ok

tmp/test.lua

@@ -0,0 +1,66 @@
+local kiwi = require("kiwi")
+
+local Var = kiwi.Var
+local Strength = kiwi.Strength
+
+local Button_mt = {}
+
+---@class Button
+---@field left kiwi.Var
+---@field width kiwi.Var
+---@overload fun(identifier: string): Button
+local Button = setmetatable({}, Button_mt)
+
+function Button_mt.__call(_, identifier)
+   return setmetatable({
+      left = Var("left" .. identifier),
+      width = Var("width" .. identifier),
+   }, {
+      __index = Button,
+      __tostring = function(self)
+         return "Button(" .. self.left:value() .. ", " .. self.width:value() .. ")"
+      end,
+   })
+end
+
+local b1 = Button("b1")
+local b2 = Button("b2")
+
+local left_limit = kiwi.Var("left")
+local right_limit = kiwi.Var("width")
+
+
+-- stylua: ignore start
+local constraints = {
+  left_limit :eq( 0 ),
+  b1.width   :eq( b2.width ),
+  b1.left    :eq( left_limit + 50),
+  right_limit:eq( b2.left + b2.width + 50),
+  b2.left    :ge( b1.left + b1.width + 100),
+
+  b1.width   :ge( 87 ),
+  b1.width   :eq( 87, Strength.STRONG),
+
+  b2.width   :ge( 113 ),
+  b2.width   :eq( 113, Strength.STRONG),
+}
+-- stylua: ignore end
+
+local s = kiwi.Solver()
+
+for _, c in ipairs(constraints) do
+   s:add_constraint(c)
+end
+
+print(constraints[4]:expression())
+print(constraints[5]:expression())
+
+kiwi.Constraint(b1.left + 1, "EQ")
+
+s:update_vars()
+
+print(b1)
+print(b2)
+print(left_limit:value())
+print(right_limit:value())
+print(s:dumps())