%% The source of this file is part of leex distribution, as such it
%% has the same Copyright as the other files in the leex
%% distribution. The Copyright is defined in the accompanying file
%% COPYRIGHT. However, the resultant scanner generated by leex is the
%% property of the creator of the scanner and is not covered by that
%% Copyright.

##module

-export([string/1,string/2,token/2,token/3,tokens/2,tokens/3]).
-export([format_error/1]).

%% User code. This is placed here to allow extra attributes.
##code

format_error({illegal,S}) -> ["illegal characters ",io_lib:write_string(S)];
format_error({user,S}) -> S.

string(String) -> string(String, 1).

string(String, Line) -> string(String, Line, String, []).

%% string(InChars, Line, TokenChars, Tokens) ->
%% {ok,Tokens,Line} | {error,ErrorInfo,Line}.
%% Note the line number going into yystate, L0, is line of token
%% start while line number returned is line of token end. We want line
%% of token start.

string([], L, [], Ts) ->                     % No partial tokens!
    {ok,yyrev(Ts),L};
string(Ics0, L0, Tcs, Ts) ->
    case yystate(yystate(), Ics0, L0, 0, reject, 0) of
        {A,Alen,Ics1,L1} ->                  % Accepting end state
            string_cont(Ics1, L1, yyaction(A, Alen, Tcs, L0), Ts);
        {A,Alen,Ics1,L1,_S1} ->              % Accepting transistion state
            string_cont(Ics1, L1, yyaction(A, Alen, Tcs, L0), Ts);
        {reject,_Alen,Tlen,_Ics1,L1,_S1} ->  % After a non-accepting state
            {error,{L0,?MODULE,{illegal,yypre(Tcs, Tlen+1)}},L1};
        {A,Alen,Tlen,_Ics1,L1,_S1} ->
            Tcs1 = yysuf(Tcs, Alen),
            L2 = adjust_line(Tlen, Alen, Tcs1, L1),
            string_cont(Tcs1, L2, yyaction(A, Alen, Tcs, L0), Ts)
    end.

%% string_cont(RestChars, Line, Token, Tokens)
%% Test for and remove the end token wrapper. Push back characters
%% are prepended to RestChars.

-dialyzer({nowarn_function, string_cont/4}).

string_cont(Rest, Line, {token,T}, Ts) ->
    string(Rest, Line, Rest, [T|Ts]);
string_cont(Rest, Line, {token,T,Push}, Ts) ->
    NewRest = Push ++ Rest,
    string(NewRest, Line, NewRest, [T|Ts]);
string_cont(Rest, Line, {end_token,T}, Ts) ->
    string(Rest, Line, Rest, [T|Ts]);
string_cont(Rest, Line, {end_token,T,Push}, Ts) ->
    NewRest = Push ++ Rest,
    string(NewRest, Line, NewRest, [T|Ts]);
string_cont(Rest, Line, skip_token, Ts) ->
    string(Rest, Line, Rest, Ts);
string_cont(Rest, Line, {skip_token,Push}, Ts) ->
    NewRest = Push ++ Rest,
    string(NewRest, Line, NewRest, Ts);
string_cont(_Rest, Line, {error,S}, _Ts) ->
    {error,{Line,?MODULE,{user,S}},Line}.

%% token(Continuation, Chars) ->
%% token(Continuation, Chars, Line) ->
%% {more,Continuation} | {done,ReturnVal,RestChars}.
%% Must be careful when re-entering to append the latest characters to the
%% after characters in an accept. The continuation is:
%% {token,State,CurrLine,TokenChars,TokenLen,TokenLine,AccAction,AccLen}

token(Cont, Chars) -> token(Cont, Chars, 1).

token([], Chars, Line) ->
    token(yystate(), Chars, Line, Chars, 0, Line, reject, 0);
token({token,State,Line,Tcs,Tlen,Tline,Action,Alen}, Chars, _) ->
    token(State, Chars, Line, Tcs ++ Chars, Tlen, Tline, Action, Alen).

%% token(State, InChars, Line, TokenChars, TokenLen, TokenLine,
%% AcceptAction, AcceptLen) ->
%% {more,Continuation} | {done,ReturnVal,RestChars}.
%% The argument order is chosen to be more efficient.

token(S0, Ics0, L0, Tcs, Tlen0, Tline, A0, Alen0) ->
    case yystate(S0, Ics0, L0, Tlen0, A0, Alen0) of
        %% Accepting end state, we have a token.
        {A1,Alen1,Ics1,L1} ->
            token_cont(Ics1, L1, yyaction(A1, Alen1, Tcs, Tline));
        %% Accepting transition state, can take more chars.
        {A1,Alen1,[],L1,S1} ->                  % Need more chars to check
            {more,{token,S1,L1,Tcs,Alen1,Tline,A1,Alen1}};
        {A1,Alen1,Ics1,L1,_S1} ->               % Take what we got
            token_cont(Ics1, L1, yyaction(A1, Alen1, Tcs, Tline));
        %% After a non-accepting state, maybe reach accept state later.
        {A1,Alen1,Tlen1,[],L1,S1} ->            % Need more chars to check
            {more,{token,S1,L1,Tcs,Tlen1,Tline,A1,Alen1}};
        {reject,_Alen1,Tlen1,eof,L1,_S1} ->     % No token match
            %% Check for partial token which is error.
            Ret = if Tlen1 > 0 -> {error,{Tline,?MODULE,
                                          %% Skip eof tail in Tcs.
                                          {illegal,yypre(Tcs, Tlen1)}},L1};
                     true -> {eof,L1}
                  end,
            {done,Ret,eof};
        {reject,_Alen1,Tlen1,Ics1,L1,_S1} ->    % No token match
            Error = {Tline,?MODULE,{illegal,yypre(Tcs, Tlen1+1)}},
            {done,{error,Error,L1},Ics1};
        {A1,Alen1,Tlen1,_Ics1,L1,_S1} ->       % Use last accept match
            Tcs1 = yysuf(Tcs, Alen1),
            L2 = adjust_line(Tlen1, Alen1, Tcs1, L1),
            token_cont(Tcs1, L2, yyaction(A1, Alen1, Tcs, Tline))
    end.

%% token_cont(RestChars, Line, Token)
%% If we have a token or error then return done, else if we have a
%% skip_token then continue.

-dialyzer({nowarn_function, token_cont/3}).

token_cont(Rest, Line, {token,T}) ->
    {done,{ok,T,Line},Rest};
token_cont(Rest, Line, {token,T,Push}) ->
    NewRest = Push ++ Rest,
    {done,{ok,T,Line},NewRest};
token_cont(Rest, Line, {end_token,T}) ->
    {done,{ok,T,Line},Rest};
token_cont(Rest, Line, {end_token,T,Push}) ->
    NewRest = Push ++ Rest,
    {done,{ok,T,Line},NewRest};
token_cont(Rest, Line, skip_token) ->
    token(yystate(), Rest, Line, Rest, 0, Line, reject, 0);
token_cont(Rest, Line, {skip_token,Push}) ->
    NewRest = Push ++ Rest,
    token(yystate(), NewRest, Line, NewRest, 0, Line, reject, 0);
token_cont(Rest, Line, {error,S}) ->
    {done,{error,{Line,?MODULE,{user,S}},Line},Rest}.

%% tokens(Continuation, Chars, Line) ->
%% {more,Continuation} | {done,ReturnVal,RestChars}.
%% Must be careful when re-entering to append the latest characters to the
%% after characters in an accept. The continuation is:
%% {tokens,State,CurrLine,TokenChars,TokenLen,TokenLine,Tokens,AccAction,AccLen}
%% {skip_tokens,State,CurrLine,TokenChars,TokenLen,TokenLine,Error,AccAction,AccLen}

tokens(Cont, Chars) -> tokens(Cont, Chars, 1).

tokens([], Chars, Line) ->
    tokens(yystate(), Chars, Line, Chars, 0, Line, [], reject, 0);
tokens({tokens,State,Line,Tcs,Tlen,Tline,Ts,Action,Alen}, Chars, _) ->
    tokens(State, Chars, Line, Tcs ++ Chars, Tlen, Tline, Ts, Action, Alen);
tokens({skip_tokens,State,Line,Tcs,Tlen,Tline,Error,Action,Alen}, Chars, _) ->
    skip_tokens(State, Chars, Line, Tcs ++ Chars, Tlen, Tline, Error, Action, Alen).

%% tokens(State, InChars, Line, TokenChars, TokenLen, TokenLine, Tokens,
%% AcceptAction, AcceptLen) ->
%% {more,Continuation} | {done,ReturnVal,RestChars}.

tokens(S0, Ics0, L0, Tcs, Tlen0, Tline, Ts, A0, Alen0) ->
    case yystate(S0, Ics0, L0, Tlen0, A0, Alen0) of
        %% Accepting end state, we have a token.
        {A1,Alen1,Ics1,L1} ->
            tokens_cont(Ics1, L1, yyaction(A1, Alen1, Tcs, Tline), Ts);
        %% Accepting transition state, can take more chars.
        {A1,Alen1,[],L1,S1} ->                  % Need more chars to check
            {more,{tokens,S1,L1,Tcs,Alen1,Tline,Ts,A1,Alen1}};
        {A1,Alen1,Ics1,L1,_S1} ->               % Take what we got
            tokens_cont(Ics1, L1, yyaction(A1, Alen1, Tcs, Tline), Ts);
        %% After a non-accepting state, maybe reach accept state later.
        {A1,Alen1,Tlen1,[],L1,S1} ->            % Need more chars to check
            {more,{tokens,S1,L1,Tcs,Tlen1,Tline,Ts,A1,Alen1}};
        {reject,_Alen1,Tlen1,eof,L1,_S1} ->     % No token match
            %% Check for partial token which is error, no need to skip here.
            Ret = if Tlen1 > 0 -> {error,{Tline,?MODULE,
                                          %% Skip eof tail in Tcs.
                                          {illegal,yypre(Tcs, Tlen1)}},L1};
                     Ts == [] -> {eof,L1};
                     true -> {ok,yyrev(Ts),L1}
                  end,
            {done,Ret,eof};
        {reject,_Alen1,Tlen1,_Ics1,L1,_S1} ->
            %% Skip rest of tokens.
            Error = {L1,?MODULE,{illegal,yypre(Tcs, Tlen1+1)}},
            skip_tokens(yysuf(Tcs, Tlen1+1), L1, Error);
        {A1,Alen1,Tlen1,_Ics1,L1,_S1} ->
            Token = yyaction(A1, Alen1, Tcs, Tline),
            Tcs1 = yysuf(Tcs, Alen1),
            L2 = adjust_line(Tlen1, Alen1, Tcs1, L1),
            tokens_cont(Tcs1, L2, Token, Ts)
    end.

%% tokens_cont(RestChars, Line, Token, Tokens)
%% If we have an end_token or error then return done, else if we have
%% a token then save it and continue, else if we have a skip_token
%% just continue.

-dialyzer({nowarn_function, tokens_cont/4}).

tokens_cont(Rest, Line, {token,T}, Ts) ->
    tokens(yystate(), Rest, Line, Rest, 0, Line, [T|Ts], reject, 0);
tokens_cont(Rest, Line, {token,T,Push}, Ts) ->
    NewRest = Push ++ Rest,
    tokens(yystate(), NewRest, Line, NewRest, 0, Line, [T|Ts], reject, 0);
tokens_cont(Rest, Line, {end_token,T}, Ts) ->
    {done,{ok,yyrev(Ts, [T]),Line},Rest};
tokens_cont(Rest, Line, {end_token,T,Push}, Ts) ->
    NewRest = Push ++ Rest,
    {done,{ok,yyrev(Ts, [T]),Line},NewRest};
tokens_cont(Rest, Line, skip_token, Ts) ->
    tokens(yystate(), Rest, Line, Rest, 0, Line, Ts, reject, 0);
tokens_cont(Rest, Line, {skip_token,Push}, Ts) ->
    NewRest = Push ++ Rest,
    tokens(yystate(), NewRest, Line, NewRest, 0, Line, Ts, reject, 0);
tokens_cont(Rest, Line, {error,S}, _Ts) ->
    skip_tokens(Rest, Line, {Line,?MODULE,{user,S}}).

%%skip_tokens(InChars, Line, Error) -> {done,{error,Error,Line},Ics}.
%% Skip tokens until an end token, junk everything and return the error.

skip_tokens(Ics, Line, Error) ->
    skip_tokens(yystate(), Ics, Line, Ics, 0, Line, Error, reject, 0).

%% skip_tokens(State, InChars, Line, TokenChars, TokenLen, TokenLine, Tokens,
%% AcceptAction, AcceptLen) ->
%% {more,Continuation} | {done,ReturnVal,RestChars}.

skip_tokens(S0, Ics0, L0, Tcs, Tlen0, Tline, Error, A0, Alen0) ->
    case yystate(S0, Ics0, L0, Tlen0, A0, Alen0) of
        {A1,Alen1,Ics1,L1} ->                  % Accepting end state
            skip_cont(Ics1, L1, yyaction(A1, Alen1, Tcs, Tline), Error);
        {A1,Alen1,[],L1,S1} ->                 % After an accepting state
            {more,{skip_tokens,S1,L1,Tcs,Alen1,Tline,Error,A1,Alen1}};
        {A1,Alen1,Ics1,L1,_S1} ->
            skip_cont(Ics1, L1, yyaction(A1, Alen1, Tcs, Tline), Error);
        {A1,Alen1,Tlen1,[],L1,S1} ->           % After a non-accepting state
            {more,{skip_tokens,S1,L1,Tcs,Tlen1,Tline,Error,A1,Alen1}};
        {reject,_Alen1,_Tlen1,eof,L1,_S1} ->
            {done,{error,Error,L1},eof};
        {reject,_Alen1,Tlen1,_Ics1,L1,_S1} ->
            skip_tokens(yysuf(Tcs, Tlen1+1), L1, Error);
        {A1,Alen1,Tlen1,_Ics1,L1,_S1} ->
            Token = yyaction(A1, Alen1, Tcs, Tline),
            Tcs1 = yysuf(Tcs, Alen1),
            L2 = adjust_line(Tlen1, Alen1, Tcs1, L1),
            skip_cont(Tcs1, L2, Token, Error)
    end.

%% skip_cont(RestChars, Line, Token, Error)
%% Skip tokens until we have an end_token or error then return done
%% with the original rror.

-dialyzer({nowarn_function, skip_cont/4}).

skip_cont(Rest, Line, {token,_T}, Error) ->
    skip_tokens(yystate(), Rest, Line, Rest, 0, Line, Error, reject, 0);
skip_cont(Rest, Line, {token,_T,Push}, Error) ->
    NewRest = Push ++ Rest,
    skip_tokens(yystate(), NewRest, Line, NewRest, 0, Line, Error, reject, 0);
skip_cont(Rest, Line, {end_token,_T}, Error) ->
    {done,{error,Error,Line},Rest};
skip_cont(Rest, Line, {end_token,_T,Push}, Error) ->
    NewRest = Push ++ Rest,
    {done,{error,Error,Line},NewRest};
skip_cont(Rest, Line, skip_token, Error) ->
    skip_tokens(yystate(), Rest, Line, Rest, 0, Line, Error, reject, 0);
skip_cont(Rest, Line, {skip_token,Push}, Error) ->
    NewRest = Push ++ Rest,
    skip_tokens(yystate(), NewRest, Line, NewRest, 0, Line, Error, reject, 0);
skip_cont(Rest, Line, {error,_S}, Error) ->
    skip_tokens(yystate(), Rest, Line, Rest, 0, Line, Error, reject, 0).

yyrev(List) -> lists:reverse(List).
yyrev(List, Tail) -> lists:reverse(List, Tail).
yypre(List, N) -> lists:sublist(List, N).
yysuf(List, N) -> lists:nthtail(N, List).

%% adjust_line(TokenLength, AcceptLength, Chars, Line) -> NewLine
%% Make sure that newlines in Chars are not counted twice.
%% Line has been updated with respect to newlines in the prefix of
%% Chars consisting of (TokenLength - AcceptLength) characters.

adjust_line(N, N, _Cs, L) -> L;
adjust_line(T, A, [$\n|Cs], L) ->
    adjust_line(T-1, A, Cs, L-1);
adjust_line(T, A, [_|Cs], L) ->
    adjust_line(T-1, A, Cs, L).

%% yystate() -> InitialState.
%% yystate(State, InChars, Line, CurrTokLen, AcceptAction, AcceptLen) ->
%% {Action, AcceptLen, RestChars, Line} |
%% {Action, AcceptLen, RestChars, Line, State} |
%% {reject, AcceptLen, CurrTokLen, RestChars, Line, State} |
%% {Action, AcceptLen, CurrTokLen, RestChars, Line, State}.
%% Generated state transition functions. The non-accepting end state
%% return signal either an unrecognised character or end of current
%% input.

##dfa

%% yyaction(Action, TokenLength, TokenChars, TokenLine) ->
%% {token,Token} | {end_token, Token} | skip_token | {error,String}.
%% Generated action function.

##actions

