Fast YAML is an Erlang wrapper for libyaml "C" library.
It is designed to be fast and efficient.
Fast YAML depends on native LibYaml library. You need development headers for LibYaml library to build it.
The minimum required Erlang/OTP version is 18.0
You can trigger build with:
./configure && make
You can install LibYaml and with Homebrew:
brew install libyaml
You can then export environment variable to use LibYaml as installed by Homebrew, before issuing compilation commands:
export LDFLAGS="-L/usr/local/lib"
export CFLAGS="-I/usr/local/include"
export CPPFLAGS="-I/usr/local/include"
./configure && make
erl -pa ebin -pa deps/*/ebin
Erlang/OTP 18 [erts-7.1] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]
Eshell V7.1 (abort with ^G)
1> application:start(fast_yaml).
ok
2> fast_yaml:decode(<<"a: 1\nb: -3.0">>).
{ok,[[{<<"a">>,1},{<<"b">>,-3.0}]]}Converts all unquoted YAML values to atoms
3> fast_yaml:decode(<<"a: 1\nb: -3.0">>, [{plain_as_atom, true}]).
{ok,[[{a,1},{b,-3.0}]]}
4> fast_yaml:decode(<<"a: b\nc">>).
{error,{scanner_error,<<"could not find expected ':'">>,2,
0}}.
5> fast_yaml:decode_from_file("test/test2.yml", [plain_as_atom]).
{ok,[[[{step,[{instrument,<<"Lasik 2000">>},
{pulseEnergy,5.4},
{pulseDuration,12},
{repetition,1000},
{spotSize,<<"1mm">>}]}],
[{step,[{instrument,<<"Lasik 2000">>},
{pulseEnergy,5.0},
{pulseDuration,10},
{repetition,500},
{spotSize,<<"2mm">>}]}],
[{step,<<"id001">>}],
[{step,<<"id002">>}],
[{step,<<"id001">>}],
[{step,<<"id002">>}]]]}Converts the following scalar values to their Erlang-native data type:
"null" → undefined
"true" → true
"false" → false
Integer and float values also get converted. All other scalar values stay binaries. Key in mappings also stay binary and never get coerced into int / float / atom .
An unquoted mapping value that is an empty string gets converted into
undefined. (e.g. the string "foo:" decodes as [{<<"foo">>, undefined}])
Convert YAML mappings into Erlang maps.
7> fast_yaml:decode(<<"a: true\nb: -3.0\nc: string">>, [{maps, true}]).
{ok, [#{"a" => "true", "b" => -3.0, "c" => "string"}]}For compatibility with the
yamerlandYamlElixirlibraries, use the[sane_scalars, maps]options.
You can run eunit test with the command:
make test