[Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Cyrill Gorcunov]

In the series we implement support for internal taranool types
such as ULL. To be able to do so we implement own serializer
thus the output is simiar to encodings in yaml mode.

Once things settle down we will drop serpent module. I guess
I need to explain why serpent didn't fit: there is no interface
inside serpent to fetch internal tarantool types and adding it
means more work to do than implement an own serializer.

v-2:
 - address issues with achors encoding

issue https://github.com/tarantool/tarantool/issues/4682
branch gorcunov/gh-4682-console-numbers-2

Cyrill Gorcunov (7):
  box/console: console_session_vtab -- use designated initialization
  box/console: use tabs instead of spaces in consolelib
  box/console: rename format to format_yaml
  box/console: rename luaL_yaml_default to serializer_yaml
  box/console: implement lua serializer
  box/console: switch to new lua serializer
  test: extend console lua test

 src/box/CMakeLists.txt            |    1 +
 src/box/lua/console.c             |  111 ++-
 src/box/lua/console.lua           |   80 +--
 src/box/lua/serialize_lua.c       | 1059 +++++++++++++++++++++++++++++
 src/box/lua/serialize_lua.h       |   67 ++
 test/app-tap/console_lua.test.lua |   33 +-
 6 files changed, 1280 insertions(+), 71 deletions(-)
 create mode 100644 src/box/lua/serialize_lua.c
 create mode 100644 src/box/lua/serialize_lua.h

-- 
2.26.2

[Tarantool-patches] [PATCH 1/7] box/console: console_session_vtab -- use designated initialization

[Cyrill Gorcunov]

For better maintainance.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/box/lua/console.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/box/lua/console.c b/src/box/lua/console.c
index b941f50c6..d937d684e 100644
--- a/src/box/lua/console.c
+++ b/src/box/lua/console.c
@@ -582,9 +582,9 @@ tarantool_lua_console_init(struct lua_State *L)
 	 */
 	lua_setfield(L, -2, "formatter");
 	struct session_vtab console_session_vtab = {
-		/* .push = */ console_session_push,
-		/* .fd = */ console_session_fd,
-		/* .sync = */ generic_session_sync,
+		.push	= console_session_push,
+		.fd	= console_session_fd,
+		.sync	= generic_session_sync,
 	};
 	session_vtab_registry[SESSION_TYPE_CONSOLE] = console_session_vtab;
 	session_vtab_registry[SESSION_TYPE_REPL] = console_session_vtab;
-- 
2.26.2

[Tarantool-patches] [PATCH 2/7] box/console: use tabs instead of spaces in consolelib

[Cyrill Gorcunov]

For some reason we're using spaces here to adjust code.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/box/lua/console.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/box/lua/console.c b/src/box/lua/console.c
index d937d684e..d437ff3fe 100644
--- a/src/box/lua/console.c
+++ b/src/box/lua/console.c
@@ -552,11 +552,11 @@ void
 tarantool_lua_console_init(struct lua_State *L)
 {
 	static const struct luaL_Reg consolelib[] = {
-		{"load_history",       lbox_console_load_history},
-		{"save_history",       lbox_console_save_history},
-		{"add_history",        lbox_console_add_history},
-		{"completion_handler", lbox_console_completion_handler},
-		{"format",             lbox_console_format},
+		{"load_history",	lbox_console_load_history},
+		{"save_history",	lbox_console_save_history},
+		{"add_history",		lbox_console_add_history},
+		{"completion_handler",	lbox_console_completion_handler},
+		{"format_yaml",		lbox_console_format_yaml},
 		{NULL, NULL}
 	};
 	luaL_register_module(L, "console", consolelib);
-- 
2.26.2

[Tarantool-patches] [PATCH 3/7] box/console: rename format to format_yaml

[Cyrill Gorcunov]

This will allow us to implement own formatter for
Lua output mode, so to be precise which exactly formatter
is caller lets rename general "format" to "format_yaml".

Part-of #4682

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/box/lua/console.c   | 2 +-
 src/box/lua/console.lua | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/box/lua/console.c b/src/box/lua/console.c
index d437ff3fe..734c0ee47 100644
--- a/src/box/lua/console.c
+++ b/src/box/lua/console.c
@@ -352,7 +352,7 @@ lbox_console_add_history(struct lua_State *L)
  *         parameter.
  */
 static int
-lbox_console_format(struct lua_State *L)
+lbox_console_format_yaml(struct lua_State *L)
 {
 	int arg_count = lua_gettop(L);
 	if (arg_count == 0) {
diff --git a/src/box/lua/console.lua b/src/box/lua/console.lua
index 2add9a79d..5642ca956 100644
--- a/src/box/lua/console.lua
+++ b/src/box/lua/console.lua
@@ -53,7 +53,7 @@ output_handlers["yaml"] = function(status, opts, ...)
     local err
     if status then
         -- serializer can raise an exception
-        status, err = pcall(internal.format, ...)
+        status, err = pcall(internal.format_yaml, ...)
         if status then
             return err
         else
@@ -66,7 +66,7 @@ output_handlers["yaml"] = function(status, opts, ...)
             err = box.NULL
         end
     end
-    return internal.format({ error = err })
+    return internal.format_yaml({ error = err })
 end
 
 -- A map for internal symbols in case if they
-- 
2.26.2

[Tarantool-patches] [PATCH 4/7] box/console: rename luaL_yaml_default to serializer_yaml

[Cyrill Gorcunov]

As we gonna implement lua output serializer lets
rename luaL_yaml_default to serializer_yaml which
will be more general name, for other serializers
we will use same serializer_ prefix.

Part-of #4682

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/box/lua/console.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/box/lua/console.c b/src/box/lua/console.c
index 734c0ee47..c8e0dea58 100644
--- a/src/box/lua/console.c
+++ b/src/box/lua/console.c
@@ -49,7 +49,7 @@
 
 extern char serpent_lua[];
 
-static struct luaL_serializer *luaL_yaml_default = NULL;
+static struct luaL_serializer *serializer_yaml;
 
 /*
  * Completion engine (Mike Paul's).
@@ -369,7 +369,7 @@ lbox_console_format_yaml(struct lua_State *L)
 	}
 	lua_replace(L, 1);
 	lua_settop(L, 1);
-	return lua_yaml_encode(L, luaL_yaml_default, NULL, NULL);
+	return lua_yaml_encode(L, serializer_yaml, NULL, NULL);
 }
 
 int
@@ -404,7 +404,7 @@ console_dump_plain(struct lua_State *L, uint32_t *size)
 {
 	enum output_format fmt = console_get_output_format();
 	if (fmt == OUTPUT_FORMAT_YAML) {
-		int rc = lua_yaml_encode(L, luaL_yaml_default, "!push!",
+		int rc = lua_yaml_encode(L, serializer_yaml, "!push!",
 					 "tag:tarantool.io/push,2018");
 		if (rc == 2) {
 			/*
@@ -566,11 +566,11 @@ tarantool_lua_console_init(struct lua_State *L)
 	lua_pushcclosure(L, lbox_console_readline, 1);
 	lua_setfield(L, -2, "readline");
 
-	luaL_yaml_default = lua_yaml_new_serializer(L);
-	luaL_yaml_default->encode_invalid_numbers = 1;
-	luaL_yaml_default->encode_load_metatables = 1;
-	luaL_yaml_default->encode_use_tostring = 1;
-	luaL_yaml_default->encode_invalid_as_nil = 1;
+	serializer_yaml = lua_yaml_new_serializer(L);
+	serializer_yaml->encode_invalid_numbers = 1;
+	serializer_yaml->encode_load_metatables = 1;
+	serializer_yaml->encode_use_tostring = 1;
+	serializer_yaml->encode_invalid_as_nil = 1;
 	/*
 	 * Hold reference to the formatter in module local
 	 * variable.
-- 
2.26.2

[Tarantool-patches] [PATCH 5/7] box/console: implement lua serializer

[Cyrill Gorcunov]

When we print output in console (especially in Lua mode)
it is impossible to find out the internal type an entry
represents, which in turn leads to inability to encode
"ULL" entries properly. Moreover we always introduce new
types (for example decimals, uuids) and the serpent module
we currently use for encodings has no clue about them.

Thus lets implement own lua serializer similarly to the
yaml encoder. This allows us to properly detect every
field and encode it accordingly.

Part-of #4682

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/box/CMakeLists.txt      |    1 +
 src/box/lua/serialize_lua.c | 1059 +++++++++++++++++++++++++++++++++++
 src/box/lua/serialize_lua.h |   67 +++
 3 files changed, 1127 insertions(+)
 create mode 100644 src/box/lua/serialize_lua.c
 create mode 100644 src/box/lua/serialize_lua.h

diff --git a/src/box/CMakeLists.txt b/src/box/CMakeLists.txt
index c931ecdfe..08ffe7177 100644
--- a/src/box/CMakeLists.txt
+++ b/src/box/CMakeLists.txt
@@ -148,6 +148,7 @@ add_library(box STATIC
     lua/call.c
     lua/cfg.cc
     lua/console.c
+    lua/serialize_lua.c
     lua/tuple.c
     lua/slab.c
     lua/index.c
diff --git a/src/box/lua/serialize_lua.c b/src/box/lua/serialize_lua.c
new file mode 100644
index 000000000..caa08a60f
--- /dev/null
+++ b/src/box/lua/serialize_lua.c
@@ -0,0 +1,1059 @@
+/*
+ * Copyright 2010-2020, Tarantool AUTHORS, please see AUTHORS file.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ *    copyright notice, this list of conditions and the
+ *    following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <ctype.h>
+#include <lua.h>
+
+#include "trivia/util.h"
+#include "lua/utils.h"
+#include "say.h"
+
+#include "lib/core/decimal.h"
+#include "mp_extension_types.h"
+#include "uuid/tt_uuid.h"
+
+#include "lua-yaml/b64.h"
+
+#include "serialize_lua.h"
+
+#if 0
+# define SERIALIZER_TRACE
+#endif
+
+/* Serializer for Lua output mode */
+static struct luaL_serializer *serializer_lua;
+
+enum {
+	NODE_NONE_BIT		= 0,
+	NODE_ROOT_BIT		= 1,
+	NODE_RAW_BIT		= 2,
+	NODE_LVALUE_BIT		= 3,
+	NODE_RVALUE_BIT		= 4,
+	NODE_MAP_KEY_BIT	= 5,
+	NODE_MAP_VALUE_BIT	= 6,
+	NODE_EMBRACE_BIT	= 7,
+	NODE_QUOTE_BIT		= 8,
+
+	NODE_MAX
+};
+
+enum {
+	NODE_NONE		= (1u << NODE_NONE_BIT),
+	NODE_ROOT		= (1u << NODE_ROOT_BIT),
+	NODE_RAW		= (1u << NODE_RAW_BIT),
+	NODE_LVALUE		= (1u << NODE_LVALUE_BIT),
+	NODE_RVALUE		= (1u << NODE_RVALUE_BIT),
+	NODE_MAP_KEY		= (1u << NODE_MAP_KEY_BIT),
+	NODE_MAP_VALUE		= (1u << NODE_MAP_VALUE_BIT),
+	NODE_EMBRACE		= (1u << NODE_EMBRACE_BIT),
+	NODE_QUOTE		= (1u << NODE_QUOTE_BIT),
+};
+
+struct node {
+	/** Link with previous node or key */
+	union {
+		struct node *prev;
+		struct node *key;
+	};
+
+	/** The field data we're paring */
+	struct luaL_field field;
+
+	/** Node mask NODE_x */
+	int mask;
+
+	/** Node index in a map */
+	int index;
+};
+
+/**
+ * Serializer context.
+ */
+struct lua_dumper {
+	/** Lua state to fetch data from */
+	lua_State *L;
+
+	/** General configure options */
+	struct luaL_serializer *cfg;
+
+	/** Lua dumper options */
+	lua_dumper_opts_t *opts;
+
+	/** Output state */
+	lua_State *outputL;
+	/** Output buffer */
+	luaL_Buffer luabuf;
+
+	/** Anchors for self references */
+	int anchortable_index;
+	unsigned int anchor_number;
+
+	/** Error message buffer */
+	char err_msg[256];
+	int err;
+
+	/** Indentation buffer */
+	char indent_buf[256];
+
+	/** Output suffix */
+	char suffix_buf[32];
+	int suffix_len;
+
+	/** Previous node mask */
+	int prev_nd_mask;
+
+	/** Ignore indents */
+	bool noindent;
+};
+
+#ifdef SERIALIZER_TRACE
+
+#define __gen_mp_name(__v) [__v] = # __v
+static const char *mp_type_names[] = {
+	__gen_mp_name(MP_NIL),
+	__gen_mp_name(MP_UINT),
+	__gen_mp_name(MP_INT),
+	__gen_mp_name(MP_STR),
+	__gen_mp_name(MP_BIN),
+	__gen_mp_name(MP_ARRAY),
+	__gen_mp_name(MP_MAP),
+	__gen_mp_name(MP_BOOL),
+	__gen_mp_name(MP_FLOAT),
+	__gen_mp_name(MP_DOUBLE),
+	__gen_mp_name(MP_EXT),
+};
+
+static const char *mp_ext_type_names[] = {
+	__gen_mp_name(MP_DECIMAL),
+	__gen_mp_name(MP_UUID),
+	__gen_mp_name(MP_ERROR),
+};
+#undef __gen_mp_name
+
+#define __gen_nd_name(__v) [__v ##_BIT] = # __v
+static const char *nd_type_names[] = {
+	__gen_nd_name(NODE_NONE),
+	__gen_nd_name(NODE_ROOT),
+	__gen_nd_name(NODE_RAW),
+	__gen_nd_name(NODE_LVALUE),
+	__gen_nd_name(NODE_RVALUE),
+	__gen_nd_name(NODE_MAP_KEY),
+	__gen_nd_name(NODE_MAP_VALUE),
+	__gen_nd_name(NODE_EMBRACE),
+	__gen_nd_name(NODE_QUOTE),
+};
+#undef __gen_nd_name
+
+static char *
+trace_nd_mask_str(unsigned int nd_mask)
+{
+	static char mask_str[256];
+	int left = sizeof(mask_str);
+	int pos = 0;
+
+	for (int i = 0; i < NODE_MAX; i++) {
+		if (!(nd_mask & (1u << i)))
+			continue;
+
+		int nd_len = strlen(nd_type_names[i]);
+		if (left >= nd_len + 1) {
+			strcpy(&mask_str[pos], nd_type_names[i]);
+			pos += nd_len;
+			mask_str[pos++] = '|';
+			left = sizeof(mask_str) - pos;
+		}
+	}
+
+	if (pos != 0)
+		mask_str[--pos] = '\0';
+	else
+		strcpy(mask_str, "UNKNOWN");
+
+	return mask_str;
+}
+
+static void
+trace_node(struct lua_dumper *d)
+{
+	int ltype = lua_type(d->L, -1);
+	say_info("serializer-trace: node    : lua type %d -> %s",
+		 ltype, lua_typename(d->L, ltype));
+
+	if (d->err != 0)
+		return;
+
+	char mp_type[64], *type_str = mp_type;
+	int top = lua_gettop(d->L);
+	struct luaL_field field;
+
+	memset(&field, 0, sizeof(field));
+	luaL_checkfield(d->L, d->cfg, lua_gettop(d->L), &field);
+
+	if (field.type < lengthof(mp_type_names)) {
+		if (field.type == MP_EXT) {
+			size_t max_ext = lengthof(mp_ext_type_names);
+			snprintf(mp_type, sizeof(mp_type), "%s/%s",
+				 mp_type_names[field.type],
+				 field.ext_type < max_ext ?
+				 mp_ext_type_names[field.ext_type] :
+				 "UNKNOWN");
+		} else {
+			type_str = (char *)mp_type_names[field.type];
+		}
+	} else {
+		type_str = "UNKNOWN";
+	}
+
+	memset(&field, 0, sizeof(field));
+
+	luaL_checkfield(d->L, d->cfg, top, &field);
+	say_info("serializer-trace: node    :\tfield type %s (%d)",
+		 type_str, field.type);
+}
+
+static char *
+trace_string(const char *src, size_t len)
+{
+	static char buf[128];
+	size_t pos = 0;
+
+	if (len > sizeof(buf)-1)
+		len = sizeof(buf)-1;
+
+	while (pos < len) {
+		if (src[pos] == '\n') {
+			buf[pos++] = '\\';
+			buf[pos++] = 'n';
+			continue;
+		}
+		buf[pos] = src[pos];
+		pos++;
+	}
+	buf[pos] = '\0';
+	return buf;
+}
+
+static void
+trace_emit(struct lua_dumper *d, int nd_mask, int indent,
+	   const char *str, size_t len)
+{
+	if (d->suffix_len) {
+		say_info("serializer-trace: emit-sfx: \"%s\"",
+			 trace_string(d->suffix_buf,
+				      d->suffix_len));
+	}
+
+	static_assert(NODE_MAX < sizeof(int) * 8,
+		      "NODE_MAX is too big");
+
+	char *names = trace_nd_mask_str(nd_mask);
+
+	say_info("serializer-trace: emit    : type %s (0x%x) "
+		 "indent %d val \"%s\" len %zu",
+		 names, nd_mask, indent,
+		 trace_string(str, len), len);
+}
+
+static void
+trace_anchor(const char *s, bool alias)
+{
+	say_info("serializer-trace: anchor  : alias %d name %s",
+		 alias, s);
+}
+
+#else /* SERIALIZER_TRACE */
+
+static void
+trace_node(struct lua_dumper *d)
+{
+	(void)d;
+}
+
+static void
+trace_emit(struct lua_dumper *d, int nd_mask, int indent,
+	   const char *str, size_t len)
+{
+	(void)d;
+	(void)nd_mask;
+	(void)indent;
+	(void)str;
+	(void)len;
+}
+
+static void
+trace_anchor(const char *s, bool alias)
+{
+	(void)s;
+	(void)alias;
+}
+
+#endif /* SERIALIZER_TRACE */
+
+static const char *lua_keywords[] = {
+	"and", "break", "do", "else",
+	"elseif", "end", "false", "for",
+	"function", "if", "in", "local",
+	"nil", "not", "or", "repeat",
+	"return", "then", "true", "until",
+	"while", "and",
+};
+
+static int
+dump_node(struct lua_dumper *d, struct node *nd, int indent);
+
+static int
+emit_node(struct lua_dumper *d, struct node *nd, int indent,
+	  const char *str, size_t len);
+
+/**
+ * Generate anchor numbers for self references.
+ */
+static const char *
+get_lua_anchor(struct lua_dumper *d)
+{
+	const char *s = "";
+
+	lua_pushvalue(d->L, -1);
+	lua_rawget(d->L, d->anchortable_index);
+	if (!lua_toboolean(d->L, -1)) {
+		lua_pop(d->L, 1);
+		return NULL;
+	}
+
+	if (lua_isboolean(d->L, -1)) {
+		/*
+		 * This element is referenced more
+		 * than once but has not been named.
+		 */
+		char buf[32];
+		snprintf(buf, sizeof(buf), "%u", d->anchor_number++);
+		lua_pop(d->L, 1);
+		lua_pushvalue(d->L, -1);
+		lua_pushstring(d->L, buf);
+		s = lua_tostring(d->L, -1);
+		lua_rawset(d->L, d->anchortable_index);
+		trace_anchor(s, false);
+	} else {
+		/*
+		 * An aliased element.
+		 *
+		 * FIXME: Need an example to use.
+		 *
+		 * const char *str = lua_tostring(d->L, -1);
+		 */
+		const char *str = lua_tostring(d->L, -1);
+		trace_anchor(str, true);
+		lua_pop(d->L, 1);
+	}
+	return s;
+}
+
+static void
+suffix_append(struct lua_dumper *d, const char *str, int len)
+{
+	int left = (int)sizeof(d->suffix_buf) - d->suffix_len;
+	if (len < left) {
+		memcpy(&d->suffix_buf[d->suffix_len], str, len);
+		d->suffix_len += len;
+		d->suffix_buf[d->suffix_len] = '\0';
+	}
+}
+
+static inline void
+suffix_reset(struct lua_dumper *d)
+{
+	d->suffix_len = 0;
+}
+
+static void
+suffix_flush(struct lua_dumper *d)
+{
+	if (d->suffix_len) {
+		luaL_addlstring(&d->luabuf, d->suffix_buf, d->suffix_len);
+		suffix_reset(d);
+	}
+}
+
+static int
+gen_indent(struct lua_dumper *d, int indent)
+{
+	static_assert(sizeof(d->indent_buf) > 0,
+		      "indent buffer is too small");
+
+	if (indent > 0 && d->opts->block_mode && !d->noindent) {
+		snprintf(d->indent_buf, sizeof(d->indent_buf),
+			 "%*s", indent, "");
+		size_t len = strlen(d->indent_buf);
+		d->indent_buf[len] = '\0';
+		return len;
+	}
+
+	return 0;
+}
+
+static void
+emit_hex_char(struct lua_dumper *d, unsigned char c)
+{
+	luaL_addchar(&d->luabuf, '\\');
+	luaL_addchar(&d->luabuf, 'x');
+
+#define __emit_hex(v)						\
+	do {							\
+		if (v <= 9)				\
+			luaL_addchar(&d->luabuf, '0' + v);	\
+		else						\
+			luaL_addchar(&d->luabuf, v - 10 + 'a');	\
+	} while (0)
+
+	__emit_hex((c >> 4));
+	__emit_hex((c & 0xf));
+#undef __emit_hex
+}
+
+/**
+ * Emit the string with escapes if needed.
+ *
+ * FIXME: Probably should to revisit and make
+ * sure we've not miss anything here (octal numbers
+ * are missed for now and etc...).
+ */
+static void
+emit_string(struct lua_dumper *d, const char *str, size_t len)
+{
+	for (size_t i = 0; i < len; i++) {
+		if ((str[i]) == '\'' || str[i] == '\"') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, str[i]);
+		} else if (str[i] == '\0') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, '0');
+		} else if (str[i] == '\a') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, 'a');
+		} else if (str[i] == '\b') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, 'b');
+		} else if (str[i] == '\f') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, 'f');
+		} else if (str[i] == '\v') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, 'v');
+		} else if (str[i] == '\r') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, 'r');
+		} else if (str[i] == '\n') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, 'n');
+		} else if (str[i] == '\t') {
+			luaL_addchar(&d->luabuf, '\\');
+			luaL_addchar(&d->luabuf, 't');
+		} else if (str[i] == '\xef') {
+			if (i < len-1 && i < len-2 &&
+			    str[i+1] == '\xbb' &&
+			    str[i+2] == '\xbf') {
+				emit_hex_char(d, 0xef);
+				emit_hex_char(d, 0xbb);
+				emit_hex_char(d, 0xbf);
+			} else {
+				emit_hex_char(d, str[i]);
+			}
+		} else if (isprint(str[i]) == 0) {
+			emit_hex_char(d, str[i]);
+		} else {
+			luaL_addchar(&d->luabuf, str[i]);
+		}
+	}
+}
+
+/**
+ * Emit value into output buffer.
+ */
+static void
+emit_value(struct lua_dumper *d, struct node *nd,
+	   int indent, const char *str, size_t len)
+{
+	trace_emit(d, nd->mask, indent, str, len);
+
+	/*
+	 * There might be previous closing symbols
+	 * in the suffix queue. Since we're about
+	 * to emit new values don't forget to prepend
+	 * ending ones.
+	 */
+	suffix_flush(d);
+
+	luaL_addlstring(&d->luabuf, d->indent_buf,
+			gen_indent(d, indent));
+
+	if (nd->mask & NODE_EMBRACE)
+		luaL_addlstring(&d->luabuf, "[", 1);
+	if (nd->mask & NODE_QUOTE)
+		luaL_addlstring(&d->luabuf, "\"", 1);
+
+	if (nd->field.type == MP_STR) {
+		emit_string(d, str, len);
+	} else {
+		luaL_addlstring(&d->luabuf, str, len);
+	}
+
+	if (nd->mask & NODE_QUOTE)
+		luaL_addlstring(&d->luabuf, "\"", 1);
+	if (nd->mask & NODE_EMBRACE)
+		luaL_addlstring(&d->luabuf, "]", 1);
+}
+
+/**
+ * Emit a raw string into output.
+ */
+static void
+emit_raw_value(struct lua_dumper *d, int indent,
+	       const char *str, size_t len)
+{
+	struct node node = {
+		.mask = NODE_RAW,
+	};
+
+	emit_value(d, &node, indent, str, len);
+}
+
+/**
+ * Put an opening brace into the output.
+ */
+static int
+emit_brace_open(struct lua_dumper *d, int indent)
+{
+	if (d->opts->block_mode) {
+		int _indent;
+		if (d->noindent)
+			_indent = 0;
+		else
+			_indent = indent;
+
+		emit_raw_value(d, _indent, "{\n", 2);
+		if (d->noindent && d->prev_nd_mask & NODE_LVALUE)
+			d->noindent = false;
+	} else {
+		emit_raw_value(d, indent, "{", 1);
+	}
+
+	return indent + d->opts->indent_lvl;
+}
+
+/**
+ * Put a closing brace into the output.
+ */
+static void
+emit_brace_close(struct lua_dumper *d, int indent)
+{
+	suffix_reset(d);
+
+	if (d->opts->block_mode)
+		emit_raw_value(d, 0, "\n", 1);
+
+	indent -= d->opts->indent_lvl;
+	emit_raw_value(d, indent, "}", 1);
+
+	if (d->opts->block_mode)
+		suffix_append(d, ",\n", 2);
+	else
+		suffix_append(d, ", ", 2);
+}
+
+/**
+ * Handling self references. It is yaml specific
+ * and I don't think we might even need it. Still
+ * better to get noticed if something went in
+ * an unexpected way.
+ */
+static bool
+emit_anchor(struct lua_dumper *d, struct node *nd, int indent)
+{
+	const char *anchor = get_lua_anchor(d);
+	if (anchor && !*anchor) {
+		emit_node(d, nd, indent, "nil", 3);
+		return true;
+	}
+	return false;
+}
+
+/**
+ * Dump an array entry.
+ */
+static void
+dump_array(struct lua_dumper *d, struct node *nd, int indent)
+{
+	indent = emit_brace_open(d, indent);
+	if (emit_anchor(d, nd, indent))
+		goto out;
+
+	for (int i = 0; i < (int)nd->field.size; i++) {
+		lua_rawgeti(d->L, -1, i + 1);
+		struct node node = {
+			.prev = nd,
+			.mask = NODE_RVALUE,
+		};
+		dump_node(d, &node, indent);
+		lua_pop(d->L, 1);
+	}
+out:
+	emit_brace_close(d, indent);
+}
+
+/**
+ * Dump a map entry.
+ */
+static void
+dump_table(struct lua_dumper *d, struct node *nd, int indent)
+{
+	int index = 0;
+
+	indent = emit_brace_open(d, indent);
+	if (emit_anchor(d, nd, indent))
+		goto out;
+
+	/*
+	 * In sake of speed we don't sort
+	 * keys but provide them as is. Thus
+	 * simply walk over keys and their
+	 * values.
+	 */
+	lua_pushnil(d->L);
+	while (lua_next(d->L, -2)) {
+		lua_pushvalue(d->L, -2);
+		struct node node_key = {
+			.prev	= nd,
+			.mask	= NODE_LVALUE | NODE_MAP_KEY,
+			.index	= index++,
+		};
+		dump_node(d, &node_key, indent);
+		lua_pop(d->L, 1);
+
+		struct node node_val = {
+			.key	= &node_key,
+			.mask	= NODE_RVALUE | NODE_MAP_VALUE,
+		};
+		dump_node(d, &node_val, indent);
+		lua_pop(d->L, 1);
+	}
+out:
+	emit_brace_close(d, indent);
+}
+
+/**
+ * Figure out if we need to decorate a map key
+ * with square braces and quotes or can leave
+ * it as a plain value.
+ */
+static void
+decorate_key(struct node *nd, const char *str, size_t len)
+{
+	assert(nd->field.type == MP_STR);
+	assert(nd->mask & NODE_MAP_KEY);
+
+	/*
+	 * We might need to put string keys
+	 * to quotes and embrace them due to
+	 * limitation of how to declare map keys
+	 * (the output from serializer should be
+	 * parsable if pasted back to a console).
+	 */
+	for (size_t i = 0; i < lengthof(lua_keywords); i++) {
+		const char *k = lua_keywords[i];
+		if (strcmp(k, str) == 0) {
+			nd->mask |= NODE_EMBRACE | NODE_QUOTE;
+			return;
+		}
+	}
+
+	/*
+	 * Plain keys may be alphanumerics with underscopes.
+	 */
+	for (size_t i = 0; i < len; i++) {
+		if (isalnum(str[i]) != 0 || str[i] == '_')
+			continue;
+		nd->mask |= NODE_EMBRACE | NODE_QUOTE;
+		return;
+	}
+
+	nd->mask &= ~NODE_QUOTE;
+}
+
+static int
+emit_node(struct lua_dumper *d, struct node *nd, int indent,
+	  const char *str, size_t len)
+{
+	struct luaL_field *field = &nd->field;
+
+	if (str == NULL) {
+		d->prev_nd_mask = nd->mask;
+		return 0;
+	}
+
+	if (nd->mask & NODE_MAP_KEY) {
+		/*
+		 * In case if key is integer and matching
+		 * the current position in the table we
+		 * can simply skip it and print value only.
+		 */
+		if (nd->field.type == MP_INT ||
+		    nd->field.type == MP_UINT) {
+			if (nd->index == (int)field->ival) {
+				d->noindent = false;
+				return 0;
+			} else {
+				nd->mask |= NODE_EMBRACE;
+			}
+		} else if (nd->field.type == MP_STR) {
+			decorate_key(nd, str, len);
+		}
+	}
+
+	d->prev_nd_mask = nd->mask;
+	emit_value(d, nd, indent, str, len);
+
+	/*
+	 * In sake of speed we do not lookahead
+	 * for next lua nodes, instead just remember
+	 * closing symbol in suffix buffer which we
+	 * will flush on next emit.
+	 */
+	if (nd->mask & NODE_RVALUE) {
+		if (d->opts->block_mode)
+			suffix_append(d, ",\n", 2);
+		else
+			suffix_append(d, ", ", 2);
+		d->noindent = false;
+	} else if (nd->mask & NODE_LVALUE) {
+		suffix_append(d, " = ", 3);
+		d->noindent = true;
+	}
+
+	return 0;
+}
+
+/**
+ * Dump a node.
+ */
+static int
+dump_node(struct lua_dumper *d, struct node *nd, int indent)
+{
+	struct luaL_field *field = &nd->field;
+	char buf[FPCONV_G_FMT_BUFSIZE];
+	int ltype = lua_type(d->L, -1);
+	const char *str = NULL;
+	size_t len = 0;
+
+	trace_node(d);
+
+	/*
+	 * We can exit early if an error
+	 * already happened, no need to
+	 * continue parsing.
+	 */
+	if (d->err != 0)
+		return -1;
+
+	memset(field, 0, sizeof(*field));
+	luaL_checkfield(d->L, d->cfg, lua_gettop(d->L), field);
+
+	switch (field->type) {
+	case MP_NIL:
+		if (ltype == LUA_TNIL) {
+			static const char str_nil[] = "nil";
+			str = str_nil;
+			len = strlen(str_nil);
+		} else {
+			static const char str_null[] = "box.NULL";
+			str = str_null;
+			len = strlen(str_null);
+		}
+		break;
+	case MP_UINT:
+		snprintf(buf, sizeof(buf), "%" PRIu64, field->ival);
+		len = strlen(buf);
+		str = buf;
+		break;
+	case MP_INT:
+		snprintf(buf, sizeof(buf), "%" PRIi64, field->ival);
+		len = strlen(buf);
+		str = buf;
+		break;
+	case MP_STR:
+		nd->mask |= NODE_QUOTE;
+		str = lua_tolstring(d->L, -1, &len);
+		if (utf8_check_printable(str, len) == 1)
+			break;
+		/* fallthrough */
+	case MP_BIN:
+		nd->mask |= NODE_QUOTE;
+		tobase64(d->L, -1);
+		str = lua_tolstring(d->L, -1, &len);
+		lua_pop(d->L, 1);
+		break;
+	case MP_ARRAY:
+		dump_array(d, nd, indent);
+		break;
+	case MP_MAP:
+		dump_table(d, nd, indent);
+		break;
+	case MP_BOOL:
+		if (field->bval) {
+			static const char str_true[] = "true";
+			len = strlen(str_true);
+			str = str_true;
+		} else {
+			static const char str_false[] = "false";
+			len = strlen(str_false);
+			str = str_false;
+		}
+		break;
+	case MP_FLOAT:
+		fpconv_g_fmt(buf, field->fval,
+			     d->cfg->encode_number_precision);
+		len = strlen(buf);
+		str = buf;
+		break;
+	case MP_DOUBLE:
+		fpconv_g_fmt(buf, field->dval,
+			     d->cfg->encode_number_precision);
+		len = strlen(buf);
+		str = buf;
+		break;
+	case MP_EXT:
+		switch (field->ext_type) {
+		case MP_DECIMAL:
+			nd->mask |= NODE_QUOTE;
+			str = decimal_to_string(field->decval);
+			len = strlen(str);
+			break;
+		case MP_UUID:
+			nd->mask |= NODE_QUOTE;
+			str = tt_uuid_str(field->uuidval);
+			len = UUID_STR_LEN;
+			break;
+		default:
+			d->err = EINVAL;
+			snprintf(d->err_msg, sizeof(d->err_msg),
+				 "serializer: Unknown field MP_EXT:%d type",
+				 field->ext_type);
+			len = strlen(d->err_msg);
+			return -1;
+		}
+		break;
+	default:
+		d->err = EINVAL;
+		snprintf(d->err_msg, sizeof(d->err_msg),
+			 "serializer: Unknown field %d type",
+			 field->type);
+		len = strlen(d->err_msg);
+		return -1;
+	}
+
+	return emit_node(d, nd, indent, str, len);
+}
+
+/**
+ * Find references to tables, we use it
+ * to find self references in tables.
+ */
+static void
+find_references(struct lua_dumper *d)
+{
+	int newval;
+
+	if (lua_type(d->L, -1) != LUA_TTABLE)
+		return;
+
+	/* Copy of a table for self refs */
+	lua_pushvalue(d->L, -1);
+	lua_rawget(d->L, d->anchortable_index);
+	if (lua_isnil(d->L, -1))
+		newval = 0;
+	else if (!lua_toboolean(d->L, -1))
+		newval = 1;
+	else
+		newval = -1;
+	lua_pop(d->L, 1);
+
+	if (newval != -1) {
+		lua_pushvalue(d->L, -1);
+		lua_pushboolean(d->L, newval);
+		lua_rawset(d->L, d->anchortable_index);
+	}
+
+	if (newval != 0)
+		return;
+
+	/*
+	 * Other values and keys in the table
+	 */
+	lua_pushnil(d->L);
+	while (lua_next(d->L, -2) != 0) {
+		find_references(d);
+		lua_pop(d->L, 1);
+		find_references(d);
+	}
+}
+
+/**
+ * Dump recursively from the root node.
+ */
+static int
+dump_root(struct lua_dumper *d)
+{
+	struct node nd = {
+		.mask = NODE_ROOT,
+	};
+	int ret;
+
+	luaL_checkfield(d->L, d->cfg, lua_gettop(d->L), &nd.field);
+
+	if (nd.field.type != MP_ARRAY || nd.field.size != 1) {
+		d->err = EINVAL;
+		snprintf(d->err_msg, sizeof(d->err_msg),
+			 "serializer: unexpected data "
+			 "(nd.field.size %d nd.field.type %d)",
+			 nd.field.size, nd.field.type);
+		return -1;
+	}
+
+	/*
+	 * We don't need to show the newly generated
+	 * table, instead dump the nested one which
+	 * is the real value.
+	 */
+	lua_rawgeti(d->L, -1, 1);
+	ret = dump_node(d, &nd, 0);
+	lua_pop(d->L, 1);
+
+	return (ret || d->err) ? -1 : 0;
+}
+
+/**
+ * Encode data to Lua compatible form.
+ */
+int
+lua_encode(lua_State *L, struct luaL_serializer *serializer,
+	   lua_dumper_opts_t *opts)
+{
+	struct lua_dumper dumper = {
+		.L	= L,
+		.cfg	= serializer,
+		.outputL= luaT_newthread(L),
+		.opts	= opts,
+	};
+
+	if (!dumper.outputL)
+		return luaL_error(L, "serializer: No free memory");
+
+	luaL_buffinit(dumper.outputL, &dumper.luabuf);
+
+	lua_newtable(L);
+
+	dumper.anchortable_index = lua_gettop(L);
+	dumper.anchor_number = 0;
+
+	/* Push copy of arg we're processing */
+	lua_pushvalue(L, 1);
+	find_references(&dumper);
+
+	if (dump_root(&dumper) != 0)
+		goto out;
+
+	/* Pop copied arg and anchor table */
+	lua_pop(L, 2);
+
+	luaL_pushresult(&dumper.luabuf);
+
+	/* Move buffer to original thread */
+	lua_xmove(dumper.outputL, L, 1);
+	return 1;
+
+out:
+	errno = dumper.err;
+	lua_pushnil(L);
+	lua_pushstring(L, dumper.err_msg);
+	return 2;
+}
+
+/**
+ * Parse serializer options.
+ */
+void
+lua_parse_opts(lua_State *L, lua_dumper_opts_t *opts)
+{
+	if (lua_gettop(L) < 2 || lua_type(L, -2) != LUA_TTABLE)
+		luaL_error(L, "serializer: Wrong options format");
+
+	memset(opts, 0, sizeof(*opts));
+
+	lua_getfield(L, -2, "block");
+	if (lua_isboolean(L, -1))
+		opts->block_mode = lua_toboolean(L, -1);
+	lua_pop(L, 1);
+
+	lua_getfield(L, -2, "indent");
+	if (lua_isnumber(L, -1))
+		opts->indent_lvl = (int)lua_tonumber(L, -1);
+	lua_pop(L, 1);
+}
+
+/**
+ * Initialize Lua serializer.
+ */
+void
+lua_serializer_init(struct lua_State *L)
+{
+	/*
+	 * We don't export it as a module
+	 * for a while, so the library
+	 * is kept empty.
+	 */
+	static const luaL_Reg lualib[] = {
+		{
+			.name = NULL,
+		},
+	};
+
+	serializer_lua = luaL_newserializer(L, NULL, lualib);
+	serializer_lua->has_compact		= 1;
+	serializer_lua->encode_invalid_numbers	= 1;
+	serializer_lua->encode_load_metatables	= 1;
+	serializer_lua->encode_use_tostring	= 1;
+	serializer_lua->encode_invalid_as_nil	= 1;
+
+	/*
+	 * Keep a reference to this module so it
+	 * won't be unloaded.
+	 */
+	lua_setfield(L, -2, "formatter_lua");
+}
diff --git a/src/box/lua/serialize_lua.h b/src/box/lua/serialize_lua.h
new file mode 100644
index 000000000..923e13be9
--- /dev/null
+++ b/src/box/lua/serialize_lua.h
@@ -0,0 +1,67 @@
+#ifndef INCLUDES_TARANTOOL_SERLIALIZE_LUA_H
+#define INCLUDES_TARANTOOL_SERLIALIZE_LUA_H
+
+/*
+ * Copyright 2010-2020, Tarantool AUTHORS, please see AUTHORS file.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ *    copyright notice, this list of conditions and the
+ *    following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(__cplusplus)
+extern "C" {
+#endif /* defined(__cplusplus) */
+
+struct luaL_serializer;
+struct lua_State;
+
+/**
+ * Serializer options.
+ */
+typedef struct {
+	/** Number of indentation spaces. */
+	unsigned int indent_lvl;
+
+	/** Block mode output. */
+	bool block_mode;
+} lua_dumper_opts_t;
+
+void
+lua_serializer_init(struct lua_State *L);
+
+int
+lua_encode(lua_State *L, struct luaL_serializer *serializer,
+	   lua_dumper_opts_t *opts);
+
+void
+lua_parse_opts(lua_State *L, lua_dumper_opts_t *opts);
+
+#if defined(__cplusplus)
+} /* extern "C" */
+#endif /* defined(__cplusplus) */
+
+#endif /* INCLUDES_TARANTOOL_SERLIALIZE_LUA_H */
-- 
2.26.2

[Tarantool-patches] [PATCH 6/7] box/console: switch to new lua serializer

[Cyrill Gorcunov]

I do not drop the serpent module for a while
since I need to make sure that everything work
as expected as we've not break backward compatibility
significantly (though we didn't claim the lua mode
output is stable enough).

Fixes #4682

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/box/lua/console.c             | 77 +++++++++++++++++++++++++++++++
 src/box/lua/console.lua           | 76 +++++++++++++-----------------
 test/app-tap/console_lua.test.lua | 18 ++++----
 3 files changed, 119 insertions(+), 52 deletions(-)

diff --git a/src/box/lua/console.c b/src/box/lua/console.c
index c8e0dea58..d1bf7949c 100644
--- a/src/box/lua/console.c
+++ b/src/box/lua/console.c
@@ -39,6 +39,7 @@
 #include "coio.h"
 #include "lua/msgpack.h"
 #include "lua-yaml/lyaml.h"
+#include "serialize_lua.h"
 #include <lua.h>
 #include <lauxlib.h>
 #include <lualib.h>
@@ -50,6 +51,7 @@
 extern char serpent_lua[];
 
 static struct luaL_serializer *serializer_yaml;
+static struct luaL_serializer *serializer_lua;
 
 /*
  * Completion engine (Mike Paul's).
@@ -68,6 +70,54 @@ lua_rl_complete(lua_State *L, const char *text, int start, int end);
  */
 static struct lua_State *readline_L;
 
+/**
+ * Encode Lua object into Lua form.
+ */
+static int
+lbox_console_format_lua(struct lua_State *L)
+{
+	lua_dumper_opts_t opts;
+	int arg_count;
+
+	/* Parse options and remove them */
+	lua_parse_opts(L, &opts);
+	lua_remove(L, 1);
+
+	arg_count = lua_gettop(L);
+
+	/* If nothing to process just exit early */
+	if (arg_count == 0)
+		return 0;
+
+	/*
+	 * When processing arguments we might
+	 * need to modify reference (for example
+	 * when __index references to object itself)
+	 * thus make a copy of incoming data.
+	 *
+	 * Note that in yaml there is no map for
+	 * Lua's "nil" value so for yaml encoder
+	 * we do
+	 *
+	 * if (lua_isnil(L, i + 1))
+	 *     luaL_pushnull(L);
+	 * else
+	 *     lua_pushvalue(L, i + 1);
+	 *
+	 *
+	 * For lua mode we have to preserve "nil".
+	 */
+	lua_createtable(L, arg_count, 0);
+	for (int i = 0; i < arg_count; ++i) {
+		lua_pushvalue(L, i + 1);
+		lua_rawseti(L, -2, i + 1);
+	}
+
+	lua_replace(L, 1);
+	lua_settop(L, 1);
+	return lua_encode(L, serializer_lua, &opts);
+}
+
 /*
  * console_completion_handler()
  * Called by readline to collect plausible completions;
@@ -557,6 +607,7 @@ tarantool_lua_console_init(struct lua_State *L)
 		{"add_history",		lbox_console_add_history},
 		{"completion_handler",	lbox_console_completion_handler},
 		{"format_yaml",		lbox_console_format_yaml},
+		{"format_lua",		lbox_console_format_lua},
 		{NULL, NULL}
 	};
 	luaL_register_module(L, "console", consolelib);
@@ -581,6 +632,32 @@ tarantool_lua_console_init(struct lua_State *L)
 	 * load_history work the same way.
 	 */
 	lua_setfield(L, -2, "formatter");
+
+	/*
+	 * We don't export it as a module
+	 * for a while, so the library
+	 * is kept empty.
+	 */
+	static const luaL_Reg lualib[] = {
+		{ },
+	};
+
+	serializer_lua = luaL_newserializer(L, NULL, lualib);
+	serializer_lua->has_compact		= 1;
+	serializer_lua->encode_invalid_numbers	= 1;
+	serializer_lua->encode_load_metatables	= 1;
+	serializer_lua->encode_use_tostring	= 1;
+	serializer_lua->encode_invalid_as_nil	= 1;
+
+	/*
+	 * Keep a reference to this module so it
+	 * won't be unloaded.
+	 */
+	lua_setfield(L, -2, "formatter_lua");
+
+	/* Output formatter in Lua mode */
+	lua_serializer_init(L);
+
 	struct session_vtab console_session_vtab = {
 		.push	= console_session_push,
 		.fd	= console_session_fd,
diff --git a/src/box/lua/console.lua b/src/box/lua/console.lua
index 5642ca956..6ea27a393 100644
--- a/src/box/lua/console.lua
+++ b/src/box/lua/console.lua
@@ -69,60 +69,50 @@ output_handlers["yaml"] = function(status, opts, ...)
     return internal.format_yaml({ error = err })
 end
 
--- A map for internal symbols in case if they
--- are not inside tables and serpent won't be
--- able to handle them properly.
-local lua_map_direct_symbols = {
-    [box.NULL]      = 'box.NULL',
-}
-
--- A map for internal symbols in case if they
--- are coming from tables and we need to depict
--- them into user known values.
-local lua_map_table_symbols = {
-    ['"cdata<void %*>: NULL"']  = 'box.NULL'
-}
-
 --
--- Map internal symbols which serpent doesn't
--- know about to a known representation.
-local serpent_map_symbols = function(tag, head, body, tail, level)
-    for k,v in pairs(lua_map_table_symbols) do
-        body = body:gsub(k, v)
+-- Format a Lua value.
+local function format_lua_value(status, internal_opts, value)
+    local err
+    if status then
+        status, err = pcall(internal.format_lua, internal_opts, value)
+        if status then
+            return err
+        else
+            local m = 'console: exception while formatting output: "%s"'
+            err = m:format(tostring(err))
+        end
+    else
+        err = value
+        if err == nil then
+            err = box.NULL
+        end
     end
-    return tag..head..body..tail
+    return internal.format_lua(internal_opts, { error = err })
 end
 
 --
--- Format a Lua value.
-local function format_lua_value(value, opts)
-    for k,v in pairs(lua_map_direct_symbols) do
-        if k == value then
-            return v
-        end
-    end
-    local serpent_opts = {
-        custom  = serpent_map_symbols,
-        comment = false,
-        nocode  = true,
-    }
+-- Convert options from user form to the internal format.
+local function gen_lua_opts(opts)
     if opts == "block" then
-        return serpent.block(value, serpent_opts)
+        return {block=true, indent=2}
+    else
+        return {block=false, indent=2}
     end
-    return serpent.line(value, serpent_opts)
 end
 
 output_handlers["lua"] = function(status, opts, ...)
     local collect = {}
     --
-    -- If no data present at least EOS should be put,
-    -- otherwise wire readers won't be able to find
-    -- where the end of string is.
-    if not ... then
-        return output_eos["lua"]
-    end
+    -- Convert options to internal dictionary.
+    local internal_opts = gen_lua_opts(opts)
     for i = 1, select('#', ...) do
-        collect[i] = format_lua_value(select(i, ...), opts)
+        collect[i] = format_lua_value(status, internal_opts, select(i, ...))
+        if collect[i] == nil then
+            --
+            -- table.concat doesn't work for nil
+            -- so convert it explicitly.
+            collect[i] = "nil"
+        end
     end
     return table.concat(collect, ', ') .. output_eos["lua"]
 end
@@ -210,8 +200,8 @@ end
 
 -- Used by console_session_push.
 box_internal.format_lua_push = function(value)
-    local opts = current_output()["opts"]
-    value = format_lua_value(value, opts)
+    local internal_opts = gen_lua_opts(current_output()["opts"])
+    value = format_lua_value(true, internal_opts, value)
     return '-- Push\n' .. value .. ';'
 end
 
diff --git a/test/app-tap/console_lua.test.lua b/test/app-tap/console_lua.test.lua
index 3ed6aad97..8bb6eb0b3 100755
--- a/test/app-tap/console_lua.test.lua
+++ b/test/app-tap/console_lua.test.lua
@@ -102,29 +102,29 @@ local cases = {
         prepare     = 'a = {1, 2, 3}',
         opts        = {block = false},
         input       = '1, 2, nil, a',
-        expected    = '1, 2, box.NULL, {1, 2, 3}',
+        expected    = '1, 2, nil, {1, 2, 3}',
         cleanup     = 'a = nil',
     }, {
         name        = 'multireturn block mode',
         prepare     = 'a = {1, 2, 3}',
         opts        = {block = true},
         input       = '1, 2, nil, a',
-        expected    = '1, 2, box.NULL, {\n  1,\n  2,\n  3\n}',
+        expected    = '1, 2, nil, {\n  1,\n  2,\n  3\n}',
         cleanup     = 'a = nil',
     }, {
-        name        = 'trailing nils, line mode',
+        name        = 'trailing nils, box.NULL, line mode',
         opts        = {block = false},
-        input       = '1, nil, nil, nil',
-        expected    = '1, box.NULL, box.NULL, box.NULL',
+        input       = '1, nil, box.NULL, nil',
+        expected    = '1, nil, box.NULL, nil',
     }, {
-        name        = 'trailing nils, block mode',
+        name        = 'trailing nils, box.NULL, block mode',
         opts        = {block = true},
-        input       = '1, nil, nil, nil',
-        expected    = '1, box.NULL, box.NULL, box.NULL',
+        input       = '1, nil, box.NULL, nil',
+        expected    = '1, nil, box.NULL, nil',
     }, {
         name        = 'empty output',
         input       = '\\set output',
-        expected    = '"Specify output format: lua or yaml."',
+        expected    = '{error = \"Specify output format: lua or yaml.\"}',
     }
 }
 
-- 
2.26.2

[Tarantool-patches] [PATCH 7/7] test: extend console lua test

[Cyrill Gorcunov]

To make sure ULL constants are not broken.

Part-of #4682

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 test/app-tap/console_lua.test.lua | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/test/app-tap/console_lua.test.lua b/test/app-tap/console_lua.test.lua
index 8bb6eb0b3..dbfc3da11 100755
--- a/test/app-tap/console_lua.test.lua
+++ b/test/app-tap/console_lua.test.lua
@@ -116,11 +116,26 @@ local cases = {
         opts        = {block = false},
         input       = '1, nil, box.NULL, nil',
         expected    = '1, nil, box.NULL, nil',
+    }, {
+        name        = 'leading nils, box.NULL, line mode',
+        opts        = {block = false},
+        input       = 'nil, 1, nil, box.NULL, nil',
+        expected    = 'nil, 1, nil, box.NULL, nil',
     }, {
         name        = 'trailing nils, box.NULL, block mode',
         opts        = {block = true},
         input       = '1, nil, box.NULL, nil',
         expected    = '1, nil, box.NULL, nil',
+    }, {
+        name        = 'ULL constants, multireturn',
+        opts        = {block = false},
+        input       = '-1ULL, -2ULL, 1ULL, 2ULL',
+        expected    = '18446744073709551615, 18446744073709551614, 1, 2',
+    }, {
+        name        = 'ULL key',
+        opts        = {block = false},
+        input       = '{[-1ULL] = 1}',
+        expected    = '{[18446744073709551615] = 1}',
     }, {
         name        = 'empty output',
         input       = '\\set output',
-- 
2.26.2

Re: [Tarantool-patches] [PATCH 1/7] box/console: console_session_vtab -- use designated initialization

[Oleg Babin]

Hi! Thanks for your patch. LGTM.

On 12/05/2020 16:50, Cyrill Gorcunov wrote:
> For better maintainance.
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>   src/box/lua/console.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/box/lua/console.c b/src/box/lua/console.c
> index b941f50c6..d937d684e 100644
> --- a/src/box/lua/console.c
> +++ b/src/box/lua/console.c
> @@ -582,9 +582,9 @@ tarantool_lua_console_init(struct lua_State *L)
>   	 */
>   	lua_setfield(L, -2, "formatter");
>   	struct session_vtab console_session_vtab = {
> -		/* .push = */ console_session_push,
> -		/* .fd = */ console_session_fd,
> -		/* .sync = */ generic_session_sync,
> +		.push	= console_session_push,
> +		.fd	= console_session_fd,
> +		.sync	= generic_session_sync,
>   	};
>   	session_vtab_registry[SESSION_TYPE_CONSOLE] = console_session_vtab;
>   	session_vtab_registry[SESSION_TYPE_REPL] = console_session_vtab;
> 

Re: [Tarantool-patches] [PATCH 2/7] box/console: use tabs instead of spaces in consolelib

[Oleg Babin]

LGTM

On 12/05/2020 16:50, Cyrill Gorcunov wrote:
> For some reason we're using spaces here to adjust code.
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>   src/box/lua/console.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/src/box/lua/console.c b/src/box/lua/console.c
> index d937d684e..d437ff3fe 100644
> --- a/src/box/lua/console.c
> +++ b/src/box/lua/console.c
> @@ -552,11 +552,11 @@ void
>   tarantool_lua_console_init(struct lua_State *L)
>   {
>   	static const struct luaL_Reg consolelib[] = {
> -		{"load_history",       lbox_console_load_history},
> -		{"save_history",       lbox_console_save_history},
> -		{"add_history",        lbox_console_add_history},
> -		{"completion_handler", lbox_console_completion_handler},
> -		{"format",             lbox_console_format},
> +		{"load_history",	lbox_console_load_history},
> +		{"save_history",	lbox_console_save_history},
> +		{"add_history",		lbox_console_add_history},
> +		{"completion_handler",	lbox_console_completion_handler},
> +		{"format_yaml",		lbox_console_format_yaml},
>   		{NULL, NULL}
>   	};
>   	luaL_register_module(L, "console", consolelib);
> 

Re: [Tarantool-patches] [PATCH 3/7] box/console: rename format to format_yaml

[Oleg Babin]

LGTM

On 12/05/2020 16:50, Cyrill Gorcunov wrote:
> This will allow us to implement own formatter for
> Lua output mode, so to be precise which exactly formatter
> is caller lets rename general "format" to "format_yaml".
> 
> Part-of #4682
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>   src/box/lua/console.c   | 2 +-
>   src/box/lua/console.lua | 4 ++--
>   2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/box/lua/console.c b/src/box/lua/console.c
> index d437ff3fe..734c0ee47 100644
> --- a/src/box/lua/console.c
> +++ b/src/box/lua/console.c
> @@ -352,7 +352,7 @@ lbox_console_add_history(struct lua_State *L)
>    *         parameter.
>    */
>   static int
> -lbox_console_format(struct lua_State *L)
> +lbox_console_format_yaml(struct lua_State *L)
>   {
>   	int arg_count = lua_gettop(L);
>   	if (arg_count == 0) {
> diff --git a/src/box/lua/console.lua b/src/box/lua/console.lua
> index 2add9a79d..5642ca956 100644
> --- a/src/box/lua/console.lua
> +++ b/src/box/lua/console.lua
> @@ -53,7 +53,7 @@ output_handlers["yaml"] = function(status, opts, ...)
>       local err
>       if status then
>           -- serializer can raise an exception
> -        status, err = pcall(internal.format, ...)
> +        status, err = pcall(internal.format_yaml, ...)
>           if status then
>               return err
>           else
> @@ -66,7 +66,7 @@ output_handlers["yaml"] = function(status, opts, ...)
>               err = box.NULL
>           end
>       end
> -    return internal.format({ error = err })
> +    return internal.format_yaml({ error = err })
>   end
>   
>   -- A map for internal symbols in case if they
> 

Re: [Tarantool-patches] [PATCH 4/7] box/console: rename luaL_yaml_default to serializer_yaml

[Oleg Babin]

Hi! I'm not sure that we really should do that. Functions with LuaL 
prefix is a part of Lua code convention AFAIK.
(https://www.lua.org/manual/5.1/manual.html#4)

But LGTM if nobody doesn't have objections.

On 12/05/2020 16:50, Cyrill Gorcunov wrote:
> As we gonna implement lua output serializer lets
> rename luaL_yaml_default to serializer_yaml which
> will be more general name, for other serializers
> we will use same serializer_ prefix.
> 
> Part-of #4682
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>   src/box/lua/console.c | 16 ++++++++--------
>   1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/src/box/lua/console.c b/src/box/lua/console.c
> index 734c0ee47..c8e0dea58 100644
> --- a/src/box/lua/console.c
> +++ b/src/box/lua/console.c
> @@ -49,7 +49,7 @@
>   
>   extern char serpent_lua[];
>   
> -static struct luaL_serializer *luaL_yaml_default = NULL;
> +static struct luaL_serializer *serializer_yaml;
>   
>   /*
>    * Completion engine (Mike Paul's).
> @@ -369,7 +369,7 @@ lbox_console_format_yaml(struct lua_State *L)
>   	}
>   	lua_replace(L, 1);
>   	lua_settop(L, 1);
> -	return lua_yaml_encode(L, luaL_yaml_default, NULL, NULL);
> +	return lua_yaml_encode(L, serializer_yaml, NULL, NULL);
>   }
>   
>   int
> @@ -404,7 +404,7 @@ console_dump_plain(struct lua_State *L, uint32_t *size)
>   {
>   	enum output_format fmt = console_get_output_format();
>   	if (fmt == OUTPUT_FORMAT_YAML) {
> -		int rc = lua_yaml_encode(L, luaL_yaml_default, "!push!",
> +		int rc = lua_yaml_encode(L, serializer_yaml, "!push!",
>   					 "tag:tarantool.io/push,2018");
>   		if (rc == 2) {
>   			/*
> @@ -566,11 +566,11 @@ tarantool_lua_console_init(struct lua_State *L)
>   	lua_pushcclosure(L, lbox_console_readline, 1);
>   	lua_setfield(L, -2, "readline");
>   
> -	luaL_yaml_default = lua_yaml_new_serializer(L);
> -	luaL_yaml_default->encode_invalid_numbers = 1;
> -	luaL_yaml_default->encode_load_metatables = 1;
> -	luaL_yaml_default->encode_use_tostring = 1;
> -	luaL_yaml_default->encode_invalid_as_nil = 1;
> +	serializer_yaml = lua_yaml_new_serializer(L);
> +	serializer_yaml->encode_invalid_numbers = 1;
> +	serializer_yaml->encode_load_metatables = 1;
> +	serializer_yaml->encode_use_tostring = 1;
> +	serializer_yaml->encode_invalid_as_nil = 1;
>   	/*
>   	 * Hold reference to the formatter in module local
>   	 * variable.
> 

Re: [Tarantool-patches] [PATCH 5/7] box/console: implement lua serializer

[Oleg Babin]

I've checked your changes. That's ok. There are several issues that are 
still relevant but I hope it will be done in the scope of separate 
patches. LGTM.

On 12/05/2020 16:50, Cyrill Gorcunov wrote:
> When we print output in console (especially in Lua mode)
> it is impossible to find out the internal type an entry
> represents, which in turn leads to inability to encode
> "ULL" entries properly. Moreover we always introduce new
> types (for example decimals, uuids) and the serpent module
> we currently use for encodings has no clue about them.
> 

But why does yaml serializer recognize such types and lua doesn't do that?

> Thus lets implement own lua serializer similarly to the
> yaml encoder. This allows us to properly detect every
> field and encode it accordingly.
> 
> Part-of #4682
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>   src/box/CMakeLists.txt      |    1 +
>   src/box/lua/serialize_lua.c | 1059 +++++++++++++++++++++++++++++++++++
>   src/box/lua/serialize_lua.h |   67 +++
>   3 files changed, 1127 insertions(+)
>   create mode 100644 src/box/lua/serialize_lua.c
>   create mode 100644 src/box/lua/serialize_lua.h
> 
> diff --git a/src/box/CMakeLists.txt b/src/box/CMakeLists.txt
> index c931ecdfe..08ffe7177 100644
> --- a/src/box/CMakeLists.txt
> +++ b/src/box/CMakeLists.txt
> @@ -148,6 +148,7 @@ add_library(box STATIC
>       lua/call.c
>       lua/cfg.cc
>       lua/console.c
> +    lua/serialize_lua.c
>       lua/tuple.c
>       lua/slab.c
>       lua/index.c
> diff --git a/src/box/lua/serialize_lua.c b/src/box/lua/serialize_lua.c
> new file mode 100644
> index 000000000..caa08a60f
> --- /dev/null
> +++ b/src/box/lua/serialize_lua.c
> @@ -0,0 +1,1059 @@
> +/*
> + * Copyright 2010-2020, Tarantool AUTHORS, please see AUTHORS file.
> + *
> + * Redistribution and use in source and binary forms, with or
> + * without modification, are permitted provided that the following
> + * conditions are met:
> + *
> + * 1. Redistributions of source code must retain the above
> + *    copyright notice, this list of conditions and the
> + *    following disclaimer.
> + *
> + * 2. Redistributions in binary form must reproduce the above
> + *    copyright notice, this list of conditions and the following
> + *    disclaimer in the documentation and/or other materials
> + *    provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
> + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
> + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
> + * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
> + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
> + * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#include <ctype.h>
> +#include <lua.h>
> +
> +#include "trivia/util.h"
> +#include "lua/utils.h"
> +#include "say.h"
> +
> +#include "lib/core/decimal.h"
> +#include "mp_extension_types.h"
> +#include "uuid/tt_uuid.h"
> +
> +#include "lua-yaml/b64.h"
> +
> +#include "serialize_lua.h"
> +
> +#if 0
> +# define SERIALIZER_TRACE
> +#endif
> +
> +/* Serializer for Lua output mode */
> +static struct luaL_serializer *serializer_lua;
> +
> +enum {
> +	NODE_NONE_BIT		= 0,
> +	NODE_ROOT_BIT		= 1,
> +	NODE_RAW_BIT		= 2,
> +	NODE_LVALUE_BIT		= 3,
> +	NODE_RVALUE_BIT		= 4,
> +	NODE_MAP_KEY_BIT	= 5,
> +	NODE_MAP_VALUE_BIT	= 6,
> +	NODE_EMBRACE_BIT	= 7,
> +	NODE_QUOTE_BIT		= 8,
> +
> +	NODE_MAX
> +};
> +
> +enum {
> +	NODE_NONE		= (1u << NODE_NONE_BIT),
> +	NODE_ROOT		= (1u << NODE_ROOT_BIT),
> +	NODE_RAW		= (1u << NODE_RAW_BIT),
> +	NODE_LVALUE		= (1u << NODE_LVALUE_BIT),
> +	NODE_RVALUE		= (1u << NODE_RVALUE_BIT),
> +	NODE_MAP_KEY		= (1u << NODE_MAP_KEY_BIT),
> +	NODE_MAP_VALUE		= (1u << NODE_MAP_VALUE_BIT),
> +	NODE_EMBRACE		= (1u << NODE_EMBRACE_BIT),
> +	NODE_QUOTE		= (1u << NODE_QUOTE_BIT),
> +};
> +
> +struct node {
> +	/** Link with previous node or key */
> +	union {
> +		struct node *prev;
> +		struct node *key;
> +	};
> +
> +	/** The field data we're paring */
> +	struct luaL_field field;
> +
> +	/** Node mask NODE_x */
> +	int mask;
> +
> +	/** Node index in a map */
> +	int index;
> +};
> +
> +/**
> + * Serializer context.
> + */
> +struct lua_dumper {
> +	/** Lua state to fetch data from */
> +	lua_State *L;
> +
> +	/** General configure options */
> +	struct luaL_serializer *cfg;
> +
> +	/** Lua dumper options */
> +	lua_dumper_opts_t *opts;
> +
> +	/** Output state */
> +	lua_State *outputL;
> +	/** Output buffer */
> +	luaL_Buffer luabuf;
> +
> +	/** Anchors for self references */
> +	int anchortable_index;
> +	unsigned int anchor_number;
> +
> +	/** Error message buffer */
> +	char err_msg[256];
> +	int err;
> +
> +	/** Indentation buffer */
> +	char indent_buf[256];
> +
> +	/** Output suffix */
> +	char suffix_buf[32];
> +	int suffix_len;
> +
> +	/** Previous node mask */
> +	int prev_nd_mask;
> +
> +	/** Ignore indents */
> +	bool noindent;
> +};
> +
> +#ifdef SERIALIZER_TRACE
> +
> +#define __gen_mp_name(__v) [__v] = # __v
> +static const char *mp_type_names[] = {
> +	__gen_mp_name(MP_NIL),
> +	__gen_mp_name(MP_UINT),
> +	__gen_mp_name(MP_INT),
> +	__gen_mp_name(MP_STR),
> +	__gen_mp_name(MP_BIN),
> +	__gen_mp_name(MP_ARRAY),
> +	__gen_mp_name(MP_MAP),
> +	__gen_mp_name(MP_BOOL),
> +	__gen_mp_name(MP_FLOAT),
> +	__gen_mp_name(MP_DOUBLE),
> +	__gen_mp_name(MP_EXT),
> +};
> +
> +static const char *mp_ext_type_names[] = {
> +	__gen_mp_name(MP_DECIMAL),
> +	__gen_mp_name(MP_UUID),
> +	__gen_mp_name(MP_ERROR),
> +};
> +#undef __gen_mp_name
> +
> +#define __gen_nd_name(__v) [__v ##_BIT] = # __v
> +static const char *nd_type_names[] = {
> +	__gen_nd_name(NODE_NONE),
> +	__gen_nd_name(NODE_ROOT),
> +	__gen_nd_name(NODE_RAW),
> +	__gen_nd_name(NODE_LVALUE),
> +	__gen_nd_name(NODE_RVALUE),
> +	__gen_nd_name(NODE_MAP_KEY),
> +	__gen_nd_name(NODE_MAP_VALUE),
> +	__gen_nd_name(NODE_EMBRACE),
> +	__gen_nd_name(NODE_QUOTE),
> +};
> +#undef __gen_nd_name
> +
> +static char *
> +trace_nd_mask_str(unsigned int nd_mask)
> +{
> +	static char mask_str[256];
> +	int left = sizeof(mask_str);
> +	int pos = 0;
> +
> +	for (int i = 0; i < NODE_MAX; i++) {
> +		if (!(nd_mask & (1u << i)))
> +			continue;
> +
> +		int nd_len = strlen(nd_type_names[i]);
> +		if (left >= nd_len + 1) {
> +			strcpy(&mask_str[pos], nd_type_names[i]);
> +			pos += nd_len;
> +			mask_str[pos++] = '|';
> +			left = sizeof(mask_str) - pos;
> +		}
> +	}
> +
> +	if (pos != 0)
> +		mask_str[--pos] = '\0';
> +	else
> +		strcpy(mask_str, "UNKNOWN");
> +
> +	return mask_str;
> +}
> +
> +static void
> +trace_node(struct lua_dumper *d)
> +{
> +	int ltype = lua_type(d->L, -1);
> +	say_info("serializer-trace: node    : lua type %d -> %s",
> +		 ltype, lua_typename(d->L, ltype));
> +
> +	if (d->err != 0)
> +		return;
> +
> +	char mp_type[64], *type_str = mp_type;
> +	int top = lua_gettop(d->L);
> +	struct luaL_field field;
> +
> +	memset(&field, 0, sizeof(field));
> +	luaL_checkfield(d->L, d->cfg, lua_gettop(d->L), &field);
> +
> +	if (field.type < lengthof(mp_type_names)) {
> +		if (field.type == MP_EXT) {
> +			size_t max_ext = lengthof(mp_ext_type_names);
> +			snprintf(mp_type, sizeof(mp_type), "%s/%s",
> +				 mp_type_names[field.type],
> +				 field.ext_type < max_ext ?
> +				 mp_ext_type_names[field.ext_type] :
> +				 "UNKNOWN");
> +		} else {
> +			type_str = (char *)mp_type_names[field.type];
> +		}
> +	} else {
> +		type_str = "UNKNOWN";
> +	}
> +
> +	memset(&field, 0, sizeof(field));
> +
> +	luaL_checkfield(d->L, d->cfg, top, &field);
> +	say_info("serializer-trace: node    :\tfield type %s (%d)",
> +		 type_str, field.type);
> +}
> +
> +static char *
> +trace_string(const char *src, size_t len)
> +{
> +	static char buf[128];
> +	size_t pos = 0;
> +
> +	if (len > sizeof(buf)-1)
> +		len = sizeof(buf)-1;
> +
> +	while (pos < len) {
> +		if (src[pos] == '\n') {
> +			buf[pos++] = '\\';
> +			buf[pos++] = 'n';
> +			continue;
> +		}
> +		buf[pos] = src[pos];
> +		pos++;
> +	}
> +	buf[pos] = '\0';
> +	return buf;
> +}
> +
> +static void
> +trace_emit(struct lua_dumper *d, int nd_mask, int indent,
> +	   const char *str, size_t len)
> +{
> +	if (d->suffix_len) {
> +		say_info("serializer-trace: emit-sfx: \"%s\"",
> +			 trace_string(d->suffix_buf,
> +				      d->suffix_len));
> +	}
> +
> +	static_assert(NODE_MAX < sizeof(int) * 8,
> +		      "NODE_MAX is too big");
> +
> +	char *names = trace_nd_mask_str(nd_mask);
> +
> +	say_info("serializer-trace: emit    : type %s (0x%x) "
> +		 "indent %d val \"%s\" len %zu",
> +		 names, nd_mask, indent,
> +		 trace_string(str, len), len);
> +}
> +
> +static void
> +trace_anchor(const char *s, bool alias)
> +{
> +	say_info("serializer-trace: anchor  : alias %d name %s",
> +		 alias, s);
> +}
> +
> +#else /* SERIALIZER_TRACE */
> +
> +static void
> +trace_node(struct lua_dumper *d)
> +{
> +	(void)d;
> +}
> +
> +static void
> +trace_emit(struct lua_dumper *d, int nd_mask, int indent,
> +	   const char *str, size_t len)
> +{
> +	(void)d;
> +	(void)nd_mask;
> +	(void)indent;
> +	(void)str;
> +	(void)len;
> +}
> +
> +static void
> +trace_anchor(const char *s, bool alias)
> +{
> +	(void)s;
> +	(void)alias;
> +}
> +
> +#endif /* SERIALIZER_TRACE */
> +
> +static const char *lua_keywords[] = {
> +	"and", "break", "do", "else",
> +	"elseif", "end", "false", "for",
> +	"function", "if", "in", "local",
> +	"nil", "not", "or", "repeat",
> +	"return", "then", "true", "until",
> +	"while", "and",
> +};
> +
> +static int
> +dump_node(struct lua_dumper *d, struct node *nd, int indent);
> +
> +static int
> +emit_node(struct lua_dumper *d, struct node *nd, int indent,
> +	  const char *str, size_t len);
> +
> +/**
> + * Generate anchor numbers for self references.
> + */
> +static const char *
> +get_lua_anchor(struct lua_dumper *d)
> +{
> +	const char *s = "";
> +
> +	lua_pushvalue(d->L, -1);
> +	lua_rawget(d->L, d->anchortable_index);
> +	if (!lua_toboolean(d->L, -1)) {
> +		lua_pop(d->L, 1);
> +		return NULL;
> +	}
> +
> +	if (lua_isboolean(d->L, -1)) {
> +		/*
> +		 * This element is referenced more
> +		 * than once but has not been named.
> +		 */
> +		char buf[32];
> +		snprintf(buf, sizeof(buf), "%u", d->anchor_number++);
> +		lua_pop(d->L, 1);
> +		lua_pushvalue(d->L, -1);
> +		lua_pushstring(d->L, buf);
> +		s = lua_tostring(d->L, -1);
> +		lua_rawset(d->L, d->anchortable_index);
> +		trace_anchor(s, false);
> +	} else {
> +		/*
> +		 * An aliased element.
> +		 *
> +		 * FIXME: Need an example to use.
> +		 *
> +		 * const char *str = lua_tostring(d->L, -1);
> +		 */
> +		const char *str = lua_tostring(d->L, -1);
> +		trace_anchor(str, true);
> +		lua_pop(d->L, 1);
> +	}
> +	return s;
> +}
> +
> +static void
> +suffix_append(struct lua_dumper *d, const char *str, int len)
> +{
> +	int left = (int)sizeof(d->suffix_buf) - d->suffix_len;
> +	if (len < left) {
> +		memcpy(&d->suffix_buf[d->suffix_len], str, len);
> +		d->suffix_len += len;
> +		d->suffix_buf[d->suffix_len] = '\0';
> +	}
> +}
> +
> +static inline void
> +suffix_reset(struct lua_dumper *d)
> +{
> +	d->suffix_len = 0;
> +}
> +
> +static void
> +suffix_flush(struct lua_dumper *d)
> +{
> +	if (d->suffix_len) {
> +		luaL_addlstring(&d->luabuf, d->suffix_buf, d->suffix_len);
> +		suffix_reset(d);
> +	}
> +}
> +
> +static int
> +gen_indent(struct lua_dumper *d, int indent)
> +{
> +	static_assert(sizeof(d->indent_buf) > 0,
> +		      "indent buffer is too small");
> +
> +	if (indent > 0 && d->opts->block_mode && !d->noindent) {
> +		snprintf(d->indent_buf, sizeof(d->indent_buf),
> +			 "%*s", indent, "");
> +		size_t len = strlen(d->indent_buf);
> +		d->indent_buf[len] = '\0';
> +		return len;
> +	}
> +
> +	return 0;
> +}
> +
> +static void
> +emit_hex_char(struct lua_dumper *d, unsigned char c)
> +{
> +	luaL_addchar(&d->luabuf, '\\');
> +	luaL_addchar(&d->luabuf, 'x');
> +
> +#define __emit_hex(v)						\
> +	do {							\
> +		if (v <= 9)				\
> +			luaL_addchar(&d->luabuf, '0' + v);	\
> +		else						\
> +			luaL_addchar(&d->luabuf, v - 10 + 'a');	\
> +	} while (0)
> +
> +	__emit_hex((c >> 4));
> +	__emit_hex((c & 0xf));
> +#undef __emit_hex
> +}
> +
> +/**
> + * Emit the string with escapes if needed.
> + *
> + * FIXME: Probably should to revisit and make
> + * sure we've not miss anything here (octal numbers
> + * are missed for now and etc...).
> + */
> +static void
> +emit_string(struct lua_dumper *d, const char *str, size_t len)
> +{
> +	for (size_t i = 0; i < len; i++) {
> +		if ((str[i]) == '\'' || str[i] == '\"') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, str[i]);
> +		} else if (str[i] == '\0') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, '0');
> +		} else if (str[i] == '\a') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, 'a');
> +		} else if (str[i] == '\b') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, 'b');
> +		} else if (str[i] == '\f') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, 'f');
> +		} else if (str[i] == '\v') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, 'v');
> +		} else if (str[i] == '\r') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, 'r');
> +		} else if (str[i] == '\n') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, 'n');
> +		} else if (str[i] == '\t') {
> +			luaL_addchar(&d->luabuf, '\\');
> +			luaL_addchar(&d->luabuf, 't');
> +		} else if (str[i] == '\xef') {
> +			if (i < len-1 && i < len-2 &&
> +			    str[i+1] == '\xbb' &&
> +			    str[i+2] == '\xbf') {
> +				emit_hex_char(d, 0xef);
> +				emit_hex_char(d, 0xbb);
> +				emit_hex_char(d, 0xbf);
> +			} else {
> +				emit_hex_char(d, str[i]);
> +			}
> +		} else if (isprint(str[i]) == 0) {
> +			emit_hex_char(d, str[i]);
> +		} else {
> +			luaL_addchar(&d->luabuf, str[i]);
> +		}
> +	}
> +}
> +
> +/**
> + * Emit value into output buffer.
> + */
> +static void
> +emit_value(struct lua_dumper *d, struct node *nd,
> +	   int indent, const char *str, size_t len)
> +{
> +	trace_emit(d, nd->mask, indent, str, len);
> +
> +	/*
> +	 * There might be previous closing symbols
> +	 * in the suffix queue. Since we're about
> +	 * to emit new values don't forget to prepend
> +	 * ending ones.
> +	 */
> +	suffix_flush(d);
> +
> +	luaL_addlstring(&d->luabuf, d->indent_buf,
> +			gen_indent(d, indent));
> +
> +	if (nd->mask & NODE_EMBRACE)
> +		luaL_addlstring(&d->luabuf, "[", 1);
> +	if (nd->mask & NODE_QUOTE)
> +		luaL_addlstring(&d->luabuf, "\"", 1);
> +
> +	if (nd->field.type == MP_STR) {
> +		emit_string(d, str, len);
> +	} else {
> +		luaL_addlstring(&d->luabuf, str, len);
> +	}
> +
> +	if (nd->mask & NODE_QUOTE)
> +		luaL_addlstring(&d->luabuf, "\"", 1);
> +	if (nd->mask & NODE_EMBRACE)
> +		luaL_addlstring(&d->luabuf, "]", 1);
> +}
> +
> +/**
> + * Emit a raw string into output.
> + */
> +static void
> +emit_raw_value(struct lua_dumper *d, int indent,
> +	       const char *str, size_t len)
> +{
> +	struct node node = {
> +		.mask = NODE_RAW,
> +	};
> +
> +	emit_value(d, &node, indent, str, len);
> +}
> +
> +/**
> + * Put an opening brace into the output.
> + */
> +static int
> +emit_brace_open(struct lua_dumper *d, int indent)
> +{
> +	if (d->opts->block_mode) {
> +		int _indent;
> +		if (d->noindent)
> +			_indent = 0;
> +		else
> +			_indent = indent;
> +
> +		emit_raw_value(d, _indent, "{\n", 2);
> +		if (d->noindent && d->prev_nd_mask & NODE_LVALUE)
> +			d->noindent = false;
> +	} else {
> +		emit_raw_value(d, indent, "{", 1);
> +	}
> +
> +	return indent + d->opts->indent_lvl;
> +}
> +
> +/**
> + * Put a closing brace into the output.
> + */
> +static void
> +emit_brace_close(struct lua_dumper *d, int indent)
> +{
> +	suffix_reset(d);
> +
> +	if (d->opts->block_mode)
> +		emit_raw_value(d, 0, "\n", 1);
> +
> +	indent -= d->opts->indent_lvl;
> +	emit_raw_value(d, indent, "}", 1);
> +
> +	if (d->opts->block_mode)
> +		suffix_append(d, ",\n", 2);
> +	else
> +		suffix_append(d, ", ", 2);
> +}
> +
> +/**
> + * Handling self references. It is yaml specific
> + * and I don't think we might even need it. Still
> + * better to get noticed if something went in
> + * an unexpected way.
> + */
> +static bool
> +emit_anchor(struct lua_dumper *d, struct node *nd, int indent)
> +{
> +	const char *anchor = get_lua_anchor(d);
> +	if (anchor && !*anchor) {
> +		emit_node(d, nd, indent, "nil", 3);
> +		return true;
> +	}
> +	return false;
> +}
> +
> +/**
> + * Dump an array entry.
> + */
> +static void
> +dump_array(struct lua_dumper *d, struct node *nd, int indent)
> +{
> +	indent = emit_brace_open(d, indent);
> +	if (emit_anchor(d, nd, indent))
> +		goto out;
> +
> +	for (int i = 0; i < (int)nd->field.size; i++) {
> +		lua_rawgeti(d->L, -1, i + 1);
> +		struct node node = {
> +			.prev = nd,
> +			.mask = NODE_RVALUE,
> +		};
> +		dump_node(d, &node, indent);
> +		lua_pop(d->L, 1);
> +	}
> +out:
> +	emit_brace_close(d, indent);
> +}
> +
> +/**
> + * Dump a map entry.
> + */
> +static void
> +dump_table(struct lua_dumper *d, struct node *nd, int indent)
> +{
> +	int index = 0;
> +
> +	indent = emit_brace_open(d, indent);
> +	if (emit_anchor(d, nd, indent))
> +		goto out;
> +
> +	/*
> +	 * In sake of speed we don't sort
> +	 * keys but provide them as is. Thus
> +	 * simply walk over keys and their
> +	 * values.
> +	 */
> +	lua_pushnil(d->L);
> +	while (lua_next(d->L, -2)) {
> +		lua_pushvalue(d->L, -2);
> +		struct node node_key = {
> +			.prev	= nd,
> +			.mask	= NODE_LVALUE | NODE_MAP_KEY,
> +			.index	= index++,
> +		};
> +		dump_node(d, &node_key, indent);
> +		lua_pop(d->L, 1);
> +
> +		struct node node_val = {
> +			.key	= &node_key,
> +			.mask	= NODE_RVALUE | NODE_MAP_VALUE,
> +		};
> +		dump_node(d, &node_val, indent);
> +		lua_pop(d->L, 1);
> +	}
> +out:
> +	emit_brace_close(d, indent);
> +}
> +
> +/**
> + * Figure out if we need to decorate a map key
> + * with square braces and quotes or can leave
> + * it as a plain value.
> + */
> +static void
> +decorate_key(struct node *nd, const char *str, size_t len)
> +{
> +	assert(nd->field.type == MP_STR);
> +	assert(nd->mask & NODE_MAP_KEY);
> +
> +	/*
> +	 * We might need to put string keys
> +	 * to quotes and embrace them due to
> +	 * limitation of how to declare map keys
> +	 * (the output from serializer should be
> +	 * parsable if pasted back to a console).
> +	 */
> +	for (size_t i = 0; i < lengthof(lua_keywords); i++) {
> +		const char *k = lua_keywords[i];
> +		if (strcmp(k, str) == 0) {
> +			nd->mask |= NODE_EMBRACE | NODE_QUOTE;
> +			return;
> +		}
> +	}
> +
> +	/*
> +	 * Plain keys may be alphanumerics with underscopes.
> +	 */
> +	for (size_t i = 0; i < len; i++) {
> +		if (isalnum(str[i]) != 0 || str[i] == '_')
> +			continue;
> +		nd->mask |= NODE_EMBRACE | NODE_QUOTE;
> +		return;
> +	}
> +
> +	nd->mask &= ~NODE_QUOTE;
> +}
> +
> +static int
> +emit_node(struct lua_dumper *d, struct node *nd, int indent,
> +	  const char *str, size_t len)
> +{
> +	struct luaL_field *field = &nd->field;
> +
> +	if (str == NULL) {
> +		d->prev_nd_mask = nd->mask;
> +		return 0;
> +	}
> +
> +	if (nd->mask & NODE_MAP_KEY) {
> +		/*
> +		 * In case if key is integer and matching
> +		 * the current position in the table we
> +		 * can simply skip it and print value only.
> +		 */
> +		if (nd->field.type == MP_INT ||
> +		    nd->field.type == MP_UINT) {
> +			if (nd->index == (int)field->ival) {
> +				d->noindent = false;
> +				return 0;
> +			} else {
> +				nd->mask |= NODE_EMBRACE;
> +			}
> +		} else if (nd->field.type == MP_STR) {
> +			decorate_key(nd, str, len);
> +		}
> +	}
> +
> +	d->prev_nd_mask = nd->mask;
> +	emit_value(d, nd, indent, str, len);
> +
> +	/*
> +	 * In sake of speed we do not lookahead
> +	 * for next lua nodes, instead just remember
> +	 * closing symbol in suffix buffer which we
> +	 * will flush on next emit.
> +	 */
> +	if (nd->mask & NODE_RVALUE) {
> +		if (d->opts->block_mode)
> +			suffix_append(d, ",\n", 2);
> +		else
> +			suffix_append(d, ", ", 2);
> +		d->noindent = false;
> +	} else if (nd->mask & NODE_LVALUE) {
> +		suffix_append(d, " = ", 3);
> +		d->noindent = true;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * Dump a node.
> + */
> +static int
> +dump_node(struct lua_dumper *d, struct node *nd, int indent)
> +{
> +	struct luaL_field *field = &nd->field;
> +	char buf[FPCONV_G_FMT_BUFSIZE];
> +	int ltype = lua_type(d->L, -1);
> +	const char *str = NULL;
> +	size_t len = 0;
> +
> +	trace_node(d);
> +
> +	/*
> +	 * We can exit early if an error
> +	 * already happened, no need to
> +	 * continue parsing.
> +	 */
> +	if (d->err != 0)
> +		return -1;
> +
> +	memset(field, 0, sizeof(*field));
> +	luaL_checkfield(d->L, d->cfg, lua_gettop(d->L), field);
> +
> +	switch (field->type) {
> +	case MP_NIL:
> +		if (ltype == LUA_TNIL) {
> +			static const char str_nil[] = "nil";
> +			str = str_nil;
> +			len = strlen(str_nil);
> +		} else {
> +			static const char str_null[] = "box.NULL";
> +			str = str_null;
> +			len = strlen(str_null);
> +		}
> +		break;
> +	case MP_UINT:
> +		snprintf(buf, sizeof(buf), "%" PRIu64, field->ival);
> +		len = strlen(buf);
> +		str = buf;
> +		break;
> +	case MP_INT:
> +		snprintf(buf, sizeof(buf), "%" PRIi64, field->ival);
> +		len = strlen(buf);
> +		str = buf;
> +		break;
> +	case MP_STR:
> +		nd->mask |= NODE_QUOTE;
> +		str = lua_tolstring(d->L, -1, &len);
> +		if (utf8_check_printable(str, len) == 1)
> +			break;
> +		/* fallthrough */
> +	case MP_BIN:
> +		nd->mask |= NODE_QUOTE;
> +		tobase64(d->L, -1);
> +		str = lua_tolstring(d->L, -1, &len);
> +		lua_pop(d->L, 1);
> +		break;
> +	case MP_ARRAY:
> +		dump_array(d, nd, indent);
> +		break;
> +	case MP_MAP:
> +		dump_table(d, nd, indent);
> +		break;
> +	case MP_BOOL:
> +		if (field->bval) {
> +			static const char str_true[] = "true";
> +			len = strlen(str_true);
> +			str = str_true;
> +		} else {
> +			static const char str_false[] = "false";
> +			len = strlen(str_false);
> +			str = str_false;
> +		}
> +		break;
> +	case MP_FLOAT:
> +		fpconv_g_fmt(buf, field->fval,
> +			     d->cfg->encode_number_precision);
> +		len = strlen(buf);
> +		str = buf;
> +		break;
> +	case MP_DOUBLE:
> +		fpconv_g_fmt(buf, field->dval,
> +			     d->cfg->encode_number_precision);
> +		len = strlen(buf);
> +		str = buf;
> +		break;
> +	case MP_EXT:
> +		switch (field->ext_type) {
> +		case MP_DECIMAL:
> +			nd->mask |= NODE_QUOTE;
> +			str = decimal_to_string(field->decval);
> +			len = strlen(str);
> +			break;
> +		case MP_UUID:
> +			nd->mask |= NODE_QUOTE;
> +			str = tt_uuid_str(field->uuidval);
> +			len = UUID_STR_LEN;
> +			break;
> +		default:
> +			d->err = EINVAL;
> +			snprintf(d->err_msg, sizeof(d->err_msg),
> +				 "serializer: Unknown field MP_EXT:%d type",
> +				 field->ext_type);
> +			len = strlen(d->err_msg);
> +			return -1;
> +		}
> +		break;
> +	default:
> +		d->err = EINVAL;
> +		snprintf(d->err_msg, sizeof(d->err_msg),
> +			 "serializer: Unknown field %d type",
> +			 field->type);
> +		len = strlen(d->err_msg);
> +		return -1;
> +	}
> +
> +	return emit_node(d, nd, indent, str, len);
> +}
> +
> +/**
> + * Find references to tables, we use it
> + * to find self references in tables.
> + */
> +static void
> +find_references(struct lua_dumper *d)
> +{
> +	int newval;
> +
> +	if (lua_type(d->L, -1) != LUA_TTABLE)
> +		return;
> +
> +	/* Copy of a table for self refs */
> +	lua_pushvalue(d->L, -1);
> +	lua_rawget(d->L, d->anchortable_index);
> +	if (lua_isnil(d->L, -1))
> +		newval = 0;
> +	else if (!lua_toboolean(d->L, -1))
> +		newval = 1;
> +	else
> +		newval = -1;
> +	lua_pop(d->L, 1);
> +
> +	if (newval != -1) {
> +		lua_pushvalue(d->L, -1);
> +		lua_pushboolean(d->L, newval);
> +		lua_rawset(d->L, d->anchortable_index);
> +	}
> +
> +	if (newval != 0)
> +		return;
> +
> +	/*
> +	 * Other values and keys in the table
> +	 */
> +	lua_pushnil(d->L);
> +	while (lua_next(d->L, -2) != 0) {
> +		find_references(d);
> +		lua_pop(d->L, 1);
> +		find_references(d);
> +	}
> +}
> +
> +/**
> + * Dump recursively from the root node.
> + */
> +static int
> +dump_root(struct lua_dumper *d)
> +{
> +	struct node nd = {
> +		.mask = NODE_ROOT,
> +	};
> +	int ret;
> +
> +	luaL_checkfield(d->L, d->cfg, lua_gettop(d->L), &nd.field);
> +
> +	if (nd.field.type != MP_ARRAY || nd.field.size != 1) {
> +		d->err = EINVAL;
> +		snprintf(d->err_msg, sizeof(d->err_msg),
> +			 "serializer: unexpected data "
> +			 "(nd.field.size %d nd.field.type %d)",
> +			 nd.field.size, nd.field.type);
> +		return -1;
> +	}
> +
> +	/*
> +	 * We don't need to show the newly generated
> +	 * table, instead dump the nested one which
> +	 * is the real value.
> +	 */
> +	lua_rawgeti(d->L, -1, 1);
> +	ret = dump_node(d, &nd, 0);
> +	lua_pop(d->L, 1);
> +
> +	return (ret || d->err) ? -1 : 0;
> +}
> +
> +/**
> + * Encode data to Lua compatible form.
> + */
> +int
> +lua_encode(lua_State *L, struct luaL_serializer *serializer,
> +	   lua_dumper_opts_t *opts)
> +{
> +	struct lua_dumper dumper = {
> +		.L	= L,
> +		.cfg	= serializer,
> +		.outputL= luaT_newthread(L),
> +		.opts	= opts,
> +	};
> +
> +	if (!dumper.outputL)
> +		return luaL_error(L, "serializer: No free memory");
> +
> +	luaL_buffinit(dumper.outputL, &dumper.luabuf);
> +
> +	lua_newtable(L);
> +
> +	dumper.anchortable_index = lua_gettop(L);
> +	dumper.anchor_number = 0;
> +
> +	/* Push copy of arg we're processing */
> +	lua_pushvalue(L, 1);
> +	find_references(&dumper);
> +
> +	if (dump_root(&dumper) != 0)
> +		goto out;
> +
> +	/* Pop copied arg and anchor table */
> +	lua_pop(L, 2);
> +
> +	luaL_pushresult(&dumper.luabuf);
> +
> +	/* Move buffer to original thread */
> +	lua_xmove(dumper.outputL, L, 1);
> +	return 1;
> +
> +out:
> +	errno = dumper.err;
> +	lua_pushnil(L);
> +	lua_pushstring(L, dumper.err_msg);
> +	return 2;
> +}
> +
> +/**
> + * Parse serializer options.
> + */
> +void
> +lua_parse_opts(lua_State *L, lua_dumper_opts_t *opts)
> +{
> +	if (lua_gettop(L) < 2 || lua_type(L, -2) != LUA_TTABLE)
> +		luaL_error(L, "serializer: Wrong options format");
> +
> +	memset(opts, 0, sizeof(*opts));
> +
> +	lua_getfield(L, -2, "block");
> +	if (lua_isboolean(L, -1))
> +		opts->block_mode = lua_toboolean(L, -1);
> +	lua_pop(L, 1);
> +
> +	lua_getfield(L, -2, "indent");
> +	if (lua_isnumber(L, -1))
> +		opts->indent_lvl = (int)lua_tonumber(L, -1);
> +	lua_pop(L, 1);
> +}
> +
> +/**
> + * Initialize Lua serializer.
> + */
> +void
> +lua_serializer_init(struct lua_State *L)
> +{
> +	/*
> +	 * We don't export it as a module
> +	 * for a while, so the library
> +	 * is kept empty.
> +	 */
> +	static const luaL_Reg lualib[] = {
> +		{
> +			.name = NULL,
> +		},
> +	};
> +
> +	serializer_lua = luaL_newserializer(L, NULL, lualib);
> +	serializer_lua->has_compact		= 1;
> +	serializer_lua->encode_invalid_numbers	= 1;
> +	serializer_lua->encode_load_metatables	= 1;
> +	serializer_lua->encode_use_tostring	= 1;
> +	serializer_lua->encode_invalid_as_nil	= 1;
> +
> +	/*
> +	 * Keep a reference to this module so it
> +	 * won't be unloaded.
> +	 */
> +	lua_setfield(L, -2, "formatter_lua");
> +}
> diff --git a/src/box/lua/serialize_lua.h b/src/box/lua/serialize_lua.h
> new file mode 100644
> index 000000000..923e13be9
> --- /dev/null
> +++ b/src/box/lua/serialize_lua.h
> @@ -0,0 +1,67 @@
> +#ifndef INCLUDES_TARANTOOL_SERLIALIZE_LUA_H
> +#define INCLUDES_TARANTOOL_SERLIALIZE_LUA_H
> +
> +/*
> + * Copyright 2010-2020, Tarantool AUTHORS, please see AUTHORS file.
> + *
> + * Redistribution and use in source and binary forms, with or
> + * without modification, are permitted provided that the following
> + * conditions are met:
> + *
> + * 1. Redistributions of source code must retain the above
> + *    copyright notice, this list of conditions and the
> + *    following disclaimer.
> + *
> + * 2. Redistributions in binary form must reproduce the above
> + *    copyright notice, this list of conditions and the following
> + *    disclaimer in the documentation and/or other materials
> + *    provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
> + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
> + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
> + * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
> + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
> + * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#if defined(__cplusplus)
> +extern "C" {
> +#endif /* defined(__cplusplus) */
> +
> +struct luaL_serializer;
> +struct lua_State;
> +
> +/**
> + * Serializer options.
> + */
> +typedef struct {
> +	/** Number of indentation spaces. */
> +	unsigned int indent_lvl;
> +
> +	/** Block mode output. */
> +	bool block_mode;
> +} lua_dumper_opts_t;
> +
> +void
> +lua_serializer_init(struct lua_State *L);
> +
> +int
> +lua_encode(lua_State *L, struct luaL_serializer *serializer,
> +	   lua_dumper_opts_t *opts);
> +
> +void
> +lua_parse_opts(lua_State *L, lua_dumper_opts_t *opts);
> +
> +#if defined(__cplusplus)
> +} /* extern "C" */
> +#endif /* defined(__cplusplus) */
> +
> +#endif /* INCLUDES_TARANTOOL_SERLIALIZE_LUA_H */
> 

Re: [Tarantool-patches] [PATCH 6/7] box/console: switch to new lua serializer

[Oleg Babin]

Hi! Thanks for your patch. LGTM.
Please file an issue to remove serpent in the next version.

On 12/05/2020 16:50, Cyrill Gorcunov wrote:
> I do not drop the serpent module for a while
> since I need to make sure that everything work
> as expected as we've not break backward compatibility
> significantly (though we didn't claim the lua mode
> output is stable enough).
> 
> Fixes #4682
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>   src/box/lua/console.c             | 77 +++++++++++++++++++++++++++++++
>   src/box/lua/console.lua           | 76 +++++++++++++-----------------
>   test/app-tap/console_lua.test.lua | 18 ++++----
>   3 files changed, 119 insertions(+), 52 deletions(-)
> 
> diff --git a/src/box/lua/console.c b/src/box/lua/console.c
> index c8e0dea58..d1bf7949c 100644
> --- a/src/box/lua/console.c
> +++ b/src/box/lua/console.c
> @@ -39,6 +39,7 @@
>   #include "coio.h"
>   #include "lua/msgpack.h"
>   #include "lua-yaml/lyaml.h"
> +#include "serialize_lua.h"
>   #include <lua.h>
>   #include <lauxlib.h>
>   #include <lualib.h>
> @@ -50,6 +51,7 @@
>   extern char serpent_lua[];
>   
>   static struct luaL_serializer *serializer_yaml;
> +static struct luaL_serializer *serializer_lua;
>   
>   /*
>    * Completion engine (Mike Paul's).
> @@ -68,6 +70,54 @@ lua_rl_complete(lua_State *L, const char *text, int start, int end);
>    */
>   static struct lua_State *readline_L;
>   
> +/**
> + * Encode Lua object into Lua form.
> + */
> +static int
> +lbox_console_format_lua(struct lua_State *L)
> +{
> +	lua_dumper_opts_t opts;
> +	int arg_count;
> +
> +	/* Parse options and remove them */
> +	lua_parse_opts(L, &opts);
> +	lua_remove(L, 1);
> +
> +	arg_count = lua_gettop(L);
> +
> +	/* If nothing to process just exit early */
> +	if (arg_count == 0)
> +		return 0;
> +
> +	/*
> +	 * When processing arguments we might
> +	 * need to modify reference (for example
> +	 * when __index references to object itself)
> +	 * thus make a copy of incoming data.
> +	 *
> +	 * Note that in yaml there is no map for
> +	 * Lua's "nil" value so for yaml encoder
> +	 * we do
> +	 *
> +	 * if (lua_isnil(L, i + 1))
> +	 *     luaL_pushnull(L);
> +	 * else
> +	 *     lua_pushvalue(L, i + 1);
> +	 *
> +	 *
> +	 * For lua mode we have to preserve "nil".
> +	 */
> +	lua_createtable(L, arg_count, 0);
> +	for (int i = 0; i < arg_count; ++i) {
> +		lua_pushvalue(L, i + 1);
> +		lua_rawseti(L, -2, i + 1);
> +	}
> +
> +	lua_replace(L, 1);
> +	lua_settop(L, 1);
> +	return lua_encode(L, serializer_lua, &opts);
> +}
> +
>   /*
>    * console_completion_handler()
>    * Called by readline to collect plausible completions;
> @@ -557,6 +607,7 @@ tarantool_lua_console_init(struct lua_State *L)
>   		{"add_history",		lbox_console_add_history},
>   		{"completion_handler",	lbox_console_completion_handler},
>   		{"format_yaml",		lbox_console_format_yaml},
> +		{"format_lua",		lbox_console_format_lua},
>   		{NULL, NULL}
>   	};
>   	luaL_register_module(L, "console", consolelib);
> @@ -581,6 +632,32 @@ tarantool_lua_console_init(struct lua_State *L)
>   	 * load_history work the same way.
>   	 */
>   	lua_setfield(L, -2, "formatter");
> +
> +	/*
> +	 * We don't export it as a module
> +	 * for a while, so the library
> +	 * is kept empty.
> +	 */
> +	static const luaL_Reg lualib[] = {
> +		{ },
> +	};
> +
> +	serializer_lua = luaL_newserializer(L, NULL, lualib);
> +	serializer_lua->has_compact		= 1;
> +	serializer_lua->encode_invalid_numbers	= 1;
> +	serializer_lua->encode_load_metatables	= 1;
> +	serializer_lua->encode_use_tostring	= 1;
> +	serializer_lua->encode_invalid_as_nil	= 1;
> +
> +	/*
> +	 * Keep a reference to this module so it
> +	 * won't be unloaded.
> +	 */
> +	lua_setfield(L, -2, "formatter_lua");
> +
> +	/* Output formatter in Lua mode */
> +	lua_serializer_init(L);
> +
>   	struct session_vtab console_session_vtab = {
>   		.push	= console_session_push,
>   		.fd	= console_session_fd,
> diff --git a/src/box/lua/console.lua b/src/box/lua/console.lua
> index 5642ca956..6ea27a393 100644
> --- a/src/box/lua/console.lua
> +++ b/src/box/lua/console.lua
> @@ -69,60 +69,50 @@ output_handlers["yaml"] = function(status, opts, ...)
>       return internal.format_yaml({ error = err })
>   end
>   
> --- A map for internal symbols in case if they
> --- are not inside tables and serpent won't be
> --- able to handle them properly.
> -local lua_map_direct_symbols = {
> -    [box.NULL]      = 'box.NULL',
> -}
> -
> --- A map for internal symbols in case if they
> --- are coming from tables and we need to depict
> --- them into user known values.
> -local lua_map_table_symbols = {
> -    ['"cdata<void %*>: NULL"']  = 'box.NULL'
> -}
> -
>   --
> --- Map internal symbols which serpent doesn't
> --- know about to a known representation.
> -local serpent_map_symbols = function(tag, head, body, tail, level)
> -    for k,v in pairs(lua_map_table_symbols) do
> -        body = body:gsub(k, v)
> +-- Format a Lua value.
> +local function format_lua_value(status, internal_opts, value)
> +    local err
> +    if status then
> +        status, err = pcall(internal.format_lua, internal_opts, value)
> +        if status then
> +            return err
> +        else
> +            local m = 'console: exception while formatting output: "%s"'
> +            err = m:format(tostring(err))
> +        end
> +    else
> +        err = value
> +        if err == nil then
> +            err = box.NULL
> +        end
>       end
> -    return tag..head..body..tail
> +    return internal.format_lua(internal_opts, { error = err })
>   end
>   
>   --
> --- Format a Lua value.
> -local function format_lua_value(value, opts)
> -    for k,v in pairs(lua_map_direct_symbols) do
> -        if k == value then
> -            return v
> -        end
> -    end
> -    local serpent_opts = {
> -        custom  = serpent_map_symbols,
> -        comment = false,
> -        nocode  = true,
> -    }
> +-- Convert options from user form to the internal format.
> +local function gen_lua_opts(opts)
>       if opts == "block" then
> -        return serpent.block(value, serpent_opts)
> +        return {block=true, indent=2}
> +    else
> +        return {block=false, indent=2}
>       end
> -    return serpent.line(value, serpent_opts)
>   end
>   
>   output_handlers["lua"] = function(status, opts, ...)
>       local collect = {}
>       --
> -    -- If no data present at least EOS should be put,
> -    -- otherwise wire readers won't be able to find
> -    -- where the end of string is.
> -    if not ... then
> -        return output_eos["lua"]
> -    end
> +    -- Convert options to internal dictionary.
> +    local internal_opts = gen_lua_opts(opts)
>       for i = 1, select('#', ...) do
> -        collect[i] = format_lua_value(select(i, ...), opts)
> +        collect[i] = format_lua_value(status, internal_opts, select(i, ...))
> +        if collect[i] == nil then
> +            --
> +            -- table.concat doesn't work for nil
> +            -- so convert it explicitly.
> +            collect[i] = "nil"
> +        end
>       end
>       return table.concat(collect, ', ') .. output_eos["lua"]
>   end
> @@ -210,8 +200,8 @@ end
>   
>   -- Used by console_session_push.
>   box_internal.format_lua_push = function(value)
> -    local opts = current_output()["opts"]
> -    value = format_lua_value(value, opts)
> +    local internal_opts = gen_lua_opts(current_output()["opts"])
> +    value = format_lua_value(true, internal_opts, value)
>       return '-- Push\n' .. value .. ';'
>   end
>   
> diff --git a/test/app-tap/console_lua.test.lua b/test/app-tap/console_lua.test.lua
> index 3ed6aad97..8bb6eb0b3 100755
> --- a/test/app-tap/console_lua.test.lua
> +++ b/test/app-tap/console_lua.test.lua
> @@ -102,29 +102,29 @@ local cases = {
>           prepare     = 'a = {1, 2, 3}',
>           opts        = {block = false},
>           input       = '1, 2, nil, a',
> -        expected    = '1, 2, box.NULL, {1, 2, 3}',
> +        expected    = '1, 2, nil, {1, 2, 3}',
>           cleanup     = 'a = nil',
>       }, {
>           name        = 'multireturn block mode',
>           prepare     = 'a = {1, 2, 3}',
>           opts        = {block = true},
>           input       = '1, 2, nil, a',
> -        expected    = '1, 2, box.NULL, {\n  1,\n  2,\n  3\n}',
> +        expected    = '1, 2, nil, {\n  1,\n  2,\n  3\n}',
>           cleanup     = 'a = nil',
>       }, {
> -        name        = 'trailing nils, line mode',
> +        name        = 'trailing nils, box.NULL, line mode',
>           opts        = {block = false},
> -        input       = '1, nil, nil, nil',
> -        expected    = '1, box.NULL, box.NULL, box.NULL',
> +        input       = '1, nil, box.NULL, nil',
> +        expected    = '1, nil, box.NULL, nil',
>       }, {
> -        name        = 'trailing nils, block mode',
> +        name        = 'trailing nils, box.NULL, block mode',
>           opts        = {block = true},
> -        input       = '1, nil, nil, nil',
> -        expected    = '1, box.NULL, box.NULL, box.NULL',
> +        input       = '1, nil, box.NULL, nil',
> +        expected    = '1, nil, box.NULL, nil',
>       }, {
>           name        = 'empty output',
>           input       = '\\set output',
> -        expected    = '"Specify output format: lua or yaml."',
> +        expected    = '{error = \"Specify output format: lua or yaml.\"}',
>       }
>   }
>   
> 

Re: [Tarantool-patches] [PATCH 7/7] test: extend console lua test

[Oleg Babin]

Hi. Thanks for your patch! LGTM.

On 12/05/2020 16:50, Cyrill Gorcunov wrote:
> To make sure ULL constants are not broken.
> 
> Part-of #4682
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>   test/app-tap/console_lua.test.lua | 15 +++++++++++++++
>   1 file changed, 15 insertions(+)
> 
> diff --git a/test/app-tap/console_lua.test.lua b/test/app-tap/console_lua.test.lua
> index 8bb6eb0b3..dbfc3da11 100755
> --- a/test/app-tap/console_lua.test.lua
> +++ b/test/app-tap/console_lua.test.lua
> @@ -116,11 +116,26 @@ local cases = {
>           opts        = {block = false},
>           input       = '1, nil, box.NULL, nil',
>           expected    = '1, nil, box.NULL, nil',
> +    }, {
> +        name        = 'leading nils, box.NULL, line mode',
> +        opts        = {block = false},
> +        input       = 'nil, 1, nil, box.NULL, nil',
> +        expected    = 'nil, 1, nil, box.NULL, nil',
>       }, {
>           name        = 'trailing nils, box.NULL, block mode',
>           opts        = {block = true},
>           input       = '1, nil, box.NULL, nil',
>           expected    = '1, nil, box.NULL, nil',
> +    }, {
> +        name        = 'ULL constants, multireturn',
> +        opts        = {block = false},
> +        input       = '-1ULL, -2ULL, 1ULL, 2ULL',
> +        expected    = '18446744073709551615, 18446744073709551614, 1, 2',
> +    }, {
> +        name        = 'ULL key',
> +        opts        = {block = false},
> +        input       = '{[-1ULL] = 1}',
> +        expected    = '{[18446744073709551615] = 1}',
>       }, {
>           name        = 'empty output',
>           input       = '\\set output',
> 

Re: [Tarantool-patches] [PATCH 7/7] test: extend console lua test

[Cyrill Gorcunov]

On Mon, May 18, 2020 at 03:22:13PM +0300, Oleg Babin wrote:
> Hi. Thanks for your patch! LGTM.
> 

Thanks for looking in! Lets spin it inside master branch
for stabilization reason and I'll drop the serpent then.

Re: [Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Kirill Yukhin]

Hello,

On 12 май 16:50, Cyrill Gorcunov wrote:
> In the series we implement support for internal taranool types
> such as ULL. To be able to do so we implement own serializer
> thus the output is simiar to encodings in yaml mode.
> 
> Once things settle down we will drop serpent module. I guess
> I need to explain why serpent didn't fit: there is no interface
> inside serpent to fetch internal tarantool types and adding it
> means more work to do than implement an own serializer.
> 
> v-2:
>  - address issues with achors encoding
> 
> issue https://github.com/tarantool/tarantool/issues/4682
> branch gorcunov/gh-4682-console-numbers-2
> 
> Cyrill Gorcunov (7):
>   box/console: console_session_vtab -- use designated initialization
>   box/console: use tabs instead of spaces in consolelib
>   box/console: rename format to format_yaml
>   box/console: rename luaL_yaml_default to serializer_yaml
>   box/console: implement lua serializer
>   box/console: switch to new lua serializer
>   test: extend console lua test

LGTM.

I've checked your patch into 2.4 and master.
I didn't committed it further. Maybe will do that in future.

--
Regards, Kirill Yukhin

Re: [Tarantool-patches] [PATCH 4/7] box/console: rename luaL_yaml_default to serializer_yaml

[Igor Munkin]

Oleg,

On 18.05.20, Oleg Babin wrote:
> Hi! I'm not sure that we really should do that. Functions with LuaL 
> prefix is a part of Lua code convention AFAIK.
> (https://www.lua.org/manual/5.1/manual.html#4)

No, it doesn't relate to Lua code convention (at least to the one you've
mentioned). luaL_ is just a custom prefix for functions declared/defined
in lauxlib.h header, which is a part of Lua public API.

| All functions from the auxiliary library are defined in header file
| lauxlib.h and have a prefix luaL_.

However this prefix is also used for auxiliary functions provided by
Tarantool (e.g luaL_pushcdata). This *might* be an argument for
convention saving but it's definitely a weak one for these changes. I
see no problems with the renaming Cyrill made within this patch, since
it just affects the name of the static global variable. Please also
consider the issue[1] that closely relates to the subj.

> 

<snipped>

[1]: https://github.com/tarantool/tarantool/issues/4577

-- 
Best regards,
IM

Re: [Tarantool-patches] [PATCH 4/7] box/console: rename luaL_yaml_default to serializer_yaml

[Oleg Babin]

Igor, thanks for explanation! Yes, then my comment is not relevant.

On 19/05/2020 00:17, Igor Munkin wrote:
> Oleg,
> 
> On 18.05.20, Oleg Babin wrote:
>> Hi! I'm not sure that we really should do that. Functions with LuaL
>> prefix is a part of Lua code convention AFAIK.
>> (https://www.lua.org/manual/5.1/manual.html#4)
> 
> No, it doesn't relate to Lua code convention (at least to the one you've
> mentioned). luaL_ is just a custom prefix for functions declared/defined
> in lauxlib.h header, which is a part of Lua public API.
> 
> | All functions from the auxiliary library are defined in header file
> | lauxlib.h and have a prefix luaL_.
> 
> However this prefix is also used for auxiliary functions provided by
> Tarantool (e.g luaL_pushcdata). This *might* be an argument for
> convention saving but it's definitely a weak one for these changes. I
> see no problems with the renaming Cyrill made within this patch, since
> it just affects the name of the static global variable. Please also
> consider the issue[1] that closely relates to the subj.
> 
>>
> 
> <snipped>
> 
> [1]: https://github.com/tarantool/tarantool/issues/4577
> 

Re: [Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Cyrill Gorcunov]

On Tue, May 12, 2020 at 08:06:07PM +0300, Mons Anderson wrote:
> >> I'm not sure that we should return errors in such way:
> >> ```
> >> tarantool> x
> >> {error = "[string \"return x\"]:1: variable \'x\' is not declared"};
> >> ```
> > 
> > Yes. This allows to paste the result back to the console.
> > This is change in behaviour but while we're not claiming
> > that th lua mode is stable I think we can do so.
> 
> Then it would be great to return it as
> 
> error “[string \"return x\"]:1: variable \'x\' is not declared"
> 
> or even better
> 
> error [[[string "return x"]:1: variable 'x' is not declared]]

This breaks the idea of having output suitable for pasting back
to the console. Take a look on yaml ouput, I made the same.

...
> 
> There is a possibility to take a length or result (select(‘#’,...))

Already fixed in v2 of the seies.

Re: [Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Mons Anderson]

> On 8 May 2020, at 19:19, Cyrill Gorcunov <gorcunov@gmail.com> wrote:
> 
> On Fri, May 08, 2020 at 07:04:26PM +0300, Oleg Babin wrote:
>> Hi! Thanks for patchset! I have a few comments.
>> 
>> I'm not sure that we should return errors in such way:
>> ```
>> tarantool> x
>> {error = "[string \"return x\"]:1: variable \'x\' is not declared"};
>> ```
> 
> Yes. This allows to paste the result back to the console.
> This is change in behaviour but while we're not claiming
> that th lua mode is stable I think we can do so.

Then it would be great to return it as

error “[string \"return x\"]:1: variable \'x\' is not declared"

or even better

error [[[string "return x"]:1: variable 'x' is not declared]]

> 
>> 
>> Or is it expected behaviour?
>> 
>> Also `nil` value is ignored in some cases.
>> ```
>> tarantool> nil
>> ;
>> tarantool> nil, 2, 3
>> ;
>> tarantool> 1, nil, 3
>> 1, nil, 3;
>> ```
> 
> Thanks! I'll take a look.


There is a possibility to take a length or result (select(‘#’,...))

Re: [Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Cyrill Gorcunov]

On Fri, May 08, 2020 at 02:47:07PM +0300, Cyrill Gorcunov wrote:
> In the series we implement support for internal taranool types
> such as ULL. To be able to do so we implement own serializer
> thus the output is simiar to encodings in yaml mode.

drop this series please, v2 been sent out

Re: [Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Cyrill Gorcunov]

On Fri, May 08, 2020 at 07:04:26PM +0300, Oleg Babin wrote:
> Hi! Thanks for patchset! I have a few comments.
> 
> I'm not sure that we should return errors in such way:
> ```
> tarantool> x
> {error = "[string \"return x\"]:1: variable \'x\' is not declared"};
> ```

Yes. This allows to paste the result back to the console.
This is change in behaviour but while we're not claiming
that th lua mode is stable I think we can do so.

> 
> Or is it expected behaviour?
> 
> Also `nil` value is ignored in some cases.
> ```
> tarantool> nil
> ;
> tarantool> nil, 2, 3
> ;
> tarantool> 1, nil, 3
> 1, nil, 3;
> ```

Thanks! I'll take a look.

> 
> And I've met strange output:
> ```
> tarantool> box.space.test.index
> {[0] = {unique = true, parts = {{type = "integer", is_nullable = "false",
> fieldno = "3"}, {type = "unsigned", is_nullable = "false", fieldno = "5"}},
> type = "TREE", id = "0", space_id = "520", name = "id"}, [1] = {unique =
> false, parts = {{type = "unsigned", is_nullable = "false", fieldno = "1"}},
> id = 1, space_id = 520, type = "TREE", name = "bucket_id"}, [bucket_id]1
>  = !!!*anchor[id]0
>  = !!!*anchor};
> ```
> 
> "!!!*anchor" looks strange. Seems it occurs when you mix map and array.

Yes, this is self reference. I need to revisit this moment. Thank you!

Re: [Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Oleg Babin]

Hi! Thanks for patchset! I have a few comments.

I'm not sure that we should return errors in such way:
```
tarantool> x
{error = "[string \"return x\"]:1: variable \'x\' is not declared"};
```

Or is it expected behaviour?

Also `nil` value is ignored in some cases.
```
tarantool> nil
;
tarantool> nil, 2, 3
;
tarantool> 1, nil, 3
1, nil, 3;
```

And I've met strange output:
```
tarantool> box.space.test.index
{[0] = {unique = true, parts = {{type = "integer", is_nullable = 
"false", fieldno = "3"}, {type = "unsigned", is_nullable = "false", 
fieldno = "5"}}, type = "TREE", id = "0", space_id = "520", name = 
"id"}, [1] = {unique = false, parts = {{type = "unsigned", is_nullable = 
"false", fieldno = "1"}}, id = 1, space_id = 520, type = "TREE", name = 
"bucket_id"}, [bucket_id]1
  = !!!*anchor[id]0
  = !!!*anchor};
```

"!!!*anchor" looks strange. Seems it occurs when you mix map and array.

On 08/05/2020 14:47, Cyrill Gorcunov wrote:
> In the series we implement support for internal taranool types
> such as ULL. To be able to do so we implement own serializer
> thus the output is simiar to encodings in yaml mode.
> 
> Once things settle down we will drop serpent module. I guess
> I need to explain why serpent didn't fit: there is no interface
> inside serpent to fetch internal tarantool types and adding it
> means more work to do than implement an own serializer.
> 
> issue https://github.com/tarantool/tarantool/issues/4682
> branch gorcunov/gh-4682-console-numbers
> 
> Cyrill Gorcunov (7):
>    box/console: console_session_vtab -- use designated initialization
>    box/console: use tabs instead of spaces in consolelib
>    box/console: rename format to format_yaml
>    box/console: rename luaL_yaml_default to serializer_yaml
>    box/console: implement lua serializer
>    box/console: switch to new lua serializer
>    test: extend console lua test
> 
>   src/box/CMakeLists.txt            |    1 +
>   src/box/lua/console.c             |  111 +++-
>   src/box/lua/console.lua           |   75 +--
>   src/box/lua/serialize_lua.c       | 1021 +++++++++++++++++++++++++++++
>   src/box/lua/serialize_lua.h       |   67 ++
>   test/app-tap/console_lua.test.lua |   28 +-
>   6 files changed, 1238 insertions(+), 65 deletions(-)
>   create mode 100644 src/box/lua/serialize_lua.c
>   create mode 100644 src/box/lua/serialize_lua.h
> 

[Tarantool-patches] [PATCH 0/7] box/console: add support for internal types

[Cyrill Gorcunov]

In the series we implement support for internal taranool types
such as ULL. To be able to do so we implement own serializer
thus the output is simiar to encodings in yaml mode.

Once things settle down we will drop serpent module. I guess
I need to explain why serpent didn't fit: there is no interface
inside serpent to fetch internal tarantool types and adding it
means more work to do than implement an own serializer.

issue https://github.com/tarantool/tarantool/issues/4682
branch gorcunov/gh-4682-console-numbers

Cyrill Gorcunov (7):
  box/console: console_session_vtab -- use designated initialization
  box/console: use tabs instead of spaces in consolelib
  box/console: rename format to format_yaml
  box/console: rename luaL_yaml_default to serializer_yaml
  box/console: implement lua serializer
  box/console: switch to new lua serializer
  test: extend console lua test

 src/box/CMakeLists.txt            |    1 +
 src/box/lua/console.c             |  111 +++-
 src/box/lua/console.lua           |   75 +--
 src/box/lua/serialize_lua.c       | 1021 +++++++++++++++++++++++++++++
 src/box/lua/serialize_lua.h       |   67 ++
 test/app-tap/console_lua.test.lua |   28 +-
 6 files changed, 1238 insertions(+), 65 deletions(-)
 create mode 100644 src/box/lua/serialize_lua.c
 create mode 100644 src/box/lua/serialize_lua.h

-- 
2.26.2