wp_find_hierarchy_loop_tortoise_hare( callable $callback, int $start, array $override = array(), array $callback_args = array(), bool $_return_loop = false ): mixed

Description

Parameters

$callbackcallable

Function that accepts ( ID, callback_arg, ... ) and outputs parent_ID.

$startint

The ID to start the loop check at.

$overridearrayoptional

An array of ( ID => parent_ID, ... ) to use instead of $callback. Default empty array.Default: array()

$callback_argsarrayoptional

Additional arguments to send to $callback. Default empty array.Default: array()

$_return_loopbooloptional

Return loop members or just detect presence of loop? Only set to true if you already know the given $start is part of a loop (otherwise the returned array might include branches). Default false.Default: false

Return

mixed

Scalar ID of some arbitrary member of the loop, or array of IDs of all members of loop if $_return_loop

Used by · 1

• wp_find_hierarchy_loop()Finds hierarchy loops using a callback function that maps object IDs to parent IDs.

Source

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7097function wp_find_hierarchy_loop_tortoise_hare( $callback, $start, $override = array(), $callback_args = array(), $_return_loop = false ) {7098	$tortoise        = $start;7099	$hare            = $start;7100	$evanescent_hare = $start;7101	$return          = array();7102 7103	// Set evanescent_hare to one past hare. Increment hare two steps.7104	while (7105		$tortoise7106	&&7107		( $evanescent_hare = isset( $override[ $hare ] ) ? $override[ $hare ] : call_user_func_array( $callback, array_merge( array( $hare ), $callback_args ) ) )7108	&&7109		( $hare = isset( $override[ $evanescent_hare ] ) ? $override[ $evanescent_hare ] : call_user_func_array( $callback, array_merge( array( $evanescent_hare ), $callback_args ) ) )7110	) {7111		if ( $_return_loop ) {7112			$return[ $tortoise ]        = true;7113			$return[ $evanescent_hare ] = true;7114			$return[ $hare ]            = true;7115		}7116 7117		// Tortoise got lapped - must be a loop.7118		if ( $tortoise === $evanescent_hare || $tortoise === $hare ) {7119			return $_return_loop ? $return : $tortoise;7120		}7121 7122		// Increment tortoise by one step.7123		$tortoise = isset( $override[ $tortoise ] ) ? $override[ $tortoise ] : call_user_func_array( $callback, array_merge( array( $tortoise ), $callback_args ) );7124	}7125 7126	return false;7127}

History

Introduced in 3.1.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.7.7 tag, from src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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