refactor: Implement complex generic parser (#108)

internal/iface.go

@@ -562,7 +562,7 @@ func (i uintptrSliceParser) ParseEnv(key string, defaltVal any, options Paramete
 type complex64Parser complex64
 
 func (d complex64Parser) ParseEnv(key string, defaltVal any, _ Parameters) any {
-	val := complex64OrDefault(key, defaltVal.(complex64))
+	val := complexOrDefaultGen(key, defaltVal.(complex64))
 
 	return val
 }
@@ -582,7 +582,7 @@ func (i complex64SliceParser) ParseEnv(key string, defaltVal any, options Parame
 type complex128Parser complex128
 
 func (d complex128Parser) ParseEnv(key string, defaltVal any, _ Parameters) any {
-	val := complex128OrDefault(key, defaltVal.(complex128))
+	val := complexOrDefaultGen(key, defaltVal.(complex128))
 
 	return val
 }

internal/parsers.go

@@ -753,25 +753,38 @@ func uintptrSliceOrDefault(key string, defaultVal []uintptr, sep string) []uintp
 	return val
 }
 
-// complex64OrDefault retrieves the complex64 value of the environment variable named
-// by the key.
-// If variable not set or value is empty - defaultVal will be returned.
-func complex64OrDefault(key string, defaultVal complex64) complex64 {
+func complexOrDefaultGen[T complex64 | complex128](key string, defaultVal T) T {
 	env := stringOrDefault(key, "")
 	if env == "" {
 		return defaultVal
 	}
 
-	const (
-		bitsize = 64
+	var (
+		bitsize int
+		castFn  func(val complex128) T
 	)
 
+	switch any(defaultVal).(type) {
+	case complex64:
+		bitsize = 64
+
+		castFn = func(val complex128) T {
+			return any(complex64(val)).(T)
+		}
+	case complex128:
+		bitsize = 128
+
+		castFn = func(val complex128) T {
+			return any(val).(T)
+		}
+	}
+
 	val, err := strconv.ParseComplex(env, bitsize)
 	if err != nil {
 		return defaultVal
 	}
 
-	return complex64(val)
+	return castFn(val)
 }
 
 // complex64SliceOrDefault retrieves the complex64 slice value of the environment variable named
@@ -801,27 +814,6 @@ func complex64SliceOrDefault(key string, defaultVal []complex64, sep string) []c
 	return val
 }
 
-// complex128OrDefault retrieves the complex128 value of the environment variable named
-// by the key.
-// If variable not set or value is empty - defaultVal will be returned.
-func complex128OrDefault(key string, defaultVal complex128) complex128 {
-	env := stringOrDefault(key, "")
-	if env == "" {
-		return defaultVal
-	}
-
-	const (
-		bitsize = 128
-	)
-
-	val, err := strconv.ParseComplex(env, bitsize)
-	if err != nil {
-		return defaultVal
-	}
-
-	return val
-}
-
 // complex128SliceOrDefault retrieves the complex128 slice value of the environment variable named
 // by the key and separated by sep.
 // If the variable is not set or the value is empty - defaultVal will be returned.

internal/parsers_test.go

@@ -3958,7 +3958,7 @@ func Test_complex64OrDefault(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			tt.precond.maybeSetEnv(t, tt.args.key)
 
-			got := complex64OrDefault(tt.args.key, tt.args.defaultVal)
+			got := complexOrDefaultGen(tt.args.key, tt.args.defaultVal)
 			assert.Equal(t, tt.expected.val, got)
 		})
 	}
@@ -4150,7 +4150,7 @@ func Test_complex128OrDefault(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			tt.precond.maybeSetEnv(t, tt.args.key)
 
-			got := complex128OrDefault(tt.args.key, tt.args.defaultVal)
+			got := complexOrDefaultGen(tt.args.key, tt.args.defaultVal)
 			assert.Equal(t, tt.expected.val, got)
 		})
 	}