%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 1996-2010. 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_pp). %%% Pretty printer for Erlang code in the same format as returned from %%% the parser. It does not always produce pretty code. -export([form/1,form/2, attribute/1,attribute/2,function/1,function/2,rule/1,rule/2, guard/1,guard/2,exprs/1,exprs/2,exprs/3,expr/1,expr/2,expr/3,expr/4]). -import(lists, [append/1,foldr/3,mapfoldl/3,reverse/1,reverse/2]). -import(io_lib, [write/1,format/2,write_char/1,write_string/1]). -import(erl_parse, [inop_prec/1,preop_prec/1,func_prec/0,max_prec/0]). -define(MAXLINE, 72). %%% %%% Exported functions %%% form(Thing) -> form(Thing, none). form(Thing, Hook) -> frmt(lform(Thing, Hook)). attribute(Thing) -> attribute(Thing, none). attribute(Thing, Hook) -> frmt(lattribute(Thing, Hook)). function(F) -> function(F, none). function(F, Hook) -> frmt(lfunction(F, Hook)). rule(R) -> rule(R, none). rule(R, Hook) -> frmt(lrule(R, Hook)). guard(Gs) -> guard(Gs, none). guard(Gs, Hook) -> frmt(lguard(Gs, Hook)). exprs(Es) -> exprs(Es, 0, none). exprs(Es, Hook) -> exprs(Es, 0, Hook). exprs(Es, I, Hook) -> frmt({seq,[],[],[$,],lexprs(Es, Hook)}, I). expr(E) -> frmt(lexpr(E, 0, none)). expr(E, Hook) -> frmt(lexpr(E, 0, Hook)). expr(E, I, Hook) -> frmt(lexpr(E, 0, Hook), I). expr(E, I, P, Hook) -> frmt(lexpr(E, P, Hook), I). %%% %%% Local functions %%% lform({attribute,Line,Name,Arg}, Hook) -> lattribute({attribute,Line,Name,Arg}, Hook); lform({function,Line,Name,Arity,Clauses}, Hook) -> lfunction({function,Line,Name,Arity,Clauses}, Hook); lform({rule,Line,Name,Arity,Clauses}, Hook) -> lrule({rule,Line,Name,Arity,Clauses}, Hook); %% These are specials to make it easier for the compiler. lform({error,E}, _Hook) -> leaf(format("~p\n", [{error,E}])); lform({warning,W}, _Hook) -> leaf(format("~p\n", [{warning,W}])); lform({eof,_Line}, _Hook) -> $\n. lattribute({attribute,_Line,type,Type}, Hook) -> [typeattr(type, Type, Hook),leaf(".\n")]; lattribute({attribute,_Line,opaque,Type}, Hook) -> [typeattr(opaque, Type, Hook),leaf(".\n")]; lattribute({attribute,_Line,spec,Arg}, _Hook) -> [specattr(Arg),leaf(".\n")]; lattribute({attribute,_Line,Name,Arg}, Hook) -> [lattribute(Name, Arg, Hook),leaf(".\n")]. lattribute(module, {M,Vs}, _Hook) -> attr("module",[{var,0,pname(M)}, foldr(fun(V, C) -> {cons,0,{var,0,V},C} end, {nil,0}, Vs)]); lattribute(module, M, _Hook) -> attr("module", [{var,0,pname(M)}]); lattribute(export, Falist, _Hook) -> call({var,0,"-export"}, [falist(Falist)], 0, none); lattribute(import, Name, _Hook) when is_list(Name) -> attr("import", [{var,0,pname(Name)}]); lattribute(import, {From,Falist}, _Hook) -> attr("import",[{var,0,pname(From)},falist(Falist)]); lattribute(file, {Name,Line}, _Hook) -> attr("file", [{var,0,format("~p", [Name])},{integer,0,Line}]); lattribute(record, {Name,Is}, Hook) -> Nl = leaf(format("-record(~w,", [Name])), [{first,Nl,record_fields(Is, Hook)},$)]; lattribute(Name, Arg, _Hook) -> attr(write(Name), [erl_parse:abstract(Arg)]). typeattr(Tag, {TypeName,Type,Args}, _Hook) -> {first,leaf("-"++atom_to_list(Tag)++" "), typed(call({atom,0,TypeName}, Args, 0, none), Type)}. ltype({ann_type,_Line,[V,T]}) -> typed(lexpr(V, none), T); ltype({paren_type,_Line,[T]}) -> [$(,ltype(T),$)]; ltype({type,_Line,union,Ts}) -> {seq,[],[],[' |'],ltypes(Ts)}; ltype({type,_Line,list,[T]}) -> {seq,$[,$],$,,[ltype(T)]}; ltype({type,_Line,nonempty_list,[T]}) -> {seq,$[,$],[$,],[ltype(T),leaf("...")]}; ltype({type,Line,nil,[]}) -> lexpr({nil,Line}, 0, none); ltype({type,Line,tuple,any}) -> simple_type({atom,Line,tuple}, []); ltype({type,_Line,tuple,Ts}) -> tuple_type(Ts, fun ltype/1); ltype({type,_Line,record,[N|Fs]}) -> record_type(N, Fs); ltype({type,_Line,range,[_I1,_I2]=Es}) -> expr_list(Es, '..', fun lexpr/2, none); ltype({type,_Line,binary,[I1,I2]}) -> binary_type(I1, I2); % except binary() ltype({type,_Line,'fun',[]}) -> leaf("fun()"); ltype({type,_,'fun',[{type,_,any},_]}=FunType) -> [fun_type(['fun',$(], FunType),$)]; ltype({type,_Line,'fun',[{type,_,product,_},_]}=FunType) -> [fun_type(['fun',$(], FunType),$)]; ltype({type,Line,T,Ts}) -> simple_type({atom,Line,T}, Ts); ltype({remote_type,Line,[M,F,Ts]}) -> simple_type({remote,Line,M,F}, Ts); ltype({atom,_,T}) -> leaf(write(T)); ltype(E) -> lexpr(E, 0, none). binary_type({integer,_,Int1}=I1, {integer,_,Int2}=I2) -> E1 = [[leaf("_:"),lexpr(I1, 0, none)] || Int1 =/= 0], E2 = [[leaf("_:_*"),lexpr(I2, 0, none)] || Int2 =/= 0], {seq,'<<','>>',[$,],E1++E2}. record_type({atom,_,Name}, Fields) -> {first,[record_name(Name)],field_types(Fields)}. field_types(Fs) -> tuple_type(Fs, fun field_type/1). field_type({type,_Line,field_type,[Name,Type]}) -> typed(lexpr(Name, none), Type). typed(B, {type,_,union,Ts}) -> %% Special layout for :: followed by union. {first,[B,$\s],{seq,[],[],[],union_type(Ts)}}; typed(B, Type) -> {list,[{cstep,[B,' ::'],ltype(Type)}]}. union_type([T|Ts]) -> [[leaf(":: "),ltype(T)] | ltypes(Ts, fun union_elem/1)]. union_elem(T) -> [leaf(" | "),ltype(T)]. tuple_type(Ts, F) -> {seq,${,$},[$,],ltypes(Ts, F)}. specattr({FuncSpec,TypeSpecs}) -> Func = case FuncSpec of {F,_A} -> format("~w", [F]); {M,F,_A} -> format("~w:~w", [M, F]) end, {first,leaf("-spec "), {list,[{first,leaf(Func),spec_clauses(TypeSpecs)}]}}. spec_clauses(TypeSpecs) -> {prefer_nl,[$;],[sig_type(T) || T <- TypeSpecs]}. sig_type({type,_Line,bounded_fun,[T,Gs]}) -> guard_type(fun_type([], T), Gs); sig_type(FunType) -> fun_type([], FunType). guard_type(Before, Gs) -> Gl = {list,[{step,'when',expr_list(Gs, [$,], fun constraint/2, none)}]}, {list,[{step,Before,Gl}]}. constraint({type,_Line,constraint,[Tag,As]}, _Hook) -> simple_type(Tag, As). fun_type(Before, {type,_,'fun',[FType,Ret]}) -> {first,Before,{step,[type_args(FType),' ->'],ltype(Ret)}}. type_args({type,_Line,any}) -> leaf("(...)"); type_args({type,_line,product,Ts}) -> targs(Ts). simple_type(Tag, Types) -> {first,lexpr(Tag, 0, none),targs(Types)}. targs(Ts) -> {seq,$(,$),[$,],ltypes(Ts)}. ltypes(Ts) -> ltypes(Ts, fun ltype/1). ltypes(Ts, F) -> [F(T) || T <- Ts]. attr(Name, Args) -> call({var,0,format("-~s", [Name])}, Args, 0, none). pname(['' | As]) -> [$. | pname(As)]; pname([A]) -> write(A); pname([A | As]) -> [write(A),$.|pname(As)]; pname(A) when is_atom(A) -> write(A). falist([]) -> {nil,0}; falist([{Name,Arity}|Falist]) -> {cons,0,{var,0,format("~w/~w", [Name,Arity])},falist(Falist)}. lfunction({function,_Line,Name,_Arity,Cs}, Hook) -> Cll = nl_clauses(fun (C, H) -> func_clause(Name, C, H) end, $;, Hook, Cs), [Cll,leaf(".\n")]. func_clause(Name, {clause,Line,Head,Guard,Body}, Hook) -> Hl = call({atom,Line,Name}, Head, 0, Hook), Gl = guard_when(Hl, Guard, Hook), Bl = body(Body, Hook), {step,Gl,Bl}. lrule({rule,_Line,Name,_Arity,Cs}, Hook) -> Cll = nl_clauses(fun (C, H) -> rule_clause(Name, C, H) end, $;, Hook, Cs), [Cll,leaf(".\n")]. rule_clause(Name, {clause,Line,Head,Guard,Body}, Hook) -> Hl = call({atom,Line,Name}, Head, 0, Hook), Gl = guard_when(Hl, Guard, Hook, leaf(" :-")), Bl = rule_body(Body, Hook), {step,Gl,Bl}. rule_body(Es, Hook) -> lc_quals(Es, Hook). guard_when(Before, Guard, Hook) -> guard_when(Before, Guard, Hook, ' ->'). guard_when(Before, Guard, Hook, After) -> Gl = lguard(Guard, Hook), [{list,[{step,Before,Gl}]},After]. lguard([E|Es], Hook) when is_list(E) -> {list,[{step,'when',expr_list([E|Es], [$;], fun guard0/2, Hook)}]}; lguard([E|Es], Hook) -> % before R6 lguard([[E|Es]], Hook); lguard([], _) -> []. guard0(Es, Hook) -> expr_list(Es, [$,], fun lexpr/2, Hook). %% body(Before, Es, Hook) -> [Char]. body([E], Hook) -> lexpr(E, Hook); body(Es, Hook) -> {prefer_nl,[$,],lexprs(Es, Hook)}. lexpr(E, Hook) -> lexpr(E, 0, Hook). lexpr({var,_,V}, _, _) when is_integer(V) -> %Special hack for Robert leaf(format("_~w", [V])); lexpr({var,_,V}, _, _) -> leaf(format("~s", [V])); lexpr({char,_,C}, _, _) -> leaf(write_char(C)); lexpr({integer,_,N}, _, _) -> leaf(write(N)); lexpr({float,_,F}, _, _) -> leaf(write(F)); lexpr({atom,_,A}, _, _) -> leaf(write(A)); lexpr({string,_,S}, _, _) -> {string,S}; lexpr({nil,_}, _, _) -> '[]'; lexpr({cons,_,H,T}, _, Hook) -> list(T, [H], Hook); lexpr({lc,_,E,Qs}, _Prec, Hook) -> Lcl = {list,[{step,[lexpr(E, Hook),leaf(" ||")],lc_quals(Qs, Hook)}]}, {list,[{seq,$[,[],[[]],[{force_nl,leaf(" "),[Lcl]}]},$]]}; %% {list,[{step,$[,Lcl},$]]}; lexpr({bc,_,E,Qs}, _Prec, Hook) -> Lcl = {list,[{step,[lexpr(E, Hook),leaf(" ||")],lc_quals(Qs, Hook)}]}, {list,[{seq,'<<',[],[[]],[{force_nl,leaf(" "),[Lcl]}]},'>>']}; %% {list,[{step,'<<',Lcl},'>>']}; lexpr({tuple,_,Elts}, _, Hook) -> tuple(Elts, Hook); %%lexpr({struct,_,Tag,Elts}, _, Hook) -> %% {first,format("~w", [Tag]),tuple(Elts, Hook)}; lexpr({record_index, _, Name, F}, Prec, Hook) -> {P,R} = preop_prec('#'), Nl = record_name(Name), El = [Nl,$.,lexpr(F, R, Hook)], maybe_paren(P, Prec, El); lexpr({record, _, Name, Fs}, Prec, Hook) -> {P,_R} = preop_prec('#'), Nl = record_name(Name), El = {first,Nl,record_fields(Fs, Hook)}, maybe_paren(P, Prec, El); lexpr({record_field, _, Rec, Name, F}, Prec, Hook) -> {L,P,R} = inop_prec('#'), Rl = lexpr(Rec, L, Hook), Nl = leaf(format("#~w.", [Name])), El = [Rl,Nl,lexpr(F, R, Hook)], maybe_paren(P, Prec, El); lexpr({record, _, Rec, Name, Fs}, Prec, Hook) -> {L,P,_R} = inop_prec('#'), Rl = lexpr(Rec, L, Hook), Nl = record_name(Name), El = {first,[Rl,Nl],record_fields(Fs, Hook)}, maybe_paren(P, Prec, El); lexpr({record_field, _, {atom,_,''}, F}, Prec, Hook) -> {_L,P,R} = inop_prec('.'), El = [$.,lexpr(F, R, Hook)], maybe_paren(P, Prec, El); lexpr({record_field, _, Rec, F}, Prec, Hook) -> {L,P,R} = inop_prec('.'), El = [lexpr(Rec, L, Hook),$.,lexpr(F, R, Hook)], maybe_paren(P, Prec, El); lexpr({block,_,Es}, _, Hook) -> {list,[{step,'begin',body(Es, Hook)},'end']}; lexpr({'if',_,Cs}, _, Hook) -> {list,[{step,'if',if_clauses(Cs, Hook)},'end']}; lexpr({'case',_,Expr,Cs}, _, Hook) -> {list,[{step,{list,[{step,'case',lexpr(Expr, Hook)},'of']}, cr_clauses(Cs, Hook)}, 'end']}; lexpr({'cond',_,Cs}, _, Hook) -> {list,[{step,leaf("cond"),cond_clauses(Cs, Hook)},'end']}; lexpr({'receive',_,Cs}, _, Hook) -> {list,[{step,'receive',cr_clauses(Cs, Hook)},'end']}; lexpr({'receive',_,Cs,To,ToOpt}, _, Hook) -> Al = {list,[{step,[lexpr(To, Hook),' ->'],body(ToOpt, Hook)}]}, {list,[{step,'receive',cr_clauses(Cs, Hook)}, {step,'after',Al}, 'end']}; lexpr({'fun',_,{function,F,A}}, _Prec, _Hook) -> leaf(format("fun ~w/~w", [F,A])); lexpr({'fun',_,{function,F,A},Extra}, _Prec, _Hook) -> {force_nl,fun_info(Extra),leaf(format("fun ~w/~w", [F,A]))}; lexpr({'fun',_,{function,M,F,A}}, _Prec, _Hook) -> leaf(format("fun ~w:~w/~w", [M,F,A])); lexpr({'fun',_,{clauses,Cs}}, _Prec, Hook) -> {list,[{first,'fun',fun_clauses(Cs, Hook)},'end']}; lexpr({'fun',_,{clauses,Cs},Extra}, _Prec, Hook) -> {force_nl,fun_info(Extra), {list,[{first,'fun',fun_clauses(Cs, Hook)},'end']}}; lexpr({'query',_,Lc}, _Prec, Hook) -> {list,[{step,leaf("query"),lexpr(Lc, 0, Hook)},'end']}; lexpr({call,_,{remote,_,{atom,_,M},{atom,_,F}=N}=Name,Args}, Prec, Hook) -> case erl_internal:bif(M, F, length(Args)) of true -> call(N, Args, Prec, Hook); false -> call(Name, Args, Prec, Hook) end; lexpr({call,_,Name,Args}, Prec, Hook) -> call(Name, Args, Prec, Hook); lexpr({'try',_,Es,Scs,Ccs,As}, _, Hook) -> {list,[if Scs =:= [] -> {step,'try',body(Es, Hook)}; true -> {step,{list,[{step,'try',body(Es, Hook)},'of']}, cr_clauses(Scs, Hook)} end, if Ccs =:= [] -> []; true -> {step,'catch',try_clauses(Ccs, Hook)} end, if As =:= [] -> []; true -> {step,'after',body(As, Hook)} end, 'end']}; lexpr({'catch',_,Expr}, Prec, Hook) -> {P,R} = preop_prec('catch'), El = {list,[{step,'catch',lexpr(Expr, R, Hook)}]}, maybe_paren(P, Prec, El); lexpr({match,_,Lhs,Rhs}, Prec, Hook) -> {L,P,R} = inop_prec('='), Pl = lexpr(Lhs, L, Hook), Rl = lexpr(Rhs, R, Hook), El = {list,[{cstep,[Pl,' ='],Rl}]}, maybe_paren(P, Prec, El); lexpr({op,_,Op,Arg}, Prec, Hook) -> {P,R} = preop_prec(Op), Ol = leaf(format("~s ", [Op])), El = [Ol,lexpr(Arg, R, Hook)], maybe_paren(P, Prec, El); lexpr({op,_,Op,Larg,Rarg}, Prec, Hook) when Op =:= 'orelse'; Op =:= 'andalso' -> %% Breaks lines since R12B. {L,P,R} = inop_prec(Op), Ll = lexpr(Larg, L, Hook), Ol = leaf(format("~s", [Op])), Lr = lexpr(Rarg, R, Hook), El = {prefer_nl,[[]],[Ll,Ol,Lr]}, maybe_paren(P, Prec, El); lexpr({op,_,Op,Larg,Rarg}, Prec, Hook) -> {L,P,R} = inop_prec(Op), Ll = lexpr(Larg, L, Hook), Ol = leaf(format("~s", [Op])), Lr = lexpr(Rarg, R, Hook), El = {list,[Ll,Ol,Lr]}, maybe_paren(P, Prec, El); %% Special expressions which are not really legal everywhere. lexpr({remote,_,M,F}, Prec, Hook) -> {L,P,R} = inop_prec(':'), NameItem = lexpr(M, L, Hook), CallItem = lexpr(F, R, Hook), maybe_paren(P, Prec, [NameItem,$:,CallItem]); %% BIT SYNTAX: lexpr({bin,_,Fs}, _, Hook) -> bit_grp(Fs, Hook); %% Special case for straight values. lexpr({value,_,Val}, _,_) -> leaf(write(Val)); %% Now do the hook. lexpr(Other, _Precedence, none) -> leaf(format("INVALID-FORM:~w:",[Other])); lexpr(HookExpr, Precedence, {Mod,Func,Eas}) when Mod =/= 'fun' -> {ehook,HookExpr,Precedence,{Mod,Func,Eas}}; lexpr(HookExpr, Precedence, Func) -> {hook,HookExpr,Precedence,Func}. call(Name, Args, Prec, Hook) -> {F,P} = func_prec(), Item = {first,lexpr(Name, F, Hook),args(Args, Hook)}, maybe_paren(P, Prec, Item). fun_info(Extra) -> leaf(format("% fun-info: ~w", [Extra])). %% BITS: bit_grp(Fs, Hook) -> append([['<<'], [try true = Fs =/= [], S = bin_string(Fs), true = io_lib:printable_list(S), {string,S} catch _:_ -> bit_elems(Fs, Hook) end], ['>>']]). bin_string([]) -> []; bin_string([{bin_element,_,{char,_,C},_,_}|Bin]) -> [C | bin_string(Bin)]. bit_elems(Es, Hook) -> expr_list(Es, $,, fun bit_elem/2, Hook). bit_elem({bin_element,_,Expr,Sz,Types}, Hook) -> P = max_prec(), VChars = lexpr(Expr, P, Hook), SChars = if Sz =/= default -> [VChars,$:,lexpr(Sz, P, Hook)]; true -> VChars end, if Types =/= default -> [SChars,$/|bit_elem_types(Types)]; true -> SChars end. bit_elem_types([T]) -> [bit_elem_type(T)]; bit_elem_types([T | Rest]) -> [bit_elem_type(T), $-|bit_elem_types(Rest)]. bit_elem_type({A,B}) -> [lexpr(erl_parse:abstract(A), none), $:, lexpr(erl_parse:abstract(B), none)]; bit_elem_type(T) -> lexpr(erl_parse:abstract(T), none). %% end of BITS record_name(Name) -> leaf(format("#~w", [Name])). record_fields(Fs, Hook) -> tuple(Fs, fun record_field/2, Hook). record_field({record_field,_,F,Val}, Hook) -> {L,_P,R} = inop_prec('='), Fl = lexpr(F, L, Hook), Vl = lexpr(Val, R, Hook), {list,[{cstep,[Fl,' ='],Vl}]}; record_field({typed_record_field,{record_field,_,F,Val},Type}, Hook) -> {L,_P,R} = inop_prec('='), Fl = lexpr(F, L, Hook), Vl = typed(lexpr(Val, R, Hook), Type), {list,[{cstep,[Fl,' ='],Vl}]}; record_field({typed_record_field,Field,Type0}, Hook) -> Type = remove_undefined(Type0), typed(record_field(Field, Hook), Type); record_field({record_field,_,F}, Hook) -> lexpr(F, 0, Hook). remove_undefined({type,L,union,[{atom,_,undefined}|T]}) -> {type,L,union,T}; remove_undefined(T) -> % cannot happen T. list({cons,_,H,T}, Es, Hook) -> list(T, [H|Es], Hook); list({nil,_}, Es, Hook) -> proper_list(reverse(Es), Hook); list(Other, Es, Hook) -> improper_list(reverse(Es, [Other]), Hook). %% if_clauses(Clauses, Hook) -> [Char]. %% Print 'if' clauses. if_clauses(Cs, Hook) -> clauses(fun if_clause/2, Hook, Cs). if_clause({clause,_,[],G,B}, Hook) -> Gl = [guard_no_when(G, Hook),' ->'], {step,Gl,body(B, Hook)}. guard_no_when([E|Es], Hook) when is_list(E) -> expr_list([E|Es], $;, fun guard0/2, Hook); guard_no_when([E|Es], Hook) -> % before R6 guard_no_when([[E|Es]], Hook); guard_no_when([], _) -> % cannot happen leaf("true"). %% cr_clauses(Clauses, Hook) -> [Char]. %% Print 'case'/'receive' clauses. cr_clauses(Cs, Hook) -> clauses(fun cr_clause/2, Hook, Cs). cr_clause({clause,_,[T],G,B}, Hook) -> El = lexpr(T, 0, Hook), Gl = guard_when(El, G, Hook), Bl = body(B, Hook), {step,Gl,Bl}. %% try_clauses(Clauses, Hook) -> [Char]. %% Print 'try' clauses. try_clauses(Cs, Hook) -> clauses(fun try_clause/2, Hook, Cs). try_clause({clause,_,[{tuple,_,[{atom,_,throw},V,S]}],G,B}, Hook) -> El = lexpr(V, 0, Hook), Sl = stack_backtrace(S, [El], Hook), Gl = guard_when(Sl, G, Hook), Bl = body(B, Hook), {step,Gl,Bl}; try_clause({clause,_,[{tuple,_,[C,V,S]}],G,B}, Hook) -> Cs = lexpr(C, 0, Hook), El = lexpr(V, 0, Hook), CsEl = [Cs,$:,El], Sl = stack_backtrace(S, CsEl, Hook), Gl = guard_when(Sl, G, Hook), Bl = body(B, Hook), {step,Gl,Bl}. stack_backtrace({var,_,'_'}, El, _Hook) -> El; stack_backtrace(S, El, Hook) -> El++[$:,lexpr(S, 0, Hook)]. %% fun_clauses(Clauses, Hook) -> [Char]. %% Print 'fun' clauses. fun_clauses(Cs, Hook) -> nl_clauses(fun fun_clause/2, [$;], Hook, Cs). fun_clause({clause,_,A,G,B}, Hook) -> El = args(A, Hook), Gl = guard_when(El, G, Hook), Bl = body(B, Hook), {step,Gl,Bl}. %% cond_clauses(Clauses, Hook) -> [Char]. %% Print 'cond' clauses. cond_clauses(Cs, Hook) -> clauses(fun cond_clause/2, Hook, Cs). cond_clause({clause,_,[],[[E]],B}, Hook) -> {step,[lexpr(E, Hook),' ->'],body(B, Hook)}. %% nl_clauses(Type, Hook, Clauses) -> [Char]. %% Generic clause printing function (always breaks lines). nl_clauses(Type, Sep, Hook, Cs) -> {prefer_nl,Sep,lexprs(Cs, Type, Hook)}. %% clauses(Type, Hook, Clauses) -> [Char]. %% Generic clause printing function (breaks lines since R12B). clauses(Type, Hook, Cs) -> {prefer_nl,[$;],lexprs(Cs, Type, Hook)}. %% lc_quals(Qualifiers, After, Hook) %% List comprehension qualifiers (breaks lines since R12B). lc_quals(Qs, Hook) -> {prefer_nl,[$,],lexprs(Qs, fun lc_qual/2, Hook)}. lc_qual({b_generate,_,Pat,E}, Hook) -> Pl = lexpr(Pat, 0, Hook), {list,[{step,[Pl,leaf(" <=")],lexpr(E, 0, Hook)}]}; lc_qual({generate,_,Pat,E}, Hook) -> Pl = lexpr(Pat, 0, Hook), {list,[{step,[Pl,leaf(" <-")],lexpr(E, 0, Hook)}]}; lc_qual(Q, Hook) -> lexpr(Q, 0, Hook). proper_list(Es, Hook) -> {seq,$[,$],$,,lexprs(Es, Hook)}. improper_list(Es, Hook) -> {seq,$[,$],{$,,$|},lexprs(Es, Hook)}. tuple(L, Hook) -> tuple(L, fun lexpr/2, Hook). tuple(Es, F, Hook) -> {seq,${,$},$,,lexprs(Es, F, Hook)}. args(As, Hook) -> {seq,$(,$),[$,],lexprs(As, Hook)}. expr_list(Es, Sep, F, Hook) -> {seq,[],[],Sep,lexprs(Es, F, Hook)}. lexprs(Es, Hook) -> lexprs(Es, fun lexpr/2, Hook). lexprs(Es, F, Hook) -> [F(E, Hook) || E <- Es]. maybe_paren(P, Prec, Expr) when P < Prec -> [$(,Expr,$)]; maybe_paren(_P, _Prec, Expr) -> Expr. leaf(S) -> {leaf,iolist_size(S),S}. %%% Do the formatting. Currently nothing fancy. Could probably have %%% done it in one single pass. frmt(Item) -> frmt(Item, 0). frmt(Item, I) -> ST = spacetab(), WT = wordtable(), {Chars,_Length} = f(Item, I, ST, WT), [Chars]. %%% What the tags mean: %%% - C: a character %%% - [I|Is]: Is follow after I without newline or space %%% - {list,IPs}: try to put all IPs on one line, if that fails newlines %%% and indentation are inserted between IPs. %%% - {first,I,IP2}: IP2 follows after I, and is output with an indentation %%% updated with the width of I. %%% - {seq,Before,After,Separator,IPs}: a sequence of Is separated by %%% Separator. Before is output before IPs, and the indentation of IPs %%% is updated with the width of Before. After follows after IPs. %%% - {force_nl,ExtraInfo,I}: fun-info (a comment) forces linebreak before I. %%% - {prefer_nl,Sep,IPs}: forces linebreak between Is unlesss negative %%% indentation. %%% - {string,S}: a string. %%% - {hook,...}, {ehook,...}: hook expressions. %%% %%% list, first, seq, force_nl, and prefer_nl all accept IPs, where each %%% element is either an item or a tuple {step|cstep,I1,I2}. step means %%% that I2 is output after linebreak and an incremented indentation. %%% cstep works similarly, but no linebreak if the width of I1 is less %%% than the indentation (this is for "A = <expression over several lines>). f([]=Nil, _I0, _ST, _WT) -> {Nil,0}; f(C, _I0, _ST, _WT) when is_integer(C) -> {C,1}; f({leaf,Length,Chars}, _I0, _ST, _WT) -> {Chars,Length}; f([Item|Items], I0, ST, WT) -> consecutive(Items, f(Item, I0, ST, WT), I0, ST, WT); f({list,Items}, I0, ST, WT) -> f({seq,[],[],[[]],Items}, I0, ST, WT); f({first,E,Item}, I0, ST, WT) -> f({seq,E,[],[[]],[Item]}, I0, ST, WT); f({seq,Before,After,Sep,LItems}, I0, ST, WT) -> BCharsSize = f(Before, I0, ST, WT), I = indent(BCharsSize, I0), CharsSizeL = fl(LItems, Sep, I, After, ST, WT), {CharsL,SizeL} = unz(CharsSizeL), {BCharsL,BSizeL} = unz1([BCharsSize]), Sizes = BSizeL ++ SizeL, NSepChars = if is_list(Sep), Sep =/= [] -> erlang:max(0, length(CharsL)-1); true -> 0 end, case same_line(I0, Sizes, NSepChars) of {yes,Size} -> Chars = if NSepChars > 0 -> insert_sep(CharsL, $\s); true -> CharsL end, {BCharsL++Chars,Size}; no -> {BCharsL++insert_newlines(CharsSizeL, I, ST), nsz(lists:last(Sizes), I0)} end; f({force_nl,_ExtraInfoItem,Item}, I, ST, WT) when I < 0 -> %% Extra info is a comment; cannot have that on the same line f(Item, I, ST, WT); f({force_nl,ExtraInfoItem,Item}, I, ST, WT) -> f({prefer_nl,[],[ExtraInfoItem,Item]}, I, ST, WT); f({prefer_nl,Sep,LItems}, I, ST, WT) when I < 0 -> f({seq,[],[],Sep,LItems}, I, ST, WT); f({prefer_nl,Sep,LItems}, I0, ST, WT) -> CharsSize2L = fl(LItems, Sep, I0, [], ST, WT), {_CharsL,Sizes} = unz(CharsSize2L), if Sizes =:= [] -> {[], 0}; true -> {insert_newlines(CharsSize2L, I0, ST),nsz(lists:last(Sizes), I0)} end; f({string,S}, I, ST, WT) -> f(write_a_string(S, I), I, ST, WT); f({hook,HookExpr,Precedence,Func}, I, _ST, _WT) -> Chars = Func(HookExpr, I, Precedence, Func), {Chars,indentation(Chars, I)}; f({ehook,HookExpr,Precedence,{Mod,Func,Eas}=ModFuncEas}, I, _ST, _WT) -> Chars = apply(Mod, Func, [HookExpr,I,Precedence,ModFuncEas|Eas]), {Chars,indentation(Chars, I)}; f(WordName, _I, _ST, WT) -> % when is_atom(WordName) word(WordName, WT). -define(IND, 4). %% fl(ListItems, I0, ST, WT) -> [[CharsSize1,CharsSize2]] %% ListItems = [{Item,Items}|Item] fl([], _Sep, I0, After, ST, WT) -> [[f(After, I0, ST, WT),{[],0}]]; fl(CItems, Sep0, I0, After, ST, WT) -> F = fun({step,Item1,Item2}, S) -> [f(Item1, I0, ST, WT),f([Item2,S], incr(I0, ?IND), ST, WT)]; ({cstep,Item1,Item2}, S) -> {_,Sz1} = CharSize1 = f(Item1, I0, ST, WT), if is_integer(Sz1), Sz1 < ?IND -> Item2p = [leaf("\s"),Item2,S], [consecutive(Item2p, CharSize1, I0, ST, WT),{[],0}]; true -> [CharSize1,f([Item2,S], incr(I0, ?IND), ST, WT)] end; (Item, S) -> [f([Item,S], I0, ST, WT),{[],0}] end, {Sep,LastSep} = case Sep0 of {_,_} -> Sep0; _ -> {Sep0,Sep0} end, fl1(CItems, F, Sep, LastSep, After). fl1([CItem], F, _Sep, _LastSep, After) -> [F(CItem,After)]; fl1([CItem1,CItem2], F, _Sep, LastSep, After) -> [F(CItem1, LastSep),F(CItem2, After)]; fl1([CItem|CItems], F, Sep, LastSep, After) -> [F(CItem, Sep)|fl1(CItems, F, Sep, LastSep, After)]. consecutive(Items, CharSize1, I0, ST, WT) -> {CharsSizes,_Length} = mapfoldl(fun(Item, Len) -> CharsSize = f(Item, Len, ST, WT), {CharsSize,indent(CharsSize, Len)} end, indent(CharSize1, I0), Items), {CharsL,SizeL} = unz1([CharSize1|CharsSizes]), {CharsL,line_size(SizeL)}. unz(CharsSizesL) -> unz1(append(CharsSizesL)). unz1(CharSizes) -> lists:unzip(nonzero(CharSizes)). nonzero(CharSizes) -> lists:filter(fun({_,Sz}) -> Sz =/= 0 end, CharSizes). insert_newlines(CharsSizesL, I, ST) when I >= 0 -> insert_nl(foldr(fun([{_C1,0},{_C2,0}], A) -> A; ([{C1,_Sz1},{_C2,0}], A) -> [C1|A]; ([{C1,_Sz1},{C2,Sz2}], A) when Sz2 > 0 -> [insert_nl([C1,C2], I+?IND, ST)|A] end, [], CharsSizesL), I, ST). insert_nl(CharsL, I, ST) -> insert_sep(CharsL, nl_indent(I, ST)). insert_sep([Chars1 | CharsL], Sep) -> [Chars1 | [[Sep,Chars] || Chars <- CharsL]]. nl_indent(0, _T) -> $\n; nl_indent(I, T) when I > 0 -> [$\n|spaces(I, T)]. same_line(I0, SizeL, NSepChars) -> try Size = lists:sum(SizeL) + NSepChars, true = incr(I0, Size) =< ?MAXLINE, {yes,Size} catch _:_ -> no end. line_size(SizeL) -> line_size(SizeL, 0, false). line_size([], Size, false) -> Size; line_size([], Size, true) -> {line,Size}; line_size([{line,Len}|SizeL], _, _) -> line_size(SizeL, Len, true); line_size([Sz|SizeL], SizeSoFar, LF) -> line_size(SizeL, SizeSoFar+Sz, LF). nsz({line,_Len}=Sz, _I) -> Sz; nsz(Size, I) when I >= 0 -> {line,Size+I}. indent({_Chars,{line,Len}}, _I) -> Len; indent({_Chars,Size}, I) -> incr(I, Size). incr(I, _Incr) when I < 0 -> I; incr(I, Incr) -> I+Incr. indentation(E, I) when I < 0 -> iolist_size(E); indentation(E, I0) -> I = io_lib_format:indentation(E, I0), case has_nl(E) of true -> {line,I}; false -> I end. has_nl([$\n|_]) -> true; has_nl([C|Cs]) when is_integer(C) -> has_nl(Cs); has_nl([C|Cs]) -> has_nl(C) orelse has_nl(Cs); has_nl([]) -> false. -define(MIN_SUBSTRING, 5). write_a_string(S, I) when I < 0; S =:= [] -> leaf(write_string(S)); write_a_string(S, I) -> Len = erlang:max(?MAXLINE-I, ?MIN_SUBSTRING), {list,write_a_string(S, Len, Len)}. write_a_string([], _N, _Len) -> []; write_a_string(S, N, Len) -> SS = string:sub_string(S, 1, N), Sl = write_string(SS), case (iolist_size(Sl) > Len) and (N > ?MIN_SUBSTRING) of true -> write_a_string(S, N-1, Len); false -> [leaf(Sl)|write_a_string(lists:nthtail(length(SS), S), Len, Len)] end. %% %% Utilities %% -define(N_SPACES, 30). spacetab() -> {[_|L],_} = mapfoldl(fun(_, A) -> {A,[$\s|A]} end, [], lists:seq(0, ?N_SPACES)), list_to_tuple(L). spaces(N, T) when N =< ?N_SPACES -> element(N, T); spaces(N, T) -> [element(?N_SPACES, T)|spaces(N-?N_SPACES, T)]. wordtable() -> L = [begin {leaf,Sz,S} = leaf(W), {S,Sz} end || W <- [" ->"," =","<<",">>","[]","after","begin","case","catch", "end","fun","if","of","receive","try","when"," ::","..", " |"]], list_to_tuple(L). word(' ->', WT) -> element(1, WT); word(' =', WT) -> element(2, WT); word('<<', WT) -> element(3, WT); word('>>', WT) -> element(4, WT); word('[]', WT) -> element(5, WT); word('after', WT) -> element(6, WT); word('begin', WT) -> element(7, WT); word('case', WT) -> element(8, WT); word('catch', WT) -> element(9, WT); word('end', WT) -> element(10, WT); word('fun', WT) -> element(11, WT); word('if', WT) -> element(12, WT); word('of', WT) -> element(13, WT); word('receive', WT) -> element(14, WT); word('try', WT) -> element(15, WT); word('when', WT) -> element(16, WT); word(' ::', WT) -> element(17, WT); word('..', WT) -> element(18, WT); word(' |', WT) -> element(19, WT).