1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
#include <cstdio>
#include "model.h"
FrameObj::FrameObj(ClassType _ftype) : ftype(_ftype) {}
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(ClassType _otype) : FrameObj(CLS_EVAL_OBJ), otype(_otype) {}
void EvalObj::prepare(Cons *pc) {}
bool EvalObj::is_simple_obj() {
return otype & CLS_SIM_OBJ;
}
bool EvalObj::is_sym_obj() {
return otype & CLS_SYM_OBJ;
}
bool EvalObj::is_opt_obj() {
return otype & CLS_OPT_OBJ;
}
#ifdef DEBUG
void EvalObj::_debug_print() {
printf("mem: 0x%llX\n%s\n\n", (unsigned long long)this,
_debug_repr().c_str());
}
#endif
bool EvalObj::is_true() {
return true;
}
Cons::Cons(EvalObj *_car, Cons *_cdr) :
EvalObj(CLS_CONS_OBJ), car(_car), cdr(_cdr), skip(false),
next(cdr == empty_list ? NULL : cdr) {}
string Cons::ext_repr() { return string("#<Cons>"); }
#ifdef DEBUG
string Cons::_debug_repr() { return ext_repr(); }
void Cons::_debug_print() {
printf("mem: 0x%llX (0x%llX . 0x%llX) | 0x%llX\n%s\n",
(unsigned long long)this,
(unsigned long long)car,
(unsigned long long)cdr,
(unsigned long long)next,
("car: " + car -> ext_repr() + "\n" + \
"cdr: " + cdr -> ext_repr() + "\n").c_str());
}
#endif
RetAddr::RetAddr(Cons *_addr) : FrameObj(CLS_RET_ADDR), addr(_addr) {}
#ifdef DEBUG
string RetAddr::_debug_repr() { return string("#<Return Address>"); }
#endif
UnspecObj::UnspecObj() : EvalObj() {}
string UnspecObj::ext_repr() { return string("#<Unspecified>"); }
#ifdef DEBUG
string UnspecObj::_debug_repr() { return ext_repr(); }
#endif
SymObj::SymObj(const string &str) :
EvalObj(CLS_SIM_OBJ | CLS_SYM_OBJ), val(str) {}
string SymObj::ext_repr() { return "#<Symbol: " + val + ">"; }
#ifdef DEBUG
string SymObj::_debug_repr() { return ext_repr(); }
#endif
OptObj::OptObj() : EvalObj(CLS_SIM_OBJ | CLS_OPT_OBJ) {}
ProcObj::ProcObj(ASTList *_body,
Environment *_envt,
SymbolList *_para_list) :
OptObj(), body(_body), envt(_envt), para_list(_para_list) {}
Cons *ProcObj::call(ArgList *args, Environment * &_envt,
Continuation * &cont, FrameObj ** &top_ptr) {
// Create a new continuation
// static_cast see `call` invocation in eval.cpp
Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
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
// static_cast<SymObj*> because the para_list is already checked
for (Cons *ptr = args->cdr, *ppar = para_list;
ptr != empty_list; ptr = ptr->cdr, ppar = ppar->cdr)
_envt->add_binding(static_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 *args, Environment * &envt,
Continuation * &cont, FrameObj ** &top_ptr) {
Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
*top_ptr++ = handler(args->cdr);
return ret_addr->next; // Move to the next instruction
}
string BuiltinProcObj::ext_repr() {
return "#<Builtin Procedure: " + name + ">";
}
#ifdef DEBUG
string BuiltinProcObj::_debug_repr() { return ext_repr(); }
#endif
Environment::Environment(Environment *_prev_envt) : prev_envt(_prev_envt) {}
bool Environment::add_binding(SymObj *sym_obj, EvalObj *eval_obj, bool def) {
bool has_key = binding.count(sym_obj->val);
if (!def && !has_key) return false;
binding[sym_obj->val] = eval_obj;
return true;
}
EvalObj *Environment::get_obj(EvalObj *obj) {
if (!obj->is_sym_obj()) return obj;
SymObj *sym_obj = static_cast<SymObj*>(obj);
string name(sym_obj->val);
for (Environment *ptr = this; ptr; ptr = ptr->prev_envt)
{
bool has_key = ptr->binding.count(name);
if (has_key) return ptr->binding[name];
}
return NULL; // Object not found
}
Continuation::Continuation(Environment *_envt, Cons *_pc,
Continuation *_prev_cont,
ASTList *_proc_body) :
envt(_envt), pc(_pc), prev_cont(_prev_cont),
proc_body(_proc_body) {}
|