-
Notifications
You must be signed in to change notification settings - Fork 0
/
pgen.go
61 lines (52 loc) · 1.22 KB
/
pgen.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
package main
import (
"flag"
"fmt"
"os"
)
func main() {
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage: %v [options] <file.cfg>\n", os.Args[0])
fmt.Fprintln(os.Stderr)
fmt.Fprintln(os.Stderr, "Options:")
flag.PrintDefaults()
}
output := flag.String("out", "", "File to output to, or stdout if blank.")
detectAmbiguity := flag.Bool("detectAmbiguity", true, "Give warnings for grammar ambiguities.")
flag.Parse()
if flag.NArg() != 1 {
flag.Usage()
os.Exit(2)
}
file, err := os.Open(flag.Arg(0))
if err != nil {
fmt.Fprintf(os.Stderr, "Error opening %q: %v", flag.Arg(0), err)
os.Exit(1)
}
defer file.Close()
g, err := LoadGrammar(file, *detectAmbiguity)
if err != nil {
fmt.Fprintf(os.Stderr, "Error loading grammar: %v", err)
os.Exit(1)
}
out := &formatter{w: os.Stdout}
if *output != "" {
file, err := os.Create(*output)
if err != nil {
fmt.Fprintf(os.Stderr, "Error creating %q: %v", *output, err)
os.Exit(1)
}
defer file.Close()
out.w = file
}
err = tmpl.Execute(out, g)
if err != nil {
fmt.Fprintf(os.Stderr, "Error printing code: %v", err)
os.Exit(1)
}
err = out.Close()
if err != nil {
fmt.Fprintf(os.Stderr, "Error formatting code: %v", err)
os.Exit(1)
}
}