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Diffstat (limited to 'lib/asn1/src/asn1ct_imm.erl')
| -rw-r--r-- | lib/asn1/src/asn1ct_imm.erl | 626 |
1 files changed, 626 insertions, 0 deletions
diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl new file mode 100644 index 0000000000..34bb0b8714 --- /dev/null +++ b/lib/asn1/src/asn1ct_imm.erl @@ -0,0 +1,626 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2012. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% +%% +-module(asn1ct_imm). +-export([per_dec_boolean/0,per_dec_enumerated/2,per_dec_enumerated/3, + per_dec_extension_map/1, + per_dec_integer/2,per_dec_length/3,per_dec_named_integer/3, + per_dec_octet_string/2,per_dec_open_type/1]). +-export([optimize_alignment/1,optimize_alignment/2, + dec_slim_cg/2,dec_code_gen/2]). +-export([effective_constraint/2]). +-import(asn1ct_gen, [emit/1]). + +-record(st, {var, + base}). + +dec_slim_cg(Imm0, BytesVar) -> + {Imm,_} = optimize_alignment(Imm0), + asn1ct_name:new(v), + [H|T] = atom_to_list(asn1ct_name:curr(v)) ++ "@", + VarBase = [H-($a-$A)|T], + St0 = #st{var=0,base=VarBase}, + {Res,Pre,_} = flatten(Imm, BytesVar, St0), + dcg_list_outside(Pre), + Res. + +dec_code_gen(Imm, BytesVar) -> + emit(["begin",nl]), + {Dst,DstBuf} = dec_slim_cg(Imm, BytesVar), + emit([",",nl, + "{",Dst,",",DstBuf,"}",nl, + "end"]), + ok. + +optimize_alignment(Imm) -> + opt_al(Imm, unknown). + +optimize_alignment(Imm, Al) -> + opt_al(Imm, Al). + + +per_dec_boolean() -> + {map,{get_bits,1,[1]},[{0,false},{1,true}]}. + +per_dec_enumerated(NamedList0, Aligned) -> + Constraint = [{'ValueRange',{0,length(NamedList0)-1}}], + NamedList = per_dec_enumerated_fix_list(NamedList0, [enum_error], 0), + Int = per_dec_integer(Constraint, Aligned), + {map,Int,NamedList}. + +per_dec_enumerated(BaseNamedList, NamedListExt0, Aligned) -> + Base = per_dec_enumerated(BaseNamedList, Aligned), + NamedListExt = per_dec_enumerated_fix_list(NamedListExt0, + [enum_default], 0), + Ext = {map,per_dec_normally_small_number(Aligned),NamedListExt}, + bit_case(Base, Ext). + +per_dec_extension_map(Aligned) -> + Len = {add,per_dec_normally_small_number(Aligned),1}, + {get_bits,Len,[1,bitstring]}. + +per_dec_integer(Constraint0, Aligned) -> + Constraint = effective_constraint(integer, Constraint0), + per_dec_integer_1(Constraint, Aligned). + +per_dec_length(SingleValue, _, _Aligned) when is_integer(SingleValue) -> + {value,SingleValue}; +per_dec_length({S,S}, _, _Aligned) when is_integer(S) -> + {value,S}; +per_dec_length({{_,_}=Constr,_}, AllowZero, Aligned) -> + bit_case(per_dec_length(Constr, AllowZero, Aligned), + per_dec_length(undefined, AllowZero, Aligned)); +per_dec_length({Lb,Ub}, _AllowZero, Aligned) when is_integer(Lb), + is_integer(Lb), + Ub =< 65535 -> + per_dec_constrained(Lb, Ub, Aligned); +per_dec_length({_,_}, AllowZero, Aligned) -> + decode_unconstrained_length(AllowZero, Aligned); +per_dec_length(undefined, AllowZero, Aligned) -> + decode_unconstrained_length(AllowZero, Aligned). + +per_dec_named_integer(Constraint, NamedList0, Aligned) -> + Int = per_dec_integer(Constraint, Aligned), + NamedList = [{K,V} || {V,K} <- NamedList0] ++ [integer_default], + {map,Int,NamedList}. + +per_dec_octet_string(Constraint, Aligned) -> + dec_string(Constraint, 8, Aligned). + +per_dec_open_type(Aligned) -> + {get_bits,decode_unconstrained_length(true, Aligned), + [8,binary,{align,Aligned}]}. + + +%%% +%%% Local functions. +%%% + +dec_string(Sv, U, _Aligned) when is_integer(Sv), U*Sv =< 16 -> + {get_bits,Sv,[U,binary]}; +dec_string(Sv, U, Aligned) when is_integer(Sv), Sv < 16#10000 -> + {get_bits,Sv,[U,binary,{align,Aligned}]}; +dec_string(C, U, Aligned) when is_list(C) -> + dec_string({hd(C),lists:max(C)}, U, Aligned); +dec_string({Sv,Sv}, U, Aligned) -> + dec_string(Sv, U, Aligned); +dec_string({{_,_}=C,_}, U, Aligned) -> + bit_case(dec_string(C, U, Aligned), + dec_string(no, U, Aligned)); +dec_string({Lb,Ub}, U, Aligned) when Ub < 16#10000 -> + Len = per_dec_constrained(Lb, Ub, Aligned), + {get_bits,Len,[U,binary,{align,Aligned}]}; +dec_string(_, U, Aligned) -> + Al = [{align,Aligned}], + DecRest = fun(V, Buf) -> + emit(["?RT_PER:decode_fragmented(",V,", ", + Buf,", ",U,")"]) + end, + {'case',[{test,{get_bits,1,[1|Al]},0, + {value,{get_bits, + {get_bits,7,[1]}, + [U,binary]}}}, + {test,{get_bits,1,[1|Al]},1, + {test,{get_bits,1,[1]},0, + {value,{get_bits, + {get_bits,14,[1]}, + [U,binary]}}}}, + {test,{get_bits,1,[1|Al]},1, + {test,{get_bits,1,[1]},1, + {value,{call,DecRest,{get_bits,6,[1]}}}}}]}. + +per_dec_enumerated_fix_list([{V,_}|T], Tail, N) -> + [{N,V}|per_dec_enumerated_fix_list(T, Tail, N+1)]; +per_dec_enumerated_fix_list([], Tail, _) -> Tail. + +per_dec_integer_1([{'SingleValue',Value}], _Aligned) -> + {value,Value}; +per_dec_integer_1([{'ValueRange',{Lb,'MAX'}}], Aligned) when is_integer(Lb) -> + per_dec_unconstrained(Aligned); +per_dec_integer_1([{'ValueRange',{Lb,Ub}}], Aligned) when is_integer(Lb), + is_integer(Ub) -> + per_dec_constrained(Lb, Ub, Aligned); +per_dec_integer_1([{{_,_}=Constr0,_}], Aligned) -> + Constr = effective_constraint(integer, [Constr0]), + bit_case(per_dec_integer(Constr, Aligned), + per_dec_unconstrained(Aligned)); +per_dec_integer_1([], Aligned) -> + per_dec_unconstrained(Aligned). + +per_dec_unconstrained(Aligned) -> + {get_bits,decode_unconstrained_length(false, Aligned),[8,signed]}. + +per_dec_constrained(Lb, Ub, false) -> + Range = Ub - Lb + 1, + Get = {get_bits,uper_num_bits(Range),[1]}, + add_lb(Lb, Get); +per_dec_constrained(Lb, Ub, true) -> + Range = Ub - Lb + 1, + Get = if + Range =< 255 -> + {get_bits,per_num_bits(Range),[1,unsigned]}; + Range == 256 -> + {get_bits,1,[8,unsigned,{align,true}]}; + Range =< 65536 -> + {get_bits,2,[8,unsigned,{align,true}]}; + true -> + RangeOctLen = byte_size(binary:encode_unsigned(Range - 1)), + {get_bits,per_dec_length({1,RangeOctLen}, false, true), + [8,unsigned,{align,true}]} + end, + add_lb(Lb, Get). + +add_lb(0, Get) -> Get; +add_lb(Lb, Get) -> {add,Get,Lb}. + +per_dec_normally_small_number(Aligned) -> + Small = {get_bits,6,[1]}, + Unlimited = per_decode_semi_constrained(0, Aligned), + bit_case(Small, Unlimited). + +per_decode_semi_constrained(Lb, Aligned) -> + add_lb(Lb, {get_bits,decode_unconstrained_length(false, Aligned),[8]}). + +bit_case(Base, Ext) -> + {'case',[{test,{get_bits,1,[1]},0,Base}, + {test,{get_bits,1,[1]},1,Ext}]}. + +decode_unconstrained_length(AllowZero, Aligned) -> + Al = [{align,Aligned}], + Zero = case AllowZero of + false -> [non_zero]; + true -> [] + end, + {'case',[{test,{get_bits,1,[1|Al]},0, + {value,{get_bits,7,[1|Zero]}}}, + {test,{get_bits,1,[1|Al]},1, + {test,{get_bits,1,[1]},0, + {value,{get_bits,14,[1|Zero]}}}}]}. + +uper_num_bits(N) -> + uper_num_bits(N, 1, 0). + +uper_num_bits(N, T, B) when N =< T -> B; +uper_num_bits(N, T, B) -> uper_num_bits(N, T bsl 1, B+1). + +per_num_bits(2) -> 1; +per_num_bits(N) when N =< 4 -> 2; +per_num_bits(N) when N =< 8 -> 3; +per_num_bits(N) when N =< 16 -> 4; +per_num_bits(N) when N =< 32 -> 5; +per_num_bits(N) when N =< 64 -> 6; +per_num_bits(N) when N =< 128 -> 7; +per_num_bits(N) when N =< 255 -> 8. + +%%% +%%% Remove unnecessary aligning to octet boundaries. +%%% + +opt_al({get_bits,E0,Opts0}, A0) -> + {E,A1} = opt_al(E0, A0), + Opts = opt_al_1(A1, Opts0), + A = update_al(A1, E, Opts), + {{get_bits,E,Opts},A}; +opt_al({call,Fun,E0}, A0) -> + {E,A} = opt_al(E0, A0), + {{call,Fun,E},A}; +opt_al({convert,Op,E0}, A0) -> + {E,A} = opt_al(E0, A0), + {{convert,Op,E},A}; +opt_al({value,E0}, A0) -> + {E,A} = opt_al(E0, A0), + {{value,E},A}; +opt_al({add,E0,I}, A0) when is_integer(I) -> + {E,A} = opt_al(E0, A0), + {{add,E,I},A}; +opt_al({test,E0,V,B0}, A0) -> + {E,A1} = opt_al(E0, A0), + {B,A2} = opt_al(B0, A1), + {{test,E,V,B},A2}; +opt_al({'case',Cs0}, A0) -> + {Cs,A} = opt_al_cs(Cs0, A0), + {{'case',Cs},A}; +opt_al({map,E0,Cs}, A0) -> + {E,A} = opt_al(E0, A0), + {{map,E,Cs},A}; +opt_al(I, A) when is_integer(I) -> + {I,A}. + +opt_al_cs([C0|Cs0], A0) -> + {C,A1} = opt_al(C0, A0), + {Cs,A2} = opt_al_cs(Cs0, A0), + {[C|Cs],merge_al(A1, A2)}; +opt_al_cs([], _) -> {[],none}. + +merge_al(unknown, _) -> unknown; +merge_al(Other, none) -> Other; +merge_al(_, unknown) -> unknown; +merge_al(I0, I1) -> + case {I0 rem 8,I1 rem 8} of + {I,I} -> I; + {_,_} -> unknown + end. + +opt_al_1(unknown, Opts) -> + Opts; +opt_al_1(A, Opts0) -> + case alignment(Opts0) of + none -> + Opts0; + full -> + case A rem 8 of + 0 -> + %% Already in alignment. + proplists:delete(align, Opts0); + Bits -> + %% Cheaper alignment with a constant padding. + Opts1 = proplists:delete(align, Opts0), + [{align,8-Bits }|Opts1] + end; + A -> %Assertion. + Opts0 + end. + +update_al(A0, E, Opts) -> + A = case alignment(Opts) of + none -> A0; + full -> 0; + Bits when is_integer(A0) -> + 0 = (A0 + Bits) rem 8; %Assertion. + _ -> + 0 + end, + [U] = [U || U <- Opts, is_integer(U)], + if + U rem 8 =:= 0 -> A; + is_integer(A), is_integer(E) -> A + U*E; + true -> unknown + end. + +%%% +%%% Flatten the intermediate format and assign temporaries. +%%% + +flatten({get_bits,I,U}, Buf0, St0) when is_integer(I) -> + {Dst,St} = new_var_pair(St0), + Gb = {get_bits,{I,Buf0},U,Dst}, + flatten_align(Gb, [], St); +flatten({get_bits,E0,U}, Buf0, St0) -> + {E,Pre,St1} = flatten(E0, Buf0, St0), + {Dst,St2} = new_var_pair(St1), + Gb = {get_bits,E,U,Dst}, + flatten_align(Gb, Pre, St2); +flatten({test,{get_bits,I,U},V,E0}, Buf0, St0) when is_integer(I) -> + {DstBuf0,St1} = new_var("Buf", St0), + Gb = {get_bits,{I,Buf0},U,{V,DstBuf0}}, + {{_Dst,DstBuf},Pre0,St2} = flatten_align(Gb, [], St1), + {E,Pre1,St3} = flatten(E0, DstBuf, St2), + {E,Pre0++Pre1,St3}; +flatten({add,E0,I}, Buf0, St0) -> + {{Src,Buf},Pre,St1} = flatten(E0, Buf0, St0), + {Dst,St} = new_var("Add", St1), + {{Dst,Buf},Pre++[{add,Src,I,Dst}],St}; +flatten({'case',Cs0}, Buf0, St0) -> + {Dst,St1} = new_var_pair(St0), + {Cs1,St} = flatten_cs(Cs0, Buf0, St1), + {Al,Cs2} = flatten_hoist_align(Cs1), + {Dst,Al++[{'case',Buf0,Cs2,Dst}],St}; +flatten({map,E0,Cs0}, Buf0, St0) -> + {{E,DstBuf},Pre,St1} = flatten(E0, Buf0, St0), + {Dst,St2} = new_var("Int", St1), + Cs = flatten_map_cs(Cs0, E), + {{Dst,DstBuf},Pre++[{'map',E,Cs,{Dst,DstBuf}}],St2}; +flatten({value,V0}, Buf0, St0) when is_integer(V0) -> + {{V0,Buf0},[],St0}; +flatten({value,V0}, Buf0, St0) -> + flatten(V0, Buf0, St0); +flatten({convert,Op,E0}, Buf0, St0) -> + {{E,Buf},Pre,St1} = flatten(E0, Buf0, St0), + {Dst,St2} = new_var("Conv", St1), + {{Dst,Buf},Pre++[{convert,Op,E,Dst}],St2}; +flatten({call,Fun,E0}, Buf0, St0) -> + {Src,Pre,St1} = flatten(E0, Buf0, St0), + {Dst,St2} = new_var_pair(St1), + {Dst,Pre++[{call,Fun,Src,Dst}],St2}. + +flatten_cs([C0|Cs0], Buf, St0) -> + {C,Pre,St1} = flatten(C0, Buf, St0), + {Cs,St2} = flatten_cs(Cs0, Buf, St0), + St3 = St2#st{var=max(St1#st.var, St2#st.var)}, + {[Pre++[{return,C}]|Cs],St3}; +flatten_cs([], _, St) -> {[],St}. + +flatten_map_cs(Cs, Var) -> + flatten_map_cs_1(Cs, {Var,Cs}). + +flatten_map_cs_1([{K,V}|Cs], DefData) -> + [{{asis,K},{asis,V}}|flatten_map_cs_1(Cs, DefData)]; +flatten_map_cs_1([integer_default], {Int,_}) -> + [{'_',Int}]; +flatten_map_cs_1([enum_default], {Int,_}) -> + [{'_',["{asn1_enum,",Int,"}"]}]; +flatten_map_cs_1([enum_error], {Var,Cs}) -> + Vs = [V || {_,V} <- Cs], + [{'_',["exit({error,{asn1,{decode_enumerated,{",Var,",", + {asis,Vs},"}}}})"]}]; +flatten_map_cs_1([], _) -> []. + +flatten_hoist_align([[{align_bits,_,_}=Ab|T]|Cs]) -> + flatten_hoist_align_1(Cs, Ab, [T]); +flatten_hoist_align(Cs) -> {[],Cs}. + +flatten_hoist_align_1([[Ab|T]|Cs], Ab, Acc) -> + flatten_hoist_align_1(Cs, Ab, [T|Acc]); +flatten_hoist_align_1([], Ab, Acc) -> + {[Ab],lists:reverse(Acc)}. + +flatten_align({get_bits,{SrcBits,SrcBuf},U,Dst}=Gb0, Pre, St0) -> + case alignment(U) of + none -> + flatten_align_1(U, Dst, Pre++[Gb0], St0); + full -> + {PadBits,St1} = new_var("Pad", St0), + {DstBuf,St2} = new_var("Buf", St1), + Ab = {align_bits,SrcBuf,PadBits}, + Agb = {get_bits,{PadBits,SrcBuf},[1],{'_',DstBuf}}, + Gb = {get_bits,{SrcBits,DstBuf},U,Dst}, + flatten_align_1(U, Dst, Pre++[Ab,Agb,Gb], St2); + PadBits when is_integer(PadBits), PadBits > 0 -> + {DstBuf,St1} = new_var("Buf", St0), + Agb = {get_bits,{PadBits,SrcBuf},[1],{'_',DstBuf}}, + Gb = {get_bits,{SrcBits,DstBuf},U,Dst}, + flatten_align_1(U, Dst, Pre++[Agb,Gb], St1) + end. + +flatten_align_1(U, {D,_}=Dst, Pre, St) -> + case is_non_zero(U) of + false -> + {Dst,Pre,St}; + true -> + {Dst,Pre++[{non_zero,D}],St} + end. + +new_var_pair(St0) -> + {Var,St1} = new_var("V", St0), + {Buf,St2} = new_var("Buf", St1), + {{Var,Buf},St2}. + +new_var(Tag, #st{base=VarBase,var=N}=St) -> + {VarBase++Tag++integer_to_list(N),St#st{var=N+1}}. + +alignment([{align,false}|_]) -> none; +alignment([{align,true}|_]) -> full; +alignment([{align,Bits}|_]) -> Bits; +alignment([_|T]) -> alignment(T); +alignment([]) -> none. + +is_non_zero(Fl) -> + lists:member(non_zero, Fl). + +%%% +%%% Generate Erlang code from the flattened intermediate format. +%%% + +dcg_list_outside([{align_bits,Buf,SzVar}|T]) -> + emit([SzVar," = bit_size(",Buf,") band 7"]), + iter_dcg_list_outside(T); +dcg_list_outside([{'case',Buf,Cs,Dst}|T]) -> + dcg_case(Buf, Cs, Dst), + iter_dcg_list_outside(T); +dcg_list_outside([{'map',Val,Cs,Dst}|T]) -> + dcg_map(Val, Cs, Dst), + iter_dcg_list_outside(T); +dcg_list_outside([{add,S1,S2,Dst}|T]) -> + emit([Dst," = ",S1," + ",S2]), + iter_dcg_list_outside(T); +dcg_list_outside([{return,{V,Buf}}|T]) -> + emit(["{",V,",",Buf,"}"]), + iter_dcg_list_outside(T); +dcg_list_outside([{call,Fun,{V,Buf},{Dst,DstBuf}}|T]) -> + emit(["{",Dst,",",DstBuf,"} = "]), + Fun(V, Buf), + iter_dcg_list_outside(T); +dcg_list_outside([{convert,Op,V,Dst}|T]) -> + emit([Dst," = ",Op,"(",V,")"]), + iter_dcg_list_outside(T); +dcg_list_outside([{get_bits,{_,Buf0},_,_}|_]=L0) -> + emit("<<"), + {L,Buf} = dcg_list_inside(L0, buf), + emit([Buf,"/bitstring>> = ",Buf0]), + iter_dcg_list_outside(L); +dcg_list_outside([]) -> + emit("ignore"), + ok. + +iter_dcg_list_outside([_|_]=T) -> + emit([",",nl]), + dcg_list_outside(T); +iter_dcg_list_outside([]) -> ok. + +dcg_case(Buf, Cs, {Dst,DstBuf}) -> + emit(["{",Dst,",",DstBuf,"} = case ",Buf," of",nl]), + dcg_case_cs(Cs), + emit("end"). + +dcg_case_cs([C|Cs]) -> + emit("<<"), + {T0,DstBuf} = dcg_list_inside(C, buf), + emit([DstBuf,"/bitstring>>"]), + T1 = dcg_guard(T0), + dcg_list_outside(T1), + case Cs of + [] -> emit([nl]); + [_|_] -> emit([";",nl]) + end, + dcg_case_cs(Cs); +dcg_case_cs([]) -> ok. + +dcg_guard([{non_zero,Src}|T]) -> + emit([" when ",Src," =/= 0 ->",nl]), + T; +dcg_guard(T) -> + emit([" ->",nl]), + T. + +dcg_map(Val, Cs, {Dst,_}) -> + emit([Dst," = case ",Val," of",nl]), + dcg_map_cs(Cs), + emit("end"). + +dcg_map_cs([{K,V}]) -> + emit([K," -> ",V,nl]); +dcg_map_cs([{K,V}|Cs]) -> + emit([K," -> ",V,";",nl]), + dcg_map_cs(Cs). + +dcg_list_inside([{get_bits,{Sz,_},Fl0,{Dst,DstBuf}}|T], _) -> + Fl = bit_flags(Fl0, []), + emit([mk_dest(Dst),":",Sz,Fl,","]), + dcg_list_inside(T, DstBuf); +dcg_list_inside(L, Dst) -> {L,Dst}. + +bit_flags([1|T], Acc) -> + bit_flags(T, Acc); +bit_flags([{align,_}|T], Acc) -> + bit_flags(T, Acc); +bit_flags([non_zero|T], Acc) -> + bit_flags(T, Acc); +bit_flags([U|T], Acc) when is_integer(U) -> + bit_flags(T, ["unit:"++integer_to_list(U)|Acc]); +bit_flags([H|T], Acc) -> + bit_flags(T, [atom_to_list(H)|Acc]); +bit_flags([], []) -> + ""; +bit_flags([], Acc) -> + "/" ++ bit_flags_1(Acc, ""). + +bit_flags_1([H|T], Sep) -> + Sep ++ H ++ bit_flags_1(T, "-"); +bit_flags_1([], _) -> []. + +mk_dest(I) when is_integer(I) -> + integer_to_list(I); +mk_dest(S) -> S. + +%% effective_constraint(Type,C) +%% Type = atom() +%% C = [C1,...] +%% C1 = {'SingleValue',SV} | {'ValueRange',VR} | {atom(),term()} +%% SV = integer() | [integer(),...] +%% VR = {Lb,Ub} +%% Lb = 'MIN' | integer() +%% Ub = 'MAX' | integer() +%% Returns a single value if C only has a single value constraint, and no +%% value range constraints, that constrains to a single value, otherwise +%% returns a value range that has the lower bound set to the lowest value +%% of all single values and lower bound values in C and the upper bound to +%% the greatest value. +effective_constraint(integer,[C={{_,_},_}|_Rest]) -> % extension + [C]; +effective_constraint(integer, C) -> + SVs = get_constraints(C, 'SingleValue'), + SV = effective_constr('SingleValue', SVs), + VRs = get_constraints(C, 'ValueRange'), + VR = effective_constr('ValueRange', VRs), + greatest_common_range(SV, VR); +effective_constraint(bitstring, C) -> + get_constraint(C, 'SizeConstraint'). + +effective_constr(_, []) -> []; +effective_constr('SingleValue', List) -> + SVList = lists:flatten(lists:map(fun(X) -> element(2, X) end, List)), + %% Sort and remove duplicates before generating SingleValue or ValueRange + %% In case of ValueRange, also check for 'MIN and 'MAX' + case lists:usort(SVList) of + [N] -> + [{'SingleValue',N}]; + [_|_]=L -> + [{'ValueRange',{least_Lb(L),greatest_Ub(L)}}] + end; +effective_constr('ValueRange', List) -> + LBs = lists:map(fun({_,{Lb,_}}) -> Lb end, List), + UBs = lists:map(fun({_,{_,Ub}}) -> Ub end, List), + Lb = least_Lb(LBs), + [{'ValueRange',{Lb,lists:max(UBs)}}]. + +greatest_common_range([], VR) -> + VR; +greatest_common_range(SV, []) -> + SV; +greatest_common_range([{_,Int}], [{_,{'MIN',Ub}}]) + when is_integer(Int), Int > Ub -> + [{'ValueRange',{'MIN',Int}}]; +greatest_common_range([{_,Int}],[{_,{Lb,Ub}}]) + when is_integer(Int), Int < Lb -> + [{'ValueRange',{Int,Ub}}]; +greatest_common_range([{_,Int}],VR=[{_,{_Lb,_Ub}}]) when is_integer(Int) -> + VR; +greatest_common_range([{_,L}],[{_,{Lb,Ub}}]) when is_list(L) -> + Min = least_Lb([Lb|L]), + Max = greatest_Ub([Ub|L]), + [{'ValueRange',{Min,Max}}]; +greatest_common_range([{_,{Lb1,Ub1}}], [{_,{Lb2,Ub2}}]) -> + Min = least_Lb([Lb1,Lb2]), + Max = greatest_Ub([Ub1,Ub2]), + [{'ValueRange',{Min,Max}}]. + + +least_Lb(L) -> + case lists:member('MIN', L) of + true -> 'MIN'; + false -> lists:min(L) + end. + +greatest_Ub(L) -> + case lists:member('MAX', L) of + true -> 'MAX'; + false -> lists:max(L) + end. + +get_constraint(C, Key) -> + case lists:keyfind(Key, 1, C) of + false -> no; + {_,V} -> V + end. + +get_constraints([{Key,_}=Pair|T], Key) -> + [Pair|get_constraints(T, Key)]; +get_constraints([_|T], Key) -> + get_constraints(T, Key); +get_constraints([], _) -> []. |