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
|
# Integer arithmetic using postfix notation
#
# Limitations:
# Division not implemented yet.
#
# To build:
# $ ./translate 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
var space/edx: grapheme <- copy 0x20
# read-eval-print loop
{
# print prompt
var x/eax: int <- draw-text-rightward screen, "> ", 0/x, 0x80/xmax, y, 3/fg/cyan, 0/bg
# read line from keyboard
clear-stream in
{
draw-cursor screen, space
var key/eax: byte <- read-key keyboard
compare key, 0xa/newline
break-if-=
compare key, 0
loop-if-=
var key2/eax: int <- copy key
append-byte in, key2
var g/eax: grapheme <- copy key2
draw-grapheme-at-cursor screen, g, 0xf/fg, 0/bg
move-cursor-right 0
loop
}
# clear cursor
draw-grapheme-at-cursor screen, space, 3/fg/never-used, 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
}
|