Implement indentation in in Lua output

pkg/yqlib/doc/usage/lua.md

@@ -2,6 +2,7 @@
 ## Basic example
 Given a sample.yml file of:
 ```yaml
+---
 hello: world
 ? look: non-string keys
 : True
@@ -14,6 +15,15 @@ yq -o=lua '.' sample.yml
 ```
 will output
 ```lua
-return {["hello"]="world";[{["look"]="non-string keys";}]=true;["numbers"]={123,456,};};
+return {
+	["hello"] = "world";
+	[{
+		["look"] = "non-string keys";
+	}] = true;
+	["numbers"] = {
+		123,
+		456,
+	};
+};
 ```
 

pkg/yqlib/encoder_lua.go

@@ -11,6 +11,8 @@ import (
 type luaEncoder struct {
 	docPrefix string
 	docSuffix string
+	indent    int
+	indentStr string
 	unquoted  bool
 	escape    *strings.Replacer
 }
@@ -66,7 +68,7 @@ func NewLuaEncoder(prefs LuaPreferences) Encoder {
 		"\\t", "\t",
 		"\\\\", "\\",
 	)
-	return &luaEncoder{unescape.Replace(prefs.DocPrefix), unescape.Replace(prefs.DocSuffix), prefs.UnquotedKeys, escape}
+	return &luaEncoder{unescape.Replace(prefs.DocPrefix), unescape.Replace(prefs.DocSuffix), 0, "\t", prefs.UnquotedKeys, escape}
 }
 
 func (le *luaEncoder) PrintDocumentSeparator(writer io.Writer) error {
@@ -81,12 +83,28 @@ func (le *luaEncoder) encodeString(writer io.Writer, node *yaml.Node) error {
 	return writeString(writer, "\""+le.escape.Replace(node.Value)+"\"")
 }
 
+func (le *luaEncoder) writeIndent(writer io.Writer) error {
+	if le.indentStr == "" {
+		return nil
+	}
+	err := writeString(writer, "\n")
+	if err != nil {
+		return err
+	}
+	return writeString(writer, strings.Repeat(le.indentStr, le.indent))
+}
+
 func (le *luaEncoder) encodeArray(writer io.Writer, node *yaml.Node) error {
 	err := writeString(writer, "{")
 	if err != nil {
 		return err
 	}
+	le.indent++
 	for _, child := range node.Content {
+		err = le.writeIndent(writer)
+		if err != nil {
+			return err
+		}
 		err := le.Encode(writer, child)
 		if err != nil {
 			return err
@@ -96,6 +114,13 @@ func (le *luaEncoder) encodeArray(writer io.Writer, node *yaml.Node) error {
 			return err
 		}
 	}
+	le.indent--
+	if len(node.Content) != 0 {
+		err = le.writeIndent(writer)
+		if err != nil {
+			return err
+		}
+	}
 	return writeString(writer, "}")
 }
 
@@ -130,6 +155,7 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *yaml.Node) error {
 	if err != nil {
 		return err
 	}
+	le.indent++
 	for i, child := range node.Content {
 		if (i % 2) == 1 {
 			// value
@@ -141,13 +167,18 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *yaml.Node) error {
 			if err != nil {
 				return err
 			}
-		} else if le.unquoted && child.Tag == "!!str" && !needsQuoting(child.Value) {
+		} else {
-			err = writeString(writer, child.Value+"=")
+			// key
+			err = le.writeIndent(writer)
+			if err != nil {
+				return err
+			}
+			if le.unquoted && child.Tag == "!!str" && !needsQuoting(child.Value) {
+				err = writeString(writer, child.Value+" = ")
 				if err != nil {
 					return err
 				}
 			} else {
-			// key
 				err := writeString(writer, "[")
 				if err != nil {
 					return err
@@ -156,12 +187,20 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *yaml.Node) error {
 				if err != nil {
 					return err
 				}
-			err = writeString(writer, "]=")
+				err = writeString(writer, "] = ")
 				if err != nil {
 					return err
 				}
 			}
 		}
+	}
+	le.indent--
+	if len(node.Content) != 0 {
+		err = le.writeIndent(writer)
+		if err != nil {
+			return err
+		}
+	}
 	return writeString(writer, "}")
 }
 

pkg/yqlib/lua_test.go

@@ -11,50 +11,65 @@ import (
 var luaScenarios = []formatScenario{
 	{
 		description: "Basic example",
-		input:        "hello: world\n? look: non-string keys\n: True\nnumbers: [123,456]\n",
+		input: `---
-		expected:     "return {[\"hello\"]=\"world\";[{[\"look\"]=\"non-string keys\";}]=true;[\"numbers\"]={123,456,};};\n",
+hello: world
+? look: non-string keys
+: True
+numbers: [123,456]
+`,
+		expected: `return {
+	["hello"] = "world";
+	[{
+		["look"] = "non-string keys";
+	}] = true;
+	["numbers"] = {
+		123,
+		456,
+	};
+};
+`,
 		scenarioType: "encode",
 	},
 	{
 		skipDoc:      true,
 		description:  "Sequence",
 		input:        "- a\n- b\n- c\n",
-		expected:     "return {\"a\",\"b\",\"c\",};\n",
+		expected:     "return {\n\t\"a\",\n\t\"b\",\n\t\"c\",\n};\n",
 		scenarioType: "encode",
 	},
 	{
 		skipDoc:      true,
 		description:  "Mapping",
 		input:        "a: b\nc:\n  d: e\nf: 0\n",
-		expected:     "return {[\"a\"]=\"b\";[\"c\"]={[\"d\"]=\"e\";};[\"f\"]=0;};\n",
+		expected:     "return {\n\t[\"a\"] = \"b\";\n\t[\"c\"] = {\n\t\t[\"d\"] = \"e\";\n\t};\n\t[\"f\"] = 0;\n};\n",
 		scenarioType: "encode",
 	},
 	{
 		skipDoc:      true,
 		description:  "Scalar str",
 		input:        "str: |\n  foo\n  bar\n",
-		expected:     "return {[\"str\"]=\"foo\\nbar\\n\";};\n",
+		expected:     "return {\n\t[\"str\"] = \"foo\\nbar\\n\";\n};\n",
 		scenarioType: "encode",
 	},
 	{
 		skipDoc:      true,
 		description:  "Scalar null",
 		input:        "x: null\n",
-		expected:     "return {[\"x\"]=nil;};\n",
+		expected:     "return {\n\t[\"x\"] = nil;\n};\n",
 		scenarioType: "encode",
 	},
 	{
 		skipDoc:      true,
 		description:  "Scalar int",
 		input:        "- 1\n- 2\n- 0x10\n- 0o30\n- -999\n",
-		expected:     "return {1,2,0x10,24,-999,};\n",
+		expected:     "return {\n\t1,\n\t2,\n\t0x10,\n\t24,\n\t-999,\n};\n",
 		scenarioType: "encode",
 	},
 	{
 		skipDoc:      true,
 		description:  "Scalar float",
 		input:        "- 1.0\n- 3.14\n- 1e100\n- .Inf\n- .NAN\n",
-		expected:     "return {1.0,3.14,1e100,(1/0),(0/0),};\n",
+		expected:     "return {\n\t1.0,\n\t3.14,\n\t1e100,\n\t(1/0),\n\t(0/0),\n};\n",
 		scenarioType: "encode",
 	},
 }