Repository files navigation

erldn is a parser for theedn specification.

implemented using leex and yecc, tested with eunit.

this is a low level parser, it gives you an erlang data structure where youhave to decide how will you actually represent things like maps, sets, vectorssince each person may have a different need, no imposition here.

./rebar compile

./rebar eunit

1> erldn:parse_str("{}").{ok,{map,[]}}2> erldn:parse_str("1").{ok,1}3> erldn:parse_str("true").{ok,true}4> erldn:parse_str("nil").{ok,nil}5> erldn:parse_str("[1 true nil]").{ok,{vector,[1,true,nil]}}6> erldn:parse_str("(1 true nil :foo)").{ok,[1,true,nil,foo]}7> erldn:parse_str("(1 true nil :foo ns/foo)").{ok,[1,true,nil,foo,{symbol,'ns/foo'}]}8> erldn:parse_str("#{1 true nil :foo ns/foo}").{ok,{set,[1,true,nil,foo,{symbol,'ns/foo'}]}}9> erldn:parse_str("#myapp/Person {:first \"Fred\" :last \"Mertz\"}").{ok,{tag,'myapp/Person',         {map,[{first,"Fred"},{last,"Mertz"}]}}}         10> erldn:parse_str("#{1 true #_ nil :foo ns/foo}").         {ok,{set,[1,true,{ignore,nil},foo,{symbol,'ns/foo'}]}}         11> erldn:parse_str("#{1 true #_ 42 :foo ns/foo}").         {ok,{set,[1,true,{ignore,42},foo,{symbol,'ns/foo'}]}} % to_string 10> {ok, Result} = erldn:parse_str("{:a 42}"). {ok,{map,[{a,42}]}} 11> io:format("~s~n", [erldn:to_string(Result)]). {:a 42} ok % to_erlang 12> erldn:to_erlang(element(2, erldn:parse_str("[1, nil, :nil, \"asd\"]"))). [1,nil,nil,<<"asd">>]

parse_str/1

parses a string with edn into an erlang data structure maintaining allthe details from the original edn

to_string/1

converts the result fromparse_str/1 into an edn string representation

to_erlang/1

converts the result fromparse_str/1 into an erlang-friendly version ofitself; see "To Erlang Mappings" below.

to_erlang/2

liketo_erlang/1 but accepts a tuplelist as a second argument with atag as the first argument and a function (fun (Tag, Value, OtherHandlers) -> .. end)as the second of each pair to handle tagged values.

check the unit tests for usage examples.

The to_erlang function transforms the incoming data structure into a moreerlang-friendly data structure, but this can't be converted back to a stringwithout transforming it again. The mappings by default are:

nothing that I can think of!

• since keywords are mapped to atoms and nil is mapped to the nil atom, ifthe nil keyword is encountered it will be mapped to {keyword, nil}.

marianoguerra

MIT + optional beer for the author if you meet me

make cleanmakeMIX_EXS=package.exs mix hex.publish