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#include "env.h"
#include "list.h"
#include "atom.h"
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
struct kv
{
const char *symbol;
struct atom *value;
};
struct list *env_new()
{
return list_new(NULL);
}
struct atom *env_lookup(struct list *env, const char *symbol)
{
env = env->next;
while (env)
{
struct kv *kv = (struct kv *) env->data;
if (strcmp(kv->symbol, symbol) == 0)
{
return kv->value;
}
env = env->next;
}
return NULL;
}
int env_set_(struct list *env, const char *symbol,
struct atom *atom, int force)
{
struct list *first = env;
struct kv *kv;
env = env->next;
while (env)
{
kv = (struct kv *) env->data;
if (strcmp(symbol, kv->symbol) == 0)
{
if (!force)
return 0;
kv->value = atom;
return 1;
}
if (!env->next)
break;
env = env->next;
}
if (!env)
env = first;
kv = calloc(1, sizeof(*kv));
kv->symbol = strdup(symbol);
kv->value = atom;
list_append(env, kv);
return 1;
}
struct list *env_extend(struct list *env, int count, ...)
{
va_list ap;
int i;
struct list *result = env_clone(env);
va_start(ap, count);
for (i = 0; i < count; ++i)
{
const char *symbol = va_arg(ap, const char *);
struct atom *atom = va_arg(ap, struct atom *);
env_set_(result, symbol, atom, 1);
}
va_end(ap);
return result;
}
// struct list *env_extend_env(struct list *enva, struct list *envb)
// {
// }
int env_set(struct list *env, const char *symbol,
struct atom *value)
{
return env_set_(env, symbol, value, 0);
}
void env_free(struct list *env)
{
}
struct list *env_clone(struct list *env)
{
struct list *clone = env_new();
struct list *last = clone;
env = env->next;
while (env)
{
struct kv *kv = (struct kv *) env->data;
struct kv *kv_clone = malloc(sizeof(*kv_clone));
kv_clone->symbol = strdup(kv->symbol);
kv_clone->value = atom_clone(kv->value);
last = list_append(last, kv_clone);
env = env->next;
}
return clone;
}
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