here's a puzzle
> to keep you up nights. If not, you'll probably just want to mutter to
> yourself "what a poor, unlucky bastard" and pass on by.
>
> I'm parsing some data files into a PHP array and am stumped. I'm at
> a loss for how to do this without grinding through character by character.
> That would work, but my subconcious is nagging at me that there's got to be
> a more elegant way to do it that I'm just not seeing, so I'm going to
> describe the problem and ask for help before I start grinding.
>
> The app I'm getting this from has 4 data types: int, string, array
> and mapping (associative array).
>
> Ints and strings are pretty straightforward, but there's no way to
> tell 0 from null int or null string. This is an annoying limitation of the
> app that just has to be ignored and dealt with by whatever gets this data
> from us. This (among other reasons) make me glad PHP is weakly-typed.
>
> Arrays are indexed from 0 and values can mix ints and strings
> freely.
>
> To start, mappings are arrays indexed by ints or strings. Mappings
> aren't just arrays, though, they have a "width" (which is really a nested
> array that I'm pretty certain is an ugly historical artifact.) Width allows
> multiple values for one key and must be the same for all values in a
> mapping, though the values (both of keys and their values) don't have to be
> of the same type. Mappings can also mix ints and strings.
>
> The tough part is that arrays and mappings can nest inside of each
> other and the only characters quoted in strings are \, " and \n. This means
> recursion must be used, but I just can't figure out a way to find the
> boundaries of each element. Anyone with a clean way to do this (probably
> with some kind of crazy regexp) will recieve my awe and gratitude.
>
> Here's an example file[1]:
>
> null_string 0
> some_string "Fourscore and seven years ago..."
> unset_int 0
> an_int 42
> negative_int -12
> null_array ({ })
> null_mapping ([ ])
> easy_array ({9,22,"test",})
> easy_mapping (["string":3,"foo":"bar",[12]:"I am not a crook!",])
> medium_array ({"a string, containing a comma and a \"",23,})
> medium_mapping (["str\"ing":3;5;7, 9:"Read my lips.";11;13;,])
> hard_array ({"comma, string",({3,4,5,}),({"'\"str'",4,({3,4,({ }),}),}),})
> hard_mapping ([17:"str";15,"foo":([ ]);17,"b'l\\a\nh":19;([21:23,]),"tour de
> force":({29,31});({([ ])}),])
>
> You may notice the last one is pathological[2]. Yes, PHP will really
> let you use " and \n in array keys. The real data do sometimes get about
> this complex; consider this a compressed version. As a fun fact, I've
> learned vim's % command doesn't work when there's an odd number of double
> quotes between your parens/braces.
>
> Calling print_r on the array this generates would return:
>
> Array
> (
> [null_string] => 0
> [some_string] => "Fourscore and seven years ago..."
> [unset_int] => 0
> [an_int] => 42
> [negative_int] => -12
> [null_array] => Array
> (
> )
>
> [null_mapping] => Array
> (
> )
>
> [easy_array] => Array
> (
> [0] => 9
> [1] => 22
> [0] => test
> )
>
> [easy_mapping] => Array
> (
> [string] => 3
> [foo] => "bar"
> [12] => "I am not a crook!"
> )
>
> [medium_array] => Array
> (
> [0] => a string, containing a comma and a "
> [1] => 23
> )
>
> [medium_mapping] => Array
> (
> [string] => Array
> (
> [0] => 3
> [1] => 5
> [2] => 7
> )
>
> [9] => Array
> (
> [0] => Read my lips.
> [1] => 11
> [2] => 13
> )
>
> )
>
> [hard_array] => Array
> (
> [0] => comma, string
> [1] => Array
> (
> [0] => 3
> [1] => 4
> [2] => 5
> )
>
> [2] => Array
> (
> [0] => '"str'
> [1] => 4
> [2] => Array
> (
> [0] => 3
> [1] => 4
> [2] => Array
> (
> )
>
> )
>
> )
>
> )
>
> [hard_mapping] => Array
> (
> [17] => Array
> (
> [0] => str
> [1] => 15
> )
>
> [foo] => Array
> (
> [0] => Array
> (
> )
>
> [1] => 17
> )
>
> [b'l\a\nh] => Array
> (
> [0] => 19
> [1] => Array
> (
> [21] => 23
> )
>
> )
>
> [tour de force] => Array
> (
> [0] => Array
> (
> [29] => 31
> )
>
> [1] => Array
> (
> [0] => Array
> (
> )
> )
>
> )
>
> )
>
> )
>
> The truly eagle-eyed will note that print_r doesn't really escape \n
> when outputting, which is ugly and should probably have a bug report filed
> on it. I've ignored this behavior of print_r to produce more readable
> output.
>
> Anyone who gets the 'tour de force' can contact me for the 'victory
> lap' puzzle if it didn't occur to them while solving this one. It's equally
> frustrating.
>
> [1] Brownie points to anyone who recognizes the app that outputs this data
> format. Yep, I'm doing web integration. Feel free to contact me off-list if
> you've any ideas/code to share or would like to see what I'm doing. Yes,
> technically, mappings can be indexed by an array or mapping. I've ignored
> this because 1. PHP can't do this and 2. Anyone doing this will be dragged
> out into the street and shot.
>
> [2] http://tuxedo.org/~esr/jargon/html/entry/pathological.html
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