splash_bench geomean against work, best of alternating runs: +12.9% with the series as submitted (the per-instruction Option<String>::take in take_allocation_error alone was +9.8%), -1.1% with this commit.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Port of the equality / fuel / error-bail slice of Octoscript's makepad-script
patch set onto the September `work` base.
equality (PORT, string compare ADAPTED): `deep_eq` moves from heap.rs into
the new equality.rs as an iterative worklist that visits each container pair
once (cycles and shared DAGs terminate), keeps NaN unequal to itself, and
charges one work unit per processed pair, queued edge and typed-array
element, capped by MAX_EQUALITY_WORK = 65,536 per comparison. Upstream's
69d78873e string early-out is kept instead of the patch's chunked byte
compare: every heap string is interned (string_heap.rs) and short strings
are inline, so string equality is exactly bit equality and a string pair
costs one unit. The raw host `ScriptHeap::deep_eq` is iterative and
unbounded and consumes no VM fuel. The `==`/`!=` opcodes go through
`deep_eq_bounded`: each unit charges one instruction of
`instruction_limit_remaining`, the hard deadline (now an f64 on the
platform clock) is sampled every 256 units so trivial comparisons never
touch the clock, and exhaustion drains diagnostics and raises an
uncatchable Bail, like the instruction limit.
uncaught errors (PORT): `handle_errors` without an active try frame drains
the diagnostic once and sets `ScriptTrapOn::Bail(error)`, so no later
instruction or host effect runs and `eval` returns the error value; active
`try` handlers recover exactly as before. The hard time-budget bail drains
its diagnostic before unwinding, as the instruction-limit bail already did.
allow_debug_output (PORT): new host-controlled `ScriptVmBase` flag,
default true so raw makepad debugging is unchanged. When false the `~` LOG
opcode raises a catchable not-allowed error and `ScriptVm::log` is a no-op.
Incidental VM prints are removed: run_core's `log!` traces, the undefined
opcode `eprintln!` (now a bail) and the loop "unknown state" `println!`
(now a bail). mod_std.rs needs no change: std.log already routes through
the gated `ScriptVm::log`.
Tests: platform/script/tests/equality_fuel_bail.rs covers cycles, shared
DAGs, NaN, string/number semantics, the host deep_eq on typed arrays and
beyond the ceiling, instruction fuel charging, the work ceiling being
uncatchable, the in-comparison hard-deadline check, the hard-budget drain,
uncaught-error bail with try recovery, and the debug-output flag.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JgSir4cQyaakzPju4h6smw
(cherry picked from commit a44f8678ed68b20a0c413d607c07a37d55186fbe)
(cherry picked from commit 353fa369faa5672e075dd874a431dc928420bafb)
