blob: 531e3b7263309fd7a0a35d8eaa0b85018368f153 (
plain) (
blame)
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
|
/*
* Copyright © 2016 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include "ao_lisp.h"
/*
* Non-recursive eval
*
* Plan: walk actuals, construct formals
*
* stack > save > actuals > actual_1
* v v
* formals . > actual_2
*/
static struct ao_lisp_cons *stack;
static struct ao_lisp_cons *actuals;
static struct ao_lisp_cons *formals;
static struct ao_lisp_cons *formals_tail;
static uint8_t been_here;
ao_lisp_poly
ao_lisp_eval(ao_lisp_poly v)
{
struct ao_lisp_cons *formal;
int cons = 0;
if (!been_here) {
been_here = 1;
ao_lisp_root_add(&ao_lisp_cons_type, &stack);
ao_lisp_root_add(&ao_lisp_cons_type, &actuals);
ao_lisp_root_add(&ao_lisp_cons_type, &formals);
ao_lisp_root_add(&ao_lisp_cons_type, &formals_tail);
}
stack = 0;
actuals = 0;
formals = 0;
formals_tail = 0;
for (;;) {
/* Build stack frames for each list */
while (ao_lisp_poly_type(v) == AO_LISP_CONS) {
if (v == AO_LISP_NIL)
break;
/* Push existing frame on the stack */
if (cons++) {
struct ao_lisp_cons *frame;
frame = ao_lisp_cons(ao_lisp_cons_poly(actuals), formals);
stack = ao_lisp_cons(ao_lisp_cons_poly(frame), stack);
}
actuals = ao_lisp_poly_cons(v);
formals = NULL;
formals_tail = NULL;
v = actuals->car;
printf("start: stack"); ao_lisp_cons_print(stack); printf("\n");
printf("start: actuals"); ao_lisp_cons_print(actuals); printf("\n");
printf("start: formals"); ao_lisp_cons_print(formals); printf("\n");
}
/* Evaluate primitive types */
switch (ao_lisp_poly_type(v)) {
case AO_LISP_INT:
case AO_LISP_STRING:
break;
case AO_LISP_ATOM:
v = ao_lisp_poly_atom(v)->val;
break;
}
for (;;) {
printf("add formal: "); ao_lisp_poly_print(v); printf("\n");
formal = ao_lisp_cons(v, NULL);
if (formals_tail)
formals_tail->cdr = formal;
else
formals = formal;
formals_tail = formal;
actuals = actuals->cdr;
printf("formals: ");
ao_lisp_cons_print(formals);
printf("\n");
printf("actuals: ");
ao_lisp_cons_print(actuals);
printf("\n");
/* Process all of the arguments */
if (actuals) {
v = actuals->car;
printf ("actual: "); ao_lisp_poly_print(v); printf("\n");
break;
}
v = formals->car;
/* Evaluate the resulting list */
if (ao_lisp_poly_type(v) == AO_LISP_BUILTIN) {
struct ao_lisp_builtin *b = ao_lisp_poly_builtin(v);
v = b->func(formals->cdr);
printf ("eval: ");
ao_lisp_cons_print(formals);
printf(" -> ");
ao_lisp_poly_print(v);
printf ("\n");
} else {
printf ("invalid eval\n");
}
if (--cons) {
struct ao_lisp_cons *frame;
/* Pop the previous frame off the stack */
frame = ao_lisp_poly_cons(stack->car);
actuals = ao_lisp_poly_cons(frame->car);
formals = frame->cdr;
/* Recompute the tail of the formals list */
for (formal = formals; formal->cdr != NULL; formal = formal->cdr);
formals_tail = formal;
stack = stack->cdr;
printf("stack pop: stack"); ao_lisp_cons_print(stack); printf("\n");
printf("stack pop: actuals"); ao_lisp_cons_print(actuals); printf("\n");
printf("stack pop: formals"); ao_lisp_cons_print(formals); printf("\n");
} else {
printf("done func\n");
break;
}
}
if (!cons)
break;
}
return v;
}
|
