diff options
Diffstat (limited to 'src/rebar_state.erl')
| -rw-r--r-- | src/rebar_state.erl | 66 |
1 files changed, 65 insertions, 1 deletions
diff --git a/src/rebar_state.erl b/src/rebar_state.erl index fa0a963..cd127c0 100644 --- a/src/rebar_state.erl +++ b/src/rebar_state.erl @@ -240,7 +240,7 @@ merge_opts(NewOpts, OldOpts) -> true -> NewValue; false -> - lists:umerge(lists:sort(NewValue), lists:sort(OldValue)) + tup_umerge(tup_sort(NewValue), tup_sort(OldValue)) end; (_Key, NewValue, _OldValue) -> NewValue @@ -362,3 +362,67 @@ add_hook(pre, {PreHooks, PostHooks}, Hook) -> {[Hook | PreHooks], PostHooks}; add_hook(post, {PreHooks, PostHooks}, Hook) -> {PreHooks, [Hook | PostHooks]}. + + +%% Sort the list in proplist-order, meaning that `{a,b}' and `{a,c}' +%% both compare as usual, and `a' and `b' do the same, but `a' and `{a,b}' will +%% compare based on the first element of the key, and in order. So the following +%% list will sort as: +%% - `[native, {native,o3}, check]' -> `[check, native, {native, o3}]' +%% - `[native, {native,o3}, {native, o2}, check]' -> `[check,native,{native,o3},{native,o2}]' +%% Meaning that: +%% a) no deduplication takes place +%% b) the key of a tuple is what counts in being sorted, but atoms are seen as {atom} +%% as far as comparison is concerned (departing from lists:ukeysort/2) +%% c) order is preserved for similar keys and tuples no matter their size (sort is stable) +%% +%% These properties let us merge proplists fairly easily. +tup_sort(List) -> + lists:sort(fun(A, B) when is_tuple(A), is_tuple(B) -> element(1, A) =< element(1, B) + ; (A, B) when is_tuple(A) -> element(1, A) =< B + ; (A, B) when is_tuple(B) -> A =< element(1, B) + ; (A, B) -> A =< B + end, List). + +%% Custom merge functions. The objective is to behave like lists:umerge/2, +%% except that we also compare the merge elements based on the key if they're a +%% tuple, such that `{key, val1}' is always prioritized over `{key, val0}' if +%% the former is from the 'new' list. +%% +%% This lets us apply proper overrides to list of elements according to profile +%% priority. This function depends on a stable proplist sort. +tup_umerge([], Olds) -> + Olds; +tup_umerge([New|News], Olds) -> + lists:reverse(umerge(News, Olds, [], New)). + +%% This is equivalent to umerge2_2 in the stdlib, except we use the expanded +%% value/key only to compare +umerge(News, [Old|Olds], Merged, Cmp) when element(1, Cmp) == element(1, Old); + element(1, Cmp) == Old; + Cmp == element(1, Old); + Cmp =< Old -> + umerge(News, Olds, [Cmp | Merged], Cmp, Old); +umerge(News, [Old|Olds], Merged, Cmp) -> + umerge(News, Olds, [Old | Merged], Cmp); +umerge(News, [], Merged, Cmp) -> + lists:reverse(News, [Cmp | Merged]). + +%% Similar to stdlib's umerge2_1 in the stdlib, except that when the expanded +%% value/keys compare equal, we check if the element is a full dupe to clear it +%% (like the stdlib function does) or otherwise keep the duplicate around in +%% an order that prioritizes 'New' elements. +umerge([New|News], Olds, Merged, CmpMerged, Cmp) when CmpMerged == Cmp -> + umerge(News, Olds, Merged, New); +umerge([New|News], Olds, Merged, _CmpMerged, Cmp) when element(1,New) == element(1, Cmp); + element(1,New) == Cmp; + New == element(1, Cmp); + New =< Cmp -> + umerge(News, Olds, [New | Merged], New, Cmp); +umerge([New|News], Olds, Merged, _CmpMerged, Cmp) -> % > + umerge(News, Olds, [Cmp | Merged], New); +umerge([], Olds, Merged, CmpMerged, Cmp) when CmpMerged == Cmp -> + lists:reverse(Olds, Merged); +umerge([], Olds, Merged, _CmpMerged, Cmp) -> + lists:reverse(Olds, [Cmp | Merged]). + |