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#include "eval.h"
#include "builtin.h"
#include "exc.h"
#include "consts.h"
#include <cstdio>
extern Cons *empty_list;
const int EVAL_STACK_SIZE = 65536;
FrameObj *eval_stack[EVAL_STACK_SIZE];
void Evaluator::add_builtin_routines() {
#define ADD_ENTRY(name, rout) \
envt->add_binding(new SymObj(name), rout)
#define ADD_BUILTIN_PROC(name, rout) \
ADD_ENTRY(name, new BuiltinProcObj(rout, name))
ADD_ENTRY("if", new SpecialOptIf());
ADD_ENTRY("lambda", new SpecialOptLambda());
ADD_ENTRY("define", new SpecialOptDefine());
ADD_ENTRY("set!", new SpecialOptSet());
ADD_ENTRY("quote", new SpecialOptQuote());
ADD_BUILTIN_PROC("+", num_add);
ADD_BUILTIN_PROC("-", num_sub);
ADD_BUILTIN_PROC("*", num_multi);
ADD_BUILTIN_PROC("/", num_div);
ADD_BUILTIN_PROC("<", num_lt);
ADD_BUILTIN_PROC(">", num_gt);
ADD_BUILTIN_PROC("=", num_eq);
ADD_BUILTIN_PROC("exact?", num_exact);
ADD_BUILTIN_PROC("inexact?", num_inexact);
ADD_BUILTIN_PROC("not", bool_not);
ADD_BUILTIN_PROC("boolean?", is_boolean);
ADD_BUILTIN_PROC("pair?", is_pair);
ADD_BUILTIN_PROC("cons", make_pair);
ADD_BUILTIN_PROC("car", pair_car);
ADD_BUILTIN_PROC("cdr", pair_cdr);
ADD_BUILTIN_PROC("set-car!", pair_set_car);
ADD_BUILTIN_PROC("set-cdr!", pair_set_cdr);
ADD_BUILTIN_PROC("null?", is_null);
ADD_BUILTIN_PROC("list?", is_list);
ADD_BUILTIN_PROC("display", display);
ADD_BUILTIN_PROC("list", make_list);
}
Evaluator::Evaluator() {
envt = new Environment(NULL); // Top-level Environment
add_builtin_routines();
}
void push(Cons * &pc, FrameObj ** &top_ptr, Environment *envt) {
if (pc->car->is_simple_obj()) // Not an opt invocation
{
*top_ptr = envt->get_obj(pc->car); // Objectify the symbol
// static_cast because of is_simple_obj() is true
static_cast<EvalObj*>(*top_ptr)->prepare(pc);
top_ptr++;
pc = pc->next; // Move to the next instruction
}
else // Operational Invocation
{
if (pc->car == empty_list)
throw NormalError(SYN_ERR_EMPTY_COMB);
*top_ptr++ = new RetAddr(pc); // Push the return address
if (!is_list(TO_CONS(pc->car)))
throw TokenError(pc->car->ext_repr(), RUN_ERR_WRONG_NUM_OF_ARGS);
// static_cast because of is_simple_obj() is false
pc = static_cast<Cons*>(pc->car); // Go deeper to enter the call
}
}
void stack_print(FrameObj **top_ptr) {
for (FrameObj **ptr = eval_stack; ptr != top_ptr; ptr++)
printf("%s\n", (*ptr)->_debug_repr().c_str());
puts("");
}
EvalObj *Evaluator::run_expr(Cons *prog) {
FrameObj **top_ptr = eval_stack;
Cons *pc = prog;
Continuation *cont = NULL;
// envt is this->envt
push(pc, top_ptr, envt);
while((*eval_stack)->is_ret_addr())
{
for (; pc && pc->skip; pc = pc->next);
if (pc)
push(pc, top_ptr, envt);
else
{
Cons *args = empty_list;
while (!(*(--top_ptr))->is_ret_addr())
args = new Cons(static_cast<EvalObj*>(*top_ptr), args);
//< static_cast because the while condition
RetAddr *ret_addr = static_cast<RetAddr*>(*top_ptr);
if (!ret_addr->addr)
{
Cons *nexp = TO_CONS(cont->proc_body->cdr);
cont->proc_body = nexp;
if (nexp == empty_list)
{
*top_ptr = args->car;
envt = cont->envt;
pc = cont->pc->next;
cont = cont->prev_cont;
}
else pc = nexp;
top_ptr++;
}
else
{
EvalObj *opt = args->car;
if (opt->is_opt_obj())
pc = static_cast<OptObj*>(opt)->
call(args, envt, cont, top_ptr);
else
throw TokenError(opt->ext_repr(), SYN_ERR_CAN_NOT_APPLY);
}
}
}
// static_cast because the previous while condition
return static_cast<EvalObj*>(*(eval_stack));
}
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