/
main.go
83 lines (72 loc) · 1.15 KB
/
main.go
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
/*
Toy interpreter executes scripts or stdin.
*/
package main
import (
"bufio"
"flag"
"fmt"
"github.com/mumax/3/script"
"io"
"log"
"os"
)
var debug = flag.Bool("g", false, "print debug output")
var (
world *script.World
ps1 string
)
func main() {
log.SetFlags(0)
flag.Parse()
world = script.NewWorld()
world.Func("exit", exit)
script.Debug = *debug
if flag.NArg() > 1 {
check(fmt.Errorf("need 0 or 1 input files"))
}
if flag.NArg() == 1 {
src, err := os.Open(flag.Arg(0))
check(err)
ps1 = ">"
interpret(src)
} else {
ps1 = ""
interpret(os.Stdin)
}
}
func interpret(in io.Reader) {
scanner := bufio.NewScanner(in)
for scanner.Scan() {
safecall(scanner.Text())
}
check(scanner.Err())
}
func safecall(code string) {
if code == "" {
return
}
defer func() {
err := recover()
if err != nil {
fmt.Fprintln(os.Stderr, "panic:", err)
}
}()
tree, err := world.Compile(code)
if err == nil {
for _, stmt := range tree.Child() {
fmt.Println(stmt.Eval())
}
} else {
fmt.Fprintln(os.Stderr, err)
}
}
func check(e error) {
if e != nil {
fmt.Fprintln(os.Stderr, e)
os.Exit(1)
}
}
func exit() {
os.Exit(0)
}