when print record format by lager:pr which has binary value, need space after '='

[yidayoung]

when print a record like #rec{field =<<"">>}, it will trans to string "#rec{field=<<"">>}"
every thing works fine, but when paste this string to shell will cause syntax error before: '=<'
because need space after '=' like this "#rec{field= <<"">>}"

so, can we change this format here

lager/src/lager_trunc_io.erl

Lines 501 to 504 in 459a3b2

	{FieldStr, FieldLen} = print(Field, Max - ExtraChars, Options),
	{ValueStr, ValueLen} = print(Value, Max - (FieldLen + ExtraChars), Options),
	{Final, FLen} = record_fields(T, Max - (FieldLen + ValueLen + ExtraChars), dec_depth(Options)),
	{[FieldStr++"="++ValueStr++Terminator|Final], FLen + FieldLen + ValueLen + ExtraChars}.

---

one way is change binary print function

lager/src/lager_trunc_io.erl

Lines 130 to 148 in 459a3b2

	print(<<>>, _Max, #print_options{depth=1}) ->
	{"<<>>", 4};
	print(Bin, _Max, #print_options{depth=1}) when is_binary(Bin) ->
	{"<<...>>", 7};
	print(<<>>, _Max, Options) ->
	case Options#print_options.force_strings of
	true ->
	{"", 0};
	false ->
	{"<<>>", 4}
	end;
	print(Binary, 0, _Options) when is_bitstring(Binary) ->
	{"<<..>>", 6};
	print(Bin, Max, _Options) when is_binary(Bin), Max < 2 ->
	{"<<...>>", 7};
	print(Binary, Max, Options) when is_binary(Binary) ->
	B = binary_to_list(Binary, 1, lists:min([Max, byte_size(Binary)])),

but this may cause some other behavior changed

or just add ensure_space after print function, like this

    {FieldStr, FieldLen} = print(Field, Max - ExtraChars, Options),
    {ValueStr, ValueLen} = print(Value, Max - (FieldLen + ExtraChars), Options),
    {ValueStr2, ValueLen2} = ensure_space(Value, ValueStr, ValueLen),
    {Final, FLen} = record_fields(T, Max - (FieldLen + ValueLen + ExtraChars), dec_depth(Options)),
    {[FieldStr++"="++ValueStr2++Terminator|Final], FLen + FieldLen + ValueLen2 + ExtraChars}.

ensure_space(Value, ValueStr, ValueLen) when is_binary(Value) ->
    {" "+ValueStr, ValueLen+1};
ensure_space(_Value, ValueStr, ValueLen) ->
    {ValueStr, ValueLen}.

---

if add ensure_space is enough, i can make a pr for this