The very simplest transform we can make is one that doesn't +change a thing. For convenience, we will at least print the forms. +This will enlighten us as to what the forms actually look like.
+ +
+-module(test_pt).
+
+-export([parse_transform/2]).
+
+parse_transform(Forms, _Options) ->
+ io:fwrite("Forms = ~p~n", [Forms]),
+ Forms.
+
+
+Trying this with a very simple module:
+ ++-module(ex1). +-export([add/2]). + +add(X,Y) -> + X + Y. ++ +
+1> c(ex1, [{parse_transform,test_pt}]).
+Forms = [{attribute,1,file,{"./ex1.erl",1}},
+ {attribute,1,module,ex1},
+ {attribute,2,export,[{add,2}]},
+ {function,4,add,2,
+ [{clause,4,
+ [{var,4,'X'},{var,4,'Y'}],
+ [],
+ [{op,5,'+',{var,5,'X'},{var,5,'Y'}}]}]},
+ {eof,6}]
+{ok,ex1}
+
+
...
diff --git a/examples/test_pt.erl b/examples/test_pt.erl index c7ed896..a596628 100644 --- a/examples/test_pt.erl +++ b/examples/test_pt.erl @@ -1,10 +1,8 @@ -module(test_pt). -export([parse_transform/2]). --compile(export_all). - -parse_transform(Forms, Options) -> +parse_transform(Forms, _Options) -> io:fwrite("Forms = ~p~n", [Forms]), Forms. diff --git a/src/parse_trans.erl b/src/parse_trans.erl index 24929b5..e03d6bd 100644 --- a/src/parse_trans.erl +++ b/src/parse_trans.erl @@ -36,6 +36,7 @@ -export([ inspect/4, transform/4, + depth_first/4, revert/1 ]). @@ -47,7 +48,8 @@ -export([ initial_context/2, do_inspect/4, - do_transform/4 + do_transform/4, + do_depth_first/4 ]). -export([do_insert_forms/4]). @@ -89,7 +91,16 @@ throw({error,get_pos(I),{unknown,R}}) end). - +%% Typer typedefs +-type form() :: any(). +-type forms() :: [form()]. +-type options() :: [{atom(), any()}]. +-type type() :: atom(). +-type xform_f() :: fun((type(), form(), #context{}, Acc) -> + {form(), bool(), Acc} + | {forms(), form(), forms(), bool(), Acc}). +-type insp_f() :: fun((type(), form(), #context{}, A) -> {bool(), A}). + %%% @spec (Reason, Form, Info) -> throw() %%% Info = [{Key,Value}] @@ -98,11 +109,15 @@ %%%Used to report errors detected during the parse transform.
%%% @end %%% +-spec error(string(), any(), [{any(),any()}]) -> + none(). error(R, F, I) -> rpt_error(R, F, I), throw({error,get_pos(I),{unknown,R}}). +-spec get_pos(list()) -> + integer(). get_pos(I) when is_list(I) -> case proplists:get_value(form, I) of undefined -> @@ -117,6 +132,8 @@ get_pos(I) when is_list(I) -> %%% Returns the name of the file being compiled. %%% @end %%% +-spec get_file(forms()) -> + string(). get_file(Forms) -> string_value(hd(get_attribute(file, Forms))). @@ -127,6 +144,8 @@ get_file(Forms) -> %%% Returns the name of the module being compiled. %%% @end %%% +-spec get_module([any()]) -> + atom(). get_module(Forms) -> atom_value(hd(get_attribute(module, Forms))). @@ -139,18 +158,29 @@ get_module(Forms) -> %%% Returns the value of the first occurence of attribute A. %%% @end %%% -get_attribute(A, [F|Forms]) -> +-spec get_attribute(atom(), [any()]) -> + false | list(). +get_attribute(A, Forms) -> + case find_attribute(A, Forms) of + false -> + throw({error, ?DUMMY_LINE, {missing_attribute, A}}); + Other -> + Other + end. + +find_attribute(A, [F|Forms]) -> case type(F) == attribute andalso atom_value(attribute_name(F)) == A of true -> attribute_arguments(F); false -> - get_attribute(A, Forms) + find_attribute(A, Forms) end; -get_attribute(A, []) -> - throw({error, ?DUMMY_LINE, {missing_attribute, A}}). - +find_attribute(_, []) -> + false. +-spec function_exists(atom(), integer(), forms()) -> + bool(). function_exists(Fname, Arity, Forms) -> Fns = proplists:get_value( functions, erl_syntax_lib:analyze_forms(Forms), []), @@ -166,6 +196,8 @@ function_exists(Fname, Arity, Forms) -> %%% name and the options passed to the transform function. %%% @end %%% +-spec initial_context(forms(), options()) -> + #context{}. initial_context(Forms, Options) -> File = get_file(Forms), io:fwrite("File = ~p~n", [File]), @@ -182,11 +214,22 @@ initial_context(Forms, Options) -> %%% @doc %%% Makes one pass %%% @end -transform(Fun, Acc, Forms, Options) when is_function(Fun, 5) -> +-spec transform(xform_f(), Acc, forms(), options()) -> + {forms(), Acc} | {error, list()}. +transform(Fun, Acc, Forms, Options) when is_function(Fun, 4) -> + do(fun do_transform/4, Fun, Acc, Forms, Options). + +-spec depth_first(xform_f(), Acc, forms(), options()) -> + {forms(), Acc} | {error, list()}. +depth_first(Fun, Acc, Forms, Options) when is_function(Fun, 4) -> + do(fun do_depth_first/4, Fun, Acc, Forms, Options). + + +do(Transform, Fun, Acc, Forms, Options) -> Context = initial_context(Forms, Options), File = Context#context.file, - try do_transform(Fun, Acc, Forms, Context) of - {_, NewForms} = Result -> + try Transform(Fun, Acc, Forms, Context) of + {NewForms, _} = Result -> optionally_pretty_print(NewForms, Options, Context), Result catch @@ -198,7 +241,8 @@ transform(Fun, Acc, Forms, Options) when is_function(Fun, 5) -> {error, [{File, [{Ln, ?MODULE, What}]}], []} end. - +-spec do_insert_forms(above | below, forms(), forms(), #context{}) -> + forms(). do_insert_forms(above, Insert, Forms, Context) when is_list(Insert) -> {NewForms, _} = do_transform( @@ -208,11 +252,11 @@ do_insert_forms(above, Insert, Forms, Context) when is_list(Insert) -> {F, _Recurse = false, Acc} end, false, Forms, Context), NewForms; -do_insert_forms(below, Insert, Forms, Context) when is_list(Insert) -> +do_insert_forms(below, Insert, Forms, _Context) when is_list(Insert) -> insert_below(Forms, Insert). -insert_below([F|Rest] = Forms, Insert) -> +insert_below([F|Rest], Insert) -> case type(F) of eof_marker -> Insert ++ [F]; @@ -220,15 +264,28 @@ insert_below([F|Rest] = Forms, Insert) -> [F|insert_below(Rest, Insert)] end. +-spec optionally_pretty_print(forms(), options(), #context{}) -> + ok. optionally_pretty_print(Result, Options, Context) -> - case lists:member(pt_pp_src, Options) of - true -> + DoPP = + case proplists:get_value(pt_pp_src, Options) of + undefined -> + case find_attribute(pt_pp_src,Result) of + [Expr] -> + type(Expr) == atom andalso + atom_value(Expr) == true; + _ -> + false + end; + V when is_boolean(V) -> + V + end, + if DoPP -> File = Context#context.file, Out = outfile(File), pp_src(Result, Out), io:fwrite("Pretty-printed in ~p~n", [Out]); - _ -> - io:fwrite("Will not pretty-print~n", []), + true -> ok end. @@ -239,6 +296,8 @@ optionally_pretty_print(Result, Options, Context) -> %%% Equvalent to do_inspect(Fun,Acc,Forms,initial_context(Forms,Options)). %%% @end %%% +-spec inspect(insp_f(), A, forms(), options()) -> + A. inspect(F, Acc, Forms, Options) -> Context = initial_context(Forms, Options), do_inspect(F, Acc, Forms, Context). @@ -312,7 +371,7 @@ do_inspect(F, Acc, Forms, Context) -> Type = type(Form), {Recurse, Acc1} = apply_F(F, Type, Form, Context, Acc0), if_recurse( - Recurse, Form, Acc1, + Recurse, Form, _Else = Acc1, fun(ListOfLists) -> lists:foldl( fun(L, AccX) -> @@ -324,38 +383,81 @@ do_inspect(F, Acc, Forms, Context) -> end, lists:foldl(F1, Forms, Acc). +if_recurse(true, Form, Else, F) -> recurse(Form, Else, F); +if_recurse(false, _, Else, _) -> Else. + +recurse(Form, Else, F) -> + case erl_syntax:subtrees(Form) of + [] -> + Else; + [_|_] = ListOfLists -> + F(ListOfLists) + end. + do_transform(F, Acc, Forms, Context) -> + Rec = fun do_transform/4, % this function F1 = fun(Form, Acc0) -> - Type = type(Form), {Before1, Form1, After1, Recurse, Acc1} = - case apply_F(F, Type, Form, Context, Acc0) of - {Form1x, Rec1x, A1x} -> - {[], Form1x, [], Rec1x, A1x}; - {_Be1, _F1, _Af1, _Rec1, _Ac1} = Res1 -> - Res1 - end, - if_recurse( - Recurse, Form, - {Before1, Form1, After1, Acc1}, - fun(ListOfLists) -> - {NewListOfLists, NewAcc} = - mapfoldl( - fun(L, AccX) -> - do_transform( - F, AccX, L, - update_context( - Form1, Context)) - end, Acc1, ListOfLists), - NewForm = - erl_syntax:update_tree( - Form, NewListOfLists), - {Before1, NewForm, After1, NewAcc} - end) + this_form_rec(F, Form, Context, Acc0), + if Recurse -> + {NewForm, NewAcc} = + enter_subtrees(Form1, F, Context, Acc1, Rec), + {Before1, NewForm, After1, NewAcc}; + true -> + {Before1, Form1, After1, Acc1} + end end, mapfoldl(F1, Acc, Forms). +do_depth_first(F, Acc, Forms, Context) -> + Rec = fun do_depth_first/4, % this function + F1 = + fun(Form, Acc0) -> + {NewForm, NewAcc} = enter_subtrees(Form, F, Context, Acc, Rec), + this_form_df(F, NewForm, Context, NewAcc) + end, + mapfoldl(F1, Acc, Forms). + + +enter_subtrees(Form, F, Context, Acc, Recurse) -> + case erl_syntax:subtrees(Form) of + [] -> + {Form, Acc}; + [_|_] = ListOfLists -> + {NewListOfLists, NewAcc} = + mapfoldl( + fun(L, AccX) -> + Recurse(F, AccX, L, Context) + end, Acc, ListOfLists), + NewForm = + erl_syntax:update_tree( + Form, NewListOfLists), + {NewForm, NewAcc} + end. + + +this_form_rec(F, Form, Context, Acc) -> + Type = type(Form), + case apply_F(F, Type, Form, Context, Acc) of + {Form1x, Rec1x, A1x} -> + {[], Form1x, [], Rec1x, A1x}; + {_Be1, _F1, _Af1, _Rec1, _Ac1} = Res1 -> + Res1 + end. +this_form_df(F, Form, Context, Acc) -> + Type = type(Form), + case apply_F(F, Type, Form, Context, Acc) of + {Form1x, A1x} -> + {[], Form1x, [], A1x}; + {_Be1, _F1, _Af1, _Ac1} = Res1 -> + Res1 + end. + + + + apply_F(F, Type, Form, Context, Acc) -> try F(Type, Form, Context, Acc) catch @@ -365,20 +467,10 @@ apply_F(F, Type, Form, Context, Acc) -> [{type, Type}, {context, Context}, {acc, Acc}, + {apply_f, F}, {form, Form}]) end. -if_recurse(true, Form, Else, F) -> - case erl_syntax:subtrees(Form) of - [] -> - Else; - [_|_] = ListOfLists -> - F(ListOfLists) - end; -if_recurse(false, _, Else, _) -> - Else. - - update_context(Form, Context0) -> case type(Form) of diff --git a/util/make_doc.beam b/util/make_doc.beam index e9fd542..30d1ab6 100644 Binary files a/util/make_doc.beam and b/util/make_doc.beam differ