Module lua_limits 

Centralized Lua VM limits and configuration constants.

Mirrors Lua 5.5’s luaconf.h / llimits.h design. All magic numbers that control VM behavior are collected here for easy tuning and configuration.

Constants

BASIC_STACK_SIZE

Initial stack capacity for new Lua states. Equivalent to 2 × LUA_MINSTACK (Lua 5.5: LUA_MINSTACK = 20).

CONCAT_STACK_BUF_SIZE

Stack-allocated buffer size for small concatenations.

CSTACKERR

Extra C-stack depth allowance granted during error-handler execution. Allows error handlers and __close metamethods to run even after a C-stack overflow.

DEFAULT_GC_MAJORMINOR

Major-to-minor GC transition threshold (percentage).

DEFAULT_GC_MINORMAJOR

Minor-to-major GC transition threshold (percentage).

DEFAULT_GC_MINORMUL

Default minor GC collection multiplier (percentage). Matches C Lua 5.5’s LUAI_GENMINORMUL = 20. A young (minor) collection will run after creating GENMINORMUL% new bytes.

DEFAULT_GC_PAUSE

Default GC pause (percentage). Controls how long GC waits before starting a new cycle. 250 = wait until memory is 2.5x the size after last collection.

DEFAULT_GC_STEPMUL

Default GC step multiplier (percentage). Controls how much work GC does per step relative to memory allocation. 200 = collect 2x the allocated speed.

EXTRA_STACK

Extra stack slots above frame_top for C function calls, temporaries, etc. Matches Lua 5.5’s EXTRA_STACK (5).

GC_SWEEPMAX

Maximum number of objects swept per single GC step.

LFIELDS_PER_FLUSH

Number of list items to flush per SETLIST instruction in table constructors. Matches Lua 5.5’s LFIELDS_PER_FLUSH.

LUAI_MAXCSTACK

Default maximum C-stack depth (Rust recursion depth). Matches C Lua 5.5’s LUAI_MAXCSTACK (200). Limits how many times we can recursively enter lua_execute, call metamethods, or call C functions.

LUAI_MAXSHORTLEN

Maximum length for “short” strings (interned in hash table). Matches Lua 5.5’s LUAI_MAXSHORTLEN.

LUAI_MAXSTACK

Default maximum stack size (number of slots). Matches Lua 5.5’s LUAI_MAXSTACK.

LUA_MAXCAPTURES

Maximum number of captures in string.find / string.gmatch patterns. Matches Lua 5.5’s LUA_MAXCAPTURES.

LUA_MINSTACK

Minimum guaranteed stack slots available to C functions. Matches Lua 5.5’s LUA_MINSTACK.

MAXCCALLS

Maximum parser recursion depth (prevents stack overflow in parser). Matches Lua 5.5’s MAXCCALLS for the parser.

MAXCCALLS_PATTERN

Maximum match recursion depth for pattern matching.

MAXINDEXRK

Maximum index for R/K operand in instructions.

MAXTAGLOOP

Maximum depth for __index / __newindex metamethod chains. Prevents infinite loops in metamethod resolution. Matches Lua 5.5’s MAXTAGLOOP.

MAXUPVAL

Maximum number of upvalues per function. Matches Lua 5.5’s MAXUPVAL.

MAXVARS

Maximum number of local variables per function. Matches Lua 5.5’s MAXVARS.

MAX_CALL_DEPTH

Default maximum Lua call-stack depth (number of call frames). This limits how deep pure-Lua calls can nest. Set high by default — the real recursion guard is LUAI_MAXCSTACK.

MAX_SRC_LEN

Maximum length of source name in error messages.

MAX_STRING_SIZE

Maximum string size (1 GB).

NO_REG

“No register” sentinel value in the compiler.

UNARY_PRIORITY

Unary operator priority in expression parser.