# Description
follow up to #8529
cleaned up version of #8892
- the original syntax is okay
```nu
def okay [rec: record] {}
```
- you can now add type annotations for fields if you know
them before hand
```nu
def okay [rec: record<name: string>] {}
```
- you can specify multiple fields
```nu
def okay [person: record<name: string age: int>] {}
# an optional comma is allowed
def okay [person: record<name: string, age: int>] {}
```
- if annotations are specified, any use of the command will be type
checked against the specified type
```nu
def unwrap [result: record<ok: bool, value: any>] {}
unwrap {ok: 2, value: "value"}
# errors with
Error: nu::parser::type_mismatch
× Type mismatch.
╭─[entry #4:1:1]
1 │ unwrap {ok: 2, value: "value"}
· ───────┬─────
· ╰── expected record<ok: bool, value: any>, found record<ok: int, value: string>
╰────
```
> here the error is in the `ok` field, since `any` is coerced into any
type
> as a result `unwrap {ok: true, value: "value"}` is okay
- the key must be a string, either quoted or unquoted
```nu
def err [rec: record<{}: list>] {}
# errors with
Error:
× `record` type annotations key not string
╭─[entry #7:1:1]
1 │ def unwrap [result: record<{}: bool, value: any>] {}
· ─┬
· ╰── must be a string
╰────
```
- a key doesn't have to have a type in which case it is assumed to be
`any`
```nu
def okay [person: record<name age>] {}
def okay [person: record<name: string age>] {}
```
- however, if you put a colon, you have to specify a type
```nu
def err [person: record<name: >] {}
# errors with
Error: nu::parser::parse_mismatch
× Parse mismatch during operation.
╭─[entry #12:1:1]
1 │ def unwrap [res: record<name: >] { $res }
· ┬
· ╰── expected type after colon
╰────
```
# User-Facing Changes
**[BREAKING CHANGES]**
- this change adds a field to `SyntaxShape::Record` so any plugins that
used it will have to update and include the field. though if you are
unsure of the type the record expects, `SyntaxShape::Record(vec![])`
will suffice
77ca73f414