Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Add from_map/2 and to_map/1 #7

Merged
merged 1 commit into from Nov 13, 2018
Merged

Add from_map/2 and to_map/1 #7

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
6 changes: 6 additions & 0 deletions README.md
View file
Open in desktop
Expand Up @@ -21,6 +21,12 @@ fields(record_name) ->

new_record(record_name) ->
#record_name{}.

from_map(record_name, Map) ->
#record_name{...}.

to_map(Record) ->
#{...}.
```

It runs at compile time using following preprocessor directive:
Expand Down
61 changes: 57 additions & 4 deletions src/dynarec.erl
View file
Open in desktop
Expand Up @@ -22,6 +22,12 @@
%%%
%%% new_record(record_name) ->
%%% #record_name{}.
%%%
%%% from_map(record_name, Map) ->
%%% #record_name{...}.
%%%
%%% to_map(Record) ->
%%% #{...}.
%%% </pre>
%%%
%%% <p>It runs at compile time using following preprocessor directive:</p>
Expand Down Expand Up @@ -52,7 +58,9 @@ parse_transform(Forms, _Options) ->
[gen_fields(Tuples) |
[gen_field_getter(Tuples) |
[gen_setter(Tuples) |
lists:reverse(Forms)]]]]]),
[gen_to_map(Records) |
[gen_from_map(Records) |
lists:reverse(Forms)]]]]]]]),
add_exports(NewForms).


Expand Down Expand Up @@ -199,14 +207,59 @@ gen_new_record(Tuples) ->
gen_new_record_clause(RecordName) ->
{clause, 0, [{atom, 0, RecordName}], [], [{record, 0, RecordName, []}]}.

field_to_name_and_default({record_field, _, {atom, _, FieldName}, Default}) ->
{FieldName, Default};
field_to_name_and_default({record_field, _, {atom, _, FieldName}}) ->
{FieldName, {atom, 0, undefined}};
field_to_name_and_default({typed_record_field, RecordField, _Typed}) ->
field_to_name_and_default(RecordField).

%% @doc Generate the from_map/2 function
gen_from_map(Records) ->
List = lists:foldl(fun(Record, Acc) -> [gen_from_map_clause(Record) | Acc] end, [], Records),
{function, 0, from_map, 2, lists:reverse(List)}.

gen_from_map_clause({attribute, _, record, {Name, Fields}}) ->
FieldNamesWithDefaults = [field_to_name_and_default(Field) || Field <- Fields],
MapName =
case Fields of
[] ->
'_Map';
_ ->
'Map'
end,
{clause, 0, [{atom, 0, Name}, {var, 0, MapName}], [],
[{record, 0, Name,
[{record_field, 0, {atom, 0, FieldName}, gen_record_field_from_map(FieldName, FieldDefault, MapName)}
|| {FieldName, FieldDefault} <- FieldNamesWithDefaults]}]}.

gen_record_field_from_map(FieldName, FieldDefault, MapName) ->
{'case', 0, {call, 0, {remote, 0, {atom, 0, maps}, {atom, 0, find}}, [{atom, 0, FieldName}, {var, 0, MapName}]},
[{clause, 0, [{tuple, 0, [{atom, 0, ok}, {var, 0, 'Val'}]}], [], [{var, 0, 'Val'}]},
{clause, 0, [{atom, 0, error}], [], [FieldDefault]}]}.

%% @doc Generate the to_map/1 function
gen_to_map(Records) ->
List = lists:foldl(fun(Record, Acc) -> [gen_to_map_clause(Record) | Acc] end, [], Records),
{function, 0, to_map, 1, lists:reverse(List)}.

gen_to_map_clause({attribute, _, record, {Name, Fields}}) ->
FieldNamesWithDefaults = [field_to_name_and_default(Field) || Field <- Fields],
{clause, 0, [{var, 0, 'Record'}], [[{call, 0, {atom, 0, is_record}, [{var, 0, 'Record'}, {atom, 0, Name}]}]],
[{map, 0,
[{map_field_assoc, 0,
{atom, 0, FieldName},
{record_field, 0, {var, 0, 'Record'}, Name, {atom, 0, FieldName}}}
|| {FieldName, _} <- FieldNamesWithDefaults]}]}.

%% @doc Adds the getter and setter functions to the list of exported functions
%% @doc Adds generated functions to the list of exported functions
add_exports(Forms) ->
case lists:keysearch(export, 3, Forms) of
{value, {attribute, N, export, Exports}} ->
lists:keyreplace(export, 3, Forms,
{attribute, N, export, [{records, 0}, {fields, 1},
{new_record, 1}, {get_value, 2}, {set_value, 3} | Exports]});
{attribute, N, export,
[{records, 0}, {fields, 1}, {from_map, 2}, {to_map, 1},
{new_record, 1}, {get_value, 2}, {set_value, 3} | Exports]});
false -> Forms
end.

Expand Down