E.08 — Life on Meridian

Hopper filters

Filter any hopper by writing what it should take, in plain text: an item, a tag, an enchantment, a potion, durability, a name, who threw it, and much more. No redstone item sorters, no filler items.

Hopper filters use Hopplet by jwkerr. This page is adapted from the Hopplet wiki (MIT licence). It replaces the old left-click item locks: hoppers you locked before are turned into the matching filter automatically the first time their area loads.

Making a filter

1
Open the filter editor
With nothing in your main hand, sneak and right-click a hopper or a hopper minecart. You can also look at it and type /hopplet edit. It only opens where you're allowed to break the hopper, so nobody can change the filters in your town.

The filter editor. Type your filter in the Filter Input box.

2
Write the filter
Type it into the Filter Input box, using the syntax and functions below (up to 512 characters).
3
Check it
Press the aqua Validate button. Any mistake shows up in red above the box, with where it is.

Validate checks the filter, Confirm saves it, Cancel closes the editor.

A mistake: the closing quote after Fruitloopins is missing.

4
Save it
Press Confirm. The hopper's name becomes your filter, in gold, and from now on it only takes items that pass.

A hopper filtered by book author took the book Fruitloopins wrote.

Good to know

Removing a filterOpen the editor, clear the box and press Confirm. The hopper takes anything again.
Gold names are filtersA hopper's filter is its gold name. Breaking and placing the hopper keeps it, like any named block.
Anvils don't make filtersNaming a hopper in an anvil just names it, so you can still label hoppers normally. Only the editor makes filters.
A broken filter takes nothingIf a filter has a mistake in it, the hopper accepts no items at all until it's fixed, so nothing ends up in the wrong place.
Old item locksHoppers locked with the old left-click lock become filters like type(diamond) (plus the potion, enchantment or name they were locked to). Left-clicking a hopper with an item doesn't lock it any more.
Need help?Ask in our Discord: the editor links here and to it.

Syntax

A filter is one or more functions (checks on the item), joined with and, or and not.

Symbol	Meaning	Example
`function(arguments)`	A check that an item has to pass.	`type(diamond)`, `name("Secret Item")`
`&`	Both sides must be true.	`type(diamond_sword) & ench(sharpness)`
`\|`	Either side can be true.	`type(gold_ingot) \| thrower(Fruitloopins)`
`!`	Not: flips the check after it.	`!enchanted()`
`( )`	Groups checks so they're worked out together first.	`type(gold_ingot) \| (author(Fruitloopins) & generation(copy_of_copy))`
`" "`	Wraps an argument so spaces and symbols are kept. It's good practice to quote every argument.	`ench("sharpness >= 4")`

Comparators

Some functions take comparisons instead of names, to set limits. For example durability(>=75, <=90) means the item has between 75% and 90% of its durability left.

Comparator	Means
`=`	equal to
`!=`	not equal to (must be in quotes)
`>`	more than
`<`	less than
`>=`	at least
`<=`	at most

Examples

What you want	Filter
Only diamonds	`type(diamond)`
Any ore block or raw ore	`type_ends_with(_ore) \| type_starts_with(raw_)`
All wool, any colour	`tag(wool)`
Food, but not rotten flesh	`edible() & !type(rotten_flesh)`
Fire resistance potions (any length)	`type(potion) & effect(fire_resistance)`
Sharpness IV or better swords	`type_ends_with(_sword) & ench("sharpness >= 4")`
Worn-out tools to repair (under 25% left)	`damaged() & durability(<25)`
Things that can go in a furnace as fuel	`fuel()`
Only items your town's players drop in	`town(YourTown)`
Everything except cobblestone	`!type(cobblestone)`

Meridian's own items

Our custom items look like ordinary items to the functions below, so they have their own function: custom(name).

Filter	Takes
`custom(debuff_resistance)`	Potions of Debuff Resistance: drinkable, splash and lingering, and Debuff Resistance arrows. Add `& type(splash_potion)` for one kind only.
`custom(wrench)`	Wrenches, but not ordinary sticks.
`custom(debuff_resistance, wrench)`	Either of them.
`type(potion) & !custom(debuff_resistance)`	Every drinkable potion except Debuff Resistance.

Functions

Every check you can use. Names in small print are shorter aliases that work the same way. Arguments are separated by commas: functions that take a list match if the item fits any of them, except where it says all. In game, /hopplet function <name> explains any of them.

Function	Takes	True when…	Example
`amount` `size`	`comparator`	Evaluates to true if an item stack's size matches all the specified amounts.	`amount(>32, <48)`
`armor_trim_material` `trim_material`	trim material	Evaluates to true if an item's armor trim material matches one of the specified materials.	`trim_material(gold)`
`armor_trim_pattern` `trim_pattern`	trim pattern	Evaluates to true if an item's armor trim pattern matches one of the specified patterns.	`trim_pattern(silence)`
`book_author` `author`	`username`	Evaluates to true if a book's author matches one of the specified strings.	`author(Fruitloopins)`
`book_generation` `generation`	generation	Evaluates to true if a book's generation matches one of the specified generations.	`generation(copy_of_copy)`
`book_title` `title`	`string`	Evaluates to true if a book's title matches one of the specified titles.	`title("Special Book")`
`display_name_contains` `name_contains`	`string`	Evaluates to true if an item's display name contains all the specified strings.	`name_contains(stone, moss)`
`display_name_ends_with` `name_ends_with`	`string`	Evaluates to true if an item's display name ends with one of the specified strings.	`name_ends_with(map)`
`display_name` `name`	`string`	Evaluates to true if an item's display name matches one of the specified strings.	`name("Super Secret Access Key")`
`display_name_starts_with` `name_starts_with`	`string`	Evaluates to true if an item's display name starts with one of the specified strings.	`name_starts_with(mossy, diamond)`
`durability` `dur`	`comparator`, `string`	Evaluates to true if an item matches all the specified damage amounts as a percentage.	`durability(max, undamaged)`, `durability(>=90)`
`enchantment` `ench`, `enchant`	enchantment	Evaluates to true if an item has all the specified enchantments.	`ench("sharpness >= 4", fire_aspect)`
`has_armor_trim` `is_trimmed`, `trimmed`	–	Evaluates to true if an item has an armor trim applied.	`trimmed()`
`has_custom_name` `is_renamed`, `renamed`	–	Evaluates to true if an item has been renamed.	`renamed()`
`has_lore` `lored`	–	Evaluates to true if an item has lore.	`lored()`
`is_compostable` `compostable`	–	Evaluates to true if an item can be composted.	`compostable()`
`is_damaged` `damaged`	–	Evaluates to true if an item is damaged.	`damaged()`
`is_edible` `edible`, `is_food`, `food`	–	Evaluates to true if an item is edible.	`edible()`
`is_enchanted` `enchanted`	–	Evaluates to true if an item is enchanted.	`enchanted()`
`is_fuel` `fuel`	–	Evaluates to true if an item is usable as fuel in a furnace.	`fuel()`
`is_repairable` `repairable`	–	Evaluates to true if an item is repairable in an anvil.	`repairable()`
`is_smeltable` `smeltable`	–	Evaluates to true if an item is smeltable in a furnace.	`smeltable()`
`is_stackable` `stackable`, `can_stack`	–	Evaluates to true if an item's type is stackable.	`stackable()`
`is_unbreakable` `unbreakable`	–	Evaluates to true if an item is unbreakable.	`unbreakable()`
`lore_contains`	`string`	Evaluates to true if an item's lore contains all the specified strings.	`lore_contains("3 levels")`
`lore_ends_with`	`string`	Evaluates to true if an item's lore ends with one of the specified strings.	`lore_ends_with("(33 experience)")`
`lore`	`string`	Evaluates to true if an item's lore matches ones of the specified strings.	`lore("3 levels (33 experience)")`
`lore_starts_with`	`string`	Evaluates to true if an item's lore starts with one of the specified strings.	`lore_starts_with("3 levels")`
`map_id` `map`	`comparator`	Evaluates to true if a map's ID matches all the specified comparators.	`map_id(>=5, <=15, 1337)`
`material_contains` `type_contains`	`string`	Evaluates to true if an item's material name contains all the specified strings.	`type_contains(stone)`
`material_ends_with` `type_ends_with`	`string`	Evaluates to true if an item's material name ends with one of the specified strings.	`type_ends_with(e)`
`material` `type`	material	Evaluates to true if an item is of any specified material.	`type(cobblestone, mossy_cobblestone)`
`material_starts_with` `type_starts_with`	`string`	Evaluates to true if an item's material name starts with one of the specified strings.	`type_starts_with(diamond, iron)`
`potion_duration` `duration`, `pot_dur`	`comparator`, `string`	Evaluates to true if a potion has all the specified durations in ticks.	`duration(>=3600)`, `duration(infinite, unlimited)`, `duration(3600)`
`potion_effect` `effect`, `pot_eff`, `eff`	potion effect	Evaluates to true if an item has all the specified potion effects.	`effect("speed = 2", invisibility, instant_health>=1)`
`potion_type` `pot_type`	potion type	Evaluates to true if a potion's base type matches one of the specified potion types.	`pot_type(mundane)`
`source_inventory_type` `source_type`, `source`	inventory type	Evaluates to true if an item's source is of one of the specified types.	`source(barrel)`
`rarity`	item rarity	Evaluates to true if an item matches one of the specified item rarities.	`rarity(common)`
`skull_owner` `head_owner`	`username`, `uuid`	Evaluates to true if a head's owner matches one of the specified UUIDs or usernames.	`head_owner(Fruitloopins)`
`skull_texture` `head_texture`	`base64`	Evaluates to true if a head's texture matches one of the specified Base64 strings.	`head_texture(eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvMjA4NGVmNjBjNjUwYjRmMjZiMDZiMDUxOTI4MWU2YzQxNjA5YTVjZDllY2JkNjk3YjljZjE2ZWViZjc4NWI0OCJ9fX0=)`
`smeltable_by`	inventory type	Evaluates to true if an item can be smelted in one of the specified furnace types.	`smeltable_by(smoker, blast_furnace)`
`stored_experience` `stored_exp`, `stored_xp`, `experience`, `exp`, `xp`	`comparator`	Evaluates to true if an experience bottle's stored experience matches all the specified amounts. (Uses bottlet, which Meridian has.)	`xp(>=1395)`
`tag` `tagged`	item tag), block tag)	Evaluates to true if an item has one of the specified tags.	`tag(wool)`, `tag(beds)`
`thrower` `thrown_by`	`username`, `uuid`	Evaluates to true if an item was thrown by one of the specified UUIDs or usernames.	`thrower(Fruitloopins, 12BarBruise)`, `thrown_by(fed0ec4a-f1ad-4b97-9443-876391668b34)`
`thrower_nation` `thrower_nation`, `nation`	`nation`	Evaluates to true if an item was thrown by a member of one of the specified nations. (Uses towny, which Meridian has.)	`nation(Australia)`
`thrower__town` `thrower_town`, `town`	`town`	Evaluates to true if an item was thrown by a member of one of the specified towns. (Uses towny, which Meridian has.)	`town(Melbourne)`

How an item gets in

Step	What happens
1. The item tries to get in	Either it's moved in from a container or hopper above or beside it, or it's lying on top of the hopper as a dropped item.
2. The filter is read	The hopper's gold name is turned into a filter (and remembered while the chunk is loaded). If the filter has a mistake in it, the hopper takes nothing until you fix it.
3. Filters go first	A hopper without a filter normally takes anything. But if a filtered hopper under or beside the same container is looking for exactly that item and has room, the item goes to the filtered hopper instead. So a row of filter hoppers under a chest catches what it's meant to, rather than an unfiltered hopper grabbing it first.
4. The item is checked	No filter: it goes in. A filter: it goes in only if it passes. If the first item in a container doesn't pass, the hopper takes the next one that does, so one wrong item can't clog a sorting line.

Commands

Command	What it does
`Sneak + right-click`	With an empty main hand, on a hopper or hopper minecart: open the filter editor.
`/hopplet edit`	Open the editor for the hopper or hopper minecart you're looking at.
`/hopplet function <name>`	Show what a function does and how to use it, e.g. `/hopplet function ench`.