Cosmo/src/cvalue.h

129 lines
4.0 KiB
C

#ifndef CVALUE_H
#define CVALUE_H
#include "cosmo.h"
typedef enum
{
COSMO_TNUMBER, // number has to be 0 because NaN box
COSMO_TBOOLEAN,
COSMO_TREF,
COSMO_TNIL,
} CosmoType;
typedef double cosmo_Number;
/*
holds primitive cosmo types
*/
#ifdef NAN_BOXXED
/*
NaN box, this is great for fitting more in the cpu cache on x86_64 or ARM64 architectures.
If you don't know how this works please reference these two articles:
https://leonardschuetz.ch/blog/nan-boxing/ and https://piotrduperas.com/posts/nan-boxing/
both are great resources :)
TL;DR: we can store payloads in the NaN value in the IEEE 754 standard.
*/
union CValue
{
uint64_t data;
cosmo_Number num;
};
# define MASK_TYPE ((uint64_t)0x0007000000000000)
# define MASK_PAYLOAD ((uint64_t)0x0000ffffffffffff)
// 3 bits (low bits) are reserved for the type
# define MAKE_PAYLOAD(x) ((uint64_t)(x)&MASK_PAYLOAD)
# define READ_PAYLOAD(x) ((x).data & MASK_PAYLOAD)
// The bits that must be set to indicate a quiet NaN.
# define MASK_QUIETNAN ((uint64_t)0x7ff8000000000000)
# define GET_TYPE(x) \
((((x).data & MASK_QUIETNAN) == MASK_QUIETNAN) ? (((x).data & MASK_TYPE) >> 48) \
: COSMO_TNUMBER)
# define SIG_MASK (MASK_QUIETNAN | MASK_TYPE)
# define BOOL_SIG (MASK_QUIETNAN | ((uint64_t)(COSMO_TBOOLEAN) << 48))
# define OBJ_SIG (MASK_QUIETNAN | ((uint64_t)(COSMO_TREF) << 48))
# define NIL_SIG (MASK_QUIETNAN | ((uint64_t)(COSMO_TNIL) << 48))
# define cosmoV_newNumber(x) ((CValue){.num = x})
# define cosmoV_newBoolean(x) ((CValue){.data = MAKE_PAYLOAD(x) | BOOL_SIG})
# define cosmoV_newRef(x) ((CValue){.data = MAKE_PAYLOAD((uintptr_t)x) | OBJ_SIG})
# define cosmoV_newNil() ((CValue){.data = NIL_SIG})
# define cosmoV_readNumber(x) ((x).num)
# define cosmoV_readBoolean(x) ((bool)READ_PAYLOAD(x))
# define cosmoV_readRef(x) ((CObj *)READ_PAYLOAD(x))
# define IS_NUMBER(x) (((x).data & MASK_QUIETNAN) != MASK_QUIETNAN)
# define IS_BOOLEAN(x) (((x).data & SIG_MASK) == BOOL_SIG)
# define IS_NIL(x) (((x).data & SIG_MASK) == NIL_SIG)
# define IS_REF(x) (((x).data & SIG_MASK) == OBJ_SIG)
#else
/*
Tagged union, this is the best platform independent solution
*/
struct CValue
{
CosmoType type;
union
{
cosmo_Number num;
bool b; // boolean
CObj *obj;
} val;
};
# define GET_TYPE(x) ((x).type)
// create CValues
# define cosmoV_newNumber(x) ((CValue){COSMO_TNUMBER, {.num = (x)}})
# define cosmoV_newBoolean(x) ((CValue){COSMO_TBOOLEAN, {.b = (x)}})
# define cosmoV_newRef(x) ((CValue){COSMO_TREF, {.obj = (CObj *)(x)}})
# define cosmoV_newNil() ((CValue){COSMO_TNIL, {.num = 0}})
// read CValues
# define cosmoV_readNumber(x) ((cosmo_Number)(x).val.num)
# define cosmoV_readBoolean(x) ((bool)(x).val.b)
// grabs the CObj* pointer from the CValue
# define cosmoV_readRef(x) ((CObj *)(x).val.obj)
# define IS_NUMBER(x) (GET_TYPE(x) == COSMO_TNUMBER)
# define IS_BOOLEAN(x) (GET_TYPE(x) == COSMO_TBOOLEAN)
# define IS_NIL(x) (GET_TYPE(x) == COSMO_TNIL)
# define IS_REF(x) (GET_TYPE(x) == COSMO_TREF)
#endif
typedef CValue *StkPtr;
struct CValueArray
{
size_t capacity;
size_t count;
CValue *values;
};
void initValArray(CState *state, CValueArray *val, size_t startCapacity);
void cleanValArray(CState *state, CValueArray *array); // cleans array
void appendValArray(CState *state, CValueArray *array, CValue val);
void printValue(CValue val);
COSMO_API bool cosmoV_equal(CState *state, CValue valA, CValue valB);
COSMO_API CObjString *cosmoV_toString(CState *state, CValue val);
COSMO_API cosmo_Number cosmoV_toNumber(CState *state, CValue val);
COSMO_API const char *cosmoV_typeStr(CValue val);
#endif