Callback Step Panel

Trace named callback-style steps as one ordered PHP replay panel.

callback_step_panel.php

<?php
function add_step($value) {
    return $value + 4;
}

function double_step($value) {
    return $value * 2;
}

$base = ;
$first = add_step($base);
$second = double_step($first);

echo "base=" . $base . "\n";
echo "first=" . $first . "\n";
echo "second=" . $second . "\n";

<?php
function add_step($value) {
    return $value + 4;
}

function double_step($value) {
    return $value * 2;
}

$base = ;
$first = add_step($base);
$second = double_step($first);

echo "base=" . $base . "\n";
echo "first=" . $first . "\n";
echo "second=" . $second . "\n";

<?php
function add_step($value) {
    return $value + 4;
}

function double_step($value) {
    return $value * 2;
}

$base = ;
$first = add_step($base);
$second = double_step($first);

echo "base=" . $base . "\n";
echo "first=" . $first . "\n";
echo "second=" . $second . "\n";

callback step Named functions keep each transformation visible in replay while PHP stays in a single execution thread.