1 files changed, 61 insertions, 0 deletions

diff --git a/spec/inputs/props.yue b/spec/inputs/props.yue
new file mode 100644
index 0000000..bbb7aae
--- /dev/null
+++ b/spec/inputs/props.yue
@@ -0,0 +1,61 @@
+class Props
+        __index: (name): nil =>
+                cls = @.<>
+                if item := cls.__getter?[name] -- access properties
+                        return item @
+                elseif item := rawget cls, name -- access member functions
+                        return item
+                else
+                        c = cls
+                        while c := c.<> -- recursive to access base classes
+                                if item := c.__getter?[name]
+                                        cls.__getter ??= {}
+                                        cls.__getter[name] = item -- cache base properties to class
+                                        return item @
+                                elseif item := rawget c, name
+                                        rawset cls, name, item -- cache base member to class
+                                        return item
+
+        __newindex: (name, value) =>
+                cls = @.<>
+                if item := cls.__setter?[name] -- access properties
+                        item @, value
+                else
+                        c = cls
+                        while c := c.<> -- recursive to access base classes
+                                if item := c.__setter?[name]
+                                        cls.__setter ??= {}
+                                        cls.__setter[name] = item -- cache base property to class
+                                        item @, value
+                                        return
+                        rawset @, name, value -- assign field to self
+
+        assignReadOnly = -> error "assigning a readonly property"
+
+        prop: (name, props) =>
+                {
+                        :get
+                        :set = assignReadOnly
+                } = props
+                if getter := rawget @__base, "__getter"
+                        getter[name] = get
+                else
+                        rawset @__base, "__getter", [name]: get
+                if setter := rawget @__base, "__setter"
+                        setter[name] = set
+                else
+                        rawset @__base, "__setter", [name]: set
+
+class A extends Props
+        @prop 'x'
+                get: => @_x + 1000
+                set: (v) => @_x = v
+        new: =>
+                @_x = 0
+                
+class B extends A
+        @prop 'abc', get: => "hello"
+
+b = B!
+b.x = 999
+print b.x, b.abc