1 function parse.boolean(str, dest_type, options)

2 if dest_type ~= atom.boolean then

3 error("parse.boolean(...) can only return booleans, but a different destination type than atom.boolean was given.")

4 end

5 local options = options or {}

6 local trimmed_str = string.match(str or "", "^%s*(.-)%s*$")

7 if options.true_as or options.false_as or options.nil_as then

8 if trimmed_str == options.true_as then

9 return true

10 elseif trimmed_str == options.false_as then

11 return false

12 elseif trimmed_str == options.nil_as or trimmed_str == "" then

13 return nil

14 else

15 error("Boolean value not recognized.")

16 end

17 else

18 local char = string.upper(string.sub(trimmed_str, 1, 1))

19 if char == "1" or char == "T" or char == "Y" then

20 return true

21 elseif char == "0" or char == "F" or char == "N" then

22 return false

23 elseif char == "" then

24 return nil

25 else

26 error("Boolean value not recognized.")

27 end

28 end

29 end