%% Copyright (c) 2017-2018, Loïc Hoguin <[email protected]>
%%
%% Permission to use, copy, modify, and/or distribute this software for any
%% purpose with or without fee is hereby granted, provided that the above
%% copyright notice and this permission notice appear in all copies.
%%
%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
%% This pass walks over the tree and parses inline elements.
-module(asciideck_inline_pass).
-export([run/1]).
-import(asciideck_block_parser, [trim/1, while/2]).
-type inline_ast() :: list(). %% @todo
-export_type([inline_ast/0]).
run([]) ->
[];
run([Data|Tail]) when is_binary(Data) ->
[inline(Data)|run(Tail)];
%% We do not do any inline formatting for verbatim blocks,
%% for example listing blocks.
%%
%% @todo subs is a list of values.
run([Item={_, #{<<"subs">> := <<"verbatim">>}, _, _}|Tail]) ->
[Item|run(Tail)];
%% Labeled lists' labels can also have inline formatting.
run([{Type, Attrs=#{label := Label}, Items, Ann}|Tail]) when is_list(Items) ->
[{Type, Attrs#{label => inline(Label)}, run(Items), Ann}|run(Tail)];
run([{Type, Attrs, Items, Ann}|Tail]) when is_list(Items) ->
[{Type, Attrs, run(Items), Ann}|run(Tail)];
run([{Type, Attrs, Data, Ann}|Tail]) ->
[{Type, Attrs, inline(Data), Ann}|run(Tail)].
%% We reduce inline content with a single text element
%% with no formatting to a simple binary.
inline(<<>>) ->
<<>>;
inline(Data) ->
case inline(Data, <<>>, []) of
[] -> <<>>;
[Text] when is_binary(Text) -> Text;
AST -> AST
end.
-spec inline(binary(), binary(), inline_ast()) -> inline_ast().
inline(<<>>, <<>>, Acc) ->
lists:reverse(Acc);
inline(<<>>, BinAcc, Acc) ->
lists:reverse([BinAcc|Acc]);
inline(Data, BinAcc, Acc) ->
oneof(Data, BinAcc, Acc, [
%% Links.
fun xref/2,
fun link/2,
fun http_link/2,
fun https_link/2,
%% Quoted text.
fun emphasized_single_quote/2,
fun emphasized_underline/2,
fun strong/2,
%% Passthrough macros.
fun inline_literal_passthrough/2
]).
%% The inline pass replaces \r\n and \n with a simple space
%% when it occurs within normal text.
oneof(<<$\r, $\n, Rest/bits>>, BinAcc, Acc, []) ->
inline(Rest, <<BinAcc/binary, $\s>>, Acc);
oneof(<<$\n, Rest/bits>>, BinAcc, Acc, []) ->
inline(Rest, <<BinAcc/binary, $\s>>, Acc);
oneof(<<C, Rest/bits>>, BinAcc, Acc, []) ->
inline(Rest, <<BinAcc/binary, C>>, Acc);
oneof(Data, BinAcc, Acc, [Parse|Tail]) ->
Prev = case BinAcc of
<<>> -> undefined;
_ -> binary:last(BinAcc)
end,
try Parse(Data, Prev) of
{ok, Inline, Rest} when BinAcc =:= <<>> ->
inline(Rest, BinAcc, [Inline|Acc]);
{ok, Inline, Rest} ->
inline(Rest, <<>>, [Inline, BinAcc|Acc]);
{skip, Text, Rest} ->
oneof(Rest, <<BinAcc/binary, Text/binary>>, Acc, Tail)
catch _:_ ->
oneof(Data, BinAcc, Acc, Tail)
end.
-ifdef(TEST).
text_test() ->
<<>> = inline(<<>>),
<<"Hello, Robert">> = inline(<<"Hello, Robert">>),
ok.
-endif.
-define(IS_BOUNDARY(C), C =:= undefined; C =:= $\s; C =:= $\t; C =:= $\r; C =:= $\n; C =:= $().
%% Asciidoc User Guide 21.2.1
%%
%% We currently do not implement the <<...>> form.
xref(<<"xref:", IDAndCaption/bits>>, Prev) when ?IS_BOUNDARY(Prev) ->
%% ID must not contain whitespace characters.
{ID, <<"[", Caption0/bits>>} = while(fun(C) ->
(C =/= $[) andalso (C =/= $\s) andalso (C =/= $\t)
end, IDAndCaption),
%% It is followed by a caption.
{Caption1, <<"]", Rest/bits>>} = while(fun(C) ->
C =/= $]
end, Caption0),
Caption = trim(Caption1),
{ok, {xref, #{
id => ID
}, Caption, inline}, Rest}.
-ifdef(TEST).
xref_test() ->
[{xref, #{
id := <<"tiger_image">>
}, <<"face of a tiger">>, _}] = inline(<<"xref:tiger_image[face of a tiger]">>),
ok.
-endif.
%% Asciidoc User Guide 21.1.3
link(<<"link:", TargetAndCaption/bits>>, Prev) when ?IS_BOUNDARY(Prev) ->
%% Target must not contain whitespace characters.
{Target, <<"[", Caption0/bits>>} = while(fun(C) ->
(C =/= $[) andalso (C =/= $\s) andalso (C =/= $\t)
andalso (C =/= $\r) andalso (C =/= $\n)
end, TargetAndCaption),
%% It is followed by a caption.
{Caption1, <<"]", Rest/bits>>} = while(fun(C) ->
C =/= $]
end, Caption0),
Caption = trim(Caption1),
{ok, {link, #{
target => Target
}, Caption, inline}, Rest}.
-ifdef(TEST).
link_test() ->
[{link, #{
target := <<"downloads/foo.zip">>
}, <<"download foo.zip">>, _}] = inline(<<"link:downloads/foo.zip[download foo.zip]">>),
[{link, #{
target := <<"chapter1.asciidoc#fragment">>
}, <<"Chapter 1.">>, _}] = inline(<<"link:chapter1.asciidoc#fragment[Chapter 1.]">>),
[
{link, #{target := <<"first.zip">>}, <<"first">>, _},
<<", ">>,
{link, #{target := <<"second.zip">>}, <<"second">>, _}
] = inline(<<"link:first.zip[first],\nlink:second.zip[second]">>),
ok.
-endif.
%% Asciidoc User Guide 21.1.3
http_link(<<"http:", Rest/bits>>, Prev) when ?IS_BOUNDARY(Prev) ->
direct_link(Rest, <<"http:">>).
direct_link(Data, Prefix) ->
%% Target must not contain whitespace characters.
{Target0, Rest0} = while(fun(C) ->
(C =/= $[) andalso (C =/= $\s) andalso (C =/= $\t)
andalso (C =/= $\r) andalso (C =/= $\n)
andalso (C =/= $,)
end, Data),
%% The link must be more than just the prefix.
false = Target0 =:= <<>>,
Target = <<Prefix/binary, Target0/binary>>,
%% It is optionally followed by a caption. Otherwise
%% the link itself is the caption.
case Rest0 of
<<"[", Caption0/bits>> ->
{Caption1, <<"]", Rest/bits>>} = while(fun(C) ->
C =/= $]
end, Caption0),
Caption = trim(Caption1),
{ok, {link, #{
target => Target
}, Caption, inline}, Rest};
_ ->
{ok, {link, #{
target => Target
}, Target, inline}, Rest0}
end.
-ifdef(TEST).
http_link_test() ->
<<"Incomplete http: link">> = inline(<<"Incomplete http: link">>),
[
{link, #{
target := <<"http://example.org:8080">>
}, <<"http://example.org:8080">>, _},
<<", continued">>
] = inline(<<"http://example.org:8080, continued">>),
[
<<"If you have ">>,
{link, #{
target := <<"http://example.org/hello#fragment">>
}, <<"http://example.org/hello#fragment">>, _},
<<" then:">>
] = inline(<<"If you have http://example.org/hello#fragment then:">>),
[
<<"If you have ">>,
{link, #{
target := <<"http://example.org/hello#fragment">>
}, <<"http://example.org/hello#fragment">>, _},
<<" then:">>
] = inline(<<"If you have http://example.org/hello#fragment\nthen:">>),
[
<<"Oh, ">>,
{link, #{
target := <<"http://example.org/hello#fragment">>
}, <<"hello there">>, _},
<<", young lad.">>
] = inline(<<"Oh, http://example.org/hello#fragment[hello there], young lad.">>),
ok.
-endif.
%% Asciidoc User Guide 21.1.3
https_link(<<"https:", Rest/bits>>, Prev) when ?IS_BOUNDARY(Prev) ->
direct_link(Rest, <<"https:">>).
-ifdef(TEST).
https_link_test() ->
<<"Incomplete https: link">> = inline(<<"Incomplete https: link">>),
[
{link, #{
target := <<"https://example.org:8080">>
}, <<"https://example.org:8080">>, _},
<<", continued">>
] = inline(<<"https://example.org:8080, continued">>),
[
<<"If you have ">>,
{link, #{
target := <<"https://example.org/hello#fragment">>
}, <<"https://example.org/hello#fragment">>, _},
<<" then:">>
] = inline(<<"If you have https://example.org/hello#fragment then:">>),
[
<<"If you have ">>,
{link, #{
target := <<"https://example.org/hello#fragment">>
}, <<"https://example.org/hello#fragment">>, _},
<<" then:">>
] = inline(<<"If you have https://example.org/hello#fragment\nthen:">>),
[
<<"Oh, ">>,
{link, #{
target := <<"https://example.org/hello#fragment">>
}, <<"hello there">>, _},
<<", young lad.">>
] = inline(<<"Oh, https://example.org/hello#fragment[hello there], young lad.">>),
ok.
-endif.
%% Asciidoc User Guide 10.1
%% @todo <<"\\**"
%% @todo <<"\\*"
%% @todo <<"**"
emphasized_single_quote(Data, Prev) ->
quoted_text(Data, Prev, emphasized, $', $').
emphasized_underline(Data, Prev) ->
quoted_text(Data, Prev, emphasized, $_, $_).
strong(Data, Prev) ->
quoted_text(Data, Prev, strong, $*, $*).
quoted_text(<<Left, Rest0/bits>>, Prev, Type, Left, Right) when ?IS_BOUNDARY(Prev) ->
{Content, <<Right, Rest/bits>>} = while(fun(C) -> C =/= Right end, Rest0),
{ok, {Type, #{
left => Left,
right => Right
}, inline(Content), inline}, Rest}.
-ifdef(TEST).
emphasized_test() ->
[
<<"Word phrases ">>,
{emphasized, #{left := $', right := $'},
<<"enclosed in single quote characters">>, _},
<<" (acute accents) or ">>,
{emphasized, #{left := $_, right := $_},
<<"underline characters">>, _},
<<" are emphasized.">>
] = inline(<<
"Word phrases 'enclosed in single quote characters' (acute accents) "
"or _underline characters_ are emphasized."
>>),
ok.
strong_test() ->
[
<<"Word phrases ">>,
{strong, #{left := $*, right := $*},
<<"enclosed in asterisk characters">>, _},
<<" are rendered in a strong font (usually bold).">>
] = inline(<<
"Word phrases *enclosed in asterisk characters* "
"are rendered in a strong font (usually bold)."
>>),
ok.
-endif.
%% Asciidoc User Guide 21.4
inline_literal_passthrough(<<"`", Rest0/bits>>, Prev) when ?IS_BOUNDARY(Prev) ->
{Content, <<"`", Rest/bits>>} = while(fun(C) -> C =/= $` end, Rest0),
{ok, {inline_literal_passthrough, #{}, Content, inline}, Rest}.
-ifdef(TEST).
inline_literal_passthrough_test() ->
[
<<"Word phrases ">>,
{inline_literal_passthrough, #{}, <<"enclosed in backtick characters">>, _},
<<" (grave accents)...">>
] = inline(<<"Word phrases `enclosed in backtick characters` (grave accents)...">>),
ok.
-endif.
