Expand description
NaN-boxed compact Value representation (8 bytes per value).
Layout: every value is a u64 interpreted as an IEEE 754 f64.
- Float: any f64 that is NOT a quiet NaN with our marker -> stored directly.
- Everything else: encoded as a quiet NaN with tag + payload in the mantissa.
IEEE 754 quiet NaN: exponent=0x7FF (all 1s), quiet bit=1, plus our marker bit.
We use 0x7FFC as 14-bit prefix (bits 63-50), leaving bits 49-0 free.
63 50 49 46 45 0
+--------+------+------------------------+
| 0x7FFC | tag | payload |
| 14 bits| 4 bit| 46 bits |
+--------+------+------------------------+Tag map: 0 = Immediate payload 0-2: false/true/unit 1 = Symbol payload bits 0-1: fn/builtin/namespace/nullary-variant; rest=symbol index 2 = Int payload bit45: 0=inline(45-bit signed), 1=arena index 3 = String payload bit45: 0=inline small string (len + 5 bytes), 1=arena index 4 = Some payload bit45: 0=inline inner, 1=arena index 5 = None singleton 6 = Ok payload bit45: 0=inline inner, 1=arena index 7 = Err payload bit45: 0=inline inner, 1=arena index 8 = List payload bit45: 0=empty list, 1=arena index 9 = Vector payload bit45: 0=empty vector, 1=arena index 10 = Map payload bit45: 0=empty map, 1=arena index 11 = Record payload bit45: 1=arena index 12 = Variant payload bit45: 1=arena index 13 = Tuple payload bit45: 1=arena index 14 = InlineVariant [45:30]=ctor_id, [29]=kind(0=int,1=imm), [28:0]=value 15 = (reserved)
Structs§
- Arena
- Arena
Usage - NanValue
- Persistent
Map - Stub
PersistentMapfor non-runtime builds (e.g. wasm-compile only).
Enums§
Constants§
- ARENA_
REF_ BIT - IMM_
FALSE - IMM_
TRUE - IMM_
UNIT - INT_
INLINE_ MAX - INT_
INLINE_ MIN - SYMBOL_
BUILTIN - SYMBOL_
FN - SYMBOL_
NAMESPACE - SYMBOL_
NULLARY_ VARIANT - TAG_ERR
- TAG_
IMMEDIATE - TAG_
INLINE_ VARIANT - TAG_INT
- TAG_
LIST - TAG_MAP
- TAG_
NONE - TAG_OK
- TAG_
RECORD - TAG_
SOME - TAG_
STRING - TAG_
SYMBOL - TAG_
TUPLE - TAG_
VARIANT - TAG_
VECTOR - WRAP_
ERR - WRAP_OK
- WRAP_
SOME
Traits§
- Arena
Types - Trait that defines the function and map types used by the arena.
- FnValue
Name - Trait for extracting a display name from a function value.
- MapLike
- Trait abstracting the persistent-map operations needed by the arena.