using glide

vendor/github.com/docopt/docopt-go/examples/config_file/config_file_example.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/docopt/docopt-go"
+	"strings"
+)
+
+func loadJSONConfig() map[string]interface{} {
+	var result map[string]interface{}
+	jsonData := []byte(`{"--force": true, "--timeout": "10", "--baud": "9600"}`)
+	json.Unmarshal(jsonData, &result)
+	return result
+}
+
+func loadIniConfig() map[string]interface{} {
+	iniData := `
+[default-arguments]
+--force
+--baud=19200
+<host>=localhost`
+	// trivial ini parser
+	// default value for an item is bool: true (for --force)
+	// otherwise the value is a string
+	iniParsed := make(map[string]map[string]interface{})
+	var section string
+	for _, line := range strings.Split(iniData, "\n") {
+		if strings.HasPrefix(line, "[") {
+			section = line
+			iniParsed[section] = make(map[string]interface{})
+		} else if section != "" {
+			kv := strings.SplitN(line, "=", 2)
+			if len(kv) == 1 {
+				iniParsed[section][kv[0]] = true
+			} else if len(kv) == 2 {
+				iniParsed[section][kv[0]] = kv[1]
+			}
+		}
+	}
+	return iniParsed["[default-arguments]"]
+}
+
+// merge combines two maps.
+// truthiness takes priority over falsiness
+// mapA takes priority over mapB
+func merge(mapA, mapB map[string]interface{}) map[string]interface{} {
+	result := make(map[string]interface{})
+	for k, v := range mapA {
+		result[k] = v
+	}
+	for k, v := range mapB {
+		if _, ok := result[k]; !ok || result[k] == nil || result[k] == false {
+			result[k] = v
+		}
+	}
+	return result
+}
+
+func main() {
+	usage := `Usage:
+  config_file_example tcp [<host>] [--force] [--timeout=<seconds>]
+  config_file_example serial <port> [--baud=<rate>] [--timeout=<seconds>]
+  config_file_example -h | --help | --version`
+
+	jsonConfig := loadJSONConfig()
+	iniConfig := loadIniConfig()
+	arguments, _ := docopt.Parse(usage, nil, true, "0.1.1rc", false)
+
+	// Arguments take priority over INI, INI takes priority over JSON
+	result := merge(arguments, merge(iniConfig, jsonConfig))
+
+	fmt.Println("JSON config: ", jsonConfig)
+	fmt.Println("INI config: ", iniConfig)
+	fmt.Println("Result: ", result)
+}