allow lists to have type annotations (#8529)

this pr refines #8270 and closes #8109

# description
examples:

the original syntax is okay
```nu
def okay [nums: list] {}         # the type of list will be list<any>
```

empty annotations are allowed in any variation
the last two may be caught by a future formatter, 
but do not affect `nu` code currently
```nu
def okay [nums: list<>] {}       # okay

def okay [nums: list<     >] {}  # weird but also okay

def okay [nums: list<
>] {}                            # also weird but okay
```

types are allowed (See [notes](#notes) below)
```nu
def okay [nums: list<int>] {}    # `test [a b c]` will throw an error 

def okay [nums: list< int > {}   # any amount of space within the angle brackets is okay

def err [nums: list <int>] {}    # this is not okay, `nums` and `<int>` will be parsed as
                                 # two separate params, 
```

nested annotations are allowed in many variations
```nu
def okay [items: list<list<int>>] {}

def okay [items: list<list>] {}
```

any unterminated annotation is caught
```nu
Error: nu::parser::unexpected_eof

  × Unexpected end of code.
   ╭─[source:1:1]
 1 │ def err [nums: list<int] {}
   ·                       ▲
   ·                       ╰── expected closing >
   ╰────
```

unknown types are flagged
```nu
Error: nu::parser::unknown_type

  × Unknown type.
   ╭─[source:1:1]
 1 │ def err [nums: list<str>] {}
   ·                     ─┬─
   ·                      ╰── unknown type
   ╰────

Error: nu::parser::unknown_type

  × Unknown type.
   ╭─[source:1:1]
 1 │ def err [nums: list<int, string>] {}
   ·                    ─────┬─────
   ·                          ╰── unknown type
   ╰────
```

# notes
the error message for mismatched types in not as intuitive
```nu
Error: nu::parser::parse_mismatch

  × Parse mismatch during operation.
   ╭─[source:1:1]
 1 │ def err [nums: list<int>] {}; err [a b c]
   ·                                    ┬
   ·                                    ╰── expected int
   ╰────
```
it should be something like this
```nu
Error: nu::parser::parse_mismatch

  × Parse mismatch during operation.
   ╭─[source:1:1]
 1 │ def err [nums: list<int>] {}; err [a b c]
   ·                                    ──┬──
   ·                                      ╰── expected list<int>
   ╰────
```
this is currently not implemented
This commit is contained in:
mike
2023-03-24 14:54:06 +03:00
committed by GitHub
parent d0aa69bfcb
commit 8cf9bc9993
7 changed files with 311 additions and 18 deletions

View File

@ -150,18 +150,6 @@ fn def_fails_with_invalid_name() {
assert!(actual.err.contains(err_msg));
}
#[test]
fn def_errors_with_specified_list_type() {
let actual = nu!(
cwd: ".", pipeline(
r#"
def test-command [ foo: list<any> ] {}
"#
));
assert!(actual.err.contains("unknown type"));
}
#[test]
fn def_with_list() {
Playground::setup("def_with_list", |dirs, _| {