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#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include "../lisp_api.h"
value *procedure_cons(env *e, value *args) {
value *v = eval(e, car(args));
return cons(v, eval(e, car(cdr(args))));
}
value *procedure_car(env *e, value *args) {
return car(eval(e, car(args)));
}
value *procedure_cdr(env *e, value *args) {
return cdr(eval(e, car(args)));
}
value *procedure_reverse(env *e, value *args) {
return reverse(eval(e, car(args)));
}
value *procedure_isnull(env *e, value *args) {
value *v = eval(e, car(args));
if(v->type == VT_NIL) {
return make_int(1);
}
return make_nil();
}
int value_eq(value *a, value *b) {
if(a->type != b->type){
return 0;
}
if(a == b){
return 1;
}
switch (a->type) {
case VT_INT: return a->as.i == b->as.i;
case VT_DOUBLE: return a->as.d == b->as.d;
case VT_SYMBOL: return !strcmp(a->as.sym, b->as.sym);
case VT_STRING: return !strcmp(a->as.sym, b->as.sym);
case VT_NIL: return 1;
case VT_PAIR:
return value_eq(car(a), car(b)) &&
value_eq(cdr(a), cdr(b));
case VT_LAMBDA:
case VT_PROCEDURE:
default:
return 0;
}
return 1;
}
value *procedure_equal(env *e, value *args) {
value *v_prev = eval(e, car(args));
args = cdr(args);
while (args->type == VT_PAIR) {
value *v_cur = eval(e, car(args));
if (!value_eq(v_prev, v_cur)) {
return make_nil();
}
v_prev = v_cur;
args = cdr(args);
}
return make_int(1);
}
value *apply_to_nums(env *e, value *args, double (*fn)(double, double)) {
double result;
value *v = eval(e, car(args));
if (v->type == VT_INT) {
result = v->as.i;
} else if (v->type == VT_DOUBLE) {
result = v->as.d;
} else {
printf("not a number: ");
println_value(v);
return make_nil();
}
args = cdr(args);
while (args->type == VT_PAIR) {
v = eval(e, car(args));
if (v->type == VT_INT) {
result = fn(result, v->as.i);
} else if (v->type == VT_DOUBLE) {
result = fn(result, v->as.d);
} else {
printf("not a number: ");
println_value(v);
return make_nil();
}
args = cdr(args);
}
if(is_integer(result)){
return make_int((int) result);
}
return make_double(result);
}
double add_fn(double x, double y) { return x+y; }
value *procedure_add(env *e, value *args) {
return apply_to_nums(e, args, add_fn);
}
double sub_fn(double x, double y) { return x-y; }
value *procedure_sub(env *e, value *args) {
return apply_to_nums(e, args, sub_fn);
}
double mul_fn(double x, double y) { return x*y; }
value *procedure_mul(env *e, value *args) {
return apply_to_nums(e, args, mul_fn);
}
double div_fn(double x, double y) { return x/y; }
value *procedure_div(env *e, value *args) {
return apply_to_nums(e, args, div_fn);
}
value *procedure_lt(env *e, value *args) {
double prev_num;
value *v = eval(e, car(args));
if (v->type == VT_INT) {
prev_num = v->as.i;
} else if (v->type == VT_DOUBLE) {
prev_num = v->as.d;
} else {
printf("not a number: ");
println_value(v);
return make_nil();
}
args = cdr(args);
while (args->type == VT_PAIR) {
v = eval(e, car(args));
double cur_num;
if (v->type == VT_INT) {
cur_num = v->as.i;
} else if (v->type == VT_DOUBLE) {
cur_num = v->as.d;
} else {
printf("not a number: ");
println_value(v);
return make_nil();
}
if(prev_num >= cur_num) {
return make_nil();
}
prev_num = cur_num;
args = cdr(args);
}
return make_int(1);
}
module_export *module_init() {
//exports[i].name = "xxx"
//exports[i].v = make_procedure(xxx);
static module_export exports[12];
exports[0].name = "cons";
exports[0].v = make_procedure(procedure_cons);
exports[1].name = "car";
exports[1].v = make_procedure(procedure_car);
exports[2].name = "cdr";
exports[2].v = make_procedure(procedure_cdr);
exports[3].name = "reverse";
exports[3].v = make_procedure(procedure_reverse);
exports[4].name = "null?";
exports[4].v = make_procedure(procedure_isnull);
exports[5].name = "equal?";
exports[5].v = make_procedure(procedure_equal);
exports[6].name = "+";
exports[6].v = make_procedure(procedure_add);
exports[7].name = "-";
exports[7].v = make_procedure(procedure_sub);
exports[8].name = "*";
exports[8].v = make_procedure(procedure_mul);
exports[9].name = "/";
exports[9].v = make_procedure(procedure_div);
exports[10].name = "<";
exports[10].v = make_procedure(procedure_lt);
exports[11].name = NULL;
exports[11].v = NULL;
return exports;
}
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