%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 1996-2011. 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(erl_eval). %% An evaluator for Erlang abstract syntax. -export([exprs/2,exprs/3,exprs/4,expr/2,expr/3,expr/4,expr/5, expr_list/2,expr_list/3,expr_list/4]). -export([new_bindings/0,bindings/1,binding/2,add_binding/3,del_binding/2]). -export([is_constant_expr/1, partial_eval/1]). %% Is used by standalone Erlang (escript). %% Also used by shell.erl. -export([match_clause/4]). -export([check_command/2, fun_data/1]). -import(lists, [reverse/1,foldl/3,member/2]). -export_type([binding_struct/0]). -type(expression() :: erl_parse:abstract_expr()). -type(expressions() :: [erl_parse:abstract_expr()]). -type(expression_list() :: [expression()]). -type(clauses() :: [erl_parse:abstract_clause()]). -type(name() :: term()). -type(value() :: term()). -type(bindings() :: [{name(), value()}]). -type(binding_struct() :: orddict:orddict()). -type(lfun_value_handler() :: fun((Name :: atom(), Arguments :: [term()]) -> Value :: value())). -type(lfun_eval_handler() :: fun((Name :: atom(), Arguments :: expression_list(), Bindings :: binding_struct()) -> {value, Value :: value(), NewBindings :: binding_struct()})). -type(local_function_handler() :: {value, lfun_value_handler()} | {eval, lfun_eval_handler()} | none). -type(func_spec() :: {Module :: module(), Function :: atom()} | function()). -type(nlfun_handler() :: fun((FuncSpec :: func_spec(), Arguments :: [term()]) -> term())). -type(non_local_function_handler() :: {value, nlfun_handler()} | none). %% exprs(ExpressionSeq, Bindings) %% exprs(ExpressionSeq, Bindings, LocalFuncHandler) %% exprs(ExpressionSeq, Bindings, LocalFuncHandler, ExternalFuncHandler) %% Returns: %% {value,Value,NewBindings} %% or {'EXIT', Reason} %% Only exprs/2 checks the command by calling erl_lint. The reason is %% that if there is a function handler present, then it is possible %% that there are valid constructs in Expression to be taken care of %% by a function handler but considerad errors by erl_lint. -spec(exprs(Expressions, Bindings) -> {value, Value, NewBindings} when Expressions :: expressions(), Bindings :: binding_struct(), Value :: value(), NewBindings :: binding_struct()). exprs(Exprs, Bs) -> case check_command(Exprs, Bs) of ok -> exprs(Exprs, Bs, none, none, none); {error,{_Line,_Mod,Error}} -> erlang:raise(error, Error, [{?MODULE,exprs,2}]) end. -spec(exprs(Expressions, Bindings, LocalFunctionHandler) -> {value, Value, NewBindings} when Expressions :: expressions(), Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), Value :: value(), NewBindings :: binding_struct()). exprs(Exprs, Bs, Lf) -> exprs(Exprs, Bs, Lf, none, none). -spec(exprs(Expressions, Bindings, LocalFunctionHandler, NonLocalFunctionHandler) -> {value, Value, NewBindings} when Expressions :: expressions(), Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), NonLocalFunctionHandler :: non_local_function_handler(), Value :: value(), NewBindings :: binding_struct()). exprs(Exprs, Bs, Lf, Ef) -> exprs(Exprs, Bs, Lf, Ef, none). exprs([E], Bs0, Lf, Ef, RBs) -> expr(E, Bs0, Lf, Ef, RBs); exprs([E|Es], Bs0, Lf, Ef, RBs) -> RBs1 = none, {value,_V,Bs} = expr(E, Bs0, Lf, Ef, RBs1), exprs(Es, Bs, Lf, Ef, RBs). %% expr(Expression, Bindings) %% expr(Expression, Bindings, LocalFuncHandler) %% expr(Expression, Bindings, LocalFuncHandler, ExternalFuncHandler) %% Returns: %% {value,Value,NewBindings} %% or {'EXIT', Reason} %% %% Only expr/2 checks the command by calling erl_lint. See exprs/2. -spec(expr(Expression, Bindings) -> {value, Value, NewBindings} when Expression :: expression(), Bindings :: binding_struct(), Value :: value(), NewBindings :: binding_struct()). expr(E, Bs) -> case check_command([E], Bs) of ok -> expr(E, Bs, none, none, none); {error,{_Line,_Mod,Error}} -> erlang:raise(error, Error, [{?MODULE,expr,2}]) end. -spec(expr(Expression, Bindings, LocalFunctionHandler) -> {value, Value, NewBindings} when Expression :: expression(), Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), Value :: value(), NewBindings :: binding_struct()). expr(E, Bs, Lf) -> expr(E, Bs, Lf, none, none). -spec(expr(Expression, Bindings, LocalFunctionHandler, NonLocalFunctionHandler) -> {value, Value, NewBindings} when Expression :: expression(), Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), NonLocalFunctionHandler :: non_local_function_handler(), Value :: value(), NewBindings :: binding_struct()). expr(E, Bs, Lf, Ef) -> expr(E, Bs, Lf, Ef, none). %% Check a command (a list of expressions) by calling erl_lint. check_command(Es, Bs) -> Opts = [bitlevel_binaries,binary_comprehension], case erl_lint:exprs_opt(Es, bindings(Bs), Opts) of {ok,_Ws} -> ok; {error,[{_File,[Error|_]}],_Ws} -> {error,Error} end. %% Check whether a term F is a function created by this module. %% Returns 'false' if not, otherwise {fun_data,Imports,Clauses}. fun_data(F) when is_function(F) -> case erlang:fun_info(F, module) of {module,erl_eval} -> {env, [FBs,_FEf,_FLf,FCs]} = erlang:fun_info(F, env), {fun_data,FBs,FCs}; _ -> false end; fun_data(_T) -> false. -spec(expr(Expression, Bindings, LocalFunctionHandler, NonLocalFunctionHandler, ReturnFormat) -> {value, Value, NewBindings} | Value when Expression :: expression(), Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), NonLocalFunctionHandler :: non_local_function_handler(), ReturnFormat :: none | value, Value :: value(), NewBindings :: binding_struct()). expr({var,_,V}, Bs, _Lf, _Ef, RBs) -> case binding(V, Bs) of {value,Val} -> ret_expr(Val, Bs, RBs); unbound -> % Should not happen. erlang:raise(error, {unbound,V}, stacktrace()) end; expr({char,_,C}, Bs, _Lf, _Ef, RBs) -> ret_expr(C, Bs, RBs); expr({integer,_,I}, Bs, _Lf, _Ef, RBs) -> ret_expr(I, Bs, RBs); expr({float,_,F}, Bs, _Lf, _Ef, RBs) -> ret_expr(F, Bs, RBs); expr({atom,_,A}, Bs, _Lf, _Ef, RBs) -> ret_expr(A, Bs, RBs); expr({string,_,S}, Bs, _Lf, _Ef, RBs) -> ret_expr(S, Bs, RBs); expr({nil, _}, Bs, _Lf, _Ef, RBs) -> ret_expr([], Bs, RBs); expr({cons,_,H0,T0}, Bs0, Lf, Ef, RBs) -> {value,H,Bs1} = expr(H0, Bs0, Lf, Ef, none), {value,T,Bs2} = expr(T0, Bs0, Lf, Ef, none), ret_expr([H|T], merge_bindings(Bs1, Bs2), RBs); expr({lc,_,E,Qs}, Bs, Lf, Ef, RBs) -> eval_lc(E, Qs, Bs, Lf, Ef, RBs); expr({bc,_,E,Qs}, Bs, Lf, Ef, RBs) -> eval_bc(E, Qs, Bs, Lf, Ef, RBs); expr({tuple,_,Es}, Bs0, Lf, Ef, RBs) -> {Vs,Bs} = expr_list(Es, Bs0, Lf, Ef), ret_expr(list_to_tuple(Vs), Bs, RBs); expr({record_field,_,_,_}=Mod, Bs, _Lf, _Ef, RBs) -> case expand_module_name(Mod, Bs) of {atom,_,A} -> ret_expr(A, Bs, RBs); %% This is the "x.y" syntax _ -> erlang:raise(error, {badexpr, '.'}, stacktrace()) end; expr({record_field,_,_,Name,_}, _Bs, _Lf, _Ef, _RBs) -> erlang:raise(error, {undef_record,Name}, stacktrace()); expr({record_index,_,Name,_}, _Bs, _Lf, _Ef, _RBs) -> erlang:raise(error, {undef_record,Name}, stacktrace()); expr({record,_,Name,_}, _Bs, _Lf, _Ef, _RBs) -> erlang:raise(error, {undef_record,Name}, stacktrace()); expr({record,_,_,Name,_}, _Bs, _Lf, _Ef, _RBs) -> erlang:raise(error, {undef_record,Name}, stacktrace()); expr({block,_,Es}, Bs, Lf, Ef, RBs) -> exprs(Es, Bs, Lf, Ef, RBs); expr({'if',_,Cs}, Bs, Lf, Ef, RBs) -> if_clauses(Cs, Bs, Lf, Ef, RBs); expr({'case',_,E,Cs}, Bs0, Lf, Ef, RBs) -> {value,Val,Bs} = expr(E, Bs0, Lf, Ef, none), case_clauses(Val, Cs, Bs, Lf, Ef, RBs); expr({'try',_,B,Cases,Catches,AB}, Bs, Lf, Ef, RBs) -> try_clauses(B, Cases, Catches, AB, Bs, Lf, Ef, RBs); expr({'receive',_,Cs}, Bs, Lf, Ef, RBs) -> receive_clauses(Cs, Bs, Lf, Ef, [], RBs); expr({'receive',_, Cs, E, TB}, Bs0, Lf, Ef, RBs) -> {value,T,Bs} = expr(E, Bs0, Lf, Ef, none), receive_clauses(T, Cs, {TB,Bs}, Bs0, Lf, Ef, [], RBs); expr({'fun',_Line,{function,Mod,Name,Arity}}, Bs, _Lf, _Ef, RBs) -> F = erlang:make_fun(Mod, Name, Arity), ret_expr(F, Bs, RBs); expr({'fun',_Line,{function,Name,Arity}}, _Bs0, _Lf, _Ef, _RBs) -> % R8 %% Don't know what to do... erlang:raise(error, undef, [{erl_eval,Name,Arity}|stacktrace()]); expr({'fun',Line,{clauses,Cs}} = Ex, Bs, Lf, Ef, RBs) -> %% Save only used variables in the function environment. %% {value,L,V} are hidden while lint finds used variables. {Ex1, _} = hide_calls(Ex, 0), {ok,Used} = erl_lint:used_vars([Ex1], Bs), En = orddict:filter(fun(K,_V) -> member(K,Used) end, Bs), %% This is a really ugly hack! F = case length(element(3,hd(Cs))) of 0 -> fun () -> eval_fun(Cs, [], En, Lf, Ef) end; 1 -> fun (A) -> eval_fun(Cs, [A], En, Lf, Ef) end; 2 -> fun (A,B) -> eval_fun(Cs, [A,B], En, Lf, Ef) end; 3 -> fun (A,B,C) -> eval_fun(Cs, [A,B,C], En, Lf, Ef) end; 4 -> fun (A,B,C,D) -> eval_fun(Cs, [A,B,C,D], En, Lf, Ef) end; 5 -> fun (A,B,C,D,E) -> eval_fun(Cs, [A,B,C,D,E], En, Lf, Ef) end; 6 -> fun (A,B,C,D,E,F) -> eval_fun(Cs, [A,B,C,D,E,F], En, Lf, Ef) end; 7 -> fun (A,B,C,D,E,F,G) -> eval_fun(Cs, [A,B,C,D,E,F,G], En, Lf, Ef) end; 8 -> fun (A,B,C,D,E,F,G,H) -> eval_fun(Cs, [A,B,C,D,E,F,G,H], En, Lf, Ef) end; 9 -> fun (A,B,C,D,E,F,G,H,I) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I], En, Lf, Ef) end; 10 -> fun (A,B,C,D,E,F,G,H,I,J) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J], En, Lf, Ef) end; 11 -> fun (A,B,C,D,E,F,G,H,I,J,K) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K], En, Lf, Ef) end; 12 -> fun (A,B,C,D,E,F,G,H,I,J,K,L) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L], En, Lf, Ef) end; 13 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M], En, Lf, Ef) end; 14 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N], En, Lf, Ef) end; 15 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O], En, Lf, Ef) end; 16 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P], En, Lf, Ef) end; 17 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q], En, Lf, Ef) end; 18 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R], En, Lf, Ef) end; 19 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S], En, Lf, Ef) end; 20 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T) -> eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T], En, Lf, Ef) end; _Other -> erlang:raise(error, {'argument_limit',{'fun',Line,Cs}}, stacktrace()) end, ret_expr(F, Bs, RBs); expr({call,_,{remote,_,{atom,_,qlc},{atom,_,q}},[{lc,_,_E,_Qs}=LC | As0]}, Bs0, Lf, Ef, RBs) when length(As0) =< 1 -> %% No expansion or evaluation of module name or function name. MaxLine = find_maxline(LC), {LC1, D} = hide_calls(LC, MaxLine), case qlc:transform_from_evaluator(LC1, Bs0) of {ok,{call,L,Remote,[QLC]}} -> QLC1 = unhide_calls(QLC, MaxLine, D), expr({call,L,Remote,[QLC1 | As0]}, Bs0, Lf, Ef, RBs); {not_ok,Error} -> ret_expr(Error, Bs0, RBs) end; expr({call,L1,{remote,L2,{record_field,_,{atom,_,''},{atom,_,qlc}=Mod}, {atom,_,q}=Func}, [{lc,_,_E,_Qs} | As0]=As}, Bs, Lf, Ef, RBs) when length(As0) =< 1 -> expr({call,L1,{remote,L2,Mod,Func},As}, Bs, Lf, Ef, RBs); expr({call,_,{remote,_,Mod,Func},As0}, Bs0, Lf, Ef, RBs) -> Mod1 = expand_module_name(Mod, Bs0), {value,M,Bs1} = expr(Mod1, Bs0, Lf, Ef, none), {value,F,Bs2} = expr(Func, Bs0, Lf, Ef, none), {As,Bs3} = expr_list(As0, merge_bindings(Bs1, Bs2), Lf, Ef), %% M could be a parameterized module (not an atom). case is_atom(M) andalso erl_internal:bif(M, F, length(As)) of true -> bif(F, As, Bs3, Ef, RBs); false -> do_apply({M,F}, As, Bs3, Ef, RBs) end; expr({call,_,{atom,_,Func},As0}, Bs0, Lf, Ef, RBs) -> case erl_internal:bif(Func, length(As0)) of true -> {As,Bs} = expr_list(As0, Bs0, Lf, Ef), bif(Func, As, Bs, Ef, RBs); false -> local_func(Func, As0, Bs0, Lf, RBs) end; expr({call,_,Func0,As0}, Bs0, Lf, Ef, RBs) -> % function or {Mod,Fun} {value,Func,Bs1} = expr(Func0, Bs0, Lf, Ef, none), {As,Bs2} = expr_list(As0, Bs1, Lf, Ef), do_apply(Func, As, Bs2, Ef, RBs); expr({'catch',_,Expr}, Bs0, Lf, Ef, RBs) -> Ref = make_ref(), case catch {Ref,expr(Expr, Bs0, Lf, Ef, none)} of {Ref,{value,V,Bs}} -> % Nothing was thrown (guaranteed). ret_expr(V, Bs, RBs); Other -> ret_expr(Other, Bs0, RBs) end; expr({match,_,Lhs,Rhs0}, Bs0, Lf, Ef, RBs) -> {value,Rhs,Bs1} = expr(Rhs0, Bs0, Lf, Ef, none), case match(Lhs, Rhs, Bs1) of {match,Bs} -> ret_expr(Rhs, Bs, RBs); nomatch -> erlang:raise(error, {badmatch,Rhs}, stacktrace()) end; expr({op,_,Op,A0}, Bs0, Lf, Ef, RBs) -> {value,A,Bs} = expr(A0, Bs0, Lf, Ef, none), eval_op(Op, A, Bs, Ef, RBs); expr({op,_,'andalso',L0,R0}, Bs0, Lf, Ef, RBs) -> {value,L,Bs1} = expr(L0, Bs0, Lf, Ef, none), V = case L of true -> {value,R,_} = expr(R0, Bs1, Lf, Ef, none), R; false -> false; _ -> erlang:raise(error, {badarg,L}, stacktrace()) end, ret_expr(V, Bs1, RBs); expr({op,_,'orelse',L0,R0}, Bs0, Lf, Ef, RBs) -> {value,L,Bs1} = expr(L0, Bs0, Lf, Ef, none), V = case L of true -> true; false -> {value,R,_} = expr(R0, Bs1, Lf, Ef, none), R; _ -> erlang:raise(error, {badarg,L}, stacktrace()) end, ret_expr(V, Bs1, RBs); expr({op,_,Op,L0,R0}, Bs0, Lf, Ef, RBs) -> {value,L,Bs1} = expr(L0, Bs0, Lf, Ef, none), {value,R,Bs2} = expr(R0, Bs0, Lf, Ef, none), eval_op(Op, L, R, merge_bindings(Bs1, Bs2), Ef, RBs); expr({bin,_,Fs}, Bs0, Lf, Ef, RBs) -> EvalFun = fun(E, B) -> expr(E, B, Lf, Ef, none) end, {value,V,Bs} = eval_bits:expr_grp(Fs, Bs0, EvalFun), ret_expr(V, Bs, RBs); expr({remote,_,_,_}, _Bs, _Lf, _Ef, _RBs) -> erlang:raise(error, {badexpr,':'}, stacktrace()); expr({value,_,Val}, Bs, _Lf, _Ef, RBs) -> % Special case straight values. ret_expr(Val, Bs, RBs). find_maxline(LC) -> put('$erl_eval_max_line', 0), F = fun(L) -> case is_integer(L) and (L > get('$erl_eval_max_line')) of true -> put('$erl_eval_max_line', L); false -> ok end end, _ = erl_lint:modify_line(LC, F), erase('$erl_eval_max_line'). hide_calls(LC, MaxLine) -> LineId0 = MaxLine + 1, {NLC, _, D} = hide(LC, LineId0, dict:new()), {NLC, D}. %% v/1 and local calls are hidden. hide({value,L,V}, Id, D) -> {{atom,Id,ok}, Id+1, dict:store(Id, {value,L,V}, D)}; hide({call,L,{atom,_,N}=Atom,Args}, Id0, D0) -> {NArgs, Id, D} = hide(Args, Id0, D0), C = case erl_internal:bif(N, length(Args)) of true -> {call,L,Atom,NArgs}; false -> {call,Id,{remote,L,{atom,L,m},{atom,L,f}},NArgs} end, {C, Id+1, dict:store(Id, {call,Atom}, D)}; hide(T0, Id0, D0) when is_tuple(T0) -> {L, Id, D} = hide(tuple_to_list(T0), Id0, D0), {list_to_tuple(L), Id, D}; hide([E0 | Es0], Id0, D0) -> {E, Id1, D1} = hide(E0, Id0, D0), {Es, Id, D} = hide(Es0, Id1, D1), {[E | Es], Id, D}; hide(E, Id, D) -> {E, Id, D}. unhide_calls({atom,Id,ok}, MaxLine, D) when Id > MaxLine -> dict:fetch(Id, D); unhide_calls({call,Id,{remote,L,_M,_F},Args}, MaxLine, D) when Id > MaxLine -> {call,Atom} = dict:fetch(Id, D), {call,L,Atom,unhide_calls(Args, MaxLine, D)}; unhide_calls(T, MaxLine, D) when is_tuple(T) -> list_to_tuple(unhide_calls(tuple_to_list(T), MaxLine, D)); unhide_calls([E | Es], MaxLine, D) -> [unhide_calls(E, MaxLine, D) | unhide_calls(Es, MaxLine, D)]; unhide_calls(E, _MaxLine, _D) -> E. %% local_func(Function, Arguments, Bindings, LocalFuncHandler, RBs) -> %% {value,Value,Bindings} | Value when %% LocalFuncHandler = {value,F} | {value,F,Eas} | %% {eval,F} | {eval,F,Eas} | none. local_func(Func, As0, Bs0, {value,F}, value) -> {As1,_Bs1} = expr_list(As0, Bs0, {value,F}), %% Make tail recursive calls when possible. F(Func, As1); local_func(Func, As0, Bs0, {value,F}, RBs) -> {As1,Bs1} = expr_list(As0, Bs0, {value,F}), ret_expr(F(Func, As1), Bs1, RBs); local_func(Func, As0, Bs0, {value,F,Eas}, RBs) -> Fun = fun(Name, Args) -> apply(F, [Name,Args|Eas]) end, local_func(Func, As0, Bs0, {value, Fun}, RBs); local_func(Func, As, Bs, {eval,F}, RBs) -> local_func2(F(Func, As, Bs), RBs); local_func(Func, As, Bs, {eval,F,Eas}, RBs) -> local_func2(apply(F, [Func,As,Bs|Eas]), RBs); %% These two clauses are for backwards compatibility. local_func(Func, As0, Bs0, {M,F}, RBs) -> {As1,Bs1} = expr_list(As0, Bs0, {M,F}), ret_expr(M:F(Func,As1), Bs1, RBs); local_func(Func, As, _Bs, {M,F,Eas}, RBs) -> local_func2(apply(M, F, [Func,As|Eas]), RBs); %% Default unknown function handler to undefined function. local_func(Func, As0, _Bs0, none, _RBs) -> erlang:raise(error, undef, [{erl_eval,Func,length(As0)}|stacktrace()]). local_func2({value,V,Bs}, RBs) -> ret_expr(V, Bs, RBs); local_func2({eval,F,As,Bs}, RBs) -> % This reply is not documented. %% The shell found F. erl_eval tries to do a tail recursive call, %% something the shell cannot do. Do not use Ef here. do_apply(F, As, Bs, none, RBs). %% bif(Name, Arguments, RBs) %% Evaluate the Erlang auto-imported function Name. erlang:apply/2,3 %% are "hidden" from the external function handler. bif(apply, [erlang,apply,As], Bs, Ef, RBs) -> bif(apply, As, Bs, Ef, RBs); bif(apply, [M,F,As], Bs, Ef, RBs) -> do_apply({M,F}, As, Bs, Ef, RBs); bif(apply, [F,As], Bs, Ef, RBs) -> do_apply(F, As, Bs, Ef, RBs); bif(Name, As, Bs, Ef, RBs) -> do_apply({erlang,Name}, As, Bs, Ef, RBs). %% do_apply(MF, Arguments, Bindings, ExternalFuncHandler, RBs) -> %% {value,Value,Bindings} | Value when %% ExternalFuncHandler = {value,F} | none. %% MF is a tuple {Module,Function} or a fun. do_apply({M,F}=Func, As, Bs0, Ef, RBs) when tuple_size(M) >= 1, is_atom(element(1, M)), is_atom(F) -> case Ef of none when RBs =:= value -> %% Make tail recursive calls when possible. apply(M, F, As); none -> ret_expr(apply(M, F, As), Bs0, RBs); {value,Fun} when RBs =:= value -> Fun(Func, As); {value,Fun} -> ret_expr(Fun(Func, As), Bs0, RBs) end; do_apply(Func, As, Bs0, Ef, RBs) -> Env = if is_function(Func) -> case {erlang:fun_info(Func, module), erlang:fun_info(Func, env)} of {{module,?MODULE},{env,Env1}} when Env1 =/= [] -> {env,Env1}; _ -> no_env end; true -> no_env end, case {Env,Ef} of {{env,[FBs, FEf, FLf, FCs]},_} -> %% If we are evaluting within another function body %% (RBs =/= none), we return RBs when this function body %% has been evalutated, otherwise we return Bs0, the %% bindings when evalution of this function body started. NRBs = if RBs =:= none -> Bs0; true -> RBs end, case {erlang:fun_info(Func, arity), length(As)} of {{arity, Arity}, Arity} -> eval_fun(FCs, As, FBs, FLf, FEf, NRBs); _ -> erlang:raise(error, {badarity,{Func,As}},stacktrace()) end; {no_env,none} when RBs =:= value -> %% Make tail recursive calls when possible. apply(Func, As); {no_env,none} -> ret_expr(apply(Func, As), Bs0, RBs); {no_env,{value,F}} when RBs =:= value -> F(Func,As); {no_env,{value,F}} -> ret_expr(F(Func, As), Bs0, RBs) end. %% eval_lc(Expr, [Qualifier], Bindings, LocalFunctionHandler, %% ExternalFuncHandler, RetBindings) -> %% {value,Value,Bindings} | Value eval_lc(E, Qs, Bs, Lf, Ef, RBs) -> ret_expr(lists:reverse(eval_lc1(E, Qs, Bs, Lf, Ef, [])), Bs, RBs). eval_lc1(E, [{generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) -> {value,L1,_Bs1} = expr(L0, Bs0, Lf, Ef, none), CompFun = fun(Bs, Acc) -> eval_lc1(E, Qs, Bs, Lf, Ef, Acc) end, eval_generate(L1, P, Bs0, Lf, Ef, CompFun, Acc0); eval_lc1(E, [{b_generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) -> {value,Bin,_Bs1} = expr(L0, Bs0, Lf, Ef, none), CompFun = fun(Bs, Acc) -> eval_lc1(E, Qs, Bs, Lf, Ef, Acc) end, eval_b_generate(Bin, P, Bs0, Lf, Ef, CompFun, Acc0); eval_lc1(E, [F|Qs], Bs0, Lf, Ef, Acc) -> CompFun = fun(Bs) -> eval_lc1(E, Qs, Bs, Lf, Ef, Acc) end, eval_filter(F, Bs0, Lf, Ef, CompFun, Acc); eval_lc1(E, [], Bs, Lf, Ef, Acc) -> {value,V,_} = expr(E, Bs, Lf, Ef, none), [V|Acc]. %% eval_bc(Expr, [Qualifier], Bindings, LocalFunctionHandler, %% ExternalFuncHandler, RetBindings) -> %% {value,Value,Bindings} | Value eval_bc(E, Qs, Bs, Lf, Ef, RBs) -> ret_expr(eval_bc1(E, Qs, Bs, Lf, Ef, <<>>), Bs, RBs). eval_bc1(E, [{b_generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) -> {value,Bin,_Bs1} = expr(L0, Bs0, Lf, Ef, none), CompFun = fun(Bs, Acc) -> eval_bc1(E, Qs, Bs, Lf, Ef, Acc) end, eval_b_generate(Bin, P, Bs0, Lf, Ef, CompFun, Acc0); eval_bc1(E, [{generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) -> {value,List,_Bs1} = expr(L0, Bs0, Lf, Ef, none), CompFun = fun(Bs, Acc) -> eval_bc1(E, Qs, Bs, Lf, Ef, Acc) end, eval_generate(List, P, Bs0, Lf, Ef, CompFun, Acc0); eval_bc1(E, [F|Qs], Bs0, Lf, Ef, Acc) -> CompFun = fun(Bs) -> eval_bc1(E, Qs, Bs, Lf, Ef, Acc) end, eval_filter(F, Bs0, Lf, Ef, CompFun, Acc); eval_bc1(E, [], Bs, Lf, Ef, Acc) -> {value,V,_} = expr(E, Bs, Lf, Ef, none), <<Acc/bitstring,V/bitstring>>. eval_generate([V|Rest], P, Bs0, Lf, Ef, CompFun, Acc) -> case match(P, V, new_bindings(), Bs0) of {match,Bsn} -> Bs2 = add_bindings(Bsn, Bs0), NewAcc = CompFun(Bs2, Acc), eval_generate(Rest, P, Bs0, Lf, Ef, CompFun, NewAcc); nomatch -> eval_generate(Rest, P, Bs0, Lf, Ef, CompFun, Acc) end; eval_generate([], _P, _Bs0, _Lf, _Ef, _CompFun, Acc) -> Acc; eval_generate(Term, _P, _Bs0, _Lf, _Ef, _CompFun, _Acc) -> erlang:raise(error, {bad_generator,Term}, stacktrace()). eval_b_generate(<<_/bitstring>>=Bin, P, Bs0, Lf, Ef, CompFun, Acc) -> Mfun = match_fun(Bs0), Efun = fun(Exp, Bs) -> expr(Exp, Bs, Lf, Ef, none) end, case eval_bits:bin_gen(P, Bin, new_bindings(), Bs0, Mfun, Efun) of {match, Rest, Bs1} -> Bs2 = add_bindings(Bs1, Bs0), NewAcc = CompFun(Bs2, Acc), eval_b_generate(Rest, P, Bs0, Lf, Ef, CompFun, NewAcc); {nomatch, Rest} -> eval_b_generate(Rest, P, Bs0, Lf, Ef, CompFun, Acc); done -> Acc end; eval_b_generate(Term, _P, _Bs0, _Lf, _Ef, _CompFun, _Acc) -> erlang:raise(error, {bad_generator,Term}, stacktrace()). eval_filter(F, Bs0, Lf, Ef, CompFun, Acc) -> case erl_lint:is_guard_test(F) of true -> case guard_test(F, Bs0, Lf, Ef) of {value,true,Bs1} -> CompFun(Bs1); {value,false,_} -> Acc end; false -> case expr(F, Bs0, Lf, Ef, none) of {value,true,Bs1} -> CompFun(Bs1); {value,false,_} -> Acc; {value,V,_} -> erlang:raise(error, {bad_filter,V}, stacktrace()) end end. %% RBs is the bindings to return when the evalution of a function %% (fun) has finished. If RBs =:= none, then the evalution took place %% outside a function. If RBs =:= value, only the value (not the bindings) %% is to be returned (to a compiled function). ret_expr(V, _Bs, value) -> V; ret_expr(V, Bs, none) -> {value,V,Bs}; ret_expr(V, _Bs, RBs) when is_list(RBs) -> {value,V,RBs}. %% eval_fun(Clauses, Arguments, Bindings, LocalFunctionHandler, %% ExternalFunctionHandler) -> Value %% This function is called when the fun is called from compiled code %% or from apply. eval_fun(Cs, As, Bs0, Lf, Ef) -> eval_fun(Cs, As, Bs0, Lf, Ef, value). eval_fun([{clause,_,H,G,B}|Cs], As, Bs0, Lf, Ef, RBs) -> case match_list(H, As, new_bindings(), Bs0) of {match,Bsn} -> % The new bindings for the head Bs1 = add_bindings(Bsn, Bs0), % which then shadow! case guard(G, Bs1, Lf, Ef) of true -> exprs(B, Bs1, Lf, Ef, RBs); false -> eval_fun(Cs, As, Bs0, Lf, Ef, RBs) end; nomatch -> eval_fun(Cs, As, Bs0, Lf, Ef, RBs) end; eval_fun([], As, _Bs, _Lf, _Ef, _RBs) -> erlang:raise(error, function_clause, [{?MODULE,'-inside-an-interpreted-fun-',As}|stacktrace()]). %% expr_list(ExpressionList, Bindings) %% expr_list(ExpressionList, Bindings, LocalFuncHandler) %% expr_list(ExpressionList, Bindings, LocalFuncHandler, ExternalFuncHandler) %% Evaluate a list of expressions "in parallel" at the same level. -spec(expr_list(ExpressionList, Bindings) -> {ValueList, NewBindings} when ExpressionList :: expression_list(), Bindings :: binding_struct(), ValueList :: [value()], NewBindings :: binding_struct()). expr_list(Es, Bs) -> expr_list(Es, Bs, none, none). -spec(expr_list(ExpressionList, Bindings, LocalFunctionHandler) -> {ValueList, NewBindings} when ExpressionList :: expression_list(), Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), ValueList :: [value()], NewBindings :: binding_struct()). expr_list(Es, Bs, Lf) -> expr_list(Es, Bs, Lf, none). -spec(expr_list(ExpressionList, Bindings, LocalFunctionHandler, NonLocalFunctionHandler) -> {ValueList, NewBindings} when ExpressionList :: expression_list(), Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), NonLocalFunctionHandler :: non_local_function_handler(), ValueList :: [value()], NewBindings :: binding_struct()). expr_list(Es, Bs, Lf, Ef) -> expr_list(Es, [], Bs, Bs, Lf, Ef). expr_list([E|Es], Vs, BsOrig, Bs0, Lf, Ef) -> {value,V,Bs1} = expr(E, BsOrig, Lf, Ef, none), expr_list(Es, [V|Vs], BsOrig, merge_bindings(Bs1, Bs0), Lf, Ef); expr_list([], Vs, _, Bs, _Lf, _Ef) -> {reverse(Vs),Bs}. eval_op(Op, Arg1, Arg2, Bs, Ef, RBs) -> do_apply({erlang,Op}, [Arg1,Arg2], Bs, Ef, RBs). eval_op(Op, Arg, Bs, Ef, RBs) -> do_apply({erlang,Op}, [Arg], Bs, Ef, RBs). %% if_clauses(Clauses, Bindings, LocalFuncHandler, ExtFuncHandler, RBs) if_clauses([{clause,_,[],G,B}|Cs], Bs, Lf, Ef, RBs) -> case guard(G, Bs, Lf, Ef) of true -> exprs(B, Bs, Lf, Ef, RBs); false -> if_clauses(Cs, Bs, Lf, Ef, RBs) end; if_clauses([], _Bs, _Lf, _Ef, _RBs) -> erlang:raise(error, if_clause, stacktrace()). %% try_clauses(Body, CaseClauses, CatchClauses, AfterBody, Bindings, %% LocalFuncHandler, ExtFuncHandler, RBs) %% When/if variable bindings between the different parts of a %% try-catch expression are introduced this will have to be rewritten. try_clauses(B, Cases, Catches, AB, Bs, Lf, Ef, RBs) -> try exprs(B, Bs, Lf, Ef, none) of {value,V,Bs1} when Cases =:= [] -> ret_expr(V, Bs1, RBs); {value,V,Bs1} -> case match_clause(Cases, [V], Bs1, Lf, Ef) of {B2,Bs2} -> exprs(B2, Bs2, Lf, Ef, RBs); nomatch -> erlang:raise(error, {try_clause,V}, stacktrace()) end catch Class:Reason when Catches =:= [] -> %% Rethrow erlang:raise(Class, Reason, stacktrace()); Class:Reason -> %%% %% Set stacktrace %%% try erlang:raise(Class, Reason, stacktrace()) %%% catch _:_ -> ok %%% end, V = {Class,Reason,erlang:get_stacktrace()}, case match_clause(Catches, [V],Bs, Lf, Ef) of {B2,Bs2} -> exprs(B2, Bs2, Lf, Ef, RBs); nomatch -> erlang:raise(Class, Reason, stacktrace()) end after if AB =:= [] -> Bs; % any true -> exprs(AB, Bs, Lf, Ef, none) end end. %% case_clauses(Value, Clauses, Bindings, LocalFuncHandler, ExtFuncHandler, %% RBs) case_clauses(Val, Cs, Bs, Lf, Ef, RBs) -> case match_clause(Cs, [Val], Bs, Lf, Ef) of {B, Bs1} -> exprs(B, Bs1, Lf, Ef, RBs); nomatch -> erlang:raise(error, {case_clause,Val}, stacktrace()) end. %% %% receive_clauses(Clauses, Bindings, LocalFuncHnd,ExtFuncHnd, Messages, RBs) %% receive_clauses(Cs, Bs, Lf, Ef, Ms, RBs) -> receive Val -> case match_clause(Cs, [Val], Bs, Lf, Ef) of {B, Bs1} -> merge_queue(Ms), exprs(B, Bs1, Lf, Ef, RBs); nomatch -> receive_clauses(Cs, Bs, Lf, Ef, [Val|Ms], RBs) end end. %% %% receive_clauses(TimeOut, Clauses, TimeoutBody, Bindings, %% ExternalFuncHandler, LocalFuncHandler, RBs) %% receive_clauses(T, Cs, TB, Bs, Lf, Ef, Ms, RBs) -> {_,_} = statistics(runtime), receive Val -> case match_clause(Cs, [Val], Bs, Lf, Ef) of {B, Bs1} -> merge_queue(Ms), exprs(B, Bs1, Lf, Ef, RBs); nomatch -> {_,T1} = statistics(runtime), if T =:= infinity -> receive_clauses(T, Cs, TB,Bs,Lf,Ef,[Val|Ms],RBs); T-T1 =< 0 -> receive_clauses(0, Cs, TB,Bs,Lf,Ef,[Val|Ms],RBs); true -> receive_clauses(T-T1, Cs,TB,Bs,Lf,Ef,[Val|Ms],RBs) end end after T -> merge_queue(Ms), {B, Bs1} = TB, exprs(B, Bs1, Lf, Ef, RBs) end. merge_queue([]) -> true; merge_queue(Ms) -> send_all(recv_all(Ms), self()). recv_all(Xs) -> receive X -> recv_all([X|Xs]) after 0 -> reverse(Xs) end. send_all([X|Xs], Self) -> Self ! X, send_all(Xs, Self); send_all([], _) -> true. %% match_clause -> {Body, Bindings} or nomatch -spec(match_clause(Clauses, ValueList, Bindings, LocalFunctionHandler) -> {Body, NewBindings} | nomatch when Clauses :: clauses(), ValueList :: [value()], Bindings :: binding_struct(), LocalFunctionHandler :: local_function_handler(), Body :: expression_list(), NewBindings :: binding_struct()). match_clause(Cs, Vs, Bs, Lf) -> match_clause(Cs, Vs, Bs, Lf, none). match_clause([{clause,_,H,G,B}|Cs], Vals, Bs, Lf, Ef) -> case match_list(H, Vals, Bs) of {match, Bs1} -> case guard(G, Bs1, Lf, Ef) of true -> {B, Bs1}; false -> match_clause(Cs, Vals, Bs, Lf, Ef) end; nomatch -> match_clause(Cs, Vals, Bs, Lf, Ef) end; match_clause([], _Vals, _Bs, _Lf, _Ef) -> nomatch. %% guard(GuardTests, Bindings, LocalFuncHandler, ExtFuncHandler) -> bool() %% Evaluate a guard. We test if the guard is a true guard. guard(L=[G|_], Bs0, Lf, Ef) when is_list(G) -> guard1(L, Bs0, Lf, Ef); guard(L, Bs0, Lf, Ef) -> guard0(L, Bs0, Lf, Ef). %% disjunction of guard conjunctions guard1([G|Gs], Bs0, Lf, Ef) when is_list(G) -> case guard0(G, Bs0, Lf, Ef) of true -> true; false -> guard1(Gs, Bs0, Lf, Ef) end; guard1([], _Bs, _Lf, _Ef) -> false. %% guard conjunction guard0([G|Gs], Bs0, Lf, Ef) -> case erl_lint:is_guard_test(G) of true -> case guard_test(G, Bs0, Lf, Ef) of {value,true,Bs} -> guard0(Gs, Bs, Lf, Ef); {value,false,_} -> false end; false -> erlang:raise(error, guard_expr, stacktrace()) end; guard0([], _Bs, _Lf, _Ef) -> true. %% guard_test(GuardTest, Bindings, LocalFuncHandler, ExtFuncHandler) -> %% {value,bool(),NewBindings}. %% Evaluate one guard test. Never fails, returns bool(). guard_test({call,L,{atom,Ln,F},As0}, Bs0, Lf, Ef) -> TT = type_test(F), guard_test({call,L,{tuple,Ln,[{atom,Ln,erlang},{atom,Ln,TT}]},As0}, Bs0, Lf, Ef); guard_test({call,L,{remote,_Lr,{atom,_Lm,erlang},{atom,_Lf,_F}=T},As0}, Bs0, Lf, Ef) -> guard_test({call,L,T,As0}, Bs0, Lf, Ef); guard_test(G, Bs0, Lf, Ef) -> try {value,true,_} = expr(G, Bs0, Lf, Ef, none) catch error:_ -> {value,false,Bs0} end. type_test(integer) -> is_integer; type_test(float) -> is_float; type_test(number) -> is_number; type_test(atom) -> is_atom; type_test(constant) -> is_constant; type_test(list) -> is_list; type_test(tuple) -> is_tuple; type_test(pid) -> is_pid; type_test(reference) -> is_reference; type_test(port) -> is_port; type_test(function) -> is_function; type_test(binary) -> is_binary; type_test(record) -> is_record; type_test(Test) -> Test. %% match(Pattern, Term, Bindings) -> %% {match,NewBindings} | nomatch %% or erlang:error({illegal_pattern, Pattern}). %% Try to match Pattern against Term with the current bindings. match(Pat, Term, Bs) -> match(Pat, Term, Bs, Bs). %% Bs are the bindings that are augmented with new bindings. BBs are %% the bindings used for "binsize" variables (in <<X:Y>>, Y is a %% binsize variable). match(Pat, Term, Bs, BBs) -> case catch match1(Pat, Term, Bs, BBs) of invalid -> erlang:raise(error, {illegal_pattern,Pat}, stacktrace()); Other -> Other end. string_to_conses([], _, Tail) -> Tail; string_to_conses([E|Rest], Line, Tail) -> {cons, Line, {integer, Line, E}, string_to_conses(Rest, Line, Tail)}. match1({atom,_,A0}, A, Bs, _BBs) -> case A of A0 -> {match,Bs}; _ -> throw(nomatch) end; match1({integer,_,I0}, I, Bs, _BBs) -> case I of I0 -> {match,Bs}; _ -> throw(nomatch) end; match1({float,_,F0}, F, Bs, _BBs) -> case F of F0 -> {match,Bs}; _ -> throw(nomatch) end; match1({char,_,C0}, C, Bs, _BBs) -> case C of C0 -> {match,Bs}; _ -> throw(nomatch) end; match1({var,_,'_'}, _, Bs, _BBs) -> %Anonymous variable matches {match,Bs}; % everything, no new bindings match1({var,_,Name}, Term, Bs, _BBs) -> case binding(Name, Bs) of {value,Term} -> {match,Bs}; {value,_} -> throw(nomatch); unbound -> {match,add_binding(Name, Term, Bs)} end; match1({match,_,Pat1,Pat2}, Term, Bs0, BBs) -> {match, Bs1} = match1(Pat1, Term, Bs0, BBs), match1(Pat2, Term, Bs1, BBs); match1({string,_,S0}, S, Bs, _BBs) -> case S of S0 -> {match,Bs}; _ -> throw(nomatch) end; match1({nil,_}, Nil, Bs, _BBs) -> case Nil of [] -> {match,Bs}; _ -> throw(nomatch) end; match1({cons,_,H,T}, [H1|T1], Bs0, BBs) -> {match,Bs} = match1(H, H1, Bs0, BBs), match1(T, T1, Bs, BBs); match1({cons,_,_,_}, _, _Bs, _BBs) -> throw(nomatch); match1({tuple,_,Elts}, Tuple, Bs, BBs) when length(Elts) =:= tuple_size(Tuple) -> match_tuple(Elts, Tuple, 1, Bs, BBs); match1({tuple,_,_}, _, _Bs, _BBs) -> throw(nomatch); match1({bin, _, Fs}, <<_/bitstring>>=B, Bs0, BBs) -> eval_bits:match_bits(Fs, B, Bs0, BBs, match_fun(BBs), fun(E, Bs) -> expr(E, Bs, none, none, none) end); match1({bin,_,_}, _, _Bs, _BBs) -> throw(nomatch); match1({op,_,'++',{nil,_},R}, Term, Bs, BBs) -> match1(R, Term, Bs, BBs); match1({op,_,'++',{cons,Li,{integer,L2,I},T},R}, Term, Bs, BBs) -> match1({cons,Li,{integer,L2,I},{op,Li,'++',T,R}}, Term, Bs, BBs); match1({op,_,'++',{cons,Li,{char,L2,C},T},R}, Term, Bs, BBs) -> match1({cons,Li,{char,L2,C},{op,Li,'++',T,R}}, Term, Bs, BBs); match1({op,_,'++',{string,Li,L},R}, Term, Bs, BBs) -> match1(string_to_conses(L, Li, R), Term, Bs, BBs); match1({op,Line,Op,A}, Term, Bs, BBs) -> case partial_eval({op,Line,Op,A}) of {op,Line,Op,A} -> throw(invalid); X -> match1(X, Term, Bs, BBs) end; match1({op,Line,Op,L,R}, Term, Bs, BBs) -> case partial_eval({op,Line,Op,L,R}) of {op,Line,Op,L,R} -> throw(invalid); X -> match1(X, Term, Bs, BBs) end; match1(_, _, _Bs, _BBs) -> throw(invalid). match_fun(BBs) -> fun(match, {L,R,Bs}) -> match1(L, R, Bs, BBs); (binding, {Name,Bs}) -> binding(Name, Bs); (add_binding, {Name,Val,Bs}) -> add_binding(Name, Val, Bs) end. match_tuple([E|Es], Tuple, I, Bs0, BBs) -> {match,Bs} = match1(E, element(I, Tuple), Bs0, BBs), match_tuple(Es, Tuple, I+1, Bs, BBs); match_tuple([], _, _, Bs, _BBs) -> {match,Bs}. %% match_list(PatternList, TermList, Bindings) -> %% {match,NewBindings} | nomatch %% Try to match a list of patterns against a list of terms with the %% current bindings. match_list(Ps, Ts, Bs) -> match_list(Ps, Ts, Bs, Bs). match_list([P|Ps], [T|Ts], Bs0, BBs) -> case match(P, T, Bs0, BBs) of {match,Bs1} -> match_list(Ps, Ts, Bs1, BBs); nomatch -> nomatch end; match_list([], [], Bs, _BBs) -> {match,Bs}; match_list(_, _, _Bs, _BBs) -> nomatch. %% new_bindings() %% bindings(Bindings) %% binding(Name, Bindings) %% add_binding(Name, Value, Bindings) %% del_binding(Name, Bindings) -spec(new_bindings() -> binding_struct()). new_bindings() -> orddict:new(). -spec(bindings(BindingStruct :: binding_struct()) -> bindings()). bindings(Bs) -> orddict:to_list(Bs). -spec(binding(Name, BindingStruct) -> {value, value()} | unbound when Name :: name(), BindingStruct :: binding_struct()). binding(Name, Bs) -> case orddict:find(Name, Bs) of {ok,Val} -> {value,Val}; error -> unbound end. -spec(add_binding(Name, Value, BindingStruct) -> binding_struct() when Name :: name(), Value :: value(), BindingStruct :: binding_struct()). add_binding(Name, Val, Bs) -> orddict:store(Name, Val, Bs). -spec(del_binding(Name, BindingStruct) -> binding_struct() when Name :: name(), BindingStruct :: binding_struct()). del_binding(Name, Bs) -> orddict:erase(Name, Bs). add_bindings(Bs1, Bs2) -> foldl(fun ({Name,Val}, Bs) -> orddict:store(Name, Val, Bs) end, Bs2, orddict:to_list(Bs1)). merge_bindings(Bs1, Bs2) -> foldl(fun ({Name,Val}, Bs) -> case orddict:find(Name, Bs) of {ok,Val} -> Bs; %Already with SAME value {ok,V1} -> erlang:raise(error, {badmatch,V1}, stacktrace()); error -> orddict:store(Name, Val, Bs) end end, Bs2, orddict:to_list(Bs1)). %% del_bindings(Bs1, Bs2) -> % del all in Bs1 from Bs2 %% orddict:fold( %% fun (Name, Val, Bs) -> %% case orddict:find(Name, Bs) of %% {ok,Val} -> orddict:erase(Name, Bs); %% {ok,V1} -> erlang:raise(error,{badmatch,V1},stacktrace()); %% error -> Bs %% end %% end, Bs2, Bs1). %%---------------------------------------------------------------------------- %% %% Evaluate expressions: %% constants and %% op A %% L op R %% Things that evaluate to constants are accepted %% and guard_bifs are allowed in constant expressions %%---------------------------------------------------------------------------- is_constant_expr(Expr) -> case eval_expr(Expr) of {ok, X} when is_number(X) -> true; _ -> false end. eval_expr(Expr) -> case catch ev_expr(Expr) of X when is_integer(X) -> {ok, X}; X when is_float(X) -> {ok, X}; X when is_atom(X) -> {ok,X}; {'EXIT',Reason} -> {error, Reason}; _ -> {error, badarg} end. partial_eval(Expr) -> Line = line(Expr), case catch ev_expr(Expr) of X when is_integer(X) -> ret_expr(Expr,{integer,Line,X}); X when is_float(X) -> ret_expr(Expr,{float,Line,X}); X when is_atom(X) -> ret_expr(Expr,{atom,Line,X}); _ -> Expr end. ev_expr({op,_,Op,L,R}) -> erlang:Op(ev_expr(L), ev_expr(R)); ev_expr({op,_,Op,A}) -> erlang:Op(ev_expr(A)); ev_expr({integer,_,X}) -> X; ev_expr({float,_,X}) -> X; ev_expr({atom,_,X}) -> X; ev_expr({tuple,_,Es}) -> list_to_tuple([ev_expr(X) || X <- Es]); ev_expr({nil,_}) -> []; ev_expr({cons,_,H,T}) -> [ev_expr(H) | ev_expr(T)]. %%ev_expr({call,Line,{atom,_,F},As}) -> %% true = erl_internal:guard_bif(F, length(As)), %% apply(erlang, F, [ev_expr(X) || X <- As]); %%ev_expr({call,Line,{remote,_,{atom,_,erlang},{atom,_,F}},As}) -> %% true = erl_internal:guard_bif(F, length(As)), %% apply(erlang, F, [ev_expr(X) || X <- As]); ret_expr(_Old, New) -> %% io:format("~w: reduced ~s => ~s~n", %% [line(Old), erl_pp:expr(Old), erl_pp:expr(New)]), New. line(Expr) -> element(2, Expr). %% In syntax trees, module/package names are atoms or lists of atoms. expand_module_name({atom,L,A} = M, Bs) -> case binding({module,A}, Bs) of {value, A1} -> {atom,L,A1}; unbound -> case packages:is_segmented(A) of true -> M; false -> %%% P = case binding({module,'$package'}, Bs) of %%% {value, P1} -> P1; %%% unbound -> "" %%% end, %%% A1 = list_to_atom(packages:concat(P, A)), %%% {atom,L,list_to_atom(A1)} {atom,L,A} end end; expand_module_name(M, _) -> case erl_parse:package_segments(M) of error -> M; M1 -> L = element(2,M), Mod = packages:concat(M1), case packages:is_valid(Mod) of true -> {atom,L,list_to_atom(Mod)}; false -> erlang:raise(error, {bad_module_name, Mod}, stacktrace()) end end. %% {?MODULE,expr,3} is still the stacktrace, despite the %% fact that expr() now takes two, three or four arguments... stacktrace() -> [{?MODULE,expr,3}].