diff options
Diffstat (limited to 'lib/stdlib/src')
| -rw-r--r-- | lib/stdlib/src/io_lib_format.erl | 3 | ||||
| -rw-r--r-- | lib/stdlib/src/io_lib_pretty.erl | 20 |
2 files changed, 22 insertions, 1 deletions
diff --git a/lib/stdlib/src/io_lib_format.erl b/lib/stdlib/src/io_lib_format.erl index 1da866dc88..c7b75961cb 100644 --- a/lib/stdlib/src/io_lib_format.erl +++ b/lib/stdlib/src/io_lib_format.erl @@ -343,7 +343,8 @@ term(T, F, Adj, P0, Pad) -> %% print(Term, Depth, Field, Adjust, Precision, PadChar, Encoding, %% Indentation) -%% Print a term. +%% Print a term. Field width sets maximum line length, Precision sets +%% initial indentation. print(T, D, none, Adj, P, Pad, E, Str, I) -> print(T, D, 80, Adj, P, Pad, E, Str, I); diff --git a/lib/stdlib/src/io_lib_pretty.erl b/lib/stdlib/src/io_lib_pretty.erl index 16ca2f41dc..94376408d1 100644 --- a/lib/stdlib/src/io_lib_pretty.erl +++ b/lib/stdlib/src/io_lib_pretty.erl @@ -97,31 +97,42 @@ print(Term, Col, Ll, D, RecDefFun) -> print(Term, Col, Ll, D, M, RecDefFun) -> print(Term, Col, Ll, D, M, RecDefFun, latin1, true). +%% D = Depth, default -1 (infinite), or LINEMAX=30 when printing from shell +%% Col = current column, default 1 +%% Ll = line length/~p field width, default 80 +%% M = CHAR_MAX (-1 if no max, 60 when printing from shell) print(_, _, _, 0, _M, _RF, _Enc, _Str) -> "..."; print(Term, Col, Ll, D, M, RecDefFun, Enc, Str) when Col =< 0 -> + %% ensure Col is at least 1 print(Term, 1, Ll, D, M, RecDefFun, Enc, Str); print(Term, Col, Ll, D, M0, RecDefFun, Enc, Str) when is_tuple(Term); is_list(Term); is_map(Term); is_bitstring(Term) -> + %% preprocess and compute total number of chars If = {_S, Len} = print_length(Term, D, RecDefFun, Enc, Str), + %% use Len as CHAR_MAX if M0 = -1 M = max_cs(M0, Len), if Len < Ll - Col, Len =< M -> + %% write the whole thing on a single line when there is room write(If); true -> + %% compute the indentation TInd for tagged tuples and records TInd = while_fail([-1, 4], fun(I) -> cind(If, Col, Ll, M, I, 0, 0) end, 1), pp(If, Col, Ll, M, TInd, indent(Col), 0, 0) end; print(Term, _Col, _Ll, _D, _M, _RF, _Enc, _Str) -> + %% atomic data types (bignums, atoms, ...) are never truncated io_lib:write(Term). %%% %%% Local functions %%% +%% use M only if nonnegative, otherwise use Len as default value max_cs(M, Len) when M < 0 -> Len; max_cs(M, _Len) -> @@ -153,6 +164,7 @@ pp({S, _Len}, _Col, _Ll, _M, _TInd, _Ind, _LD, _W) -> %% Print a tagged tuple by indenting the rest of the elements %% differently to the tag. Tuple has size >= 2. pp_tag_tuple([{Tag,Tlen} | L], Col, Ll, M, TInd, Ind, LD, W) -> + %% this uses TInd TagInd = Tlen + 2, Tcol = Col + TagInd, S = $,, @@ -207,6 +219,7 @@ pp_field({{field, Name, NameL, F}, _Len}, Col0, Ll, M, TInd, Ind0, LD, W0) -> {[Name, " = ", S | pp(F, Col, Ll, M, TInd, Ind, LD, W)], Ll}. % force nl rec_indent(RInd, TInd, Col0, Ind0, W0) -> + %% this uses TInd Nl = (TInd > 0) and (RInd > TInd), DCol = case Nl of true -> TInd; @@ -285,6 +298,7 @@ pp_binary(S, N, _N0, Ind) -> S end. +%% write the whole thing on a single line write({{tuple, _IsTagged, L}, _}) -> [${, write_list(L, $,), $}]; write({{list, L}, _}) -> @@ -344,8 +358,10 @@ print_length({}, _D, _RF, _Enc, _Str) -> print_length(#{}=M, _D, _RF, _Enc, _Str) when map_size(M) =:= 0 -> {"#{}", 3}; print_length(List, D, RF, Enc, Str) when is_list(List) -> + %% only flat lists are "printable" case Str andalso printable_list(List, D, Enc) of true -> + %% print as string, escaping double-quotes in the list S = write_string(List, Enc), {S, length(S)}; %% Truncated lists could break some existing code. @@ -401,6 +417,7 @@ print_length(<<_/bitstring>>=Bin, D, _RF, Enc, Str) -> end; print_length(Term, _D, _RF, _Enc, _Str) -> S = io_lib:write(Term), + %% S can contain unicode, so iolist_size(S) cannot be used here {S, lists:flatlength(S)}. print_length_map(_Map, 1, _RF, _Enc, _Str) -> @@ -483,6 +500,7 @@ list_length_tail({_, Len}, Acc) -> %% ?CHARS printable characters has depth 1. -define(CHARS, 4). +%% only flat lists are "printable" printable_list(_L, 1, _Enc) -> false; printable_list(L, _D, latin1) -> @@ -736,9 +754,11 @@ while_fail([], _F, V) -> while_fail([A | As], F, V) -> try F(A) catch _ -> while_fail(As, F, V) end. +%% make a string of N spaces indent(N) when is_integer(N), N > 0 -> chars($\s, N-1). +%% prepend N spaces onto Ind indent(1, Ind) -> % Optimization of common case [$\s | Ind]; indent(4, Ind) -> % Optimization of common case |