From f67e4ab57c331309a1b9d64d49eb72c1e6ee21bb Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@vlang.io>
Date: Wed, 10 Feb 2021 10:12:49 +0100
Subject: [PATCH] json: encode_pretty (p. 1)

---
 vlib/json/json_primitives.v | 18 +++++++++++++-----
 vlib/v/gen/c/fn.v           |  9 +++++++--
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/vlib/json/json_primitives.v b/vlib/json/json_primitives.v
index b2fa5a153c..b43dedda1e 100644
--- a/vlib/json/json_primitives.v
+++ b/vlib/json/json_primitives.v
@@ -7,6 +7,7 @@ module json
 #flag @VROOT/thirdparty/cJSON/cJSON.o
 #include "cJSON.h"
 #define js_get(object, key) cJSON_GetObjectItemCaseSensitive((object), (key))
+
 struct C.cJSON {
 	valueint    int
 	valuedouble f32
@@ -23,6 +24,11 @@ pub fn encode(x voidptr) string {
 	return ''
 }
 
+pub fn encode_pretty(x voidptr) string {
+	// compiler implementation
+	return ''
+}
+
 fn decode_int(root &C.cJSON) int {
 	if isnil(root) {
 		return 0
@@ -107,21 +113,17 @@ fn decode_string(root &C.cJSON) string {
 
 fn C.cJSON_IsTrue(voidptr) bool
 
-
 fn C.cJSON_CreateNumber(int) &C.cJSON
 
-
 fn C.cJSON_CreateBool(bool) &C.cJSON
 
-
 fn C.cJSON_CreateString(charptr) &C.cJSON
 
-
 fn C.cJSON_Parse(charptr) &C.cJSON
 
-
 fn C.cJSON_PrintUnformatted(voidptr) byteptr
 
+fn C.cJSON_Print(voidptr) byteptr
 
 fn decode_bool(root &C.cJSON) bool {
 	if isnil(root) {
@@ -178,6 +180,7 @@ fn encode_bool(val bool) &C.cJSON {
 fn encode_string(val string) &C.cJSON {
 	return C.cJSON_CreateString(val.str)
 }
+
 // ///////////////////////
 // user := decode_User(json_parse(js_string_var))
 fn json_parse(s string) &C.cJSON {
@@ -190,6 +193,11 @@ fn json_print(json &C.cJSON) string {
 	return unsafe { tos(s, C.strlen(s)) }
 }
 
+fn json_print_pretty(json &C.cJSON) string {
+	s := C.cJSON_Print(json)
+	return unsafe { tos(s, C.strlen(s)) }
+}
+
 // /  cjson wrappers
 // fn json_array_for_each(val, root &C.cJSON) {
 // #cJSON_ArrayForEach (val ,root)
diff --git a/vlib/v/gen/c/fn.v b/vlib/v/gen/c/fn.v
index fd31253a6f..4a38a477a8 100644
--- a/vlib/v/gen/c/fn.v
+++ b/vlib/v/gen/c/fn.v
@@ -627,6 +627,7 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 	is_print := name in ['print', 'println', 'eprint', 'eprintln']
 	print_method := name
 	is_json_encode := name == 'json.encode'
+	is_json_encode_pretty := name == 'json.encode_pretty'
 	is_json_decode := name == 'json.decode'
 	g.is_json_fn = is_json_encode || is_json_decode
 	mut json_type_str := ''
@@ -635,7 +636,7 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 		json_obj = g.new_tmp_var()
 		mut tmp2 := ''
 		cur_line := g.go_before_stmt(0)
-		if is_json_encode {
+		if is_json_encode || is_json_encode_pretty {
 			g.gen_json_for_type(node.args[0].typ)
 			json_type_str = g.typ(node.args[0].typ)
 			// `json__encode` => `json__encode_User`
@@ -650,7 +651,11 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 			g.call_args(node)
 			g.writeln(');')
 			tmp2 = g.new_tmp_var()
-			g.writeln('string $tmp2 = json__json_print($json_obj);')
+			if is_json_encode {
+				g.writeln('string $tmp2 = json__json_print($json_obj);')
+			} else {
+				g.writeln('string $tmp2 = json__json_print_pretty($json_obj);')
+			}
 		} else {
 			ast_type := node.args[0].expr as ast.Type
 			// `json.decode(User, s)` => json.decode_User(s)