Brummel
2bce825b69
User redirected at iter boundary: writing a stdlib in JSON was the wrong move. The language is supposed to be the one I program *best* in, and JSON-AST authoring is rationalisation, not strength. DESIGN.md Decision 6 captures the constraints that fall out of the "formalisable for a foreign LLM" hard requirement (no precedence, no semantic indentation, ASCII only, every AST node a uniquely-tagged form), sketches three candidate notations with the same `map` encoded in each, and picks form (A) — fully-tagged S-expressions — as the first attempt with explicit rollback path to form (C) if (A) hurts authoring. Form (A) shape: - 3-rule lexical core: sexpr / atom / token-classified-by- first-character. - Every AST node has a unique head keyword. No case-rule (no "capitalised head means ctor"); ctors are explicit via `(term-ctor TypeName CtorName args)` and `(pat-ctor CtorName fields)`. - Bare atoms get their sort from the parent slot (type-var inside `(con NAME args)`, term-var inside `(app HEAD args)`, pat-var inside `(pat-ctor CTOR fields)`, integer literal in term position, etc.). Empirical exhibits, hand-encoded: - examples/hello.ailx 5 LOC (JSON was 36 pretty / 21 canonical) - examples/box.ailx 25 LOC (JSON was 160 / 88) - examples/list_map_poly.ailx 50 LOC (JSON was 394 / 230) 4-8x line reduction, ~4x character reduction. Bigger gains on bigger programs since overhead is proportional to AST depth. None are parseable yet — header comments say "Iter 14b design exhibit, parser lands in 14c". Two small spec issues caught while writing the exhibits and folded back into DESIGN.md before committing: - Operator idents (`+`, `==`) need the token-by-first-char classification rule, not a word-shaped regex. - Bool literals (`true`/`false`) reserved in term context; unit is explicit `(lit-unit)`. Tests unchanged (this iter is paper). 25/25 e2e green. cargo doc --no-deps zero warnings. Plan 14c: new crate `ailang-surface` with PEG parser, round-trip hash-equivalence gate against every existing `examples/*.ail.json`, CLI subcommand `ail parse`. If round-trip holds, stdlib starts in `.ailx` form (Iter 14d). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
37 lines
826 B
Plaintext
37 lines
826 B
Plaintext
; Iter 14b design exhibit — Decision 6 form (A).
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; This file is NOT yet parseable by `ail`. The parser lands in
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; Iter 14c. Hash-equivalence with `box.ail.json` is the round-trip
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; test that gates that iter.
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(module box
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(data Box (vars a)
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(doc "A unary box around a polymorphic value.")
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(ctor MkBox a))
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(fn unbox
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(doc "Polymorphic projection out of a Box.")
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(type
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(forall (vars a)
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(fn-type
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(params (con Box a))
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(ret a))))
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(params b)
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(body
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(match b
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(case (pat-ctor MkBox x)
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x))))
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(fn main
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(doc "Round-trip 42 through MkBox + unbox.")
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(type
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(fn-type
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(params)
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(ret (con Unit))
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(effects IO)))
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(params)
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(body
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(do io/print_int
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(app unbox
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(term-ctor Box MkBox 42))))))
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