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Diffstat (limited to 'lib/asn1/src/asn1ct_pretty_format.erl')
| -rw-r--r-- | lib/asn1/src/asn1ct_pretty_format.erl | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/lib/asn1/src/asn1ct_pretty_format.erl b/lib/asn1/src/asn1ct_pretty_format.erl new file mode 100644 index 0000000000..a01c1db8c5 --- /dev/null +++ b/lib/asn1/src/asn1ct_pretty_format.erl @@ -0,0 +1,201 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1997-2009. 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% +%% +%% + +%% 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. + + |