Types phase 2 — the "money problem". A splice-on-demand bignum engine (runtime/native/bignum.ludic, self-contained, only intrinsics) exposed as two namespaces: - BigInt.* — arbitrary-precision integer (sign-magnitude, base-1e9 limbs): from/parse, add/sub/mul/pow, div/mod (by int), cmp/eq/is_zero, to_int, str. For idle counters and exact huge currencies that overflow a 32/64-bit int. - Decimal.* — exact base-10 fixed point (BigInt mantissa + decimal scale): from/parse, exact add/sub/mul, cmp/eq, scale/rescale (truncate), str. So 0.10 + 0.20 is exactly 0.30 — no binary rounding. Both exact => deterministic; no f32/f64. Wired: parser splice trigger (g_uses_bignum), emit_call dispatch, reseeded seed, a self-asserting example (examples/library/bignum.ludic + feat_case), and per-symbol docs + inventory. All suites green incl. golden renders byte-identical and the bootstrap fixpoint. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
22 lines
418 B
Markdown
22 lines
418 B
Markdown
---
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id: bigint-sub
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name: BigInt.sub
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category: bigint
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kind: namespace-method
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tokens: BigInt.sub
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sig: BigInt.sub(a, b) -> BigInt
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tip: Exact difference of two big integers.
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order: 3
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ns: BigInt
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member: sub
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---
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Returns the exact difference <code>a - b</code>; the result is negative when <code>b</code> is larger.
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```ludic
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program Demo {
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handler Step phase Update {
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let remaining = BigInt.sub(bank, cost)
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}
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}
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```
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