File

util/human/io.lua @ 10911:9dc34e1556d9

util.human.io.table: Allow a map callaback per column This allows e.g. mapping booleans to "yes" or "no", specific number formatting or generating virtual columns. All while not mutating the underlying data or creating additional temporary tables.
author Kim Alvefur <zash@zash.se>
date Thu, 04 Jun 2020 21:32:28 +0200
parent 10910:e890b83f08cf
child 10917:1eb83bc6f706
line wrap: on
line source

local array = require "util.array";

local function getchar(n)
	local stty_ret = os.execute("stty raw -echo 2>/dev/null");
	local ok, char;
	if stty_ret == true or stty_ret == 0 then
		ok, char = pcall(io.read, n or 1);
		os.execute("stty sane");
	else
		ok, char = pcall(io.read, "*l");
		if ok then
			char = char:sub(1, n or 1);
		end
	end
	if ok then
		return char;
	end
end

local function getline()
	local ok, line = pcall(io.read, "*l");
	if ok then
		return line;
	end
end

local function getpass()
	local stty_ret, _, status_code = os.execute("stty -echo 2>/dev/null");
	if status_code then -- COMPAT w/ Lua 5.1
		stty_ret = status_code;
	end
	if stty_ret ~= 0 then
		io.write("\027[08m"); -- ANSI 'hidden' text attribute
	end
	local ok, pass = pcall(io.read, "*l");
	if stty_ret == 0 then
		os.execute("stty sane");
	else
		io.write("\027[00m");
	end
	io.write("\n");
	if ok then
		return pass;
	end
end

local function show_yesno(prompt)
	io.write(prompt, " ");
	local choice = getchar():lower();
	io.write("\n");
	if not choice:match("%a") then
		choice = prompt:match("%[.-(%U).-%]$");
		if not choice then return nil; end
	end
	return (choice == "y");
end

local function read_password()
	local password;
	while true do
		io.write("Enter new password: ");
		password = getpass();
		if not password then
			print("No password - cancelled");
			return;
		end
		io.write("Retype new password: ");
		if getpass() ~= password then
			if not show_yesno [=[Passwords did not match, try again? [Y/n]]=] then
				return;
			end
		else
			break;
		end
	end
	return password;
end

local function show_prompt(prompt)
	io.write(prompt, " ");
	local line = getline();
	line = line and line:gsub("\n$","");
	return (line and #line > 0) and line or nil;
end

local function printf(fmt, ...)
	print(fmt:format(...));
end

local function padright(s, width)
	return s..string.rep(" ", width-#s);
end

local function padleft(s, width)
	return string.rep(" ", width-#s)..s;
end

local function new_table(col_specs, max_width)
	max_width = max_width or tonumber(os.getenv("COLUMNS")) or 80;
	local separator = " | ";

	local widths = {};
	local total_width = max_width - #separator * (#col_specs-1);
	local free_width = total_width;
	-- Calculate width of fixed-size columns
	for i = 1, #col_specs do
		local width = col_specs[i].width or "0";
		if not(type(width) == "string" and width:sub(-1) == "%") then
			local title = col_specs[i].title;
			width = math.max(tonumber(width), title and (#title+1) or 0);
			widths[i] = width;
			free_width = free_width - width;
			if i > 1 then
				free_width = free_width - #separator;
			end
		end
	end
	-- Calculate width of %-based columns
	for i = 1, #col_specs do
		if not widths[i] then
			local pc_width = tonumber((col_specs[i].width:gsub("%%$", "")));
			widths[i] = math.floor(free_width*(pc_width/100));
		end
	end

	return function (row)
		local titles;
		if not row then
			titles, row = true, array.pluck(col_specs, "title", "");
		end
		local output = {};
		for i, column in ipairs(col_specs) do
			local width = widths[i];
			local v = (not titles and column.mapper or tostring)(row[not titles and column.key or i] or "", row);
			if #v < width then
				if column.align == "right" then
					v = padleft(v, width-1).." ";
				else
					v = padright(v, width);
				end
			elseif #v > width then
				v = v:sub(1, width-1) .. "…";
			end
			table.insert(output, v);
		end
		return table.concat(output, separator);
	end;
end

return {
	getchar = getchar;
	getline = getline;
	getpass = getpass;
	show_yesno = show_yesno;
	read_password = read_password;
	show_prompt = show_prompt;
	printf = printf;
	padleft = padleft;
	padright = padright;
	table = new_table;
};