Added VM-intrinsified fastcalls for common standard library functions, reducing call overhead by ~31% (1.46x geometric mean speedup across 57 benchmarks).
When the compiler detects a call to a known stdlib function with the expected argument count, it emits OP_FASTCALL instead of OP_CALL. The VM validates at runtime that the function hasn’t been replaced and executes the operation inline, falling back to a normal call otherwise.
Fastcall emission can be disabled by passing --no-fastcall to lus.
Added --readonly-env flag that freezes _ENV and all module tables after initialization, enabling fast-dispatch fastcalls that skip runtime validation.
Added --gc-pause N flag to bound how far the heap may grow past the live set before a new GC cycle starts in incremental mode.
Added --strip-debug flag that drops debug information from every loaded chunk to save memory (~15% of loaded-code memory on small chunks, more on line-heavy files)
Regular long strings no longer store a redundant content pointer, saving 8 bytes per long string.
The string table now grows at a 1.5 load factor instead of 1.0, shrinking its bucket array by up to a third for string-heavy programs.
for ... in pairs(t)/ipairs(t)/next, t loops over tables now walk the table directly in the VM instead of calling the iterator function each step (pairs ~1.8x, ipairs ~2.3x faster).
Indexing tables with string variables (t[k]) now takes the same short-string fast path as constant fields, ~15% faster.
Integer-to-string conversion uses a direct conversion loop instead of snprintf (~20% faster interpolation-heavy code).
Release binaries for Linux and macOS are now built with profile-guided optimization (tools/pgo-build.sh), 15–45% faster across VM micro-benchmarks than a plain release build.
The worker library no longer pre-allocates a table from an untrusted declared size while deserializing messages.
Workers now inherit their parent’s pledges (sealed).
fs permission checks now canonicalize paths and fail closed.
network:http/network:tcp permission checks now match the URL/host structurally, so a pledge for example.com no longer also permits example.com.net.
Passing any -P/--pledge permission now seals the pledge store after startup.
Replaced the short-string hash with a full-content hash.
Fixed network.tcp.bind not checking network:tcp permission.
Fixed fs.createdirectory and fs.createlink not checking fs:write permission.
Fixed fs.type and fs.follow not checking fs:read permission.
Fixed JSON parser not handling \b, \f, \/, and \uXXXX escape sequences in object keys.
Fixed msgqueue_push crashing on allocation failure in the worker library.
Fixed nested catch blocks in the same function corrupting control flow on a subsequent error.
Fixed catch not closing to-be-closed variables when catching an error, which corrupted state when catching errors raised by standard-library functions that build internal buffers.
Fixed slice expressions not validating that their bounds are integers.
Fixed slicing an inline table constructor (e.g. ({1,2,3})[a,b]) producing the wrong result.
Fixed table.clone(t, true) crashing on deeply nested tables.
Fixed debug.parse leaving the garbage collector permanently disabled if it ran out of memory while building its result.
Fixed an intermittent attempt to modify a readonly table error caused by a value collision between the readonly-table flag and the table pre-set hash-node encoding.
Fixed a buffer overflow in the Windows path canonicalizer on over-long paths.
