1 files changed, 128 insertions, 0 deletions
diff --git a/meta/whimsical/rule.lua b/meta/whimsical/rule.lua
new file mode 100644
index 00000000..0715d78f
--- /dev/null
+++ b/meta/whimsical/rule.lua
@@ -0,0 +1,128 @@
+local cat
+
+cat.rule.default = function (self)
+    self.isTruly = true
+    self.truly   = self
+    self.falsy   = cat.class 'never'
+    self.view    = self.name
+end
+
+cat.rule.never = function (self)
+    self.isTruly = nil
+end
+
+cat.rule.any = function (self)
+    self.isTruly = nil
+    self.truly   = cat.class 'truly'
+    self.falsy   = cat.boolean(false) | cat.class 'nil'
+end
+
+cat.rule['nil'] = function (self)
+    self.isTruly = false
+    self.truly   = cat.class 'never'
+    self.falsy   = self
+end
+
+cat.rule.boolean = function (self)
+    if self.value == true then
+        self.isTruly = true
+        self.truly   = self
+        self.falsy   = cat.class 'never'
+    elseif self.value == false then
+        self.isTruly = false
+        self.truly   = cat.class 'never'
+        self.falsy   = self
+    else
+        self.isTruly = nil
+        self.truly   = cat.boolean(true)
+        self.falsy   = cat.boolean(false)
+    end
+end
+
+cat.rule.number = function (self)
+    self.isTruly = true
+    self.truly   = self
+    self.falsy   = cat.class 'never'
+    self.view    = tostring(self.value)
+end
+
+cat.rule.integer = function (self)
+    self.isTruly = true
+    self.truly   = self
+    self.falsy   = cat.class 'never'
+    self.view    = tostring(self.value)
+end
+
+cat.rule.string = function (self)
+    self.isTruly = true
+    self.truly   = self
+    self.falsy   = cat.class 'never'
+    self.view    = cat.util.viewString(self.value, self.quotation)
+end
+
+cat.rule.union = function (self)
+    self.isTruly = function (union)
+        local isTruly = union.subs[1].isTruly
+        if isTruly == nil then
+            return nil
+        end
+        if isTruly == true then
+            for i = 2, #union.subs do
+                if union.subs[i].isTruly ~= true then
+                    return nil
+                end
+            end
+            return true
+        else
+            for i = 2, #union.subs do
+                if union.subs[i].isTruly ~= false then
+                    return nil
+                end
+            end
+            return false
+        end
+        return nil
+    end
+    self.truly = function (union)
+        local new = cat.union()
+        for i = 1, #union.subs do
+            new:add(union.subs[i].truly)
+        end
+        if new:len() == 0 then
+            return cat.class 'never'
+        end
+        if new:len() == 1 then
+            return new[1]
+        end
+        return new
+    end
+    self.falsy = function (union)
+        local new = cat.union()
+        for i = 1, #union.subs do
+            new:add(union.subs[i].falsy)
+        end
+        if new:len() == 0 then
+            return cat.class 'never'
+        end
+        if new:len() == 1 then
+            return new[1]
+        end
+        return new
+    end
+    self.view = function (union)
+        local views = {}
+        for i = 1, #union.subs do
+            views[i] = union.subs[i].view
+        end
+        if #views == 0 then
+            return 'never'
+        end
+        return table.concat(views, '|')
+    end
+end
+
+cat.custom.dofile.onReturn = function (context)
+    local filename = context.args[1].asString
+    local file     = cat.files[filename]
+    return file.returns[1]
+end