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#include "model.h"
EmptyList *empty_list = new EmptyList();
EmptyList::EmptyList() : Cons(NULL, NULL) {}
string EmptyList::ext_repr() { return string("()"); }
#ifdef DEBUG
string EmptyList::_debug_repr() { return ext_repr(); }
#endif
bool FrameObj::is_ret_addr() {
return ftype == CLS_RET_ADDR;
}
EvalObj::EvalObj() : FrameObj() { ftype = CLS_EVAL_OBJ; }
void EvalObj::prepare(Cons *pc) {}
bool EvalObj::is_simple_obj() {
return otype == CLS_SIM_OBJ;
}
bool EvalObj::is_true() {
return true;
}
Cons::Cons(EvalObj *_car, Cons *_cdr) : EvalObj(), car(_car), cdr(_cdr), skip(false), next(NULL) {}
string Cons::ext_repr() { return string("#<Cons>"); }
#ifdef DEBUG
string Cons::_debug_repr() { return ext_repr(); }
Cons::_debug_print() {
printf("%s",
("car: " + car -> ext_repr() + "\n" + \
"cdr: " + cdr -> ext_repr() + "\n").c_str());
}
#endif
RetAddr::RetAddr(Cons *_addr) : FrameObj(), addr(_addr) {
ftype = CLS_RET_ADDR;
}
UnspecObj::UnspecObj() : EvalObj() {}
string UnspecObj::ext_repr() { return string("#<Unspecified>"); }
#ifdef DEBUG
string UnspecObj::_debug_repr() { return ext_repr(); }
#endif
SymObj::SymObj(string str) : EvalObj(), val(str) {}
string SymObj::ext_repr() { return "#<Symbol: " + val + ">"; }
#ifdef DEBUG
string SymObj::_debug_repr() { return ext_repr(); }
#endif
OptObj::OptObj() : EvalObj() {}
ProcObj::ProcObj(ASTList *_body,
Environment *_envt,
SymbolList *_para_list) :
OptObj(), body(_body), envt(_envt), para_list(_para_list) {}
Cons *ProcObj::call(ArgList *arg_list, Environment * &envt,
Continuation * &cont, FrameObj ** &top_ptr) {
// Create a new continuation
Cons *ret_addr = dynamic_cast<Cons*>(*top_ptr);
Continuation *ncont = new Continuation(envt, ret_addr, cont, body);
cont = ncont; // Add to the cont chain
envt = new Environment(envt); // Create local env and recall the closure
// TODO: Compare the arguments to the parameters
for (Cons *ptr = arg_list->cdr, *ppar = para_list;
ptr != empty_list; ptr = ptr->cdr)
envt->add_binding(dynamic_cast<SymObj*>(ppar->car), ptr->car);
*top_ptr = new RetAddr(NULL); // Mark the entrance of a cont
return body; // Move pc to the proc entry point
}
string ProcObj::ext_repr() { return string("#<Procedure"); }
#ifdef DEBUG
string ProcObj::_debug_repr() { return ext_repr(); }
#endif
SpecialOptObj::SpecialOptObj() : OptObj() {}
NumberObj::NumberObj() : EvalObj() {}
BuiltinProcObj::BuiltinProcObj(BuiltinProc f, string _name) :
OptObj(), handler(f), name(_name) {}
Cons *BuiltinProcObj::call(ArgList *arg_list, Environment * &envt,
Continuation * &cont, FrameObj ** &top_ptr) {
Cons *ret_addr = dynamic_cast<Cons*>(*top_ptr);
*top_ptr = handler(arg_list->cdr);
return ret_addr->next; // Move to the next instruction
}
Environment::Environment(Environment *_prev_envt) : prev_envt(_prev_envt) {}
void Environment::add_binding(SymObj *sym_obj, EvalObj *eval_obj) {
binding[sym_obj->val] = eval_obj;
}
EvalObj *Environment::get_obj(SymObj *sym_obj) {
string name(sym_obj->val);
for (Environment *ptr = this; ptr; ptr = prev_envt)
{
bool has_key = binding.count(name);
if (has_key) return binding[name];
}
//TODO: exc key not found
}
bool Environment::has_obj(SymObj *sym_obj) {
string name(sym_obj->val);
for (Environment *ptr = this; ptr; ptr = prev_envt)
if (binding.count(name))
return true;
return false;
}
Continuation::Continuation(Environment *_envt, Cons *_pc,
Continuation *_prev_cont,
ASTList *_proc_body,
unsigned int _body_cnt) :
envt(_envt), pc(_pc), prev_cont(_prev_cont),
proc_body(_proc_body), body_cnt(_body_cnt) {}
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