refactored and added game save function (key: s)

rule.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"log"
+	"strconv"
+	"strings"
+)
+
+// a GOL rule
+type Rule struct {
+	Birth []int
+	Death []int
+}
+
+// parse one part of a GOL rule into rule slice
+func NumbersToList(numbers string) []int {
+	list := []int{}
+
+	items := strings.Split(numbers, "")
+	for _, item := range items {
+		num, err := strconv.Atoi(item)
+		if err != nil {
+			log.Fatalf("failed to parse game rule part <%s>: %s", numbers, err)
+		}
+
+		list = append(list, num)
+	}
+
+	return list
+}
+
+// parse GOL rule, used in CheckRule()
+func ParseGameRule(rule string) *Rule {
+	parts := strings.Split(rule, "/")
+
+	if len(parts) < 2 {
+		log.Fatalf("Invalid game rule <%s>", rule)
+	}
+
+	golrule := &Rule{}
+
+	for _, part := range parts {
+		if part[0] == 'B' {
+			golrule.Birth = NumbersToList(part[1:])
+		} else {
+			golrule.Death = NumbersToList(part[1:])
+		}
+	}
+
+	return golrule
+}