%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 1997-2009. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. %% You may obtain a copy of the License at %% %% http://www.apache.org/licenses/LICENSE-2.0 %% %% Unless required by applicable law or agreed to in writing, software %% distributed under the License is distributed on an "AS IS" BASIS, %% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %% See the License for the specific language governing permissions and %% limitations under the License. %% %% %CopyrightEnd% %% %% %% usage: pretty_format:term(Term) -> PNF list of characters %% %% Note: this is usually used in expressions like: %% io:format('~s\n',[pretty_format:term(Term)]). %% %% Uses the following simple heuristics %% %% 1) Simple tuples are printed across the page %% (Simple means *all* the elements are "flat") %% 2) The Complex tuple {Arg1, Arg2, Arg3,....} is printed thus: %% {Arg1, %% Arg2, %% Arg3, %% ...} %% 3) Lists are treated as for tuples %% 4) Lists of printable characters are treated as strings %% %% This method seems to work reasonable well for {Tag, ...} type %% data structures -module(asn1ct_pretty_format). -export([term/1]). -import(io_lib, [write/1, write_string/1]). term(Term) -> element(2, term(Term, 0)). %%______________________________________________________________________ %% pretty_format:term(Term, Indent} -> {Indent', Chars} %% Format <Term> -- use <Indent> to indent the *next* line %% Note: Indent' is a new indentaion level (sometimes printing <Term> %% the next line to need an "extra" indent!). term([], Indent) -> {Indent, [$[,$]]}; term(L, Indent) when is_list(L) -> case is_string(L) of true -> {Indent, write_string(L)}; false -> case complex_list(L) of true -> write_complex_list(L, Indent); false -> write_simple_list(L, Indent) end end; term(T, Indent) when is_tuple(T) -> case complex_tuple(T) of true -> write_complex_tuple(T, Indent); false -> write_simple_tuple(T, Indent) end; term(A, Indent) -> {Indent, write(A)}. %%______________________________________________________________________ %% write_simple_list([H|T], Indent) -> {Indent', Chars} write_simple_list([H|T], Indent) -> {_, S1} = term(H, Indent), {_, S2} = write_simple_list_tail(T, Indent), {Indent, [$[,S1|S2]}. write_simple_list_tail([H|T], Indent) -> {_, S1} = term(H, Indent), {_, S2} = write_simple_list_tail(T, Indent), {Indent, [$,,S1| S2]}; write_simple_list_tail([], Indent) -> {Indent, "]"}; write_simple_list_tail(Other, Indent) -> {_, S} = term(Other, Indent), {Indent, [$|,S,$]]}. %%______________________________________________________________________ %% write_complex_list([H|T], Indent) -> {Indent', Chars} write_complex_list([H|T], Indent) -> {I1, S1} = term(H, Indent+1), {_, S2} = write_complex_list_tail(T, I1), {Indent, [$[,S1|S2]}. write_complex_list_tail([H|T], Indent) -> {I1, S1} = term(H, Indent), {_, S2} = write_complex_list_tail(T, I1), {Indent, [$,,nl_indent(Indent),S1,S2]}; write_complex_list_tail([], Indent) -> {Indent, "]"}; write_complex_list_tail(Other, Indent) -> {_, S} = term(Other, Indent), {Indent, [$|,S,$]]}. %%______________________________________________________________________ %% complex_list(List) -> true | false %% returns true if the list is complex otherwise false complex_list([]) -> false; complex_list([H|T]) when is_list(H) =:= false , is_tuple(H) =:= false -> complex_list(T); complex_list([H|T]) -> case is_string(H) of true -> complex_list(T); false -> true end; complex_list(_) -> true. %%______________________________________________________________________ %% complex_tuple(Tuple) -> true | false %% returns true if the tuple is complex otherwise false complex_tuple(T) -> complex_list(tuple_to_list(T)). %%______________________________________________________________________ %% write_simple_tuple(Tuple, Indent} -> {Indent', Chars} write_simple_tuple({}, Indent) -> {Indent, "{}"}; write_simple_tuple(Tuple, Indent) -> {_, S} = write_simple_tuple_args(tuple_to_list(Tuple), Indent), {Indent, [${, S, $}]}. write_simple_tuple_args([X], Indent) -> term(X, Indent); write_simple_tuple_args([H|T], Indent) -> {_, SH} = term(H, Indent), {_, ST} = write_simple_tuple_args(T, Indent), {Indent, [SH, $,, ST]}. %%______________________________________________________________________ %% write_complex_tuple(Tuple, Indent} -> {Indent', Chars} write_complex_tuple(Tuple, Indent) -> [H|T] = tuple_to_list(Tuple), {I1, SH} = term(H, Indent+2), {_, ST} = write_complex_tuple_args(T, I1), {Indent, [${, SH, ST, $}]}. write_complex_tuple_args([X], Indent) -> {_, S} = term(X, Indent), {Indent, [$,, nl_indent(Indent), S]}; write_complex_tuple_args([H|T], Indent) -> {I1, SH} = term(H, Indent), {_, ST} = write_complex_tuple_args(T, I1), {Indent, [$,, nl_indent(Indent) , SH, ST]}; write_complex_tuple_args([], Indent) -> {Indent, []}. %%______________________________________________________________________ %% utilities nl_indent(I) when I >= 0 -> ["\n"|indent(I)]; nl_indent(_) -> [$\s]. indent(I) when I >= 8 -> [$\t|indent(I-8)]; indent(I) when I > 0 -> [$\s|indent(I-1)]; indent(_) -> []. is_string([9|T]) -> is_string(T); is_string([10|T]) -> is_string(T); is_string([H|T]) when H >31, H < 127 -> is_string(T); is_string([]) -> true; is_string(_) -> false.