haskell_vs_php_functional.php

<?php
/* php скрипт в функциональном стиле (калька с Haskell) для статьи http://pqr7.wordpress.com/2014/09/03/haskell-vs-php/ */

ini_set('xdebug.max_nesting_level', 200000);

function parse($text) {
    return splitPerBlocks(getLines($text));
}

function getLines($text) {
    return array_map('trim', explode("\n", $text));
}

function splitPerBlocks(array $lines) {
    return splitPerBlocksRecursiveFold([], $lines);
}

function splitPerBlocksRecursiveFold(array $blocks, array $lines) {
    if (count($lines) < 20) {
        return $blocks;
    }

    $linesWithoutHeaderAndFlag = dropFlagLine(dropHeaderLine($lines));
    if (count($linesWithoutHeaderAndFlag) >= 20) {
        $first20Lines = array_slice($linesWithoutHeaderAndFlag, 0, 20);
        $otherLines = array_slice($linesWithoutHeaderAndFlag, 20);
        $newFoundBlocks = $blocks;
        $newFoundBlocks[] = $first20Lines;
        return splitPerBlocksRecursiveFold($newFoundBlocks, $otherLines);
    }

    return $blocks;
}

function dropHeaderLine(array $lines) {
    if (strpos(reset($lines), "Container No.") !== false) {
        return array_slice($lines, 1);
    }

    return $lines;
}

function dropFlagLine(array $lines)
{
    if (count($lines) <= 20) {
        return $lines;
    }

    if (strpos($lines[20], "Flag:") !== false) {
        return array_merge(array_slice($lines, 0, 20), array_slice($lines, 21));
    }

    return $lines;
}

$text = file_get_contents('php://stdin');
print count(parse($text));