Files
AILang/design/models/effects.md
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Brummel 19dc42f5ca design/ ledger: dense cross-linking via three topical splits + 88-link sweep
The first formal-links milestone shipped clause-5 + 8 links across the
existing file layout. Browsing surfaced that file-only granularity is
only as precise as the file boundaries — three files mixed two or
three navigation targets under one address, so the 8 links could not
multiply without ambiguity. This commit fixes the substrate, then
applies the sweep the original milestone deferred.

Splits (each extracts an already-self-contained section into its own
file so links land on the topic, not the parent doc's TOC):

  contracts/typeclasses.md
    → +contracts/prelude-classes.md  (Eq/Ord/Show ships, polymorphic `print`)
    → +contracts/method-dispatch.md  (5-step dispatch rule, candidate index)

  contracts/memory-model.md
    → +contracts/language-constraints.md  (the 4 binding constraints
                                           making RC sound without a
                                           cycle collector)

  models/authoring-surface.md
    → +models/prose-projection.md  (Form-B / `ail prose` / merge-prose)

Each new file enters design/INDEX.md as its own row (three contracts
share show_no_instance_e2e.rs / uniqueness.rs as ratifying tests;
prose-projection is a model). Two pre-existing links rebind to the
new topic-files (memory-model.md → method-dispatch.md;
float-semantics.md → prelude-classes.md).

Link sweep: 8 → 88 formal Markdown links over 23 files. Every file
in design/contracts/ + design/models/ now has at least one outgoing
link; the tree is fully connected. Links are file-relative
`[label](path)` per the established convention, fenced code blocks
are skipped (a `](` inside ```jsonc``` is literal text), the durable
tier (design/ + crates/ + runtime/) is enforced by clause-5.

Tests:
  - design_index_pin.rs (5/5 clauses): clean-cut, INDEX resolution,
    ratifying-test resolution, no decision-record prose in contracts/,
    body links durable + resolving.
  - docs_honesty_pin.rs (5/5): one assertion rebinds from typeclasses.md
    to prelude-classes.md (where the gated sentence now lives);
    design_corpus widens to include the 4 new files so the Wunschdenken
    / doc-archaeology sweeps continue to cover everything that used to
    live in the parents.

No spec/plan/journal for this batch — interactive collaboration after
the milestone closed; the user gated the splits explicitly before the
sweep.
2026-05-20 00:24:08 +02:00

20 lines
985 B
Markdown

# Effects — pure core + algebraic effects
## Decision 3: pure core language + algebraic effects
The default is total, pure functions. Effects are declared as a set in the
function type: `(Int) -> Int ![IO]`. The effect set is a
flat, unordered, closed set of effect names, unified by set-equality —
there is no effect row variable; a signature lists exactly the effects
its body may perform. The schema-level effect-set field on `Type::Fn`
is documented in [Data model](../contracts/data-model.md); what is
currently in scope vs. excluded lives in
[scope boundaries](../contracts/scope-boundaries.md).
In the MVP only the effect `IO` is wired up (its sole op is `io/print_str`).
`Diverge` (for non-termination) is reserved as an effect name but is
unimplemented — no op, no codegen, no checker injection — in the same
sense Decision 4 reserves refinements.
This is the most important LLM property: when I read a function, I can trust
its signature without reading the body.