128 lines
2.6 KiB
C
128 lines
2.6 KiB
C
/*
|
|
*
|
|
* s t a c k . c -- Implementation of the extended type Stack
|
|
*
|
|
*/
|
|
|
|
#include <stk.h>
|
|
|
|
static void mark_stack(SCM p);
|
|
static void free_stack(SCM p);
|
|
static void display_stack(SCM s, SCM port, int mode);
|
|
static int tc_stack;
|
|
|
|
static STk_extended_scheme_type stack_type = {
|
|
"stack", /* name */
|
|
0, /* is_procp */
|
|
mark_stack, /* gc_mark_fct */
|
|
free_stack, /* gc_sweep_fct */
|
|
NULL, /* apply_fct */
|
|
display_stack /* display_fct */
|
|
};
|
|
|
|
#define STACKP(x) (TYPEP(x, tc_stack))
|
|
#define NSTACKP(x) (NTYPEP(x, tc_stack))
|
|
#define STACK(x) ((Stack *) EXTDATA(x))
|
|
|
|
typedef struct {
|
|
int len;
|
|
SCM values;
|
|
} Stack;
|
|
|
|
static void mark_stack(SCM p)
|
|
{
|
|
STk_gc_mark(STACK(p)->values);
|
|
}
|
|
|
|
static void free_stack(SCM p)
|
|
{
|
|
free(EXTDATA(p));
|
|
}
|
|
|
|
static void display_stack(SCM s, SCM port, int mode)
|
|
{
|
|
char buffer[100];
|
|
if (mode == DSP_MODE) {
|
|
/* A verbose display */
|
|
if (STACK(s)->len) {
|
|
sprintf(buffer, "Stack length = %d\nValues = ", STACK(s)->len);
|
|
Puts(buffer, PORT_FILE(port));
|
|
STk_display(STACK(s)->values, port);
|
|
}
|
|
else
|
|
Puts("Stack is empty", PORT_FILE(port));
|
|
}
|
|
else { /* WRT_MODE or TK_MODE */
|
|
sprintf(buffer, "#<stack (length=%d) %ld>", STACK(s)->len, s);
|
|
Puts(buffer, PORT_FILE(port));
|
|
}
|
|
}
|
|
|
|
static PRIMITIVE make_stack(void)
|
|
{
|
|
SCM z;
|
|
|
|
NEWCELL(z, tc_stack);
|
|
EXTDATA(z) = STk_must_malloc(sizeof(Stack));
|
|
STACK(z)->len = 0;
|
|
STACK(z)->values = NIL;
|
|
return z;
|
|
}
|
|
|
|
static PRIMITIVE stackp(SCM s)
|
|
{
|
|
return STACKP(s)? Truth: Ntruth;
|
|
}
|
|
|
|
static PRIMITIVE stack_push(SCM s, SCM val)
|
|
{
|
|
Stack *sp;
|
|
|
|
if (NSTACKP(s)) STk_err("stack-push: bad stack", s);
|
|
|
|
sp = STACK(s);
|
|
sp->len += 1;
|
|
sp->values = Cons(val, sp->values);
|
|
|
|
return UNDEFINED;
|
|
}
|
|
|
|
static PRIMITIVE stack_pop(SCM s)
|
|
{
|
|
Stack *sp;
|
|
SCM res;
|
|
|
|
if (NSTACKP(s)) STk_err("stack-pop: bad stack", s);
|
|
|
|
sp = STACK(s);
|
|
|
|
if (sp->len == 0) STk_err("stack-pop: empty stack", s);
|
|
res = CAR(sp->values);
|
|
sp->len -= 1;
|
|
sp->values = CDR(sp->values);
|
|
|
|
return res;
|
|
}
|
|
|
|
static PRIMITIVE stack_emptyp(SCM s)
|
|
{
|
|
if (NSTACKP(s)) STk_err("stack-empty?: bad stack", s);
|
|
return (STACK(s)->len) ? Truth: Ntruth;
|
|
}
|
|
|
|
|
|
PRIMITIVE STk_init_stack(void)
|
|
{
|
|
/* Register the new type */
|
|
tc_stack = STk_add_new_type(&stack_type);
|
|
|
|
/* Declare new primitives */
|
|
STk_add_new_primitive("make-stack", tc_subr_0, make_stack);
|
|
STk_add_new_primitive("stack?", tc_subr_1, stackp);
|
|
STk_add_new_primitive("stack-push!", tc_subr_2, stack_push);
|
|
STk_add_new_primitive("stack-pop", tc_subr_1, stack_pop);
|
|
STk_add_new_primitive("stack-empty?", tc_subr_1, stack_emptyp);
|
|
|
|
return UNDEFINED;
|
|
}
|