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Fix usage output when a long option has a length that is bigger than a console line

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This commit is contained in:
Juan Jose Comellas 2012-11-19 12:25:06 -03:00
parent 46ea9c7908
commit 98f3c6f123
1 changed files with 107 additions and 84 deletions
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191
src/getopt.erl
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@ -28,25 +28,30 @@
(Char) =:= $\n orelse (Char) =:= $\r)).
%% Atom indicating the data type that an argument can be converted to.
-type arg_type() :: 'atom' | 'binary' | 'boolean' | 'float' | 'integer' | 'string'.
-type arg_type() :: 'atom' | 'binary' | 'boolean' | 'float' | 'integer' | 'string'.
%% Data type that an argument can be converted to.
-type arg_value() :: atom() | binary() | boolean() | float() | integer() | string().
-type arg_value() :: atom() | binary() | boolean() | float() | integer() | string().
%% Argument specification.
-type arg_spec() :: arg_type() | {arg_type(), arg_value()} | undefined.
-type arg_spec() :: arg_type() | {arg_type(), arg_value()} | undefined.
%% Option type and optional default argument.
-type simple_option() :: atom().
-type compound_option() :: {atom(), arg_value()}.
-type option() :: simple_option() | compound_option().
-type simple_option() :: atom().
-type compound_option() :: {atom(), arg_value()}.
-type option() :: simple_option() | compound_option().
%% Command line option specification.
-type option_spec() :: {
Name :: atom(),
Short :: char() | undefined,
Long :: string() | undefined,
ArgSpec :: arg_spec(),
Help :: string() | undefined
Name :: atom(),
Short :: char() | undefined,
Long :: string() | undefined,
ArgSpec :: arg_spec(),
Help :: string() | undefined
}.
%% Output streams
-type output_stream() :: 'standard_io' | 'standard_error'.
-type output_stream() :: 'standard_io' | 'standard_error'.
%% For internal use
-type usage_line() :: {OptionText :: string(), HelpText :: string()}.
-type usage_line_with_length() :: {OptionLength :: non_neg_integer(), OptionText :: string(), HelpText :: string()}.
-export_type([arg_type/0, arg_value/0, arg_spec/0, simple_option/0, compound_option/0, option/0, option_spec/0]).
@ -569,97 +574,115 @@ usage_cmd_line_option({Name, Short, Long, ArgSpec, _Help}) when is_tuple(ArgSpec
%% @doc Return a list of help messages to print for each of the options and arguments.
-spec usage_options([option_spec()]) -> string().
-spec usage_options([option_spec()]) -> [string()].
usage_options(OptSpecList) ->
usage_options(OptSpecList, []).
%% @doc Return a list of help messages to print for each of the options and arguments.
-spec usage_options([option_spec()], [{OptionName :: string(), Help :: string()}]) -> string().
%% @doc Return a list of usage lines to print for each of the options and arguments.
-spec usage_options([option_spec()], [{OptionName :: string(), Help :: string()}]) -> [string()].
usage_options(OptSpecList, CustomHelp) ->
{MaxLength0, OptionHelpRows0} = add_option_spec_help_rows(OptSpecList, 0, []),
{MaxLength, OptionHelpRows} = add_custom_help_rows(CustomHelp, MaxLength0, OptionHelpRows0),
%% Add the usage lines corresponding to the option specifications.
{MaxOptionLength0, UsageLines0} = add_option_spec_help_lines(OptSpecList, 0, []),
%% Add the custom usage lines.
{MaxOptionLength, UsageLines} = add_custom_help_lines(CustomHelp, MaxOptionLength0, UsageLines0),
LineLength = line_length(),
lists:reverse([format_help_line(MaxLength + 1, LineLength, OptionHelp) ||
OptionHelp <- OptionHelpRows]).
lists:reverse([format_usage_line(MaxOptionLength + 1, LineLength, UsageLine) || UsageLine <- UsageLines]).
add_option_spec_help_rows([{Name, Short, Long, _ArgSpec, _Help} = OptSpec | Tail], MaxOptionLength, Acc) ->
Option =
case Long of
undefined ->
case Short of
%% Neither short nor long form (non-option argument).
undefined -> [$<, atom_to_list(Name), $>];
%% Only short form.
_ -> [$-, Short]
end;
_ ->
case Short of
%% Only long form.
undefined -> [$-, $- | Long];
%% Both short and long form.
_ -> [$-, Short, $,, $\s, $-, $- | Long]
end
end,
{NewMaxOptionLength, OptionSpecHelpWithLength} = get_option_help_length({Option, usage_help(OptSpec)}, MaxOptionLength),
add_option_spec_help_rows(Tail, NewMaxOptionLength, [OptionSpecHelpWithLength | Acc]);
add_option_spec_help_rows([], MaxOptionLength, Acc) ->
-spec add_option_spec_help_lines([option_spec()], PrevMaxOptionLength :: non_neg_integer(), [usage_line_with_length()]) ->
{MaxOptionLength :: non_neg_integer(), [usage_line_with_length()]}.
add_option_spec_help_lines([OptSpec | Tail], PrevMaxOptionLength, Acc) ->
OptionText = usage_option_text(OptSpec),
HelpText = usage_help_text(OptSpec),
{MaxOptionLength, ColsWithLength} = get_max_option_length({OptionText, HelpText}, PrevMaxOptionLength),
add_option_spec_help_lines(Tail, MaxOptionLength, [ColsWithLength | Acc]);
add_option_spec_help_lines([], MaxOptionLength, Acc) ->
{MaxOptionLength, Acc}.
-spec usage_help(option_spec()) -> string().
usage_help({_Name, _Short, _Long, {_ArgType, ArgValue}, [_ | _] = Help}) ->
-spec add_custom_help_lines([usage_line()], PrevMaxOptionLength :: non_neg_integer(), [usage_line_with_length()]) ->
{MaxOptionLength :: non_neg_integer(), [usage_line_with_length()]}.
add_custom_help_lines([CustomCols | Tail], PrevMaxOptionLength, Acc) ->
{MaxOptionLength, ColsWithLength} = get_max_option_length(CustomCols, PrevMaxOptionLength),
add_custom_help_lines(Tail, MaxOptionLength, [ColsWithLength | Acc]);
add_custom_help_lines([], MaxOptionLength, Acc) ->
{MaxOptionLength, Acc}.
-spec usage_option_text(option_spec()) -> string().
usage_option_text({Name, undefined, undefined, _ArgSpec, _Help}) ->
%% Neither short nor long form (non-option argument).
"<" ++ atom_to_list(Name) ++ ">";
usage_option_text({_Name, Short, undefined, _ArgSpec, _Help}) ->
%% Only short form.
[$-, Short];
usage_option_text({_Name, undefined, Long, _ArgSpec, _Help}) ->
%% Only long form.
[$-, $- | Long];
usage_option_text({_Name, Short, Long, _ArgSpec, _Help}) ->
%% Both short and long form.
[$-, Short, $,, $\s, $-, $- | Long].
-spec usage_help_text(option_spec()) -> string().
usage_help_text({_Name, _Short, _Long, {_ArgType, ArgValue}, [_ | _] = Help}) ->
Help ++ " [default: " ++ default_arg_value_to_string(ArgValue) ++ "]";
usage_help({_Name, _Short, _Long, _ArgSpec, Help}) ->
usage_help_text({_Name, _Short, _Long, _ArgSpec, Help}) ->
Help.
add_custom_help_rows([CustomOptionHelp | Tail], MaxOptionLength, Acc) ->
{NewMaxOptionLength, CustomOptionHelpWithLength} = get_option_help_length(CustomOptionHelp, MaxOptionLength),
add_custom_help_rows(Tail, NewMaxOptionLength, [CustomOptionHelpWithLength | Acc]);
add_custom_help_rows([], MaxOptionLength, Acc) ->
{MaxOptionLength, Acc}.
%% @doc Calculate the maximum width of the column that shows the option's short
%% and long form.
-spec get_max_option_length(usage_line(), PrevMaxOptionLength :: non_neg_integer()) ->
{MaxOptionLength :: non_neg_integer(), usage_line_with_length()}.
get_max_option_length({OptionText, HelpText}, PrevMaxOptionLength) ->
OptionLength = length(OptionText),
{erlang:max(OptionLength, PrevMaxOptionLength), {OptionLength, OptionText, HelpText}}.
get_option_help_length({UnflattenedOption, Help}, PrevMaxOptionLength) ->
Option = lists:flatten(UnflattenedOption),
OptionLength = length(Option),
%% Calculate the maximum width of the column that shows the option's name.
MaxOptionLength = if
OptionLength > PrevMaxOptionLength -> OptionLength;
true -> PrevMaxOptionLength
end,
{MaxOptionLength, {OptionLength, Option, Help}}.
-spec format_help_line(MaxOptionLength :: non_neg_integer(), LineLength :: non_neg_integer(),
{OptionLength :: non_neg_integer(), Option :: string(), Help :: [string()]}) -> iolist().
format_help_line(MaxOptionLength, LineLength, {OptionLength, Option, [_ | _] = Help}) ->
OptionColumnWidth = MaxOptionLength + 3,
HelpLines = wrap_text_line(LineLength - OptionColumnWidth, Help),
case OptionColumnWidth < LineLength of
true ->
%% Lines in which the column with the options is narrower than that of the console
FirstLineSep = lists:duplicate(MaxOptionLength - OptionLength + 1, $\s),
Indentation = [$\n | lists:duplicate(MaxOptionLength + 3, $\s)],
[" ", Option, FirstLineSep, hd(HelpLines), [[Indentation, Line] || Line <- tl(HelpLines)], $\n];
false ->
[" ", Option, [["\n ", Line] || Line <- HelpLines], $\n]
end;
format_help_line(_MaxOptionLength, _LineLength, {_OptionLength, Option, _Help}) ->
[" ", Option, $\n].
%% @doc Format the usage line that is shown for the options' usage. Each usage
%% line has 2 columns. The first column shows the options in their short
%% and long form. The second column shows the wrapped (if necessary) help
%% text lines associated with each option. e.g.:
%%
%% -h, --host Database server host name or IP address; this is the
%% hostname of the server where the database is running
%% [default: localhost]
%% -p, --port Database server port [default: 1000]
%%
-spec format_usage_line(MaxOptionLength :: non_neg_integer(), LineLength :: non_neg_integer(),
usage_line_with_length()) -> iolist().
format_usage_line(MaxOptionLength, LineLength, {OptionLength, OptionText, [_ | _] = HelpText})
when MaxOptionLength < (LineLength div 2) ->
%% If the width of the column where the options are shown is smaller than
%% half the width of a console line then we show the help text line aligned
%% next to its corresponding option, with a separation of at least 2
%% characters.
[Head | Tail] = wrap_text_line(LineLength - MaxOptionLength - 3, HelpText),
FirstLineIndentation = lists:duplicate(MaxOptionLength - OptionLength + 1, $\s),
Indentation = [$\n | lists:duplicate(MaxOptionLength + 3, $\s)],
[" ", OptionText, FirstLineIndentation, Head,
[[Indentation, Line] || Line <- Tail], $\n];
format_usage_line(_MaxOptionLength, LineLength, {_OptionLength, OptionText, [_ | _] = HelpText}) ->
%% If the width of the first column is bigger than the width of a console
%% line, we show the help text on the next line with an indentation of 6
%% characters.
HelpLines = wrap_text_line(LineLength - 6, HelpText),
[" ", OptionText, [["\n ", Line] || Line <- HelpLines], $\n];
format_usage_line(_MaxOptionLength, _LineLength, {_OptionLength, OptionText, _HelpText}) ->
[" ", OptionText, $\n].
%% @doc Wrap a text line converting it into several text lines so that the
%% length of each one of them is never over HelpLength characters.
-spec wrap_text_line(HelpLength :: non_neg_integer(), Help :: string()) -> [string()].
wrap_text_line(HelpLength, Help) ->
wrap_text_line(HelpLength, Help, [], 0, []).
-spec wrap_text_line(Length :: non_neg_integer(), Text :: string()) -> [string()].
wrap_text_line(Length, Text) ->
wrap_text_line(Length, Text, [], 0, []).
wrap_text_line(HelpLength, [Char | Tail], Acc, Count, CurrentLineAcc) when Count < HelpLength ->
wrap_text_line(HelpLength, Tail, Acc, Count + 1, [Char | CurrentLineAcc]);
wrap_text_line(HelpLength, [_ | _] = Help, Acc, Count, CurrentLineAcc) ->
wrap_text_line(Length, [Char | Tail], Acc, Count, CurrentLineAcc) when Count < Length ->
wrap_text_line(Length, Tail, Acc, Count + 1, [Char | CurrentLineAcc]);
wrap_text_line(Length, [_ | _] = Help, Acc, Count, CurrentLineAcc) ->
%% Look for the first whitespace character in the current (reversed) line
%% buffer to get a wrapped line. If there is no whitespace just cut the
%% line at the position corresponding to the maximum length.
@ -669,11 +692,11 @@ wrap_text_line(HelpLength, [_ | _] = Help, Acc, Count, CurrentLineAcc) ->
_ ->
{[], CurrentLineAcc}
end,
wrap_text_line(HelpLength, Help, [lists:reverse(WrappedLine) | Acc], length(NextLineAcc), NextLineAcc);
wrap_text_line(_HelpLength, [], Acc, _Count, [_ | _] = CurrentLineAcc) ->
wrap_text_line(Length, Help, [lists:reverse(WrappedLine) | Acc], length(NextLineAcc), NextLineAcc);
wrap_text_line(_Length, [], Acc, _Count, [_ | _] = CurrentLineAcc) ->
%% If there was a non-empty line when we reached the buffer, add it to the accumulator
lists:reverse([lists:reverse(CurrentLineAcc) | Acc]);
wrap_text_line(_HelpLength, [], Acc, _Count, _CurrentLineAcc) ->
wrap_text_line(_Length, [], Acc, _Count, _CurrentLineAcc) ->
lists:reverse(Acc).