Namespaces

src/combat.poplar

namespace combat;

import magic;

var #mana = 0;

mcfun tick() {
    magic:heal();
    #magic:mana = #mana;
    /execute as @a run function magic:castSpell;
}

src/spells/magic.poplar

namespace magic;

var #mana = 0;

mcfun heal() {
    #mana = #mana + 1;
}

mcfun castSpell() {
    /say whoosh;
}

Each file starts with namespace <name>;. Every .poplar file in src/ is part of the pack, and folders don’t affect the result. Files with the same namespace share their names. A plain name (heal(), #mana, $item) is in the file’s namespace. A name in another namespace is written magic:heal(), #magic:mana, $magic:item or @s.#magic:mana, and the file must import magic; first.

Two namespaces can use the same names, because each has its own files and state:

In namespace combat;	Written as
mcfun heal	data/combat/function/heal.mcfunction, combat:heal
its helpers, temps and locals	combat:poplar/heal/..., the objective poplar.combat
var #mana	the objective combat.mana
var $item	the key item in the storage combat:data
predicate isSitting	data/combat/predicate/is_sitting.json

Poplar’s own functions (poplar/load, poplar/tick, the event checks) and the standard library go into the pack namespace, set by "namespace" in poplar.json. A file can use that name as its namespace too.

Each namespace can have load and tick. They run in import order: if combat imports magic, magic:load runs first, so its state is ready. Namespaces that import each other run in alphabetical order.

A namespace name uses a-z, 0-9, _ and . (bs.math). Minecraft also allows -, but in Poplar code - is the minus sign.

Costs and caveats

• Each namespace adds one objective for its temps and locals, set up in poplar/load.
• Renaming a namespace gives it different scores and storage. A world keeps the old values under the old name.
• namespace minecraft; writes into vanilla’s namespace, so it can replace vanilla functions and data. Minecraft’s load and tick tags belong to Poplar, so you can’t write those this way.