1 files changed, 55 insertions, 0 deletions
diff --git a/luaextra-boolean.lua b/luaextra-boolean.lua
new file mode 100644
index 0000000..be7ec7d
--- /dev/null
+++ b/luaextra-boolean.lua
@@ -0,0 +1,55 @@
+if not modules then modules = { } end modules ['l-boolean'] = {
+    version   = 1.001,
+    comment   = "companion to luat-lib.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+boolean = boolean or { }
+
+local type, tonumber = type, tonumber
+
+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" or str == "t"
+        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" or str == "t" then
+            return true
+        elseif str == "false" or str == "no" or str == "off" or str == "f" then
+            return false
+        end
+    end
+    return nil
+end
+
+function boolean.alwaystrue()
+    return true
+end
+
+function boolean.falsetrue()
+    return false
+end