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-rw-r--r--src/csx.c226
1 files changed, 188 insertions, 38 deletions
diff --git a/src/csx.c b/src/csx.c
index 7836793..9f83fec 100644
--- a/src/csx.c
+++ b/src/csx.c
@@ -21,17 +21,66 @@ typedef enum csx_type {
type_str
} csx_type;
-static csx_type type(void *p)
+static void setmark(void *p) { ((int *)p)[-2] = 1; }
+static int mark(void *p) { return ((int *)p)[-2]; }
+static csx_type type(void *p) { return ((int *)p)[-1]; }
+
+static void **objs = 0;
+static int objslen = 0;
+static int objssize;
+
+static void pushobj(void *p)
+{
+ if (!objs) {
+ objs = malloc(sizeof(void *));
+ objslen = 0;
+ objssize = 1;
+ }
+ if (objslen == objssize) {
+ objs = realloc(objs, (objssize *= 2) * sizeof(void *));
+ }
+ objs[objslen++] = p;
+}
+
+static void **stack = 0;
+static int stacklen = 0;
+static int stacksize;
+
+static void push(void *p)
{
- return *((int *)p - 1);
+ if (!stack) {
+ stack = malloc(sizeof(void *));
+ stacklen = 0;
+ stacksize = 1;
+ }
+ if (stacklen == stacksize) {
+ stack = realloc(stack, (stacksize *= 2) * sizeof(void *));
+ }
+ stack[stacklen++] = p;
+}
+
+static void *pop()
+{
+ return stack[--stacklen];
+}
+
+static void restore(int len)
+{
+ stacklen = len;
+ if (stacklen <= stacksize / 4) {
+ stacksize /= 2;
+ stack = realloc(stack, stacksize * sizeof(void *));
+ }
}
static void *new(csx_type type, int data_size)
{
- int *res = malloc(sizeof(int) + data_size);
+ int *res = malloc(sizeof(int) * 2 + data_size);
if (!res) exit(1);
- *res = type;
- return res + 1;
+ res[0] = 0;
+ res[1] = type;
+ pushobj(res);
+ return res + 2;
}
@@ -63,23 +112,68 @@ static int initiated = 0;
static void *null;
static void *one;
static pair_data *context;
-static pair_data *names;
-static pair_data *ints;
-static pair_data *reals;
+
+
+static void deepmark(void *p)
+{
+ if (mark(p)) return;
+ setmark(p);
+ if (type(p) == type_pair) {
+ deepmark(head(p));
+ deepmark(tail(p));
+ } else if (type(p) == type_fn || type(p) == type_sx) {
+ fn_data *fn = p;
+ deepmark(fn->params);
+ deepmark(fn->body);
+ deepmark(fn->context);
+ }
+}
+
+static void sweep()
+{
+ void **old = objs;
+ int len = objslen;
+ int i;
+ objs = 0;
+ for (i = 0; i != len; ++i) {
+ if (*(int *)(old[i])) {
+ *(int *)(old[i]) = 0;
+ pushobj(old[i]);
+ } else {
+ free(old[i]);
+ }
+ }
+ free(old);
+}
+
+static void gc()
+{
+ int i;
+ static int lastlen = 0;
+ if (objslen < lastlen * 2) return;
+ setmark(null);
+ setmark(one);
+ deepmark(context);
+ for (i = 0; i != stacklen; ++i) {
+ deepmark(stack[i]);
+ }
+ sweep();
+ lastlen = objslen;
+}
char *csx_name(const char *name)
{
if (!initiated) init();
int namesize = strlen(name) + 1;
- pair_data *p = names;
- while (type(p) == type_pair) {
- if (!memcmp(p->head, name, namesize)) return p->head;
- p = p->tail;
+ int i;
+ for (i = 0; i != objslen; ++i) {
+ void *obj = (int *)(objs[i]) + 2;
+ if (type(obj) != type_name) continue;
+ if (!strncmp(obj, name, namesize)) return obj;
}
void *res = new(type_name, namesize);
memcpy(res, name, namesize);
- names = new_pair(res, names);
return res;
}
@@ -94,28 +188,28 @@ csx_base_data *csx_base(csx_base_data base)
int *csx_int(int num)
{
if (!initiated) init();
- pair_data *p = ints;
- while (type(p) == type_pair) {
- if (*(int *)p->head == num) return p->head;
- p = p->tail;
+ int i;
+ for (i = 0; i != objslen; ++i) {
+ int *obj = (int *)(objs[i]) + 2;
+ if (type(obj) != type_int) continue;
+ if (*obj == num) return obj;
}
int *res = new(type_int, sizeof(int));
*res = num;
- ints = new_pair(res, ints);
return res;
}
double *csx_float(double num)
{
if (!initiated) init();
- pair_data *p = reals;
- while (type(p) == type_pair) {
- if (*(double *)p->head == num) return p->head;
- p = p->tail;
+ int i;
+ for (i = 0; i != objslen; ++i) {
+ double *obj = (void *)((int *)(objs[i]) + 2);
+ if (type(obj) != type_real) continue;
+ if (*obj == num) return obj;
}
double *res = new(type_real, sizeof(double));
*res = num;
- ints = new_pair(res, ints);
return res;
}
@@ -123,16 +217,22 @@ double *csx_float(double num)
static void *run_each(void *l)
{
if (type(l) != type_pair) return null;
+ push(l);
+ int ret = stacklen;
pair_data *res = new_pair(csx_run(head(l)), null);
pair_data **p = (pair_data **)&res->tail;
l = tail(l);
while (type(l) == type_pair) {
- void *saved = context;
+ push(res);
+ int resret = stacklen;
*p = new_pair(csx_run(head(l)), null);
p = (pair_data **)&(*p)->tail;
- context = saved;
+ restore(resret);
+ pop();
l = tail(l);
}
+ restore(ret);
+ pop();
return res;
}
@@ -165,11 +265,15 @@ static void *lookup(const char *name)
static void *base_set(void *arg)
{
pair_data *res;
+ push(arg);
+ int ret = stacklen;
void *name = head(arg);
void *value = csx_run(head(tail(arg)));
if (type(context) == type_null) {
void *nameval = new_pair(name, value);
context = new_pair(new_pair(nameval, null), null);
+ restore(ret);
+ pop();
return null;
}
res = lookup_frame(name);
@@ -179,6 +283,8 @@ static void *base_set(void *arg)
void **names = &context->head;
*names = new_pair(new_pair(name, value), *names);
}
+ restore(ret);
+ pop();
return null;
}
@@ -427,11 +533,13 @@ static void *base_run(void *arg)
{
arg = run_each(arg);
if (type(tail(arg)) == type_null) return csx_run(head(arg));
- void *saved = context;
+ push(context);
+ int ret = stacklen;
context = head(tail(arg));
void *res = csx_run(head(arg));
void *rescontext = context;
- context = saved;
+ restore(ret);
+ context = pop();
return new_pair(res, rescontext);
}
@@ -452,49 +560,74 @@ static void *zip(void *params, void *values)
void *csx_run(void *arg)
{
if (!initiated) init();
+ push(arg);
+ int ret = stacklen;
tailcall:
- if (type(arg) == type_name) return lookup(arg);
- else if (type(arg) == type_pair) {
+ gc();
+ if (type(arg) == type_name) {
+ restore(ret);
+ pop();
+ return lookup(arg);
+ } else if (type(arg) == type_pair) {
fn_data *fn = csx_run(head(arg));
void *ops = tail(arg);
+ push(fn);
if (type(fn) == type_base) {
csx_base_data *base = (void *)fn;
if (*base == csx_run) {
ops = run_each(ops);
arg = head(ops);
+ push(arg);
goto tailcall;
} else {
- return (*base)(ops);
+ void *res = (*base)(ops);
+ restore(ret);
+ pop();
+ return res;
}
} else if (type(fn) == type_fn) {
void *res;
- void *saved = context;
+ push(context);
+ int fnret = stacklen;
ops = run_each(ops);
context = new_pair(zip(fn->params, ops), fn->context);
res = base_do(fn->body);
- context = saved;
+ restore(fnret);
+ context = pop();
+ restore(ret);
+ pop();
return res;
} else if (type(fn) == type_sx) {
- void *saved = context;
+ push(context);
+ int sxret = stacklen;
context = new_pair(zip(fn->params, ops), fn->context);
arg = base_do(fn->body);
- context = saved;
+ restore(sxret);
+ context = pop();
goto tailcall;
} else if (type(fn) == type_pair) {
pair_data *res = (void *)fn;
int pos = *(int *)csx_run(head(ops));
while (pos--) res = res->tail;
+ restore(ret);
+ pop();
return res->head;
} else if (type(fn) == type_str) {
char *res = (void *)fn;
int pos = *(int *)csx_run(head(ops));
+ restore(ret);
+ pop();
return csx_int(res[pos]);
} else if (type(fn) == type_null) {
+ restore(ret);
+ pop();
return null;
} else {
exit(1);
}
}
+ restore(ret);
+ pop();
return arg;
}
@@ -507,13 +640,19 @@ static void *base_context(void *args)
static void new_context();
static void *base_newcontext(void *args)
{
- void *saved = context;
+ push(context);
new_context();
void *res = context;
- context = saved;
+ context = pop();
return res;
}
+static void *base_exit(void *args)
+{
+ csx_free();
+ exit(0);
+}
+
static void new_context()
{
context = new_pair(null, null);
@@ -547,6 +686,7 @@ static void new_context()
base_set(csx_list(csx_name("run"), csx_base(base_run), 0));
base_set(csx_list(csx_name("context"), csx_base(base_context), 0));
base_set(csx_list(csx_name("newcontext"), csx_base(base_newcontext), 0));
+ base_set(csx_list(csx_name("exit"), csx_base(base_exit), 0));
}
static void init()
@@ -555,12 +695,22 @@ static void init()
setbuf(stdin, 0);
setbuf(stdout, 0);
null = new(type_null, 0);
- names = null;
- ints = null;
one = csx_int(1);
new_context();
}
+void csx_free()
+{
+ initiated = 0;
+ while (objslen) {
+ free(objs[--objslen]);
+ }
+ free(objs);
+ free(stack);
+ objs = 0;
+ stack = 0;
+}
+
void *csx_list(void *head, ...)
{