Add a -max flag to limit the number of evaluations.

mito.go

@@ -67,6 +67,7 @@ func Main() int {
 	}
 	use := flag.String("use", "all", "libraries to use")
 	data := flag.String("data", "", "path to a JSON object holding input (exposed as the label "+root+")")
+	max := flag.Uint("max", 1000000, "maximum number of evaluations")
 	cfgPath := flag.String("cfg", "", "path to a YAML file holding configuration for global vars and regular expressions")
 	insecure := flag.Bool("insecure", false, "disable TLS verification in the HTTP client")
 	version := flag.Bool("version", false, "print version and exit")
@@ -183,7 +184,7 @@ func Main() int {
 		input = map[string]interface{}{root: input}
 	}
 
-	for {
+	for n := uint(0); n < *max; n++ {
 		res, val, err := eval(string(b), root, input, libs...)
 		if err != nil {
 			fmt.Fprintln(os.Stderr, err)

testdata/want_more_max.txt

@@ -0,0 +1,20 @@
+mito -data state.json -max 2 src.cel
+! stderr .
+cmp stdout want.txt
+
+-- state.json --
+{"n": 0}
+-- src.cel --
+int(state.n).as(n, {
+	"n":         n+1,
+	"want_more": n+1 < 5,
+})
+-- want.txt --
+{
+	"n": 1,
+	"want_more": true
+}
+{
+	"n": 2,
+	"want_more": true
+}