feat(jlvm): hex_to_int opcode + conformance vectors#56
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scasplte2 merged 1 commit intoJun 19, 2026
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New JLVM opcode in the canonical Scala evaluator: parse a 0x-prefixed lowercase hex string (reusing the shared HexBytes codec) as an unsigned big-endian, arbitrary-precision integer (BigInt(1, bytes)). Bridges crypto-op hex outputs (e.g. ecvrf_verify's beta) into the numeric domain for `% n` selection, etc. Empty "0x" -> 0; always non-negative; malformed / non-string / wrong-arity -> JsonLogicException. Gas = GasCost(10) (= the modulo op). JsonLogicOp.scala (enum), JsonLogicSemantics.scala (dispatch + handler), ops/HexOps.scala (impl), GasMetering.scala + JsonLogicGasEstimator.scala (gas), test HexOpsSuite.scala (23 cases). Synced the cross-language conformance vectors (src/test/resources/conformance/json_logic_test_vectors.json -> 1.5.0) so the Scala evaluator runs the same hex_to_int vectors as Rust + TS. Verified: 836 json_logic tests + SharedVectorConformanceSuite [hex_to_int] 21/21; scalafmtCheckAll clean. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
scasplte2
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Jun 19, 2026
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Summary
New JLVM opcode
hex_to_intin the canonical Scala evaluator. Sister PR for the Rust + TypeScript ports + shared vectors:Constellation-Labs/metakit-sdk#62(branchfeat/jlvm-hex-to-int).Motivation:
ecvrf_verifyreturnsbetaas a0xhex string of verifiable randomness, but JLVM had no hex→number path (string coercion only parses decimal), so contracts could verify VRF output yet not use it.hex_to_intbridges it:{"%": [{"hex_to_int":[{"var":"beta"}]}, n]}→ a deterministic, verifiable winner index. General-purpose (any crypto-op hex output → number).Semantics: arity-1 string → reuse the shared
HexBytescodec (0x+ lowercase + even-length) → unsigned big-endianIntValue(BigInt(1, bytes))."0x"→0, always non-negative; malformed / non-string / wrong-arity →JsonLogicException. (JLVM ints are arbitrary-precision BigInt, so a 512-bitbetaconverts losslessly; reduce with%.)Changes
JsonLogicOp.scala(enum),JsonLogicSemantics.scala(dispatch + handler, modeled onhandleModuloOp),ops/HexOps.scala(impl)GasMetering.scala+JsonLogicGasEstimator.scala—GasCost(10)(= the modulo op)test/.../HexOpsSuite.scala(23 cases) + synced cross-language conformance vectors (conformance/json_logic_test_vectors.json→ 1.5.0) so Scala runs the samehex_to_intvectors as Rust + TSVerification: 836
json_logictests (23 new) +SharedVectorConformanceSuite [hex_to_int] 21/21;scalafmtCheckAllclean. (Pre-existing, unrelated:project/Dependencies.scalahas scalafmt drift — left untouched.)🤖 Generated with Claude Code