1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/framework/env/parse/boolean.lua	Sun Oct 25 12:00:00 2009 +0100
     1.3 @@ -0,0 +1,29 @@
     1.4 +function parse.boolean(str, dest_type, options)
     1.5 +  if dest_type ~= atom.boolean then
     1.6 +    error("parse.boolean(...) can only return booleans, but a different destination type than atom.boolean was given.")
     1.7 +  end
     1.8 +  local options = options or {}
     1.9 +  local trimmed_str = string.match(str or "", "^%s*(.-)%s*$")
    1.10 +  if options.true_as or options.false_as or options.nil_as then
    1.11 +    if trimmed_str == options.true_as then
    1.12 +      return true
    1.13 +    elseif trimmed_str == options.false_as then
    1.14 +      return false
    1.15 +    elseif trimmed_str == options.nil_as or trimmed_str == "" then
    1.16 +      return nil
    1.17 +    else
    1.18 +      error("Boolean value not recognized.")
    1.19 +    end
    1.20 +  else
    1.21 +    local char = string.upper(string.sub(trimmed_str, 1, 1))
    1.22 +    if char == "1" or char == "T" or char == "Y" then
    1.23 +      return true
    1.24 +    elseif char == "0" or char == "F" or char == "N" then
    1.25 +      return false
    1.26 +    elseif char == "" then
    1.27 +      return nil
    1.28 +    else
    1.29 +      error("Boolean value not recognized.")
    1.30 +    end
    1.31 +  end
    1.32 +end