%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
%% 
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%% 
%% %CopyrightEnd%
%%
%%


-export([parse/1, parse_and_scan/1, format_error/1]).

-import(lists, [reverse/1]).

-ifdef(JAM).
-compile([{parse_transform,jam_yecc_pj},pj]).
-endif.


-include("icforms.hrl").



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% The parser generator will insert appropriate declarations before this line.%

parse(Tokens) ->
    case catch yeccpars1(Tokens, false, 0, [], []) of
	error ->
	    Errorline =
		if Tokens == [] -> 0; true -> element(2, hd(Tokens)) end,
	    {error,
	     {Errorline, ?MODULE, "syntax error at or after this line."}};
	Other ->
	    Other
    end.

parse_and_scan({Mod, Fun, Args}) ->
    case apply(Mod, Fun, Args) of
	{eof, _} ->
	    {ok, eof};
	{error, Descriptor, _} ->
	    {error, Descriptor};
	{ok, Tokens, _} ->
	    yeccpars1(Tokens, {Mod, Fun, Args}, 0, [], [])
    end.

format_error(Message) ->
    case io_lib:deep_char_list(Message) of
	true ->
	    Message;
	_ ->
	    io_lib:write(Message)
    end.

% To be used in grammar files to throw an error message to the parser toplevel.
% Doesn't have to be exported!
return_error(Line, Message) ->
    throw({error, {Line, ?MODULE, Message}}).


% Don't change yeccpars1/6 too much, it is called recursively by yeccpars2/8!
yeccpars1([Token | Tokens], Tokenizer, State, States, Vstack) ->
    yeccpars2(State, element(1, Token), States, Vstack, Token, Tokens,
	      Tokenizer);
yeccpars1([], {M, F, A}, State, States, Vstack) ->
    case catch apply(M, F, A) of
        {eof, Endline} ->
            {error, {Endline, ?MODULE, "end_of_file"}};
        {error, Descriptor, _Endline} ->
            {error, Descriptor};
        {'EXIT', Reason} ->
            {error, {0, ?MODULE, Reason}};
        {ok, Tokens, _Endline} ->
	    case catch yeccpars1(Tokens, {M, F, A}, State, States, Vstack) of
		error ->
		    Errorline = element(2, hd(Tokens)),
		    {error, {Errorline, ?MODULE,
			     "syntax error at or after this line."}};
		Other ->
		    Other
	    end
    end;
yeccpars1([], false, State, States, Vstack) ->
    yeccpars2(State, '$end', States, Vstack, {'$end', 999999}, [], false).

% For internal use only.
yeccerror(Token) ->
    {error,
     {element(2, Token), ?MODULE,
      ["syntax error before: ", yecctoken2string(Token)]}}.

yecctoken2string({atom, _, A}) -> io_lib:write(A);
yecctoken2string({integer,_,N}) -> io_lib:write(N);
yecctoken2string({float,_,F}) -> io_lib:write(F);
yecctoken2string({char,_,C}) -> io_lib:write_char(C);
yecctoken2string({var,_,V}) -> io_lib:format("~s", [V]);
yecctoken2string({string,_,S}) -> io_lib:write_string(S);
yecctoken2string({reserved_symbol, _, A}) -> io_lib:format("~w", [A]);
yecctoken2string({'dot', _}) -> "'.'";
yecctoken2string({'$end', _}) ->
    [];
yecctoken2string({Other, _}) when is_atom(Other) ->
    io_lib:format("~w", [Other]);
yecctoken2string({_, _, Other}) when is_list(Other) andalso is_number(hd(Other)) ->
    Other;
yecctoken2string({_, _, Other}) ->
    io_lib:format("~p", [Other]);
yecctoken2string(Other) ->
    io_lib:write(Other).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

