73 lines
1.7 KiB
C
73 lines
1.7 KiB
C
#include "../defs.h"
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#include "objects.h"
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static void walk(Object *self, void (*callback)(Object **referer, void *userp), void *userp);
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static void print(Object *obj, FILE *fp);
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static bool istypeof(Object *self, Object *other, Heap *heap, Error *error);
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typedef struct {
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Object base;
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Object *item;
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} NullableObject;
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static TypeObject t_nullable = {
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.base = (Object) { .type = &t_type, .flags = Object_STATIC },
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.name = TYPENAME_NULLABLE,
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.size = sizeof(NullableObject),
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.init = NULL,
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.free = NULL,
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.hash = NULL,
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.copy = NULL,
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.call = NULL,
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.print = print,
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.select = NULL,
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.delete = NULL,
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.insert = NULL,
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.count = NULL,
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.istypeof = istypeof,
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.op_eql = NULL,
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.walk = walk,
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.walkexts = NULL,
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};
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TypeObject *Object_GetNullableType()
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{
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return &t_nullable;
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}
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Object *Object_NewNullable(Object *item, Heap *heap, Error *error)
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{
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NullableObject *nullable = (NullableObject*) Heap_Malloc(heap, &t_nullable, error);
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if (nullable != NULL)
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nullable->item = item;
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return (Object*) nullable;
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}
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static bool
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istypeof(Object *self,
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Object *other,
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Heap *heap,
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Error *error)
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{
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NullableObject *nullable = (NullableObject*) self;
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if (Object_IsNone(other))
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return true;
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return Object_IsTypeOf(nullable->item, other, heap, error);
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}
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static void walk(Object *self, void (*callback)(Object **referer, void *userp), void *userp)
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{
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NullableObject *nullable = (NullableObject*) self;
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callback(&nullable->item, userp);
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}
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static void print(Object *obj, FILE *fp)
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{
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NullableObject *nullable = (NullableObject*) obj;
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fprintf(fp, "?");
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Object_Print(nullable->item, fp);
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} |