%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2003-2009. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(xmerl_validate).
-export([validate/2]).
-include("xmerl.hrl"). % record def, macros
%% +type validate(xmerl_scanner(),xmlElement())->
%% xmlElment() | {error,tuple()}.
validate(#xmerl_scanner{doctype_name=DTName,doctype_DTD=OpProv},
#xmlElement{name=Name})
when DTName=/=Name,OpProv=/=option_provided->
{error, {mismatched_root_element,Name,DTName}};
validate(#xmerl_scanner{rules=Rules}=S,
XML=#xmlElement{name=Name})->
catch do_validation(read_rules(Rules,Name),XML,Rules,S);
validate(_, XML) ->
{error, {no_xml_element, XML}}.
%% +type validate(rules(),xmlElement())->
%% {ok,xmlElement()} | {error,tuple()}.
do_validation(undefined,#xmlElement{name=Name}, _Rules,_S) ->
{error,{unknown_element,Name}};
do_validation(El_Rule,XML,Rules,S)->
case catch valid_attributes(El_Rule#xmlElement.attributes,
XML#xmlElement.attributes,S) of
{'EXIT',Reason} ->
{error,Reason};
{error,Reason} ->
{error,Reason};
Attr_2->
% XML_=XML#xmlElement{attributes=Attr_2},
El_Rule_Cont = El_Rule#xmlElement.content,
WSActionMode = ws_action_mode(El_Rule#xmlElement.elementdef,
El_Rule_Cont,S),
XML_Cont = XML#xmlElement.content,
check_direct_ws_SDD(XML_Cont,WSActionMode),
case valid_contents(El_Rule_Cont,
XML_Cont,Rules,S,WSActionMode) of
{error,Reason}->
{error,Reason};
{error,Reason,N}->
{error,Reason,N};
XMLS ->
XML#xmlElement{attributes=Attr_2,content=XMLS}
end
end.
check_direct_ws_SDD(XML,always_preserve) ->
case XML of
[#xmlText{}|_Rest] ->
exit({error,{illegal_whitespace_standalone_doc,XML}});
_ -> ok
end,
case lists:reverse(XML) of
[#xmlText{}|_Rest2] ->
exit({error,{illegal_whitespace_standalone_doc,XML}});
_ -> ok
end;
check_direct_ws_SDD(_,_) -> ok.
ws_action_mode({external,_},Content,#xmerl_scanner{standalone=yes}) ->
case element_content(Content) of
children ->
always_preserve;
_ ->
preserve
end;
ws_action_mode(_,_,_) ->
preserve.
element_content(A) when is_atom(A),A /= any, A /= empty ->
children;
element_content({choice,L}) when is_list(L) ->
element_content(L);
element_content({seq,L}) when is_list(L) ->
element_content(L);
element_content(['#PCDATA'|_T]) ->
mixed;
element_content('#PCDATA') ->
mixed;
element_content({'*',Rest}) ->
element_content(Rest);
element_content(_) -> children.
%% +type read_rules(DTD::atom(),Element_Name::atom())->
%% undefined | xmlElement().
read_rules(_, pcdata) ->
pcdata;
read_rules(T, Name) ->
case ets:lookup(T, {elem_def, Name}) of
[] ->
undefined;
[{_K, V}] ->
V
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%% Attributes Validation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% +deftype attribute_rule() = {Attr_Name::atom(),attribute_type(),
%% attribute_priority()}.
%% +type valid_attributes([attribute_rule()],[xmlAttribute()])->
%% [xmlAttribute()] | {error,attribute_unknow}.
valid_attributes(All_Attr,[#xmlAttribute{}|_T]=Attr,S)->
single_ID_definition(All_Attr),
vc_Name_Token_IDREFS(All_Attr,Attr),
lists:foreach(fun(#xmlAttribute{name=Name})->
case is_attribute_exist(Name,All_Attr) of
true ->
ok;
false ->
exit({error,{attribute_unknown,Name}})
end
end,
Attr),
lists:flatten(lists:foldl(fun({Name,DataType,IF,DefDecl,Env},Attr_2)->
Attr_2++
[valid_attribute(Name,DataType,IF,
DefDecl,Attr,Env,S)]
end,[],All_Attr));
valid_attributes([],[],_) ->
[];
valid_attributes(All_Attr,[],S) ->
single_ID_definition(All_Attr),
lists:flatten(lists:foldl(fun({Name,DataType,IF,DefDecl,Env},Attr_2)->
Attr_2++[valid_attribute(Name,
DataType,IF,
DefDecl,
[],
Env,S)]
end,[],All_Attr)).
%%%% [60] DefaultDecl::=
%%%% '#REQUIRED' | '#IMPLIED'
%%%% | (('#FIXED' S)? AttValue)
%% +deftype attribute_priority = '#REQUIRED'|'#FIXED'|'#IMPLIED'.
%% +type valid_attribute(Name::atom(),DataType::attribute_value(),
%% IF::attribute_priority(),[xmlAttribute()])->
%% [xmlAttribute()] | exit().
valid_attribute(Name,DataType,IF,DefaultDecl,List_of_Attributes,Env,S)->
SA = S#xmerl_scanner.standalone,
Attr=search_attr(Name,List_of_Attributes),
check_SDD_validity(SA,Env,Attr,IF),
case {DefaultDecl,IF,Attr} of
{'#REQUIRED',_,no_attribute}->
exit({error,{Name,is_required}});
{'#IMPLIED',_,no_attribute}->
[]; %% and no default value
{'#FIXED',DefVal,#xmlAttribute{value=DefVal}=Attr} ->
Attr;
{'#FIXED',A,no_attribute} ->
#xmlAttribute{name=Name,value=A}; % FIXED declare value becomes default.
{'#FIXED',A,B} ->
exit({error,{fixed_default_value_missmatch,A,B}});
{_,Value,no_attribute} when is_list(Value)->
#xmlAttribute{name=Name,value=Value};
{_,_,#xmlAttribute{}=Attr}->
%% do test data value, and default_value
test_attribute_value(DataType,Attr,IF,S);
{DefDecl,Else,XML} ->
exit({error,{unknow_attribute_type,DefDecl,Else,XML}})
end.
vc_Name_Token_IDREFS([{Name,Type,_,_,_}|Rest],Attrs)
when Type=='NMTOKEN';Type=='NMTOKENS'->
case lists:keysearch(Name,#xmlAttribute.name,Attrs) of
{value,A} ->
valid_nmtoken_value(A#xmlAttribute.value,Type);
_ -> ok
end,
vc_Name_Token_IDREFS(Rest,Attrs);
vc_Name_Token_IDREFS([{Name,Type,_,_,_}|Rest],Attrs)
when Type=='IDREFS'->
case lists:keysearch(Name,#xmlAttribute.name,Attrs) of
{value,A} ->
valid_IDREFS(A#xmlAttribute.value,Type);
_ -> ok
end,
vc_Name_Token_IDREFS(Rest,Attrs);
vc_Name_Token_IDREFS([_H|Rest],Attrs) ->
vc_Name_Token_IDREFS(Rest,Attrs);
vc_Name_Token_IDREFS([],_) -> ok.
valid_nmtoken_value([],'NMTOKENS') ->
exit({error,{at_least_one_Nmtoken_required}});
% valid_nmtoken_value([H|_T] = L,'NMTOKENS') when is_list(H) ->
% ValidChar =
% fun(X) ->
% case xmerl_lib:is_namechar(X) of
% false ->
% exit({error,{invalid_character_in_Nmtoken,X}});
% _ -> ok
% end
% end,
% ValidCharList =
% fun([Nmtok|T],F) ->
% lists:foreach(ValidChar,Nmtok),
% F(T,F);
% ([],_) -> ok
% end,
% ValidCharList(L,ValidChar);
valid_nmtoken_value(Nmtok,_) ->
ValidChar =
fun(X) when ?whitespace(X),Nmtok=='NMTOKENS' ->
ok;
(X) ->
case xmerl_lib:is_namechar(X) of
false ->
exit({error,{invalid_character_in_Nmtoken,X}});
_ -> ok
end
end,
lists:foreach(ValidChar,Nmtok).
valid_IDREFS([],'IDREFS') ->
exit({error,{at_least_one_IDREF_Name_required}});
valid_IDREFS(_Str,'IDREFS') ->
ok.
single_ID_definition([{_,'ID',_,_,_}=Att1|Rest]) ->
case lists:keysearch('ID',2,Rest) of
{value,Att2} ->
exit({error,{just_one_ID_definition_allowed,Att1,Att2}});
_ -> ok
end;
single_ID_definition([_H|T]) ->
single_ID_definition(T);
single_ID_definition([]) ->
ok.
check_SDD_validity(yes,{external,_},#xmlAttribute{name=Name,normalized=true},_) ->
exit({error,{externally_defed_attribute_normalized_in_standalone_doc,Name}});
check_SDD_validity(yes,{external,_},no_attribute,V) when V /= no_value->
exit({error,{externally_defed_attribute_with_default_value_missing_in_standalone_doc}});
check_SDD_validity(_,_,_,_) ->
ok.
search_attr(Name,[#xmlAttribute{name=Name}=H|_T])->
H;
search_attr(Name,[#xmlAttribute{}|T])->
search_attr(Name,T);
search_attr(_Name,_T) ->
no_attribute.
is_attribute_exist(Name,[{Name,_,_,_,_}|_T])->
true;
is_attribute_exist(Name,[{_Attr,_,_,_,_}|T]) ->
is_attribute_exist(Name,T);
is_attribute_exist(_Name,[]) ->
false.
%%%%[54] AttType::= StringType | TokenizedType | EnumeratedType
%%%%[55] StringType::= 'CDATA'
%%%%[56] TokenizedType::= 'ID'|'IDREF'| 'IDREFS'|'ENTITY'| 'ENTITIES'
%%%% | 'NMTOKEN'| 'NMTOKENS'
%%%%[57] EnumeratedType::= NotationType | Enumeration
%%%%[58] NotationType::= 'NOTATION' S '(' S? Name (S? '|' S? Name)* S? ')'
%%%%[59] Enumeration ::= '(' S? Nmtoken (S? '|' S? Nmtoken)* S? ')'
%% +deftype attribute_type()-> 'CDATA' | 'ID'|'IDREF'| 'IDREFS'|'ENTITY'|
%% 'ENTITIES'| 'NMTOKEN'| 'NMTOKENS'
%% {enumeration,[List_of_value::atom()]}.
%% +type test_attribute_value(attribute_type(),xmlAttribute())->
%% xmlAttribute()| exit.
%%%% test the constraint validity of Attribute value.
test_attribute_value('CDATA',#xmlAttribute{}=Attr,_,_) ->
Attr;
test_attribute_value('NMTOKEN',#xmlAttribute{name=Name,value=V}=Attr,
Default,_S) ->
Fun =
fun (X)->
case xmerl_lib:is_namechar(X) of
true->
ok;
false->
%%io:format("Warning*** nmtoken,value_incorrect: ~p~n",[V]),
exit({error,{invalid_value_nmtoken,Name,V}})
end
end,
lists:foreach(Fun,V),
if
is_list(Default) ->
lists:foreach(Fun,Default);
true -> ok
end,
Attr;
test_attribute_value('NMTOKENS',#xmlAttribute{name=Name,value=V}=Attr,
Default,_S) ->
Fun =
fun (X)->
case xmerl_lib:is_namechar(X) of
true->
ok;
false when ?whitespace(X)->
ok;
false ->
exit({error,{invalid_value_nmtokens,Name,V}})
end
end,
lists:foreach(Fun,V),
if
is_list(Default) ->
lists:foreach(Fun,Default);
true -> ok
end,
Attr;
test_attribute_value(Ent,#xmlAttribute{name=_Name,value=V}=Attr,_Default,
S=#xmerl_scanner{rules_read_fun=Read})
when Ent == 'ENTITY'; Ent == 'ENTITIES'->
%% The default value is already checked
NameListFun =
fun([],Acc,_) ->
lists:reverse(Acc);
(Str,Acc,Fun) ->
{N,Str2} = scan_name(Str,[]),
Fun(Str2,[N|Acc],Fun)
end,
NameList = NameListFun(V,[],NameListFun),
VC_Entity_Name =
fun(X) ->
case Read(entity,X,S) of
{_,external,{_,{ndata,_}}} ->
ok;
_ -> exit({error,{vc_Entity_Name,X,V}})
end
end,
lists:foreach(VC_Entity_Name,NameList),
Attr;
test_attribute_value({Type,L},#xmlAttribute{value=Value}=Attr,Default,_S)
when Type == enumeration; Type == notation ->
ValidDefault =
if
is_atom(Default) -> true;
true -> lists:member(list_to_atom(Default),L)
end,
NoDuplicatesFun =
fun(_,_,notation) -> true;
([],_,_) -> true;
([H|T],F,Enum) ->
case lists:member(H,T) of
true -> false;
_ -> F(T,F,Enum)
end
end,
NoDuplicates = NoDuplicatesFun(L,NoDuplicatesFun,Type),
case {lists:member(list_to_atom(Value),L),ValidDefault,NoDuplicates} of
{true,true,true}->
Attr;
{false,_,_} ->
exit({error,{attribute_value_unknow,Value,{list,L}}});
{_,false,_} ->
exit({error,{attribute_default_value_unknow,Default,{list,L}}});
{_,_,false} ->
exit({error,{duplicate_tokens_not_allowed,{list,L}}})
end;
test_attribute_value(_Rule,Attr,_,_) ->
% io:format("Attr Value*****~nRule~p~nValue~p~n",[Rule,Attr]),
Attr.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%% Contents Validation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%Element-content Models
%%%%[47] children::= (choice | seq) ('?' | '*' | '+')?
%%%%[48] cp::= (Name | choice | seq) ('?' | '*' | '+')?
%%%%[49] choice::= '(' S? cp ( S? '|' S? cp )+ S? ')'
%%%%[50] seq::= '(' S? cp ( S? ',' S? cp )* S? ')'
%%%%[51] Mixed::= '(' S? '#PCDATA' (S? '|' S? Name)* S? ')*'
%%%% | '(' S? '#PCDATA' S? ')'
%% +type valid_contents([rule()],[xmlElement()])->
%% [xmlElement() | {error,???}.
valid_contents(Rule,XMLS,Rules,S,WSActionMode)->
case parse(Rule,XMLS,Rules,WSActionMode,S) of
{XML_N,[]}->
lists:flatten(XML_N);
{_,[#xmlElement{name=Name}|_T]} ->
exit({error,{element,Name,isnt_comprise_in_the_rule,Rule}});
{_,[#xmlText{}=Txt|_T]} ->
exit({error,{element,text,Txt,isnt_comprise_in_the_rule,Rule}});
{error,Reason} ->
{error,Reason};
{error,Reason,N} ->
{error,Reason,N}
end.
parse({'*',SubRule},XMLS,Rules,WSaction,S)->
star(SubRule,XMLS,Rules,WSaction,[],S);
parse({'+',SubRule},XMLS,Rules,WSaction,S) ->
plus(SubRule,XMLS,Rules,WSaction,S);
parse({choice,CHOICE},XMLS,Rules,WSaction,S)->
% case XMLS of
% [] ->
% io:format("~p~n",[{choice,CHOICE,[]}]);
% [#xmlElement{name=Name,pos=Pos}|_] ->
% io:format("~p~n",[{choice,CHOICE,{Name,Pos}}]);
% [#xmlText{value=V}|_] ->
% io:format("~p~n",[{choice,CHOICE,{text,V}}])
% end,
choice(CHOICE,XMLS,Rules,WSaction,S);
parse(empty,[],_Rules,_WSaction,_S) ->
{[],[]};
parse({'?',SubRule},XMLS,Rules,_WSaction,S)->
question(SubRule,XMLS,Rules,S);
parse({seq,List},XMLS,Rules,WSaction,S) ->
seq(List,XMLS,Rules,WSaction,S);
parse(El_Name,[#xmlElement{name=El_Name}=XML|T],Rules,_WSaction,S)
when is_atom(El_Name)->
case do_validation(read_rules(Rules,El_Name),XML,Rules,S) of
{error,R} ->
% {error,R};
exit(R);
{error,R,_N}->
% {error,R,N};
exit(R);
XML_->
{[XML_],T}
end;
parse(any,Cont,Rules,_WSaction,S) ->
case catch parse_any(Cont,Rules,S) of
Err = {error,_} -> Err;
ValidContents -> {ValidContents,[]}
end;
parse(El_Name,[#xmlElement{name=Name}|_T]=S,_Rules,_WSa,_S) when is_atom(El_Name)->
{error,
{element_seq_not_conform,{wait,El_Name},{is,Name}},
{{next,S},{act,[]}} };
parse(_El_Name,[#xmlPI{}=H|T],_Rules,_WSa,_S) ->
{[H],T};
parse('#PCDATA',XML,_Rules,_WSa,_S)->
%%% PCDATA it is 0 , 1 or more #xmlText{}.
parse_pcdata(XML);
parse(El_Name,[#xmlText{}|_T]=S,_Rules,_WSa,_S)->
{error,
{text_in_place_of,El_Name},
{{next,S},{act,[]}}};
parse([],_,_,_,_) ->
{error,no_rule};
parse(Rule,[],_,_,_) ->
{error,{no_xml_element,Rule}}.
parse_any([],_Rules,_S) ->
[];
parse_any([H|T],Rules,S) ->
case parse_any(H,Rules,S) of
[Cont] ->
[Cont|parse_any(T,Rules,S)];
Err -> throw(Err)
end;
parse_any(#xmlElement{}=XML,Rules,S) ->
case do_validation(read_rules(Rules,el_name(XML)),XML,Rules,S) of
{error,R} ->
{error,R};
{error,R,N}->
{error,R,N};
XML_->
[XML_]
end;
parse_any(El,_Rules,_S) ->
[El].
%% XXX remove first function clause
% choice(_Choice,[#xmlText{}=T|R],_Rules) ->
% {[T],R};
choice([CH|CHS],[_XML|_T]=XMLS,Rules,WSaction,S)->
{WS,XMLS1} = whitespace_action(XMLS,ws_action(WSaction,remove)),
case parse(CH,XMLS1,Rules,ws_action(WSaction,remove),S) of
{error,_R} ->
choice(CHS,XMLS,Rules,WSaction,S);
{error,_R,_N} ->
choice(CHS,XMLS,Rules,WSaction,S); %% XXX add a case {[],XML}
{[],XMLS1} -> %% Maybe a sequence with * or ? elements that
%% didn't match
case CHS of
[] -> % choice has succeded but without matching XMLS1
{[],XMLS1};
_ -> % there are more choice alternatives to try with
choice(CHS,XMLS1,Rules,WSaction,S)
end;
%% choice(CHS,XMLS1,Rules,WSaction,S);
{Tree,XMLS2}->
{WS2,XMLS3} = whitespace_action(XMLS2,ws_action(WSaction,remove)),
{WS2++[Tree]++WS,XMLS3}
end;
choice([],XMLS,_,WSaction,_S)->
case whitespace_action(XMLS,ws_action(WSaction,remove)) of
Res={_,[]} -> Res;
_ ->
{error,element_unauthorize_in_choice,{{next,XMLS},{act,[]}}}
end;
choice(_,[],_,_,_S) ->
{[],[]}.
plus(Rule,XMLS,Rules,WSaction,S) ->
%% 1 or more
{WS,XMLS1}=whitespace_action(XMLS,WSaction),
case parse(Rule,XMLS1,Rules,WSaction,S) of
{error, Reason,_XML} ->
{error, Reason};
{error, X} ->
{error, X};
{Tree, XMLS2} ->
case star(Rule, XMLS2,Rules,WSaction,[],S) of
{[], _} ->
{WS++[Tree], XMLS2};
{Tree_1, XMLS3} ->
{WS++[Tree]++Tree_1, XMLS3}
end
end.
star(_Rule,XML,_Rules,_WSa,Tree,_S) when length(XML)==0->
{[Tree],[]};
star(Rule,XMLS,Rules,WSaction,Tree,S) ->
{WS,XMLS1} = whitespace_action(XMLS,WSaction),
case parse(Rule,XMLS1,Rules,WSaction,S) of
{error, _E, {{next,N},{act,A}}}->
%%io:format("Error~p~n",[_E]),
{WS++Tree++A,N};
{error, _E}->
%%io:format("Error~p~n",[_E]),
% {WS++[Tree],[]};
case whitespace_action(XMLS,ws_action(WSaction,remove)) of
{[],_} ->
{WS++[Tree],XMLS};
{WS2,XMLS2} ->
{WS2++[Tree],XMLS2}
end;
{Tree1,XMLS2}->
star(Rule,XMLS2,Rules,WSaction,Tree++WS++[Tree1],S)
end.
question(_Rule, [],_Rules,_S) ->
{[],[]};
question(Rule, Toks,Rules,S) ->
%% 0 or 1
case parse(Rule, Toks,Rules,preserve,S) of
{error, _E, _Next}->
{[],Toks};
{error, _E} ->
{[], Toks};
{T,Toks1} ->
{T, Toks1}
end.
seq(H,Toks,Rules,WSaction,S)->
case seq2(H,Toks,Rules,[],WSaction,S) of
{error,E}->
{error,E};
{error,R,N}->
{error,R,N};
{Tree,Toks2}->
{Tree,Toks2}
end.
seq2([],[],_,Tree,_WSa,_S)->
{Tree,[]};
% seq2([],[#xmlElement{name=Name}|_T]=XMLS,_,Tree,_WSa,_S)->
% {error,{sequence_finish,Name,isnt_in_the_right_place},
% {{next,XMLS},{act,Tree}}};
seq2([],[#xmlText{}]=XML,_,Tree,_WSa,_S)->
case whitespace_action(XML,remove) of
{[],_} ->
{error,sequence_finish,{{next,XML},{act,Tree}}};
{WS,Rest} ->
{WS++Tree,Rest}
end;
seq2([],Rest,_,Tree,_WSa,_S) ->
{WS,Rest2}=whitespace_action(Rest,remove),
{WS++Tree,Rest2};
seq2([H|T],Toks,Rules,Tree,WSaction,S) ->
{WS,Toks1} = whitespace_action(Toks,ws_action(WSaction,remove)),
case parse(H,Toks1,Rules,remove,S) of %% H maybe only match parts of Toks
{error,Reason,_XML}->
{error,Reason};
{error,E}->
{error,E};
{[],Toks2}->
seq2(T,Toks2,Rules,Tree,WSaction,S);
{Tree1,Toks2} when is_list(Tree1)->
seq2(T,Toks2,Rules,Tree++WS++Tree1,WSaction,S);
{Tree1,Toks2}->
seq2(T,Toks2,Rules,Tree++WS++[Tree1],WSaction,S)
end.
el_name(#xmlElement{name=Name})->
Name.
parse_pcdata([#xmlText{}=H|T])->
parse_pcdata(T,[H]);
parse_pcdata(H) ->
{[],H}.
parse_pcdata([#xmlText{}=H|T],Acc)->
parse_pcdata(T,Acc++[H]);
parse_pcdata(H,Acc) ->
{Acc,H}.
whitespace([]) ->
true;
whitespace([H|T]) when ?whitespace(H) ->
whitespace(T);
whitespace(_) ->
false.
whitespace_action(XML,remove) ->
whitespace_remove(XML,[]);
whitespace_action(XML,_) ->
{[],XML}.
whitespace_remove([#xmlText{value=V,type=text}=T|R]=L,Acc) ->
case whitespace(V) of
true ->
whitespace_remove(R,[T|Acc]);
_ ->
{lists:reverse(Acc),L}
end;
whitespace_remove(L,Acc) ->
{lists:reverse(Acc),L}.
ws_action(always_preserve=A,_) ->
A;
ws_action(_,B) ->
B.
scan_name(N,_) when is_atom(N) ->
N;
scan_name([$\s|T],Acc) ->
{list_to_atom(lists:reverse(Acc)),T};
scan_name([H|T],Acc) ->
scan_name(T,[H|Acc]);
scan_name("",Acc) ->
{list_to_atom(lists:reverse(Acc)),[]}.
