Initial commit

value.h

@@ -0,0 +1,95 @@
+#ifndef clox_value_h
+#define clox_value_h
+
+#include <string.h>
+
+#include "common.h"
+
+typedef struct Obj Obj;
+typedef struct ObjString ObjString;
+
+#ifdef NAN_BOXING
+#define SIGN_BIT ((uint64_t)0b1000000000000000000000000000000000000000000000000000000000000000)
+#define QNAN ((uint64_t)0b0111111111111100000000000000000000000000000000000000000000000000)
+
+#define TAG_NIL 0b01
+#define TAG_FALSE 0b10
+#define TAG_TRUE 0b11
+
+typedef uint64_t Value;
+
+#define IS_BOOL(value) (((value) | 0b01) == TRUE_VAL)
+#define IS_NIL(value) ((value) == NIL_VAL)
+#define IS_NUMBER(value) (((value) & QNAN) != QNAN)
+#define IS_OBJ(value) (((value) & (QNAN | SIGN_BIT)) == (QNAN | SIGN_BIT))
+
+#define AS_OBJ(value) ((Obj*)(uintptr_t)((value) & ~(SIGN_BIT | QNAN)))
+#define AS_BOOL(value) ((value) == TRUE_VAL)
+#define AS_NUMBER(value) valueToNum(value)
+
+#define BOOL_VAL(value) ((value) ? TRUE_VAL : FALSE_VAL)
+#define FALSE_VAL ((Value)(uint64_t)(QNAN | TAG_FALSE))
+#define TRUE_VAL ((Value)(uint64_t)(QNAN | TAG_TRUE))
+#define NIL_VAL ((Value)(uint64_t)(QNAN | TAG_NIL))
+#define NUMBER_VAL(value) numToValue(value)
+#define OBJ_VAL(object) ((Value)(SIGN_BIT | QNAN | (uint64_t)(uintptr_t)(object)))
+
+static inline double valueToNum(Value value)
+{
+    double num;
+    memcpy(&num, &value, sizeof(Value));
+    return num;
+}
+
+static inline Value numToValue(double num)
+{
+    Value value;
+    memcpy(&value, &num, sizeof(double));
+    return value;
+}
+#else
+typedef enum {
+    VAL_BOOL,
+    VAL_NIL,
+    VAL_NUMBER,
+    VAL_OBJ,
+} ValueType;
+
+typedef struct {
+    ValueType type;
+    union {
+        bool boolean;
+        double number;
+        Obj* obj;
+    } as;
+} Value;
+
+#define IS_BOOL(value) ((value).type == VAL_BOOL)
+#define IS_NIL(value) ((value).type == VAL_NIL)
+#define IS_NUMBER(value) ((value).type == VAL_NUMBER)
+#define IS_OBJ(value) ((value).type == VAL_OBJ)
+
+#define AS_OBJ(value) ((value).as.obj)
+#define AS_BOOL(value) ((value).as.boolean)
+#define AS_NUMBER(value) ((value).as.number)
+
+#define BOOL_VAL(value) ((Value){ .type = VAL_BOOL, .as = { .boolean = value } })
+#define NIL_VAL ((Value){ .type = VAL_NIL, .as = { .number = 0 } })
+#define NUMBER_VAL(value) ((Value){ .type = VAL_NUMBER, .as = { .number = value } })
+#define OBJ_VAL(object) ((Value){ .type = VAL_OBJ, .as = { .obj = (Obj*)object } })
+#endif
+
+typedef struct {
+    int capacity;
+    int count;
+    Value* values;
+} ValueArray;
+
+bool valuesEqual(Value a, Value b);
+void initValueArray(ValueArray* array);
+void writeValueArray(ValueArray* array, Value value);
+void freeValueArray(ValueArray* array);
+void printValue(Value value);
+
+#endif // clox_value_h
+