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
|
# Integer arithmetic using postfix notation
#
# Limitations:
# Division not implemented yet.
#
# To build:
# $ ./translate apps/rpn.mu
#
# Example session:
# $ qemu-system-i386 code.img
# > 4
# 4
# > 5 3 -
# 2
#
# Error handling is non-existent. This is just a prototype.
fn main screen: (addr screen), keyboard: (addr keyboard), data-disk: (addr disk) {
var in-storage: (stream byte 0x80)
var in/esi: (addr stream byte) <- address in-storage
var y/ecx: int <- copy 0
# read-eval-print loop
{
var x/eax: int <- draw-text-rightward screen, "> ", 0/x, 0x80/xmax, y, 3/fg/cyan, 0/bg
read-line-from-keyboard keyboard, in, screen, 0xf/fg 0/bg
# parse and eval
var out/eax: int <- simplify in
# print
y <- increment
out, y <- draw-int32-decimal-wrapping-right-then-down screen, out, 0/xmin, y, 0x80/xmax, 0x30/ymax, 0/x, y, 7/fg, 0/bg
# newline
y <- increment
#
loop
}
}
type int-stack {
data: (handle array int)
top: int
}
fn simplify in: (addr stream byte) -> _/eax: int {
var word-storage: slice
var word/ecx: (addr slice) <- address word-storage
var stack-storage: int-stack
var stack/esi: (addr int-stack) <- address stack-storage
initialize-int-stack stack, 0x10
$simplify:word-loop: {
next-word in, word
var done?/eax: boolean <- slice-empty? word
compare done?, 0
break-if-!=
# if word is an operator, perform it
{
var is-add?/eax: boolean <- slice-equal? word, "+"
compare is-add?, 0
break-if-=
var _b/eax: int <- pop-int-stack stack
var b/edx: int <- copy _b
var a/eax: int <- pop-int-stack stack
a <- add b
push-int-stack stack, a
loop $simplify:word-loop
}
{
var is-sub?/eax: boolean <- slice-equal? word, "-"
compare is-sub?, 0
break-if-=
var _b/eax: int <- pop-int-stack stack
var b/edx: int <- copy _b
var a/eax: int <- pop-int-stack stack
a <- subtract b
push-int-stack stack, a
loop $simplify:word-loop
}
{
var is-mul?/eax: boolean <- slice-equal? word, "*"
compare is-mul?, 0
break-if-=
var _b/eax: int <- pop-int-stack stack
var b/edx: int <- copy _b
var a/eax: int <- pop-int-stack stack
a <- multiply b
push-int-stack stack, a
loop $simplify:word-loop
}
# otherwise it's an int
var n/eax: int <- parse-decimal-int-from-slice word
push-int-stack stack, n
loop
}
var result/eax: int <- pop-int-stack stack
return result
}
fn initialize-int-stack _self: (addr int-stack), n: int {
var self/esi: (addr int-stack) <- copy _self
var d/edi: (addr handle array int) <- get self, data
populate d, n
var top/eax: (addr int) <- get self, top
copy-to *top, 0
}
fn push-int-stack _self: (addr int-stack), _val: int {
var self/esi: (addr int-stack) <- copy _self
var top-addr/ecx: (addr int) <- get self, top
var data-ah/edx: (addr handle array int) <- get self, data
var data/eax: (addr array int) <- lookup *data-ah
var top/edx: int <- copy *top-addr
var dest-addr/edx: (addr int) <- index data, top
var val/eax: int <- copy _val
copy-to *dest-addr, val
add-to *top-addr, 1
}
fn pop-int-stack _self: (addr int-stack) -> _/eax: int {
var self/esi: (addr int-stack) <- copy _self
var top-addr/ecx: (addr int) <- get self, top
{
compare *top-addr, 0
break-if->
return 0
}
subtract-from *top-addr, 1
var data-ah/edx: (addr handle array int) <- get self, data
var data/eax: (addr array int) <- lookup *data-ah
var top/edx: int <- copy *top-addr
var result-addr/eax: (addr int) <- index data, top
var val/eax: int <- copy *result-addr
return val
}
|