Add new helper string related to justified MCQ flag

libfic/mcq_justification.go

@@ -0,0 +1,31 @@
+package fic
+
+import (
+	"errors"
+	"strings"
+	"strconv"
+)
+
+type FlagLabel struct {
+	Label    string
+	IdChoice int64
+	Checksum []byte
+	Solved   bool
+}
+
+// IsMCQJustification tells you if this key represent a justification from a MCQ.
+func (k Flag) IsMCQJustification() (bool) {
+	return len(k.Label) > 0 && k.Label[0] == '%'
+}
+
+// GetMCQJustification returns the structure corresponding to the given flag.
+func (k Flag) GetMCQJustification() (fl FlagLabel, err error) {
+	spl := strings.Split(k.Label, "%")
+	if len(spl) >= 3 && len(spl[0]) == 0 {
+		fl.IdChoice, err = strconv.ParseInt(spl[1], 10, 64)
+		fl.Label = strings.Join(spl[2:], "%")
+	} else {
+		err = errors.New("This is not a MCQ justification")
+	}
+	return
+}