ini: add method to convert key-value to map

AsMap return the INI contents as mapping of
(section "." subsection "." var) as key
and the variable's value as slice of string.
For example, given the following INI file,

	[section1]
	key = value

	[section2 "sub"]
	key2 = value2
	key2 = value3

it will be mapped as,

	map["section1..key"] = []string{"value"}
	map["section2.sub.key2"] = []string{"value2", "value3"}

2 files changed, 89 insertions, 0 deletions

diff --git a/lib/ini/ini.go b/lib/ini/ini.go
index 597b3b80..0b541e54 100644
--- a/lib/ini/ini.go
+++ b/lib/ini/ini.go
@@ -163,6 +163,55 @@ func Parse(text []byte) (in *Ini, err error) {
 }
 
 //
+// AsMap return the INI contents as mapping of
+// (section-name ":" subsection-name ":" variable-name) as key
+// and the variable's values as slice of string.
+// For example, given the following INI file,
+//
+//	[section1]
+//	key = value
+//
+//	[section2 "sub"]
+//	key2 = value2
+//	key2 = value3
+//
+// it will be mapped as,
+//
+//	map["section1::key"] = []string{"value"}
+//	map["section2:sub:key2"] = []string{"value2", "value3"}
+//
+func (in *Ini) AsMap() (out map[string][]string) {
+	sep := ":"
+	out = make(map[string][]string)
+
+	for x := 0; x < len(in.secs); x++ {
+		sec := in.secs[x]
+
+		for y := 0; y < len(sec.Vars); y++ {
+			v := sec.Vars[y]
+
+			if v.mode == varModeEmpty {
+				continue
+			}
+			if v.mode&varModeSection > 0 || v.mode&varModeSubsection > 0 {
+				continue
+			}
+
+			key := sec.NameLower + sep + sec.Sub + sep + v.KeyLower
+
+			vals, ok := out[key]
+			if !ok {
+				out[key] = []string{v.Value}
+			} else {
+				out[key] = libstrings.AppendUniq(vals, v.Value)
+			}
+		}
+	}
+
+	return
+}
+
+//
 // Save the current parsed Ini into file `filename`. It will overwrite the
 // destination file if it's exist.
 //
diff --git a/lib/ini/ini_example_test.go b/lib/ini/ini_example_test.go
new file mode 100644
index 00000000..a2cb3d44
--- /dev/null
+++ b/lib/ini/ini_example_test.go
@@ -0,0 +1,40 @@
+package ini
+
+import (
+	"fmt"
+	"log"
+)
+
+func ExampleIni_AsMap() {
+	input := []byte(`
+[section]
+key=value1
+key2=
+
+[section "sub"]
+key=value1
+
+[section]
+key=value2
+key2=false
+
+[section "sub"]
+key=value2
+key=value3
+`)
+
+	inis, err := Parse(input)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	iniMap := inis.AsMap()
+
+	for k, v := range iniMap {
+		fmt.Println(k, "=", v)
+	}
+	// Unordered output:
+	// section::key = [value1 value2]
+	// section::key2 = [true false]
+	// section:sub:key = [value1 value2 value3]
+}