existing-records.md

@@ -2,3 +2,71 @@
 This page is used to discuss _minor_ tweaks to the existing record system if it is decided that it will be left in basically unchanged. radical or brand new record systems should be discussed elsewhere.
 
 
+- reallow punning, Foo {x,y,z} would be interpreted as Foo {x = x, y = y, z = z} in both declaration and pattern matching contexts.
+
+- update syntax should not bottom out when fields are undefined. as in
+
+```wiki
+
+data Foo = Foo { x :: String, y :: Int } | Bar { x :: String }
+
+foo = Bar { x = "hello }
+
+baz = foo { y = 3 }
+
+should not result in an error, but rather pass foo through unchanged. update should update the record if it exists, but pass the type through otherwise.
+
+this would make the update syntax actually useful
+
+```
+
+- label-based pattern matching
+
+
+the function:
+
+
+```wiki
+  f val { x = "foo" } = 4
+```
+
+
+should match if passed a Foo or a Bar with x being equal to "foo" and val would be bound to its argument (like an @ pattern)
+
+
+```wiki
+ g _ { y = 3 } = 4
+```
+
+
+would match only the Bar constructor since it is the only one with a  y field.
+
+
+
+This would mitigate the problems caused by accessors being partial functions since you can use a simple case statement to get the effect of an accesor that returns its result in a Maybe
+
+
+- first class update and setting syntax (more advanced, needs better syntax)
+
+
+A syntax for updating and setting fields should be allowed.
+
+
+
+some possibilites are 
+
+
+```wiki
+
+foo { x = }
+
+would be equivalant to (\v -> foo { x = v })
+
+foo { x \ }
+
+would be equivalant to 
+
+(\f -> foo { x = case foo of _ {x} -> foo { x = f x }; _ -> foo }) 
+
+
+```
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