From 975b789449c63a2903f0997f8a84a539d5c49862 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Wed, 1 Oct 2014 18:23:57 +0200 Subject: compiler: Properly support Map aliasing Matching of type: #{K := V1} = #{K := V2} = M, Will alias (coalesce) to #{K := V1 = V2} = M. --- lib/compiler/src/v3_core.erl | 41 +++++++++++++++++++++++++---------------- 1 file changed, 25 insertions(+), 16 deletions(-) (limited to 'lib') diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl index 6d4a49d308..3d9fc3a609 100644 --- a/lib/compiler/src/v3_core.erl +++ b/lib/compiler/src/v3_core.erl @@ -1635,9 +1635,9 @@ pattern({bin,L,Ps}, St) -> %% no need to hold any used/new annotations in a pattern. {#c_binary{anno=lineno_anno(L, St),segments=pat_bin(Ps, St)},[],St}; pattern({match,_,P1,P2}, St) -> - {Cp1,[],St1} = pattern(P1, St), - {Cp2,[],St2} = pattern(P2, St1), - {pat_alias(Cp1,Cp2),[],St2}. + {Cp1,Eps1,St1} = pattern(P1,St), + {Cp2,Eps2,St2} = pattern(P2,St1), + {pat_alias(Cp1,Cp2),Eps1++Eps2,St2}. %% pattern_map_pairs([MapFieldExact],State) -> [#c_map_pairs{}] pattern_map_pairs(Ps, St) -> @@ -1651,14 +1651,13 @@ pattern_map_pairs(Ps, St) -> {CMapPair,EpsP,Sti1} = pattern_map_pair(P,Sti0), {CMapPair, {EpsM++EpsP,Sti1}} end, {[],St}, Ps), - {pattern_alias_map_pairs(CMapPairs,[]),Eps,St1}. + {pat_alias_map_pairs(CMapPairs,[]),Eps,St1}. %% remove cluddering annotations pattern_map_clean_key(#c_literal{val=V}) -> {literal,V}; -pattern_map_clean_key(#c_var{name=V}) -> {var,V}; -pattern_map_clean_key(_) -> erlang:throw(nomatch). +pattern_map_clean_key(#c_var{name=V}) -> {var,V}. -pattern_alias_map_pairs(Ps1,Ps2) -> +pat_alias_map_pairs(Ps1,Ps2) -> Ps = Ps1 ++ Ps2, F = fun(#c_map_pair{key=Ck,val=Cv},Dbi) -> K = pattern_map_clean_key(Ck), @@ -1668,24 +1667,24 @@ pattern_alias_map_pairs(Ps1,Ps2) -> end end, Kdb = lists:foldl(F,dict:new(),Ps), - pattern_alias_map_pairs(Ps,Kdb,sets:new()). + pat_alias_map_pairs(Ps,Kdb,sets:new()). -pattern_alias_map_pairs([],_,_) -> []; -pattern_alias_map_pairs([#c_map_pair{key=Ck}=Pair|Pairs],Kdb,Set) -> +pat_alias_map_pairs([],_,_) -> []; +pat_alias_map_pairs([#c_map_pair{key=Ck}=Pair|Pairs],Kdb,Set) -> K = pattern_map_clean_key(Ck), case sets:is_element(K,Set) of true -> - pattern_alias_map_pairs(Pairs,Kdb,Set); + pat_alias_map_pairs(Pairs,Kdb,Set); false -> Cvs = dict:fetch(K,Kdb), - Cv = pattern_alias_map_pair_values(Cvs), + Cv = pat_alias_map_pair_values(Cvs), Set1 = sets:add_element(K,Set), - [Pair#c_map_pair{val=Cv}|pattern_alias_map_pairs(Pairs,Kdb,Set1)] + [Pair#c_map_pair{val=Cv}|pat_alias_map_pairs(Pairs,Kdb,Set1)] end. -pattern_alias_map_pair_values([Cv]) -> Cv; -pattern_alias_map_pair_values([Cv1,Cv2|Cvs]) -> - pattern_alias_map_pair_values([pat_alias(Cv1,Cv2)|Cvs]). +pat_alias_map_pair_values([Cv]) -> Cv; +pat_alias_map_pair_values([Cv1,Cv2|Cvs]) -> + pat_alias_map_pair_values([pat_alias(Cv1,Cv2)|Cvs]). pattern_map_pair({map_field_exact,L,K,V}, St0) -> {Ck,EpsK,St1} = safe_pattern_expr(K,St0), @@ -1712,6 +1711,8 @@ pat_segment({bin_element,_,Val,Size,[Type,{unit,Unit}|Flags]}, St) -> pat_alias(#c_var{name=V1}, P2) -> #c_alias{var=#c_var{name=V1},pat=P2}; pat_alias(P1, #c_var{name=V2}) -> #c_alias{var=#c_var{name=V2},pat=P1}; + +%% alias cons pat_alias(#c_cons{}=Cons, #c_literal{anno=A,val=[H|T]}=S) -> pat_alias(Cons, ann_c_cons_skel(A, #c_literal{anno=A,val=H}, S#c_literal{val=T})); @@ -1720,6 +1721,8 @@ pat_alias(#c_literal{anno=A,val=[H|T]}=S, #c_cons{}=Cons) -> S#c_literal{val=T}), Cons); pat_alias(#c_cons{anno=Anno,hd=H1,tl=T1}, #c_cons{hd=H2,tl=T2}) -> ann_c_cons(Anno, pat_alias(H1, H2), pat_alias(T1, T2)); + +%% alias tuples pat_alias(#c_tuple{anno=Anno,es=Es1}, #c_literal{val=T}) when is_tuple(T) -> Es2 = [#c_literal{val=E} || E <- tuple_to_list(T)], ann_c_tuple(Anno, pat_alias_list(Es1, Es2)); @@ -1728,6 +1731,12 @@ pat_alias(#c_literal{anno=Anno,val=T}, #c_tuple{es=Es2}) when is_tuple(T) -> ann_c_tuple(Anno, pat_alias_list(Es1, Es2)); pat_alias(#c_tuple{anno=Anno,es=Es1}, #c_tuple{es=Es2}) -> ann_c_tuple(Anno, pat_alias_list(Es1, Es2)); + +%% alias maps +%% There are no literals in maps patterns (patterns are always abstract) +pat_alias(#c_map{es=Es1}=M,#c_map{es=Es2}) -> + M#c_map{es=pat_alias_map_pairs(Es1,Es2)}; + pat_alias(#c_alias{var=V1,pat=P1}, #c_alias{var=V2,pat=P2}) -> if V1 =:= V2 -> #c_alias{var=V1,pat=pat_alias(P1, P2)}; -- cgit v1.2.3