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Meld address forms๏ƒ

๐ŸŸข Beginner ยท Lesson 26

THE ADDRESS LAW (run-proven + doc-canon): every spell lives at one (frame_key, binding_key) address - frame_key is your spellframe, or the spell's normalized name if you gave none; binding_key is your binding_name, or the default slot. The meld forms are just three ways to CONSTRUCT that key - so a frameless, nameless bind answers to the spell object and to spell_name; a framed+named bind answers only at (frame, name).

Before you run๏ƒ

Use the Beginner guide for prerequisite concepts. Run from a checkout with Melder installed and Python 3.14 free-threading selected. The collection download includes the level's local helper modules.

Run the saved script๏ƒ

python UX_and_AIX_experiences/01_beginner/26_meld_address_forms.py

py -3.14t UX_and_AIX_experiences/01_beginner/26_meld_address_forms.py

Download this collection ยท Source on GitHub

Public surface๏ƒ

meld(Class), meld("SpellName"), meld(spell_id=...), meld(spellframe=..., binding_name=...)

Code๏ƒ

 1"""
 2TIER: beginner (26)
 3GOAL: THE ADDRESS LAW (run-proven + doc-canon): every spell lives at
 4      one (frame_key, binding_key) address - frame_key is your spellframe,
 5      or the spell's normalized name if you gave none; binding_key is
 6      your binding_name, or the default slot. The meld forms are just
 7      three ways to CONSTRUCT that key - so a frameless, nameless bind
 8      answers to the spell object and to spell_name; a framed+named
 9      bind answers only at (frame, name).
10SURFACE EXERCISED: meld(Class), meld("SpellName"), meld(spell_id=...),
11                   meld(spellframe=..., binding_name=...)
12"""
13import melder as md
14
15
16class BillingService:
17    def total(self) -> int:
18        return 42
19
20
21class LedgerService:
22    pass
23
24
25def main() -> None:
26    book = md.Spellbook()
27    # default address: ("billingservice", default slot)
28    spell_id = book.bind(spell=BillingService, existence="unique")
29    # explicit address: ("finance", "ledger")
30    book.bind(spell=LedgerService, existence="unique",
31              spellframe="finance", binding_name="ledger")
32    conduit = book.conjure()
33
34    by_object = conduit.meld(spell=BillingService)
35    by_name = conduit.meld(spell="BillingService")
36    # Explicit machine form: SHA identity never shares the human string slot.
37    by_id = conduit.meld(spell_id=spell_id)
38    assert by_object is by_name is by_id
39    print("default-address spell answers all three:", by_object.total())
40
41    ledger = conduit.meld(spellframe="finance", binding_name="ledger")
42    assert isinstance(ledger, LedgerService)
43    print("framed spell answers at (frame, name)")
44
45    try:
46        conduit.meld(spell="LedgerService")
47    except KeyError as err:
48        print("name-derived key misses a framed bind:", err)
49
50    try:
51        conduit.meld(binding_name="ledger")
52    except ValueError as err:
53        print("binding_name alone refused:", err)
54
55
56if __name__ == "__main__":
57    main()

Check the outcome๏ƒ

The script contains its own assertions or demonstrated refusal paths. Run it to evaluate those checks against your installed version. The code above is taken directly from the saved file; no run output is invented here.

More beginner examples ยท Level guide