LearnBraille

-- Learn Braille 0.0.1

-- Configure
local CONVERSION_TABLE = "--forward unicode.dis,it-it-comp6.utb"
local BLACK_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
--local BLACK_CHARS = ',.;:@$?![]'
local REPEAT_CHAR_QUIZ = 2

-- Do not edit.

local function braille(str)
	local h = io.popen("echo -n '" .. str .. "' | lou_translate " .. CONVERSION_TABLE)
	local b = h:read("*l") -- * for old lua versions
	h:close()
	return b
end

local function random()
	local question = {}
	local chars = BLACK_CHARS
	local len = #chars
	local repeatchar = {}

	if REPEAT_CHAR_QUIZ < 1 then
		print("Error: REPEAT_CHAR_QUIZ < 1")
		os.exit(1)
	end
	math.randomseed(os.time())
	while len > 0 do
		local r = math.random(1, len)
		local c = string.sub(chars, r, r)
		table.insert(question, c)
		repeatchar[c] = 1 + (repeatchar[c] or 0)
		if repeatchar[c] == REPEAT_CHAR_QUIZ then
			chars = string.sub(chars, 1, r-1) .. string.sub(chars, r + 1)
		end
		len = #chars
	end

	return question
end

print("LearnBraille 0.0.1\n")

io.write(string.format("Conversion table: %s\n", CONVERSION_TABLE))
io.write(string.format("Black chars:      %s\n", BLACK_CHARS))
io.write(string.format("Repeat a char:    %s\n\n", REPEAT_CHAR_QUIZ))

local quiz = random()
local nquiz = #quiz
local curr = 0
local nerrors = 0
local c = table.remove(quiz)

while c do
	curr = curr + 1
	io.write(string.format("Question [%d/%d]\n", curr, nquiz))
	io.write(string.format(" |%s|? ", braille(c)))
	local input = io.read()
	if c == input then
		print "\tCorrect!\n"
	else
		io.write(string.format("\tError! The char is:  %s\n\n", c))
		nerrors = nerrors + 1
		nquiz = nquiz + 1
		table.insert(quiz, 1, c)
	end
	c = table.remove(quiz)
end

print("\n")
local correct = nquiz - nerrors
io.write(string.format("Questions: %i, ", nquiz))
io.write(string.format("Correct: %i (%.0f%%), ", correct, (correct * 100) / nquiz))
io.write(string.format("Errors: %i (%.0f%%)", nerrors, (nerrors * 100) / nquiz))
print("\n\n")