Current File : //usr/share/doc/re2c/examples/go/reuse/usedir.re
//go:generate re2go $INPUT -o $OUTPUT
package main
// This example shows how to combine reusable re2c blocks: two blocks
// ('colors' and 'fish') are merged into one. The 'salmon' rule occurs
// in both blocks; the 'fish' block takes priority because it is used
// earlier. Default rule * occurs in all three blocks; the local (not
// inherited) definition takes priority.
const (
Color = iota
Fish
Dunno
)
/*!rules:re2c:colors
* { panic("eh!") }
"red" | "salmon" | "magenta" { return Color }
*/
/*!rules:re2c:fish
* { panic("oh!") }
"haddock" | "salmon" | "eel" { return Fish }
*/
func lex(str string) int {
var cur, mar int
/*!re2c
re2c:yyfill:enable = 0;
re2c:define:YYCTYPE = byte;
re2c:define:YYPEEK = "str[cur]";
re2c:define:YYSKIP = "cur += 1";
re2c:define:YYBACKUP = "mar = cur";
re2c:define:YYRESTORE = "cur = mar";
!use:fish;
!use:colors;
* { return Dunno } // overrides inherited '*' rules
*/
}
func main() {
assert_eq := func(x, y int) { if x != y { panic("error") } }
assert_eq(lex("salmon"), Fish);
assert_eq(lex("what?"), Dunno);
}
Mini Shell