juvix/tests/negative/UnexpectedFieldUpdate.juvix

module UnexpectedFieldUpdate;

type T := t;

type R := mkR {
 r : T;
};

f : R;
f := (mkR t) @R{x := 1};
Record updates (#2263) - Closes #1642. This pr introduces syntax for convenient record updates. Example: ``` type Triple (A B C : Type) := \| mkTriple { fst : A; snd : B; thd : C; }; main : Triple Nat Nat Nat; main := let p : Triple Nat Nat Nat := mkTriple 2 2 2; p' : Triple Nat Nat Nat := p @Triple{ fst := fst + 1; snd := snd * 3 }; f : Triple Nat Nat Nat -> Triple Nat Nat Nat := (@Triple{fst := fst * 10}); in f p'; ``` We write `@InductiveType{..}` to update the contents of a record. The `@` is used for parsing. The `InductiveType` symbol indicates the type of the record update. Inside the braces we have a list of `fieldName := newValue` items separated by semicolon. The `fieldName` is bound in `newValue` with the old value of the field. Thus, we can write something like `p @Triple{fst := fst + 1;}`. Record updates `X@{..}` are parsed as postfix operators with higher priority than application, so `f x y @X{q := 1}` is equivalent to `f x (y @X{q := 1})`. It is possible the use a record update with no argument by wrapping the update in parentheses. See `f` in the above example. 2023-08-07 13:35:36 +03:00			`module UnexpectedFieldUpdate;`

			`type T := t;`

			`type R := mkR {`
			`r : T;`
			`};`

			`f : R;`
			`f := (mkR t) @R{x := 1};`