⬆️ update dependencies, ✨ implement user store

vendor/github.com/alecthomas/kong/interpolate.go

@@ -0,0 +1,39 @@
+package kong
+
+import (
+	"fmt"
+	"regexp"
+)
+
+var interpolationRegex = regexp.MustCompile(`((?:\${([[:alpha:]_][[:word:]]*))(?:=([^}]+))?})|(\$)|([^$]+)`)
+
+// Interpolate variables from vars into s for substrings in the form ${var} or ${var=default}.
+func interpolate(s string, vars Vars, updatedVars map[string]string) (string, error) {
+	out := ""
+	matches := interpolationRegex.FindAllStringSubmatch(s, -1)
+	if len(matches) == 0 {
+		return s, nil
+	}
+	for key, val := range updatedVars {
+		if vars[key] != val {
+			vars = vars.CloneWith(updatedVars)
+			break
+		}
+	}
+	for _, match := range matches {
+		if name := match[2]; name != "" {
+			value, ok := vars[name]
+			if !ok {
+				// No default value.
+				if match[3] == "" {
+					return "", fmt.Errorf("undefined variable ${%s}", name)
+				}
+				value = match[3]
+			}
+			out += value
+		} else {
+			out += match[0]
+		}
+	}
+	return out, nil
+}