-- filename : l-boolean.lua -- comment : split off from luat-lib -- author : Hans Hagen, PRAGMA-ADE, Hasselt NL -- copyright: PRAGMA ADE / ConTeXt Development Team -- license : see context related readme files if not versions then versions = { } end versions['l-boolean'] = 1.001 if not boolean then boolean = { } end function boolean.tonumber(b) if b then return 1 else return 0 end end function toboolean(str,tolerant) if tolerant then local tstr = type(str) if tstr == "string" then return str == "true" or str == "yes" or str == "on" or str == "1" elseif tstr == "number" then return tonumber(str) ~= 0 elseif tstr == "nil" then return false else return str end elseif str == "true" then return true elseif str == "false" then return false else return str end end function string.is_boolean(str) if type(str) == "string" then if str == "true" or str == "yes" or str == "on" then return true elseif str == "false" or str == "no" or str == "off" then return false end end return nil end function boolean.alwaystrue() return true end function boolean.falsetrue() return false end